xref: /OK3568_Linux_fs/kernel/arch/x86/Kconfig (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun# SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun# Select 32 or 64 bit
3*4882a593Smuzhiyunconfig 64BIT
4*4882a593Smuzhiyun	bool "64-bit kernel" if "$(ARCH)" = "x86"
5*4882a593Smuzhiyun	default "$(ARCH)" != "i386"
6*4882a593Smuzhiyun	help
7*4882a593Smuzhiyun	  Say yes to build a 64-bit kernel - formerly known as x86_64
8*4882a593Smuzhiyun	  Say no to build a 32-bit kernel - formerly known as i386
9*4882a593Smuzhiyun
10*4882a593Smuzhiyunconfig X86_32
11*4882a593Smuzhiyun	def_bool y
12*4882a593Smuzhiyun	depends on !64BIT
13*4882a593Smuzhiyun	# Options that are inherently 32-bit kernel only:
14*4882a593Smuzhiyun	select ARCH_WANT_IPC_PARSE_VERSION
15*4882a593Smuzhiyun	select CLKSRC_I8253
16*4882a593Smuzhiyun	select CLONE_BACKWARDS
17*4882a593Smuzhiyun	select HAVE_DEBUG_STACKOVERFLOW
18*4882a593Smuzhiyun	select MODULES_USE_ELF_REL
19*4882a593Smuzhiyun	select OLD_SIGACTION
20*4882a593Smuzhiyun	select GENERIC_VDSO_32
21*4882a593Smuzhiyun	select ARCH_SPLIT_ARG64
22*4882a593Smuzhiyun
23*4882a593Smuzhiyunconfig X86_64
24*4882a593Smuzhiyun	def_bool y
25*4882a593Smuzhiyun	depends on 64BIT
26*4882a593Smuzhiyun	# Options that are inherently 64-bit kernel only:
27*4882a593Smuzhiyun	select ARCH_HAS_GIGANTIC_PAGE
28*4882a593Smuzhiyun	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
29*4882a593Smuzhiyun	select ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT
30*4882a593Smuzhiyun	select ARCH_USE_CMPXCHG_LOCKREF
31*4882a593Smuzhiyun	select HAVE_ARCH_SOFT_DIRTY
32*4882a593Smuzhiyun	select MODULES_USE_ELF_RELA
33*4882a593Smuzhiyun	select NEED_DMA_MAP_STATE
34*4882a593Smuzhiyun	select SWIOTLB
35*4882a593Smuzhiyun
36*4882a593Smuzhiyunconfig FORCE_DYNAMIC_FTRACE
37*4882a593Smuzhiyun	def_bool y
38*4882a593Smuzhiyun	depends on X86_32
39*4882a593Smuzhiyun	depends on FUNCTION_TRACER
40*4882a593Smuzhiyun	select DYNAMIC_FTRACE
41*4882a593Smuzhiyun	help
42*4882a593Smuzhiyun	 We keep the static function tracing (!DYNAMIC_FTRACE) around
43*4882a593Smuzhiyun	 in order to test the non static function tracing in the
44*4882a593Smuzhiyun	 generic code, as other architectures still use it. But we
45*4882a593Smuzhiyun	 only need to keep it around for x86_64. No need to keep it
46*4882a593Smuzhiyun	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
47*4882a593Smuzhiyun#
48*4882a593Smuzhiyun# Arch settings
49*4882a593Smuzhiyun#
50*4882a593Smuzhiyun# ( Note that options that are marked 'if X86_64' could in principle be
51*4882a593Smuzhiyun#   ported to 32-bit as well. )
52*4882a593Smuzhiyun#
53*4882a593Smuzhiyunconfig X86
54*4882a593Smuzhiyun	def_bool y
55*4882a593Smuzhiyun	#
56*4882a593Smuzhiyun	# Note: keep this list sorted alphabetically
57*4882a593Smuzhiyun	#
58*4882a593Smuzhiyun	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
59*4882a593Smuzhiyun	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
60*4882a593Smuzhiyun	select ARCH_32BIT_OFF_T			if X86_32
61*4882a593Smuzhiyun	select ARCH_CLOCKSOURCE_INIT
62*4882a593Smuzhiyun	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
63*4882a593Smuzhiyun	select ARCH_HAS_DEBUG_VIRTUAL
64*4882a593Smuzhiyun	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
65*4882a593Smuzhiyun	select ARCH_HAS_DEVMEM_IS_ALLOWED
66*4882a593Smuzhiyun	select ARCH_HAS_EARLY_DEBUG		if KGDB
67*4882a593Smuzhiyun	select ARCH_HAS_ELF_RANDOMIZE
68*4882a593Smuzhiyun	select ARCH_HAS_FAST_MULTIPLIER
69*4882a593Smuzhiyun	select ARCH_HAS_FILTER_PGPROT
70*4882a593Smuzhiyun	select ARCH_HAS_FORTIFY_SOURCE
71*4882a593Smuzhiyun	select ARCH_HAS_GCOV_PROFILE_ALL
72*4882a593Smuzhiyun	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
73*4882a593Smuzhiyun	select ARCH_HAS_MEM_ENCRYPT
74*4882a593Smuzhiyun	select ARCH_HAS_MEMBARRIER_SYNC_CORE
75*4882a593Smuzhiyun	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
76*4882a593Smuzhiyun	select ARCH_HAS_PMEM_API		if X86_64
77*4882a593Smuzhiyun	select ARCH_HAS_PTE_DEVMAP		if X86_64
78*4882a593Smuzhiyun	select ARCH_HAS_PTE_SPECIAL
79*4882a593Smuzhiyun	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
80*4882a593Smuzhiyun	select ARCH_HAS_COPY_MC			if X86_64
81*4882a593Smuzhiyun	select ARCH_HAS_SET_MEMORY
82*4882a593Smuzhiyun	select ARCH_HAS_SET_DIRECT_MAP
83*4882a593Smuzhiyun	select ARCH_HAS_STRICT_KERNEL_RWX
84*4882a593Smuzhiyun	select ARCH_HAS_STRICT_MODULE_RWX
85*4882a593Smuzhiyun	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
86*4882a593Smuzhiyun	select ARCH_HAS_SYSCALL_WRAPPER
87*4882a593Smuzhiyun	select ARCH_HAS_UBSAN_SANITIZE_ALL
88*4882a593Smuzhiyun	select ARCH_HAS_DEBUG_WX
89*4882a593Smuzhiyun	select ARCH_HAVE_NMI_SAFE_CMPXCHG
90*4882a593Smuzhiyun	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
91*4882a593Smuzhiyun	select ARCH_MIGHT_HAVE_PC_PARPORT
92*4882a593Smuzhiyun	select ARCH_MIGHT_HAVE_PC_SERIO
93*4882a593Smuzhiyun	select ARCH_STACKWALK
94*4882a593Smuzhiyun	select ARCH_SUPPORTS_ACPI
95*4882a593Smuzhiyun	select ARCH_SUPPORTS_ATOMIC_RMW
96*4882a593Smuzhiyun	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
97*4882a593Smuzhiyun	select ARCH_SUPPORTS_LTO_CLANG		if X86_64
98*4882a593Smuzhiyun	select ARCH_SUPPORTS_LTO_CLANG_THIN	if X86_64
99*4882a593Smuzhiyun	select ARCH_USE_BUILTIN_BSWAP
100*4882a593Smuzhiyun	select ARCH_USE_QUEUED_RWLOCKS
101*4882a593Smuzhiyun	select ARCH_USE_QUEUED_SPINLOCKS
102*4882a593Smuzhiyun	select ARCH_USE_SYM_ANNOTATIONS
103*4882a593Smuzhiyun	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
104*4882a593Smuzhiyun	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
105*4882a593Smuzhiyun	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
106*4882a593Smuzhiyun	select ARCH_WANT_HUGE_PMD_SHARE
107*4882a593Smuzhiyun	select ARCH_WANT_LD_ORPHAN_WARN
108*4882a593Smuzhiyun	select ARCH_WANTS_THP_SWAP		if X86_64
109*4882a593Smuzhiyun	select BUILDTIME_TABLE_SORT
110*4882a593Smuzhiyun	select CLKEVT_I8253
111*4882a593Smuzhiyun	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
112*4882a593Smuzhiyun	select CLOCKSOURCE_WATCHDOG
113*4882a593Smuzhiyun	select DCACHE_WORD_ACCESS
114*4882a593Smuzhiyun	select EDAC_ATOMIC_SCRUB
115*4882a593Smuzhiyun	select EDAC_SUPPORT
116*4882a593Smuzhiyun	select GENERIC_CLOCKEVENTS
117*4882a593Smuzhiyun	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
118*4882a593Smuzhiyun	select GENERIC_CLOCKEVENTS_MIN_ADJUST
119*4882a593Smuzhiyun	select GENERIC_CMOS_UPDATE
120*4882a593Smuzhiyun	select GENERIC_CPU_AUTOPROBE
121*4882a593Smuzhiyun	select GENERIC_CPU_VULNERABILITIES
122*4882a593Smuzhiyun	select GENERIC_EARLY_IOREMAP
123*4882a593Smuzhiyun	select GENERIC_ENTRY
124*4882a593Smuzhiyun	select GENERIC_FIND_FIRST_BIT
125*4882a593Smuzhiyun	select GENERIC_IOMAP
126*4882a593Smuzhiyun	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
127*4882a593Smuzhiyun	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
128*4882a593Smuzhiyun	select GENERIC_IRQ_MIGRATION		if SMP
129*4882a593Smuzhiyun	select GENERIC_IRQ_PROBE
130*4882a593Smuzhiyun	select GENERIC_IRQ_RESERVATION_MODE
131*4882a593Smuzhiyun	select GENERIC_IRQ_SHOW
132*4882a593Smuzhiyun	select GENERIC_PENDING_IRQ		if SMP
133*4882a593Smuzhiyun	select GENERIC_PTDUMP
134*4882a593Smuzhiyun	select GENERIC_SMP_IDLE_THREAD
135*4882a593Smuzhiyun	select GENERIC_STRNCPY_FROM_USER
136*4882a593Smuzhiyun	select GENERIC_STRNLEN_USER
137*4882a593Smuzhiyun	select GENERIC_TIME_VSYSCALL
138*4882a593Smuzhiyun	select GENERIC_GETTIMEOFDAY
139*4882a593Smuzhiyun	select GENERIC_VDSO_TIME_NS
140*4882a593Smuzhiyun	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
141*4882a593Smuzhiyun	select HARDIRQS_SW_RESEND
142*4882a593Smuzhiyun	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
143*4882a593Smuzhiyun	select HAVE_ACPI_APEI			if ACPI
144*4882a593Smuzhiyun	select HAVE_ACPI_APEI_NMI		if ACPI
145*4882a593Smuzhiyun	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
146*4882a593Smuzhiyun	select HAVE_ARCH_AUDITSYSCALL
147*4882a593Smuzhiyun	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
148*4882a593Smuzhiyun	select HAVE_ARCH_JUMP_LABEL
149*4882a593Smuzhiyun	select HAVE_ARCH_JUMP_LABEL_RELATIVE
150*4882a593Smuzhiyun	select HAVE_ARCH_KASAN			if X86_64
151*4882a593Smuzhiyun	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
152*4882a593Smuzhiyun	select HAVE_ARCH_KFENCE
153*4882a593Smuzhiyun	select HAVE_ARCH_KGDB
154*4882a593Smuzhiyun	select HAVE_ARCH_MMAP_RND_BITS		if MMU
155*4882a593Smuzhiyun	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
156*4882a593Smuzhiyun	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
157*4882a593Smuzhiyun	select HAVE_ARCH_PREL32_RELOCATIONS
158*4882a593Smuzhiyun	select HAVE_ARCH_SECCOMP_FILTER
159*4882a593Smuzhiyun	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
160*4882a593Smuzhiyun	select HAVE_ARCH_STACKLEAK
161*4882a593Smuzhiyun	select HAVE_ARCH_TRACEHOOK
162*4882a593Smuzhiyun	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
163*4882a593Smuzhiyun	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
164*4882a593Smuzhiyun	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
165*4882a593Smuzhiyun	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
166*4882a593Smuzhiyun	select HAVE_ARCH_VMAP_STACK		if X86_64
167*4882a593Smuzhiyun	select HAVE_ARCH_WITHIN_STACK_FRAMES
168*4882a593Smuzhiyun	select HAVE_ASM_MODVERSIONS
169*4882a593Smuzhiyun	select HAVE_CMPXCHG_DOUBLE
170*4882a593Smuzhiyun	select HAVE_CMPXCHG_LOCAL
171*4882a593Smuzhiyun	select HAVE_CONTEXT_TRACKING		if X86_64
172*4882a593Smuzhiyun	select HAVE_C_RECORDMCOUNT
173*4882a593Smuzhiyun	select HAVE_OBJTOOL_MCOUNT		if STACK_VALIDATION
174*4882a593Smuzhiyun	select HAVE_DEBUG_KMEMLEAK
175*4882a593Smuzhiyun	select HAVE_DMA_CONTIGUOUS
176*4882a593Smuzhiyun	select HAVE_DYNAMIC_FTRACE
177*4882a593Smuzhiyun	select HAVE_DYNAMIC_FTRACE_WITH_REGS
178*4882a593Smuzhiyun	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
179*4882a593Smuzhiyun	select HAVE_EBPF_JIT
180*4882a593Smuzhiyun	select HAVE_EFFICIENT_UNALIGNED_ACCESS
181*4882a593Smuzhiyun	select HAVE_EISA
182*4882a593Smuzhiyun	select HAVE_EXIT_THREAD
183*4882a593Smuzhiyun	select HAVE_FAST_GUP
184*4882a593Smuzhiyun	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
185*4882a593Smuzhiyun	select HAVE_FTRACE_MCOUNT_RECORD
186*4882a593Smuzhiyun	select HAVE_FUNCTION_GRAPH_TRACER
187*4882a593Smuzhiyun	select HAVE_FUNCTION_TRACER
188*4882a593Smuzhiyun	select HAVE_GCC_PLUGINS
189*4882a593Smuzhiyun	select HAVE_HW_BREAKPOINT
190*4882a593Smuzhiyun	select HAVE_IDE
191*4882a593Smuzhiyun	select HAVE_IOREMAP_PROT
192*4882a593Smuzhiyun	select HAVE_IRQ_TIME_ACCOUNTING
193*4882a593Smuzhiyun	select HAVE_KERNEL_BZIP2
194*4882a593Smuzhiyun	select HAVE_KERNEL_GZIP
195*4882a593Smuzhiyun	select HAVE_KERNEL_LZ4
196*4882a593Smuzhiyun	select HAVE_KERNEL_LZMA
197*4882a593Smuzhiyun	select HAVE_KERNEL_LZO
198*4882a593Smuzhiyun	select HAVE_KERNEL_XZ
199*4882a593Smuzhiyun	select HAVE_KERNEL_ZSTD
200*4882a593Smuzhiyun	select HAVE_KPROBES
201*4882a593Smuzhiyun	select HAVE_KPROBES_ON_FTRACE
202*4882a593Smuzhiyun	select HAVE_FUNCTION_ERROR_INJECTION
203*4882a593Smuzhiyun	select HAVE_KRETPROBES
204*4882a593Smuzhiyun	select HAVE_KVM
205*4882a593Smuzhiyun	select HAVE_LIVEPATCH			if X86_64
206*4882a593Smuzhiyun	select HAVE_MIXED_BREAKPOINTS_REGS
207*4882a593Smuzhiyun	select HAVE_MOD_ARCH_SPECIFIC
208*4882a593Smuzhiyun	select HAVE_MOVE_PMD
209*4882a593Smuzhiyun	select HAVE_MOVE_PUD
210*4882a593Smuzhiyun	select HAVE_NMI
211*4882a593Smuzhiyun	select HAVE_OPROFILE
212*4882a593Smuzhiyun	select HAVE_OPTPROBES
213*4882a593Smuzhiyun	select HAVE_PCSPKR_PLATFORM
214*4882a593Smuzhiyun	select HAVE_PERF_EVENTS
215*4882a593Smuzhiyun	select HAVE_PERF_EVENTS_NMI
216*4882a593Smuzhiyun	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
217*4882a593Smuzhiyun	select HAVE_PCI
218*4882a593Smuzhiyun	select HAVE_PERF_REGS
219*4882a593Smuzhiyun	select HAVE_PERF_USER_STACK_DUMP
220*4882a593Smuzhiyun	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
221*4882a593Smuzhiyun	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
222*4882a593Smuzhiyun	select HAVE_REGS_AND_STACK_ACCESS_API
223*4882a593Smuzhiyun	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
224*4882a593Smuzhiyun	select HAVE_FUNCTION_ARG_ACCESS_API
225*4882a593Smuzhiyun	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
226*4882a593Smuzhiyun	select HAVE_STACK_VALIDATION		if X86_64
227*4882a593Smuzhiyun	select HAVE_STATIC_CALL
228*4882a593Smuzhiyun	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
229*4882a593Smuzhiyun	select HAVE_RSEQ
230*4882a593Smuzhiyun	select HAVE_SYSCALL_TRACEPOINTS
231*4882a593Smuzhiyun	select HAVE_UNSTABLE_SCHED_CLOCK
232*4882a593Smuzhiyun	select HAVE_USER_RETURN_NOTIFIER
233*4882a593Smuzhiyun	select HAVE_GENERIC_VDSO
234*4882a593Smuzhiyun	select HOTPLUG_SMT			if SMP
235*4882a593Smuzhiyun	select IRQ_FORCED_THREADING
236*4882a593Smuzhiyun	select NEED_SG_DMA_LENGTH
237*4882a593Smuzhiyun	select PCI_DOMAINS			if PCI
238*4882a593Smuzhiyun	select PCI_LOCKLESS_CONFIG		if PCI
239*4882a593Smuzhiyun	select PERF_EVENTS
240*4882a593Smuzhiyun	select RTC_LIB
241*4882a593Smuzhiyun	select RTC_MC146818_LIB
242*4882a593Smuzhiyun	select SPARSE_IRQ
243*4882a593Smuzhiyun	select SRCU
244*4882a593Smuzhiyun	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
245*4882a593Smuzhiyun	select SYSCTL_EXCEPTION_TRACE
246*4882a593Smuzhiyun	select THREAD_INFO_IN_TASK
247*4882a593Smuzhiyun	select USER_STACKTRACE_SUPPORT
248*4882a593Smuzhiyun	select VIRT_TO_BUS
249*4882a593Smuzhiyun	select HAVE_ARCH_KCSAN			if X86_64
250*4882a593Smuzhiyun	select X86_FEATURE_NAMES		if PROC_FS
251*4882a593Smuzhiyun	select PROC_PID_ARCH_STATUS		if PROC_FS
252*4882a593Smuzhiyun	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
253*4882a593Smuzhiyun
254*4882a593Smuzhiyunconfig INSTRUCTION_DECODER
255*4882a593Smuzhiyun	def_bool y
256*4882a593Smuzhiyun	depends on KPROBES || PERF_EVENTS || UPROBES
257*4882a593Smuzhiyun
258*4882a593Smuzhiyunconfig OUTPUT_FORMAT
259*4882a593Smuzhiyun	string
260*4882a593Smuzhiyun	default "elf32-i386" if X86_32
261*4882a593Smuzhiyun	default "elf64-x86-64" if X86_64
262*4882a593Smuzhiyun
263*4882a593Smuzhiyunconfig LOCKDEP_SUPPORT
264*4882a593Smuzhiyun	def_bool y
265*4882a593Smuzhiyun
266*4882a593Smuzhiyunconfig STACKTRACE_SUPPORT
267*4882a593Smuzhiyun	def_bool y
268*4882a593Smuzhiyun
269*4882a593Smuzhiyunconfig MMU
270*4882a593Smuzhiyun	def_bool y
271*4882a593Smuzhiyun
272*4882a593Smuzhiyunconfig ARCH_MMAP_RND_BITS_MIN
273*4882a593Smuzhiyun	default 28 if 64BIT
274*4882a593Smuzhiyun	default 8
275*4882a593Smuzhiyun
276*4882a593Smuzhiyunconfig ARCH_MMAP_RND_BITS_MAX
277*4882a593Smuzhiyun	default 32 if 64BIT
278*4882a593Smuzhiyun	default 16
279*4882a593Smuzhiyun
280*4882a593Smuzhiyunconfig ARCH_MMAP_RND_COMPAT_BITS_MIN
281*4882a593Smuzhiyun	default 8
282*4882a593Smuzhiyun
283*4882a593Smuzhiyunconfig ARCH_MMAP_RND_COMPAT_BITS_MAX
284*4882a593Smuzhiyun	default 16
285*4882a593Smuzhiyun
286*4882a593Smuzhiyunconfig SBUS
287*4882a593Smuzhiyun	bool
288*4882a593Smuzhiyun
289*4882a593Smuzhiyunconfig GENERIC_ISA_DMA
290*4882a593Smuzhiyun	def_bool y
291*4882a593Smuzhiyun	depends on ISA_DMA_API
292*4882a593Smuzhiyun
293*4882a593Smuzhiyunconfig GENERIC_BUG
294*4882a593Smuzhiyun	def_bool y
295*4882a593Smuzhiyun	depends on BUG
296*4882a593Smuzhiyun	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
297*4882a593Smuzhiyun
298*4882a593Smuzhiyunconfig GENERIC_BUG_RELATIVE_POINTERS
299*4882a593Smuzhiyun	bool
300*4882a593Smuzhiyun
301*4882a593Smuzhiyunconfig ARCH_MAY_HAVE_PC_FDC
302*4882a593Smuzhiyun	def_bool y
303*4882a593Smuzhiyun	depends on ISA_DMA_API
304*4882a593Smuzhiyun
305*4882a593Smuzhiyunconfig GENERIC_CALIBRATE_DELAY
306*4882a593Smuzhiyun	def_bool y
307*4882a593Smuzhiyun
308*4882a593Smuzhiyunconfig ARCH_HAS_CPU_RELAX
309*4882a593Smuzhiyun	def_bool y
310*4882a593Smuzhiyun
311*4882a593Smuzhiyunconfig ARCH_HAS_CACHE_LINE_SIZE
312*4882a593Smuzhiyun	def_bool y
313*4882a593Smuzhiyun
314*4882a593Smuzhiyunconfig ARCH_HAS_FILTER_PGPROT
315*4882a593Smuzhiyun	def_bool y
316*4882a593Smuzhiyun
317*4882a593Smuzhiyunconfig HAVE_SETUP_PER_CPU_AREA
318*4882a593Smuzhiyun	def_bool y
319*4882a593Smuzhiyun
320*4882a593Smuzhiyunconfig NEED_PER_CPU_EMBED_FIRST_CHUNK
321*4882a593Smuzhiyun	def_bool y
322*4882a593Smuzhiyun
323*4882a593Smuzhiyunconfig NEED_PER_CPU_PAGE_FIRST_CHUNK
324*4882a593Smuzhiyun	def_bool y
325*4882a593Smuzhiyun
326*4882a593Smuzhiyunconfig ARCH_HIBERNATION_POSSIBLE
327*4882a593Smuzhiyun	def_bool y
328*4882a593Smuzhiyun
329*4882a593Smuzhiyunconfig ARCH_SUSPEND_POSSIBLE
330*4882a593Smuzhiyun	def_bool y
331*4882a593Smuzhiyun
332*4882a593Smuzhiyunconfig ARCH_WANT_GENERAL_HUGETLB
333*4882a593Smuzhiyun	def_bool y
334*4882a593Smuzhiyun
335*4882a593Smuzhiyunconfig ZONE_DMA32
336*4882a593Smuzhiyun	def_bool y if X86_64
337*4882a593Smuzhiyun
338*4882a593Smuzhiyunconfig AUDIT_ARCH
339*4882a593Smuzhiyun	def_bool y if X86_64
340*4882a593Smuzhiyun
341*4882a593Smuzhiyunconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC
342*4882a593Smuzhiyun	def_bool y
343*4882a593Smuzhiyun
344*4882a593Smuzhiyunconfig KASAN_SHADOW_OFFSET
345*4882a593Smuzhiyun	hex
346*4882a593Smuzhiyun	depends on KASAN
347*4882a593Smuzhiyun	default 0xdffffc0000000000
348*4882a593Smuzhiyun
349*4882a593Smuzhiyunconfig HAVE_INTEL_TXT
350*4882a593Smuzhiyun	def_bool y
351*4882a593Smuzhiyun	depends on INTEL_IOMMU && ACPI
352*4882a593Smuzhiyun
353*4882a593Smuzhiyunconfig X86_32_SMP
354*4882a593Smuzhiyun	def_bool y
355*4882a593Smuzhiyun	depends on X86_32 && SMP
356*4882a593Smuzhiyun
357*4882a593Smuzhiyunconfig X86_64_SMP
358*4882a593Smuzhiyun	def_bool y
359*4882a593Smuzhiyun	depends on X86_64 && SMP
360*4882a593Smuzhiyun
361*4882a593Smuzhiyunconfig X86_32_LAZY_GS
362*4882a593Smuzhiyun	def_bool y
363*4882a593Smuzhiyun	depends on X86_32 && !STACKPROTECTOR
364*4882a593Smuzhiyun
365*4882a593Smuzhiyunconfig ARCH_SUPPORTS_UPROBES
366*4882a593Smuzhiyun	def_bool y
367*4882a593Smuzhiyun
368*4882a593Smuzhiyunconfig FIX_EARLYCON_MEM
369*4882a593Smuzhiyun	def_bool y
370*4882a593Smuzhiyun
371*4882a593Smuzhiyunconfig DYNAMIC_PHYSICAL_MASK
372*4882a593Smuzhiyun	bool
373*4882a593Smuzhiyun
374*4882a593Smuzhiyunconfig PGTABLE_LEVELS
375*4882a593Smuzhiyun	int
376*4882a593Smuzhiyun	default 5 if X86_5LEVEL
377*4882a593Smuzhiyun	default 4 if X86_64
378*4882a593Smuzhiyun	default 3 if X86_PAE
379*4882a593Smuzhiyun	default 2
380*4882a593Smuzhiyun
381*4882a593Smuzhiyunconfig CC_HAS_SANE_STACKPROTECTOR
382*4882a593Smuzhiyun	bool
383*4882a593Smuzhiyun	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
384*4882a593Smuzhiyun	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
385*4882a593Smuzhiyun	help
386*4882a593Smuzhiyun	   We have to make sure stack protector is unconditionally disabled if
387*4882a593Smuzhiyun	   the compiler produces broken code.
388*4882a593Smuzhiyun
389*4882a593Smuzhiyunmenu "Processor type and features"
390*4882a593Smuzhiyun
391*4882a593Smuzhiyunconfig ZONE_DMA
392*4882a593Smuzhiyun	bool "DMA memory allocation support" if EXPERT
393*4882a593Smuzhiyun	default y
394*4882a593Smuzhiyun	help
395*4882a593Smuzhiyun	  DMA memory allocation support allows devices with less than 32-bit
396*4882a593Smuzhiyun	  addressing to allocate within the first 16MB of address space.
397*4882a593Smuzhiyun	  Disable if no such devices will be used.
398*4882a593Smuzhiyun
399*4882a593Smuzhiyun	  If unsure, say Y.
400*4882a593Smuzhiyun
401*4882a593Smuzhiyunconfig SMP
402*4882a593Smuzhiyun	bool "Symmetric multi-processing support"
403*4882a593Smuzhiyun	help
404*4882a593Smuzhiyun	  This enables support for systems with more than one CPU. If you have
405*4882a593Smuzhiyun	  a system with only one CPU, say N. If you have a system with more
406*4882a593Smuzhiyun	  than one CPU, say Y.
407*4882a593Smuzhiyun
408*4882a593Smuzhiyun	  If you say N here, the kernel will run on uni- and multiprocessor
409*4882a593Smuzhiyun	  machines, but will use only one CPU of a multiprocessor machine. If
410*4882a593Smuzhiyun	  you say Y here, the kernel will run on many, but not all,
411*4882a593Smuzhiyun	  uniprocessor machines. On a uniprocessor machine, the kernel
412*4882a593Smuzhiyun	  will run faster if you say N here.
413*4882a593Smuzhiyun
414*4882a593Smuzhiyun	  Note that if you say Y here and choose architecture "586" or
415*4882a593Smuzhiyun	  "Pentium" under "Processor family", the kernel will not work on 486
416*4882a593Smuzhiyun	  architectures. Similarly, multiprocessor kernels for the "PPro"
417*4882a593Smuzhiyun	  architecture may not work on all Pentium based boards.
418*4882a593Smuzhiyun
419*4882a593Smuzhiyun	  People using multiprocessor machines who say Y here should also say
420*4882a593Smuzhiyun	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
421*4882a593Smuzhiyun	  Management" code will be disabled if you say Y here.
422*4882a593Smuzhiyun
423*4882a593Smuzhiyun	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
424*4882a593Smuzhiyun	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
425*4882a593Smuzhiyun	  <http://www.tldp.org/docs.html#howto>.
426*4882a593Smuzhiyun
427*4882a593Smuzhiyun	  If you don't know what to do here, say N.
428*4882a593Smuzhiyun
429*4882a593Smuzhiyunconfig X86_FEATURE_NAMES
430*4882a593Smuzhiyun	bool "Processor feature human-readable names" if EMBEDDED
431*4882a593Smuzhiyun	default y
432*4882a593Smuzhiyun	help
433*4882a593Smuzhiyun	  This option compiles in a table of x86 feature bits and corresponding
434*4882a593Smuzhiyun	  names.  This is required to support /proc/cpuinfo and a few kernel
435*4882a593Smuzhiyun	  messages.  You can disable this to save space, at the expense of
436*4882a593Smuzhiyun	  making those few kernel messages show numeric feature bits instead.
437*4882a593Smuzhiyun
438*4882a593Smuzhiyun	  If in doubt, say Y.
439*4882a593Smuzhiyun
440*4882a593Smuzhiyunconfig X86_X2APIC
441*4882a593Smuzhiyun	bool "Support x2apic"
442*4882a593Smuzhiyun	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
443*4882a593Smuzhiyun	help
444*4882a593Smuzhiyun	  This enables x2apic support on CPUs that have this feature.
445*4882a593Smuzhiyun
446*4882a593Smuzhiyun	  This allows 32-bit apic IDs (so it can support very large systems),
447*4882a593Smuzhiyun	  and accesses the local apic via MSRs not via mmio.
448*4882a593Smuzhiyun
449*4882a593Smuzhiyun	  If you don't know what to do here, say N.
450*4882a593Smuzhiyun
451*4882a593Smuzhiyunconfig X86_MPPARSE
452*4882a593Smuzhiyun	bool "Enable MPS table" if ACPI || SFI
453*4882a593Smuzhiyun	default y
454*4882a593Smuzhiyun	depends on X86_LOCAL_APIC
455*4882a593Smuzhiyun	help
456*4882a593Smuzhiyun	  For old smp systems that do not have proper acpi support. Newer systems
457*4882a593Smuzhiyun	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
458*4882a593Smuzhiyun
459*4882a593Smuzhiyunconfig GOLDFISH
460*4882a593Smuzhiyun	def_bool y
461*4882a593Smuzhiyun	depends on X86_GOLDFISH
462*4882a593Smuzhiyun
463*4882a593Smuzhiyunconfig X86_CPU_RESCTRL
464*4882a593Smuzhiyun	bool "x86 CPU resource control support"
465*4882a593Smuzhiyun	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
466*4882a593Smuzhiyun	select KERNFS
467*4882a593Smuzhiyun	select PROC_CPU_RESCTRL		if PROC_FS
468*4882a593Smuzhiyun	help
469*4882a593Smuzhiyun	  Enable x86 CPU resource control support.
470*4882a593Smuzhiyun
471*4882a593Smuzhiyun	  Provide support for the allocation and monitoring of system resources
472*4882a593Smuzhiyun	  usage by the CPU.
473*4882a593Smuzhiyun
474*4882a593Smuzhiyun	  Intel calls this Intel Resource Director Technology
475*4882a593Smuzhiyun	  (Intel(R) RDT). More information about RDT can be found in the
476*4882a593Smuzhiyun	  Intel x86 Architecture Software Developer Manual.
477*4882a593Smuzhiyun
478*4882a593Smuzhiyun	  AMD calls this AMD Platform Quality of Service (AMD QoS).
479*4882a593Smuzhiyun	  More information about AMD QoS can be found in the AMD64 Technology
480*4882a593Smuzhiyun	  Platform Quality of Service Extensions manual.
481*4882a593Smuzhiyun
482*4882a593Smuzhiyun	  Say N if unsure.
483*4882a593Smuzhiyun
484*4882a593Smuzhiyunif X86_32
485*4882a593Smuzhiyunconfig X86_BIGSMP
486*4882a593Smuzhiyun	bool "Support for big SMP systems with more than 8 CPUs"
487*4882a593Smuzhiyun	depends on SMP
488*4882a593Smuzhiyun	help
489*4882a593Smuzhiyun	  This option is needed for the systems that have more than 8 CPUs.
490*4882a593Smuzhiyun
491*4882a593Smuzhiyunconfig X86_EXTENDED_PLATFORM
492*4882a593Smuzhiyun	bool "Support for extended (non-PC) x86 platforms"
493*4882a593Smuzhiyun	default y
494*4882a593Smuzhiyun	help
495*4882a593Smuzhiyun	  If you disable this option then the kernel will only support
496*4882a593Smuzhiyun	  standard PC platforms. (which covers the vast majority of
497*4882a593Smuzhiyun	  systems out there.)
498*4882a593Smuzhiyun
499*4882a593Smuzhiyun	  If you enable this option then you'll be able to select support
500*4882a593Smuzhiyun	  for the following (non-PC) 32 bit x86 platforms:
501*4882a593Smuzhiyun		Goldfish (Android emulator)
502*4882a593Smuzhiyun		AMD Elan
503*4882a593Smuzhiyun		RDC R-321x SoC
504*4882a593Smuzhiyun		SGI 320/540 (Visual Workstation)
505*4882a593Smuzhiyun		STA2X11-based (e.g. Northville)
506*4882a593Smuzhiyun		Moorestown MID devices
507*4882a593Smuzhiyun
508*4882a593Smuzhiyun	  If you have one of these systems, or if you want to build a
509*4882a593Smuzhiyun	  generic distribution kernel, say Y here - otherwise say N.
510*4882a593Smuzhiyunendif
511*4882a593Smuzhiyun
512*4882a593Smuzhiyunif X86_64
513*4882a593Smuzhiyunconfig X86_EXTENDED_PLATFORM
514*4882a593Smuzhiyun	bool "Support for extended (non-PC) x86 platforms"
515*4882a593Smuzhiyun	default y
516*4882a593Smuzhiyun	help
517*4882a593Smuzhiyun	  If you disable this option then the kernel will only support
518*4882a593Smuzhiyun	  standard PC platforms. (which covers the vast majority of
519*4882a593Smuzhiyun	  systems out there.)
520*4882a593Smuzhiyun
521*4882a593Smuzhiyun	  If you enable this option then you'll be able to select support
522*4882a593Smuzhiyun	  for the following (non-PC) 64 bit x86 platforms:
523*4882a593Smuzhiyun		Numascale NumaChip
524*4882a593Smuzhiyun		ScaleMP vSMP
525*4882a593Smuzhiyun		SGI Ultraviolet
526*4882a593Smuzhiyun
527*4882a593Smuzhiyun	  If you have one of these systems, or if you want to build a
528*4882a593Smuzhiyun	  generic distribution kernel, say Y here - otherwise say N.
529*4882a593Smuzhiyunendif
530*4882a593Smuzhiyun# This is an alphabetically sorted list of 64 bit extended platforms
531*4882a593Smuzhiyun# Please maintain the alphabetic order if and when there are additions
532*4882a593Smuzhiyunconfig X86_NUMACHIP
533*4882a593Smuzhiyun	bool "Numascale NumaChip"
534*4882a593Smuzhiyun	depends on X86_64
535*4882a593Smuzhiyun	depends on X86_EXTENDED_PLATFORM
536*4882a593Smuzhiyun	depends on NUMA
537*4882a593Smuzhiyun	depends on SMP
538*4882a593Smuzhiyun	depends on X86_X2APIC
539*4882a593Smuzhiyun	depends on PCI_MMCONFIG
540*4882a593Smuzhiyun	help
541*4882a593Smuzhiyun	  Adds support for Numascale NumaChip large-SMP systems. Needed to
542*4882a593Smuzhiyun	  enable more than ~168 cores.
543*4882a593Smuzhiyun	  If you don't have one of these, you should say N here.
544*4882a593Smuzhiyun
545*4882a593Smuzhiyunconfig X86_VSMP
546*4882a593Smuzhiyun	bool "ScaleMP vSMP"
547*4882a593Smuzhiyun	select HYPERVISOR_GUEST
548*4882a593Smuzhiyun	select PARAVIRT
549*4882a593Smuzhiyun	depends on X86_64 && PCI
550*4882a593Smuzhiyun	depends on X86_EXTENDED_PLATFORM
551*4882a593Smuzhiyun	depends on SMP
552*4882a593Smuzhiyun	help
553*4882a593Smuzhiyun	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
554*4882a593Smuzhiyun	  supposed to run on these EM64T-based machines.  Only choose this option
555*4882a593Smuzhiyun	  if you have one of these machines.
556*4882a593Smuzhiyun
557*4882a593Smuzhiyunconfig X86_UV
558*4882a593Smuzhiyun	bool "SGI Ultraviolet"
559*4882a593Smuzhiyun	depends on X86_64
560*4882a593Smuzhiyun	depends on X86_EXTENDED_PLATFORM
561*4882a593Smuzhiyun	depends on NUMA
562*4882a593Smuzhiyun	depends on EFI
563*4882a593Smuzhiyun	depends on KEXEC_CORE
564*4882a593Smuzhiyun	depends on X86_X2APIC
565*4882a593Smuzhiyun	depends on PCI
566*4882a593Smuzhiyun	help
567*4882a593Smuzhiyun	  This option is needed in order to support SGI Ultraviolet systems.
568*4882a593Smuzhiyun	  If you don't have one of these, you should say N here.
569*4882a593Smuzhiyun
570*4882a593Smuzhiyun# Following is an alphabetically sorted list of 32 bit extended platforms
571*4882a593Smuzhiyun# Please maintain the alphabetic order if and when there are additions
572*4882a593Smuzhiyun
573*4882a593Smuzhiyunconfig X86_GOLDFISH
574*4882a593Smuzhiyun	bool "Goldfish (Virtual Platform)"
575*4882a593Smuzhiyun	depends on X86_EXTENDED_PLATFORM
576*4882a593Smuzhiyun	help
577*4882a593Smuzhiyun	 Enable support for the Goldfish virtual platform used primarily
578*4882a593Smuzhiyun	 for Android development. Unless you are building for the Android
579*4882a593Smuzhiyun	 Goldfish emulator say N here.
580*4882a593Smuzhiyun
581*4882a593Smuzhiyunconfig X86_INTEL_CE
582*4882a593Smuzhiyun	bool "CE4100 TV platform"
583*4882a593Smuzhiyun	depends on PCI
584*4882a593Smuzhiyun	depends on PCI_GODIRECT
585*4882a593Smuzhiyun	depends on X86_IO_APIC
586*4882a593Smuzhiyun	depends on X86_32
587*4882a593Smuzhiyun	depends on X86_EXTENDED_PLATFORM
588*4882a593Smuzhiyun	select X86_REBOOTFIXUPS
589*4882a593Smuzhiyun	select OF
590*4882a593Smuzhiyun	select OF_EARLY_FLATTREE
591*4882a593Smuzhiyun	help
592*4882a593Smuzhiyun	  Select for the Intel CE media processor (CE4100) SOC.
593*4882a593Smuzhiyun	  This option compiles in support for the CE4100 SOC for settop
594*4882a593Smuzhiyun	  boxes and media devices.
595*4882a593Smuzhiyun
596*4882a593Smuzhiyunconfig X86_INTEL_MID
597*4882a593Smuzhiyun	bool "Intel MID platform support"
598*4882a593Smuzhiyun	depends on X86_EXTENDED_PLATFORM
599*4882a593Smuzhiyun	depends on X86_PLATFORM_DEVICES
600*4882a593Smuzhiyun	depends on PCI
601*4882a593Smuzhiyun	depends on X86_64 || (PCI_GOANY && X86_32)
602*4882a593Smuzhiyun	depends on X86_IO_APIC
603*4882a593Smuzhiyun	select SFI
604*4882a593Smuzhiyun	select I2C
605*4882a593Smuzhiyun	select DW_APB_TIMER
606*4882a593Smuzhiyun	select APB_TIMER
607*4882a593Smuzhiyun	select INTEL_SCU_PCI
608*4882a593Smuzhiyun	select MFD_INTEL_MSIC
609*4882a593Smuzhiyun	help
610*4882a593Smuzhiyun	  Select to build a kernel capable of supporting Intel MID (Mobile
611*4882a593Smuzhiyun	  Internet Device) platform systems which do not have the PCI legacy
612*4882a593Smuzhiyun	  interfaces. If you are building for a PC class system say N here.
613*4882a593Smuzhiyun
614*4882a593Smuzhiyun	  Intel MID platforms are based on an Intel processor and chipset which
615*4882a593Smuzhiyun	  consume less power than most of the x86 derivatives.
616*4882a593Smuzhiyun
617*4882a593Smuzhiyunconfig X86_INTEL_QUARK
618*4882a593Smuzhiyun	bool "Intel Quark platform support"
619*4882a593Smuzhiyun	depends on X86_32
620*4882a593Smuzhiyun	depends on X86_EXTENDED_PLATFORM
621*4882a593Smuzhiyun	depends on X86_PLATFORM_DEVICES
622*4882a593Smuzhiyun	depends on X86_TSC
623*4882a593Smuzhiyun	depends on PCI
624*4882a593Smuzhiyun	depends on PCI_GOANY
625*4882a593Smuzhiyun	depends on X86_IO_APIC
626*4882a593Smuzhiyun	select IOSF_MBI
627*4882a593Smuzhiyun	select INTEL_IMR
628*4882a593Smuzhiyun	select COMMON_CLK
629*4882a593Smuzhiyun	help
630*4882a593Smuzhiyun	  Select to include support for Quark X1000 SoC.
631*4882a593Smuzhiyun	  Say Y here if you have a Quark based system such as the Arduino
632*4882a593Smuzhiyun	  compatible Intel Galileo.
633*4882a593Smuzhiyun
634*4882a593Smuzhiyunconfig X86_INTEL_LPSS
635*4882a593Smuzhiyun	bool "Intel Low Power Subsystem Support"
636*4882a593Smuzhiyun	depends on X86 && ACPI && PCI
637*4882a593Smuzhiyun	select COMMON_CLK
638*4882a593Smuzhiyun	select PINCTRL
639*4882a593Smuzhiyun	select IOSF_MBI
640*4882a593Smuzhiyun	help
641*4882a593Smuzhiyun	  Select to build support for Intel Low Power Subsystem such as
642*4882a593Smuzhiyun	  found on Intel Lynxpoint PCH. Selecting this option enables
643*4882a593Smuzhiyun	  things like clock tree (common clock framework) and pincontrol
644*4882a593Smuzhiyun	  which are needed by the LPSS peripheral drivers.
645*4882a593Smuzhiyun
646*4882a593Smuzhiyunconfig X86_AMD_PLATFORM_DEVICE
647*4882a593Smuzhiyun	bool "AMD ACPI2Platform devices support"
648*4882a593Smuzhiyun	depends on ACPI
649*4882a593Smuzhiyun	select COMMON_CLK
650*4882a593Smuzhiyun	select PINCTRL
651*4882a593Smuzhiyun	help
652*4882a593Smuzhiyun	  Select to interpret AMD specific ACPI device to platform device
653*4882a593Smuzhiyun	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
654*4882a593Smuzhiyun	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
655*4882a593Smuzhiyun	  implemented under PINCTRL subsystem.
656*4882a593Smuzhiyun
657*4882a593Smuzhiyunconfig IOSF_MBI
658*4882a593Smuzhiyun	tristate "Intel SoC IOSF Sideband support for SoC platforms"
659*4882a593Smuzhiyun	depends on PCI
660*4882a593Smuzhiyun	help
661*4882a593Smuzhiyun	  This option enables sideband register access support for Intel SoC
662*4882a593Smuzhiyun	  platforms. On these platforms the IOSF sideband is used in lieu of
663*4882a593Smuzhiyun	  MSR's for some register accesses, mostly but not limited to thermal
664*4882a593Smuzhiyun	  and power. Drivers may query the availability of this device to
665*4882a593Smuzhiyun	  determine if they need the sideband in order to work on these
666*4882a593Smuzhiyun	  platforms. The sideband is available on the following SoC products.
667*4882a593Smuzhiyun	  This list is not meant to be exclusive.
668*4882a593Smuzhiyun	   - BayTrail
669*4882a593Smuzhiyun	   - Braswell
670*4882a593Smuzhiyun	   - Quark
671*4882a593Smuzhiyun
672*4882a593Smuzhiyun	  You should say Y if you are running a kernel on one of these SoC's.
673*4882a593Smuzhiyun
674*4882a593Smuzhiyunconfig IOSF_MBI_DEBUG
675*4882a593Smuzhiyun	bool "Enable IOSF sideband access through debugfs"
676*4882a593Smuzhiyun	depends on IOSF_MBI && DEBUG_FS
677*4882a593Smuzhiyun	help
678*4882a593Smuzhiyun	  Select this option to expose the IOSF sideband access registers (MCR,
679*4882a593Smuzhiyun	  MDR, MCRX) through debugfs to write and read register information from
680*4882a593Smuzhiyun	  different units on the SoC. This is most useful for obtaining device
681*4882a593Smuzhiyun	  state information for debug and analysis. As this is a general access
682*4882a593Smuzhiyun	  mechanism, users of this option would have specific knowledge of the
683*4882a593Smuzhiyun	  device they want to access.
684*4882a593Smuzhiyun
685*4882a593Smuzhiyun	  If you don't require the option or are in doubt, say N.
686*4882a593Smuzhiyun
687*4882a593Smuzhiyunconfig X86_RDC321X
688*4882a593Smuzhiyun	bool "RDC R-321x SoC"
689*4882a593Smuzhiyun	depends on X86_32
690*4882a593Smuzhiyun	depends on X86_EXTENDED_PLATFORM
691*4882a593Smuzhiyun	select M486
692*4882a593Smuzhiyun	select X86_REBOOTFIXUPS
693*4882a593Smuzhiyun	help
694*4882a593Smuzhiyun	  This option is needed for RDC R-321x system-on-chip, also known
695*4882a593Smuzhiyun	  as R-8610-(G).
696*4882a593Smuzhiyun	  If you don't have one of these chips, you should say N here.
697*4882a593Smuzhiyun
698*4882a593Smuzhiyunconfig X86_32_NON_STANDARD
699*4882a593Smuzhiyun	bool "Support non-standard 32-bit SMP architectures"
700*4882a593Smuzhiyun	depends on X86_32 && SMP
701*4882a593Smuzhiyun	depends on X86_EXTENDED_PLATFORM
702*4882a593Smuzhiyun	help
703*4882a593Smuzhiyun	  This option compiles in the bigsmp and STA2X11 default
704*4882a593Smuzhiyun	  subarchitectures.  It is intended for a generic binary
705*4882a593Smuzhiyun	  kernel. If you select them all, kernel will probe it one by
706*4882a593Smuzhiyun	  one and will fallback to default.
707*4882a593Smuzhiyun
708*4882a593Smuzhiyun# Alphabetically sorted list of Non standard 32 bit platforms
709*4882a593Smuzhiyun
710*4882a593Smuzhiyunconfig X86_SUPPORTS_MEMORY_FAILURE
711*4882a593Smuzhiyun	def_bool y
712*4882a593Smuzhiyun	# MCE code calls memory_failure():
713*4882a593Smuzhiyun	depends on X86_MCE
714*4882a593Smuzhiyun	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
715*4882a593Smuzhiyun	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
716*4882a593Smuzhiyun	depends on X86_64 || !SPARSEMEM
717*4882a593Smuzhiyun	select ARCH_SUPPORTS_MEMORY_FAILURE
718*4882a593Smuzhiyun
719*4882a593Smuzhiyunconfig STA2X11
720*4882a593Smuzhiyun	bool "STA2X11 Companion Chip Support"
721*4882a593Smuzhiyun	depends on X86_32_NON_STANDARD && PCI
722*4882a593Smuzhiyun	select SWIOTLB
723*4882a593Smuzhiyun	select MFD_STA2X11
724*4882a593Smuzhiyun	select GPIOLIB
725*4882a593Smuzhiyun	help
726*4882a593Smuzhiyun	  This adds support for boards based on the STA2X11 IO-Hub,
727*4882a593Smuzhiyun	  a.k.a. "ConneXt". The chip is used in place of the standard
728*4882a593Smuzhiyun	  PC chipset, so all "standard" peripherals are missing. If this
729*4882a593Smuzhiyun	  option is selected the kernel will still be able to boot on
730*4882a593Smuzhiyun	  standard PC machines.
731*4882a593Smuzhiyun
732*4882a593Smuzhiyunconfig X86_32_IRIS
733*4882a593Smuzhiyun	tristate "Eurobraille/Iris poweroff module"
734*4882a593Smuzhiyun	depends on X86_32
735*4882a593Smuzhiyun	help
736*4882a593Smuzhiyun	  The Iris machines from EuroBraille do not have APM or ACPI support
737*4882a593Smuzhiyun	  to shut themselves down properly.  A special I/O sequence is
738*4882a593Smuzhiyun	  needed to do so, which is what this module does at
739*4882a593Smuzhiyun	  kernel shutdown.
740*4882a593Smuzhiyun
741*4882a593Smuzhiyun	  This is only for Iris machines from EuroBraille.
742*4882a593Smuzhiyun
743*4882a593Smuzhiyun	  If unused, say N.
744*4882a593Smuzhiyun
745*4882a593Smuzhiyunconfig SCHED_OMIT_FRAME_POINTER
746*4882a593Smuzhiyun	def_bool y
747*4882a593Smuzhiyun	prompt "Single-depth WCHAN output"
748*4882a593Smuzhiyun	depends on X86
749*4882a593Smuzhiyun	help
750*4882a593Smuzhiyun	  Calculate simpler /proc/<PID>/wchan values. If this option
751*4882a593Smuzhiyun	  is disabled then wchan values will recurse back to the
752*4882a593Smuzhiyun	  caller function. This provides more accurate wchan values,
753*4882a593Smuzhiyun	  at the expense of slightly more scheduling overhead.
754*4882a593Smuzhiyun
755*4882a593Smuzhiyun	  If in doubt, say "Y".
756*4882a593Smuzhiyun
757*4882a593Smuzhiyunmenuconfig HYPERVISOR_GUEST
758*4882a593Smuzhiyun	bool "Linux guest support"
759*4882a593Smuzhiyun	help
760*4882a593Smuzhiyun	  Say Y here to enable options for running Linux under various hyper-
761*4882a593Smuzhiyun	  visors. This option enables basic hypervisor detection and platform
762*4882a593Smuzhiyun	  setup.
763*4882a593Smuzhiyun
764*4882a593Smuzhiyun	  If you say N, all options in this submenu will be skipped and
765*4882a593Smuzhiyun	  disabled, and Linux guest support won't be built in.
766*4882a593Smuzhiyun
767*4882a593Smuzhiyunif HYPERVISOR_GUEST
768*4882a593Smuzhiyun
769*4882a593Smuzhiyunconfig PARAVIRT
770*4882a593Smuzhiyun	bool "Enable paravirtualization code"
771*4882a593Smuzhiyun	help
772*4882a593Smuzhiyun	  This changes the kernel so it can modify itself when it is run
773*4882a593Smuzhiyun	  under a hypervisor, potentially improving performance significantly
774*4882a593Smuzhiyun	  over full virtualization.  However, when run without a hypervisor
775*4882a593Smuzhiyun	  the kernel is theoretically slower and slightly larger.
776*4882a593Smuzhiyun
777*4882a593Smuzhiyunconfig PARAVIRT_XXL
778*4882a593Smuzhiyun	bool
779*4882a593Smuzhiyun
780*4882a593Smuzhiyunconfig PARAVIRT_DEBUG
781*4882a593Smuzhiyun	bool "paravirt-ops debugging"
782*4882a593Smuzhiyun	depends on PARAVIRT && DEBUG_KERNEL
783*4882a593Smuzhiyun	help
784*4882a593Smuzhiyun	  Enable to debug paravirt_ops internals.  Specifically, BUG if
785*4882a593Smuzhiyun	  a paravirt_op is missing when it is called.
786*4882a593Smuzhiyun
787*4882a593Smuzhiyunconfig PARAVIRT_SPINLOCKS
788*4882a593Smuzhiyun	bool "Paravirtualization layer for spinlocks"
789*4882a593Smuzhiyun	depends on PARAVIRT && SMP
790*4882a593Smuzhiyun	help
791*4882a593Smuzhiyun	  Paravirtualized spinlocks allow a pvops backend to replace the
792*4882a593Smuzhiyun	  spinlock implementation with something virtualization-friendly
793*4882a593Smuzhiyun	  (for example, block the virtual CPU rather than spinning).
794*4882a593Smuzhiyun
795*4882a593Smuzhiyun	  It has a minimal impact on native kernels and gives a nice performance
796*4882a593Smuzhiyun	  benefit on paravirtualized KVM / Xen kernels.
797*4882a593Smuzhiyun
798*4882a593Smuzhiyun	  If you are unsure how to answer this question, answer Y.
799*4882a593Smuzhiyun
800*4882a593Smuzhiyunconfig X86_HV_CALLBACK_VECTOR
801*4882a593Smuzhiyun	def_bool n
802*4882a593Smuzhiyun
803*4882a593Smuzhiyunsource "arch/x86/xen/Kconfig"
804*4882a593Smuzhiyun
805*4882a593Smuzhiyunconfig KVM_GUEST
806*4882a593Smuzhiyun	bool "KVM Guest support (including kvmclock)"
807*4882a593Smuzhiyun	depends on PARAVIRT
808*4882a593Smuzhiyun	select PARAVIRT_CLOCK
809*4882a593Smuzhiyun	select ARCH_CPUIDLE_HALTPOLL
810*4882a593Smuzhiyun	select X86_HV_CALLBACK_VECTOR
811*4882a593Smuzhiyun	default y
812*4882a593Smuzhiyun	help
813*4882a593Smuzhiyun	  This option enables various optimizations for running under the KVM
814*4882a593Smuzhiyun	  hypervisor. It includes a paravirtualized clock, so that instead
815*4882a593Smuzhiyun	  of relying on a PIT (or probably other) emulation by the
816*4882a593Smuzhiyun	  underlying device model, the host provides the guest with
817*4882a593Smuzhiyun	  timing infrastructure such as time of day, and system time
818*4882a593Smuzhiyun
819*4882a593Smuzhiyunconfig ARCH_CPUIDLE_HALTPOLL
820*4882a593Smuzhiyun	def_bool n
821*4882a593Smuzhiyun	prompt "Disable host haltpoll when loading haltpoll driver"
822*4882a593Smuzhiyun	help
823*4882a593Smuzhiyun	  If virtualized under KVM, disable host haltpoll.
824*4882a593Smuzhiyun
825*4882a593Smuzhiyunconfig PVH
826*4882a593Smuzhiyun	bool "Support for running PVH guests"
827*4882a593Smuzhiyun	help
828*4882a593Smuzhiyun	  This option enables the PVH entry point for guest virtual machines
829*4882a593Smuzhiyun	  as specified in the x86/HVM direct boot ABI.
830*4882a593Smuzhiyun
831*4882a593Smuzhiyunconfig PARAVIRT_TIME_ACCOUNTING
832*4882a593Smuzhiyun	bool "Paravirtual steal time accounting"
833*4882a593Smuzhiyun	depends on PARAVIRT
834*4882a593Smuzhiyun	help
835*4882a593Smuzhiyun	  Select this option to enable fine granularity task steal time
836*4882a593Smuzhiyun	  accounting. Time spent executing other tasks in parallel with
837*4882a593Smuzhiyun	  the current vCPU is discounted from the vCPU power. To account for
838*4882a593Smuzhiyun	  that, there can be a small performance impact.
839*4882a593Smuzhiyun
840*4882a593Smuzhiyun	  If in doubt, say N here.
841*4882a593Smuzhiyun
842*4882a593Smuzhiyunconfig PARAVIRT_CLOCK
843*4882a593Smuzhiyun	bool
844*4882a593Smuzhiyun
845*4882a593Smuzhiyunconfig JAILHOUSE_GUEST
846*4882a593Smuzhiyun	bool "Jailhouse non-root cell support"
847*4882a593Smuzhiyun	depends on X86_64 && PCI
848*4882a593Smuzhiyun	select X86_PM_TIMER
849*4882a593Smuzhiyun	help
850*4882a593Smuzhiyun	  This option allows to run Linux as guest in a Jailhouse non-root
851*4882a593Smuzhiyun	  cell. You can leave this option disabled if you only want to start
852*4882a593Smuzhiyun	  Jailhouse and run Linux afterwards in the root cell.
853*4882a593Smuzhiyun
854*4882a593Smuzhiyunconfig ACRN_GUEST
855*4882a593Smuzhiyun	bool "ACRN Guest support"
856*4882a593Smuzhiyun	depends on X86_64
857*4882a593Smuzhiyun	select X86_HV_CALLBACK_VECTOR
858*4882a593Smuzhiyun	help
859*4882a593Smuzhiyun	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
860*4882a593Smuzhiyun	  a flexible, lightweight reference open-source hypervisor, built with
861*4882a593Smuzhiyun	  real-time and safety-criticality in mind. It is built for embedded
862*4882a593Smuzhiyun	  IOT with small footprint and real-time features. More details can be
863*4882a593Smuzhiyun	  found in https://projectacrn.org/.
864*4882a593Smuzhiyun
865*4882a593Smuzhiyunendif #HYPERVISOR_GUEST
866*4882a593Smuzhiyun
867*4882a593Smuzhiyunsource "arch/x86/Kconfig.cpu"
868*4882a593Smuzhiyun
869*4882a593Smuzhiyunconfig HPET_TIMER
870*4882a593Smuzhiyun	def_bool X86_64
871*4882a593Smuzhiyun	prompt "HPET Timer Support" if X86_32
872*4882a593Smuzhiyun	help
873*4882a593Smuzhiyun	  Use the IA-PC HPET (High Precision Event Timer) to manage
874*4882a593Smuzhiyun	  time in preference to the PIT and RTC, if a HPET is
875*4882a593Smuzhiyun	  present.
876*4882a593Smuzhiyun	  HPET is the next generation timer replacing legacy 8254s.
877*4882a593Smuzhiyun	  The HPET provides a stable time base on SMP
878*4882a593Smuzhiyun	  systems, unlike the TSC, but it is more expensive to access,
879*4882a593Smuzhiyun	  as it is off-chip.  The interface used is documented
880*4882a593Smuzhiyun	  in the HPET spec, revision 1.
881*4882a593Smuzhiyun
882*4882a593Smuzhiyun	  You can safely choose Y here.  However, HPET will only be
883*4882a593Smuzhiyun	  activated if the platform and the BIOS support this feature.
884*4882a593Smuzhiyun	  Otherwise the 8254 will be used for timing services.
885*4882a593Smuzhiyun
886*4882a593Smuzhiyun	  Choose N to continue using the legacy 8254 timer.
887*4882a593Smuzhiyun
888*4882a593Smuzhiyunconfig HPET_EMULATE_RTC
889*4882a593Smuzhiyun	def_bool y
890*4882a593Smuzhiyun	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
891*4882a593Smuzhiyun
892*4882a593Smuzhiyunconfig APB_TIMER
893*4882a593Smuzhiyun	def_bool y if X86_INTEL_MID
894*4882a593Smuzhiyun	prompt "Intel MID APB Timer Support" if X86_INTEL_MID
895*4882a593Smuzhiyun	select DW_APB_TIMER
896*4882a593Smuzhiyun	depends on X86_INTEL_MID && SFI
897*4882a593Smuzhiyun	help
898*4882a593Smuzhiyun	 APB timer is the replacement for 8254, HPET on X86 MID platforms.
899*4882a593Smuzhiyun	 The APBT provides a stable time base on SMP
900*4882a593Smuzhiyun	 systems, unlike the TSC, but it is more expensive to access,
901*4882a593Smuzhiyun	 as it is off-chip. APB timers are always running regardless of CPU
902*4882a593Smuzhiyun	 C states, they are used as per CPU clockevent device when possible.
903*4882a593Smuzhiyun
904*4882a593Smuzhiyun# Mark as expert because too many people got it wrong.
905*4882a593Smuzhiyun# The code disables itself when not needed.
906*4882a593Smuzhiyunconfig DMI
907*4882a593Smuzhiyun	default y
908*4882a593Smuzhiyun	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
909*4882a593Smuzhiyun	bool "Enable DMI scanning" if EXPERT
910*4882a593Smuzhiyun	help
911*4882a593Smuzhiyun	  Enabled scanning of DMI to identify machine quirks. Say Y
912*4882a593Smuzhiyun	  here unless you have verified that your setup is not
913*4882a593Smuzhiyun	  affected by entries in the DMI blacklist. Required by PNP
914*4882a593Smuzhiyun	  BIOS code.
915*4882a593Smuzhiyun
916*4882a593Smuzhiyunconfig GART_IOMMU
917*4882a593Smuzhiyun	bool "Old AMD GART IOMMU support"
918*4882a593Smuzhiyun	select DMA_OPS
919*4882a593Smuzhiyun	select IOMMU_HELPER
920*4882a593Smuzhiyun	select SWIOTLB
921*4882a593Smuzhiyun	depends on X86_64 && PCI && AMD_NB
922*4882a593Smuzhiyun	help
923*4882a593Smuzhiyun	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
924*4882a593Smuzhiyun	  GART based hardware IOMMUs.
925*4882a593Smuzhiyun
926*4882a593Smuzhiyun	  The GART supports full DMA access for devices with 32-bit access
927*4882a593Smuzhiyun	  limitations, on systems with more than 3 GB. This is usually needed
928*4882a593Smuzhiyun	  for USB, sound, many IDE/SATA chipsets and some other devices.
929*4882a593Smuzhiyun
930*4882a593Smuzhiyun	  Newer systems typically have a modern AMD IOMMU, supported via
931*4882a593Smuzhiyun	  the CONFIG_AMD_IOMMU=y config option.
932*4882a593Smuzhiyun
933*4882a593Smuzhiyun	  In normal configurations this driver is only active when needed:
934*4882a593Smuzhiyun	  there's more than 3 GB of memory and the system contains a
935*4882a593Smuzhiyun	  32-bit limited device.
936*4882a593Smuzhiyun
937*4882a593Smuzhiyun	  If unsure, say Y.
938*4882a593Smuzhiyun
939*4882a593Smuzhiyunconfig MAXSMP
940*4882a593Smuzhiyun	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
941*4882a593Smuzhiyun	depends on X86_64 && SMP && DEBUG_KERNEL
942*4882a593Smuzhiyun	select CPUMASK_OFFSTACK
943*4882a593Smuzhiyun	help
944*4882a593Smuzhiyun	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
945*4882a593Smuzhiyun	  If unsure, say N.
946*4882a593Smuzhiyun
947*4882a593Smuzhiyun#
948*4882a593Smuzhiyun# The maximum number of CPUs supported:
949*4882a593Smuzhiyun#
950*4882a593Smuzhiyun# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
951*4882a593Smuzhiyun# and which can be configured interactively in the
952*4882a593Smuzhiyun# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
953*4882a593Smuzhiyun#
954*4882a593Smuzhiyun# The ranges are different on 32-bit and 64-bit kernels, depending on
955*4882a593Smuzhiyun# hardware capabilities and scalability features of the kernel.
956*4882a593Smuzhiyun#
957*4882a593Smuzhiyun# ( If MAXSMP is enabled we just use the highest possible value and disable
958*4882a593Smuzhiyun#   interactive configuration. )
959*4882a593Smuzhiyun#
960*4882a593Smuzhiyun
961*4882a593Smuzhiyunconfig NR_CPUS_RANGE_BEGIN
962*4882a593Smuzhiyun	int
963*4882a593Smuzhiyun	default NR_CPUS_RANGE_END if MAXSMP
964*4882a593Smuzhiyun	default    1 if !SMP
965*4882a593Smuzhiyun	default    2
966*4882a593Smuzhiyun
967*4882a593Smuzhiyunconfig NR_CPUS_RANGE_END
968*4882a593Smuzhiyun	int
969*4882a593Smuzhiyun	depends on X86_32
970*4882a593Smuzhiyun	default   64 if  SMP &&  X86_BIGSMP
971*4882a593Smuzhiyun	default    8 if  SMP && !X86_BIGSMP
972*4882a593Smuzhiyun	default    1 if !SMP
973*4882a593Smuzhiyun
974*4882a593Smuzhiyunconfig NR_CPUS_RANGE_END
975*4882a593Smuzhiyun	int
976*4882a593Smuzhiyun	depends on X86_64
977*4882a593Smuzhiyun	default 8192 if  SMP && CPUMASK_OFFSTACK
978*4882a593Smuzhiyun	default  512 if  SMP && !CPUMASK_OFFSTACK
979*4882a593Smuzhiyun	default    1 if !SMP
980*4882a593Smuzhiyun
981*4882a593Smuzhiyunconfig NR_CPUS_DEFAULT
982*4882a593Smuzhiyun	int
983*4882a593Smuzhiyun	depends on X86_32
984*4882a593Smuzhiyun	default   32 if  X86_BIGSMP
985*4882a593Smuzhiyun	default    8 if  SMP
986*4882a593Smuzhiyun	default    1 if !SMP
987*4882a593Smuzhiyun
988*4882a593Smuzhiyunconfig NR_CPUS_DEFAULT
989*4882a593Smuzhiyun	int
990*4882a593Smuzhiyun	depends on X86_64
991*4882a593Smuzhiyun	default 8192 if  MAXSMP
992*4882a593Smuzhiyun	default   64 if  SMP
993*4882a593Smuzhiyun	default    1 if !SMP
994*4882a593Smuzhiyun
995*4882a593Smuzhiyunconfig NR_CPUS
996*4882a593Smuzhiyun	int "Maximum number of CPUs" if SMP && !MAXSMP
997*4882a593Smuzhiyun	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
998*4882a593Smuzhiyun	default NR_CPUS_DEFAULT
999*4882a593Smuzhiyun	help
1000*4882a593Smuzhiyun	  This allows you to specify the maximum number of CPUs which this
1001*4882a593Smuzhiyun	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1002*4882a593Smuzhiyun	  supported value is 8192, otherwise the maximum value is 512.  The
1003*4882a593Smuzhiyun	  minimum value which makes sense is 2.
1004*4882a593Smuzhiyun
1005*4882a593Smuzhiyun	  This is purely to save memory: each supported CPU adds about 8KB
1006*4882a593Smuzhiyun	  to the kernel image.
1007*4882a593Smuzhiyun
1008*4882a593Smuzhiyunconfig SCHED_SMT
1009*4882a593Smuzhiyun	def_bool y if SMP
1010*4882a593Smuzhiyun
1011*4882a593Smuzhiyunconfig SCHED_MC
1012*4882a593Smuzhiyun	def_bool y
1013*4882a593Smuzhiyun	prompt "Multi-core scheduler support"
1014*4882a593Smuzhiyun	depends on SMP
1015*4882a593Smuzhiyun	help
1016*4882a593Smuzhiyun	  Multi-core scheduler support improves the CPU scheduler's decision
1017*4882a593Smuzhiyun	  making when dealing with multi-core CPU chips at a cost of slightly
1018*4882a593Smuzhiyun	  increased overhead in some places. If unsure say N here.
1019*4882a593Smuzhiyun
1020*4882a593Smuzhiyunconfig SCHED_MC_PRIO
1021*4882a593Smuzhiyun	bool "CPU core priorities scheduler support"
1022*4882a593Smuzhiyun	depends on SCHED_MC && CPU_SUP_INTEL
1023*4882a593Smuzhiyun	select X86_INTEL_PSTATE
1024*4882a593Smuzhiyun	select CPU_FREQ
1025*4882a593Smuzhiyun	default y
1026*4882a593Smuzhiyun	help
1027*4882a593Smuzhiyun	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1028*4882a593Smuzhiyun	  core ordering determined at manufacturing time, which allows
1029*4882a593Smuzhiyun	  certain cores to reach higher turbo frequencies (when running
1030*4882a593Smuzhiyun	  single threaded workloads) than others.
1031*4882a593Smuzhiyun
1032*4882a593Smuzhiyun	  Enabling this kernel feature teaches the scheduler about
1033*4882a593Smuzhiyun	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1034*4882a593Smuzhiyun	  scheduler's CPU selection logic accordingly, so that higher
1035*4882a593Smuzhiyun	  overall system performance can be achieved.
1036*4882a593Smuzhiyun
1037*4882a593Smuzhiyun	  This feature will have no effect on CPUs without this feature.
1038*4882a593Smuzhiyun
1039*4882a593Smuzhiyun	  If unsure say Y here.
1040*4882a593Smuzhiyun
1041*4882a593Smuzhiyunconfig UP_LATE_INIT
1042*4882a593Smuzhiyun	def_bool y
1043*4882a593Smuzhiyun	depends on !SMP && X86_LOCAL_APIC
1044*4882a593Smuzhiyun
1045*4882a593Smuzhiyunconfig X86_UP_APIC
1046*4882a593Smuzhiyun	bool "Local APIC support on uniprocessors" if !PCI_MSI
1047*4882a593Smuzhiyun	default PCI_MSI
1048*4882a593Smuzhiyun	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1049*4882a593Smuzhiyun	help
1050*4882a593Smuzhiyun	  A local APIC (Advanced Programmable Interrupt Controller) is an
1051*4882a593Smuzhiyun	  integrated interrupt controller in the CPU. If you have a single-CPU
1052*4882a593Smuzhiyun	  system which has a processor with a local APIC, you can say Y here to
1053*4882a593Smuzhiyun	  enable and use it. If you say Y here even though your machine doesn't
1054*4882a593Smuzhiyun	  have a local APIC, then the kernel will still run with no slowdown at
1055*4882a593Smuzhiyun	  all. The local APIC supports CPU-generated self-interrupts (timer,
1056*4882a593Smuzhiyun	  performance counters), and the NMI watchdog which detects hard
1057*4882a593Smuzhiyun	  lockups.
1058*4882a593Smuzhiyun
1059*4882a593Smuzhiyunconfig X86_UP_IOAPIC
1060*4882a593Smuzhiyun	bool "IO-APIC support on uniprocessors"
1061*4882a593Smuzhiyun	depends on X86_UP_APIC
1062*4882a593Smuzhiyun	help
1063*4882a593Smuzhiyun	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1064*4882a593Smuzhiyun	  SMP-capable replacement for PC-style interrupt controllers. Most
1065*4882a593Smuzhiyun	  SMP systems and many recent uniprocessor systems have one.
1066*4882a593Smuzhiyun
1067*4882a593Smuzhiyun	  If you have a single-CPU system with an IO-APIC, you can say Y here
1068*4882a593Smuzhiyun	  to use it. If you say Y here even though your machine doesn't have
1069*4882a593Smuzhiyun	  an IO-APIC, then the kernel will still run with no slowdown at all.
1070*4882a593Smuzhiyun
1071*4882a593Smuzhiyunconfig X86_LOCAL_APIC
1072*4882a593Smuzhiyun	def_bool y
1073*4882a593Smuzhiyun	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1074*4882a593Smuzhiyun	select IRQ_DOMAIN_HIERARCHY
1075*4882a593Smuzhiyun	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1076*4882a593Smuzhiyun
1077*4882a593Smuzhiyunconfig X86_IO_APIC
1078*4882a593Smuzhiyun	def_bool y
1079*4882a593Smuzhiyun	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1080*4882a593Smuzhiyun
1081*4882a593Smuzhiyunconfig X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1082*4882a593Smuzhiyun	bool "Reroute for broken boot IRQs"
1083*4882a593Smuzhiyun	depends on X86_IO_APIC
1084*4882a593Smuzhiyun	help
1085*4882a593Smuzhiyun	  This option enables a workaround that fixes a source of
1086*4882a593Smuzhiyun	  spurious interrupts. This is recommended when threaded
1087*4882a593Smuzhiyun	  interrupt handling is used on systems where the generation of
1088*4882a593Smuzhiyun	  superfluous "boot interrupts" cannot be disabled.
1089*4882a593Smuzhiyun
1090*4882a593Smuzhiyun	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1091*4882a593Smuzhiyun	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1092*4882a593Smuzhiyun	  kernel does during interrupt handling). On chipsets where this
1093*4882a593Smuzhiyun	  boot IRQ generation cannot be disabled, this workaround keeps
1094*4882a593Smuzhiyun	  the original IRQ line masked so that only the equivalent "boot
1095*4882a593Smuzhiyun	  IRQ" is delivered to the CPUs. The workaround also tells the
1096*4882a593Smuzhiyun	  kernel to set up the IRQ handler on the boot IRQ line. In this
1097*4882a593Smuzhiyun	  way only one interrupt is delivered to the kernel. Otherwise
1098*4882a593Smuzhiyun	  the spurious second interrupt may cause the kernel to bring
1099*4882a593Smuzhiyun	  down (vital) interrupt lines.
1100*4882a593Smuzhiyun
1101*4882a593Smuzhiyun	  Only affects "broken" chipsets. Interrupt sharing may be
1102*4882a593Smuzhiyun	  increased on these systems.
1103*4882a593Smuzhiyun
1104*4882a593Smuzhiyunconfig X86_MCE
1105*4882a593Smuzhiyun	bool "Machine Check / overheating reporting"
1106*4882a593Smuzhiyun	select GENERIC_ALLOCATOR
1107*4882a593Smuzhiyun	default y
1108*4882a593Smuzhiyun	help
1109*4882a593Smuzhiyun	  Machine Check support allows the processor to notify the
1110*4882a593Smuzhiyun	  kernel if it detects a problem (e.g. overheating, data corruption).
1111*4882a593Smuzhiyun	  The action the kernel takes depends on the severity of the problem,
1112*4882a593Smuzhiyun	  ranging from warning messages to halting the machine.
1113*4882a593Smuzhiyun
1114*4882a593Smuzhiyunconfig X86_MCELOG_LEGACY
1115*4882a593Smuzhiyun	bool "Support for deprecated /dev/mcelog character device"
1116*4882a593Smuzhiyun	depends on X86_MCE
1117*4882a593Smuzhiyun	help
1118*4882a593Smuzhiyun	  Enable support for /dev/mcelog which is needed by the old mcelog
1119*4882a593Smuzhiyun	  userspace logging daemon. Consider switching to the new generation
1120*4882a593Smuzhiyun	  rasdaemon solution.
1121*4882a593Smuzhiyun
1122*4882a593Smuzhiyunconfig X86_MCE_INTEL
1123*4882a593Smuzhiyun	def_bool y
1124*4882a593Smuzhiyun	prompt "Intel MCE features"
1125*4882a593Smuzhiyun	depends on X86_MCE && X86_LOCAL_APIC
1126*4882a593Smuzhiyun	help
1127*4882a593Smuzhiyun	   Additional support for intel specific MCE features such as
1128*4882a593Smuzhiyun	   the thermal monitor.
1129*4882a593Smuzhiyun
1130*4882a593Smuzhiyunconfig X86_MCE_AMD
1131*4882a593Smuzhiyun	def_bool y
1132*4882a593Smuzhiyun	prompt "AMD MCE features"
1133*4882a593Smuzhiyun	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1134*4882a593Smuzhiyun	help
1135*4882a593Smuzhiyun	   Additional support for AMD specific MCE features such as
1136*4882a593Smuzhiyun	   the DRAM Error Threshold.
1137*4882a593Smuzhiyun
1138*4882a593Smuzhiyunconfig X86_ANCIENT_MCE
1139*4882a593Smuzhiyun	bool "Support for old Pentium 5 / WinChip machine checks"
1140*4882a593Smuzhiyun	depends on X86_32 && X86_MCE
1141*4882a593Smuzhiyun	help
1142*4882a593Smuzhiyun	  Include support for machine check handling on old Pentium 5 or WinChip
1143*4882a593Smuzhiyun	  systems. These typically need to be enabled explicitly on the command
1144*4882a593Smuzhiyun	  line.
1145*4882a593Smuzhiyun
1146*4882a593Smuzhiyunconfig X86_MCE_THRESHOLD
1147*4882a593Smuzhiyun	depends on X86_MCE_AMD || X86_MCE_INTEL
1148*4882a593Smuzhiyun	def_bool y
1149*4882a593Smuzhiyun
1150*4882a593Smuzhiyunconfig X86_MCE_INJECT
1151*4882a593Smuzhiyun	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1152*4882a593Smuzhiyun	tristate "Machine check injector support"
1153*4882a593Smuzhiyun	help
1154*4882a593Smuzhiyun	  Provide support for injecting machine checks for testing purposes.
1155*4882a593Smuzhiyun	  If you don't know what a machine check is and you don't do kernel
1156*4882a593Smuzhiyun	  QA it is safe to say n.
1157*4882a593Smuzhiyun
1158*4882a593Smuzhiyunconfig X86_THERMAL_VECTOR
1159*4882a593Smuzhiyun	def_bool y
1160*4882a593Smuzhiyun	depends on X86_MCE_INTEL
1161*4882a593Smuzhiyun
1162*4882a593Smuzhiyunsource "arch/x86/events/Kconfig"
1163*4882a593Smuzhiyun
1164*4882a593Smuzhiyunconfig X86_LEGACY_VM86
1165*4882a593Smuzhiyun	bool "Legacy VM86 support"
1166*4882a593Smuzhiyun	depends on X86_32
1167*4882a593Smuzhiyun	help
1168*4882a593Smuzhiyun	  This option allows user programs to put the CPU into V8086
1169*4882a593Smuzhiyun	  mode, which is an 80286-era approximation of 16-bit real mode.
1170*4882a593Smuzhiyun
1171*4882a593Smuzhiyun	  Some very old versions of X and/or vbetool require this option
1172*4882a593Smuzhiyun	  for user mode setting.  Similarly, DOSEMU will use it if
1173*4882a593Smuzhiyun	  available to accelerate real mode DOS programs.  However, any
1174*4882a593Smuzhiyun	  recent version of DOSEMU, X, or vbetool should be fully
1175*4882a593Smuzhiyun	  functional even without kernel VM86 support, as they will all
1176*4882a593Smuzhiyun	  fall back to software emulation. Nevertheless, if you are using
1177*4882a593Smuzhiyun	  a 16-bit DOS program where 16-bit performance matters, vm86
1178*4882a593Smuzhiyun	  mode might be faster than emulation and you might want to
1179*4882a593Smuzhiyun	  enable this option.
1180*4882a593Smuzhiyun
1181*4882a593Smuzhiyun	  Note that any app that works on a 64-bit kernel is unlikely to
1182*4882a593Smuzhiyun	  need this option, as 64-bit kernels don't, and can't, support
1183*4882a593Smuzhiyun	  V8086 mode. This option is also unrelated to 16-bit protected
1184*4882a593Smuzhiyun	  mode and is not needed to run most 16-bit programs under Wine.
1185*4882a593Smuzhiyun
1186*4882a593Smuzhiyun	  Enabling this option increases the complexity of the kernel
1187*4882a593Smuzhiyun	  and slows down exception handling a tiny bit.
1188*4882a593Smuzhiyun
1189*4882a593Smuzhiyun	  If unsure, say N here.
1190*4882a593Smuzhiyun
1191*4882a593Smuzhiyunconfig VM86
1192*4882a593Smuzhiyun	bool
1193*4882a593Smuzhiyun	default X86_LEGACY_VM86
1194*4882a593Smuzhiyun
1195*4882a593Smuzhiyunconfig X86_16BIT
1196*4882a593Smuzhiyun	bool "Enable support for 16-bit segments" if EXPERT
1197*4882a593Smuzhiyun	default y
1198*4882a593Smuzhiyun	depends on MODIFY_LDT_SYSCALL
1199*4882a593Smuzhiyun	help
1200*4882a593Smuzhiyun	  This option is required by programs like Wine to run 16-bit
1201*4882a593Smuzhiyun	  protected mode legacy code on x86 processors.  Disabling
1202*4882a593Smuzhiyun	  this option saves about 300 bytes on i386, or around 6K text
1203*4882a593Smuzhiyun	  plus 16K runtime memory on x86-64,
1204*4882a593Smuzhiyun
1205*4882a593Smuzhiyunconfig X86_ESPFIX32
1206*4882a593Smuzhiyun	def_bool y
1207*4882a593Smuzhiyun	depends on X86_16BIT && X86_32
1208*4882a593Smuzhiyun
1209*4882a593Smuzhiyunconfig X86_ESPFIX64
1210*4882a593Smuzhiyun	def_bool y
1211*4882a593Smuzhiyun	depends on X86_16BIT && X86_64
1212*4882a593Smuzhiyun
1213*4882a593Smuzhiyunconfig X86_VSYSCALL_EMULATION
1214*4882a593Smuzhiyun	bool "Enable vsyscall emulation" if EXPERT
1215*4882a593Smuzhiyun	default y
1216*4882a593Smuzhiyun	depends on X86_64
1217*4882a593Smuzhiyun	help
1218*4882a593Smuzhiyun	 This enables emulation of the legacy vsyscall page.  Disabling
1219*4882a593Smuzhiyun	 it is roughly equivalent to booting with vsyscall=none, except
1220*4882a593Smuzhiyun	 that it will also disable the helpful warning if a program
1221*4882a593Smuzhiyun	 tries to use a vsyscall.  With this option set to N, offending
1222*4882a593Smuzhiyun	 programs will just segfault, citing addresses of the form
1223*4882a593Smuzhiyun	 0xffffffffff600?00.
1224*4882a593Smuzhiyun
1225*4882a593Smuzhiyun	 This option is required by many programs built before 2013, and
1226*4882a593Smuzhiyun	 care should be used even with newer programs if set to N.
1227*4882a593Smuzhiyun
1228*4882a593Smuzhiyun	 Disabling this option saves about 7K of kernel size and
1229*4882a593Smuzhiyun	 possibly 4K of additional runtime pagetable memory.
1230*4882a593Smuzhiyun
1231*4882a593Smuzhiyunconfig X86_IOPL_IOPERM
1232*4882a593Smuzhiyun	bool "IOPERM and IOPL Emulation"
1233*4882a593Smuzhiyun	default y
1234*4882a593Smuzhiyun	help
1235*4882a593Smuzhiyun	  This enables the ioperm() and iopl() syscalls which are necessary
1236*4882a593Smuzhiyun	  for legacy applications.
1237*4882a593Smuzhiyun
1238*4882a593Smuzhiyun	  Legacy IOPL support is an overbroad mechanism which allows user
1239*4882a593Smuzhiyun	  space aside of accessing all 65536 I/O ports also to disable
1240*4882a593Smuzhiyun	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1241*4882a593Smuzhiyun	  capabilities and permission from potentially active security
1242*4882a593Smuzhiyun	  modules.
1243*4882a593Smuzhiyun
1244*4882a593Smuzhiyun	  The emulation restricts the functionality of the syscall to
1245*4882a593Smuzhiyun	  only allowing the full range I/O port access, but prevents the
1246*4882a593Smuzhiyun	  ability to disable interrupts from user space which would be
1247*4882a593Smuzhiyun	  granted if the hardware IOPL mechanism would be used.
1248*4882a593Smuzhiyun
1249*4882a593Smuzhiyunconfig TOSHIBA
1250*4882a593Smuzhiyun	tristate "Toshiba Laptop support"
1251*4882a593Smuzhiyun	depends on X86_32
1252*4882a593Smuzhiyun	help
1253*4882a593Smuzhiyun	  This adds a driver to safely access the System Management Mode of
1254*4882a593Smuzhiyun	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1255*4882a593Smuzhiyun	  not work on models with a Phoenix BIOS. The System Management Mode
1256*4882a593Smuzhiyun	  is used to set the BIOS and power saving options on Toshiba portables.
1257*4882a593Smuzhiyun
1258*4882a593Smuzhiyun	  For information on utilities to make use of this driver see the
1259*4882a593Smuzhiyun	  Toshiba Linux utilities web site at:
1260*4882a593Smuzhiyun	  <http://www.buzzard.org.uk/toshiba/>.
1261*4882a593Smuzhiyun
1262*4882a593Smuzhiyun	  Say Y if you intend to run this kernel on a Toshiba portable.
1263*4882a593Smuzhiyun	  Say N otherwise.
1264*4882a593Smuzhiyun
1265*4882a593Smuzhiyunconfig I8K
1266*4882a593Smuzhiyun	tristate "Dell i8k legacy laptop support"
1267*4882a593Smuzhiyun	depends on HWMON
1268*4882a593Smuzhiyun	depends on PROC_FS
1269*4882a593Smuzhiyun	select SENSORS_DELL_SMM
1270*4882a593Smuzhiyun	help
1271*4882a593Smuzhiyun	  This option enables legacy /proc/i8k userspace interface in hwmon
1272*4882a593Smuzhiyun	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1273*4882a593Smuzhiyun	  temperature and allows controlling fan speeds of Dell laptops via
1274*4882a593Smuzhiyun	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1275*4882a593Smuzhiyun	  it reports also power and hotkey status. For fan speed control is
1276*4882a593Smuzhiyun	  needed userspace package i8kutils.
1277*4882a593Smuzhiyun
1278*4882a593Smuzhiyun	  Say Y if you intend to run this kernel on old Dell laptops or want to
1279*4882a593Smuzhiyun	  use userspace package i8kutils.
1280*4882a593Smuzhiyun	  Say N otherwise.
1281*4882a593Smuzhiyun
1282*4882a593Smuzhiyunconfig X86_REBOOTFIXUPS
1283*4882a593Smuzhiyun	bool "Enable X86 board specific fixups for reboot"
1284*4882a593Smuzhiyun	depends on X86_32
1285*4882a593Smuzhiyun	help
1286*4882a593Smuzhiyun	  This enables chipset and/or board specific fixups to be done
1287*4882a593Smuzhiyun	  in order to get reboot to work correctly. This is only needed on
1288*4882a593Smuzhiyun	  some combinations of hardware and BIOS. The symptom, for which
1289*4882a593Smuzhiyun	  this config is intended, is when reboot ends with a stalled/hung
1290*4882a593Smuzhiyun	  system.
1291*4882a593Smuzhiyun
1292*4882a593Smuzhiyun	  Currently, the only fixup is for the Geode machines using
1293*4882a593Smuzhiyun	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1294*4882a593Smuzhiyun
1295*4882a593Smuzhiyun	  Say Y if you want to enable the fixup. Currently, it's safe to
1296*4882a593Smuzhiyun	  enable this option even if you don't need it.
1297*4882a593Smuzhiyun	  Say N otherwise.
1298*4882a593Smuzhiyun
1299*4882a593Smuzhiyunconfig MICROCODE
1300*4882a593Smuzhiyun	bool "CPU microcode loading support"
1301*4882a593Smuzhiyun	default y
1302*4882a593Smuzhiyun	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1303*4882a593Smuzhiyun	help
1304*4882a593Smuzhiyun	  If you say Y here, you will be able to update the microcode on
1305*4882a593Smuzhiyun	  Intel and AMD processors. The Intel support is for the IA32 family,
1306*4882a593Smuzhiyun	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1307*4882a593Smuzhiyun	  AMD support is for families 0x10 and later. You will obviously need
1308*4882a593Smuzhiyun	  the actual microcode binary data itself which is not shipped with
1309*4882a593Smuzhiyun	  the Linux kernel.
1310*4882a593Smuzhiyun
1311*4882a593Smuzhiyun	  The preferred method to load microcode from a detached initrd is described
1312*4882a593Smuzhiyun	  in Documentation/x86/microcode.rst. For that you need to enable
1313*4882a593Smuzhiyun	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1314*4882a593Smuzhiyun	  initrd for microcode blobs.
1315*4882a593Smuzhiyun
1316*4882a593Smuzhiyun	  In addition, you can build the microcode into the kernel. For that you
1317*4882a593Smuzhiyun	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1318*4882a593Smuzhiyun	  config option.
1319*4882a593Smuzhiyun
1320*4882a593Smuzhiyunconfig MICROCODE_INTEL
1321*4882a593Smuzhiyun	bool "Intel microcode loading support"
1322*4882a593Smuzhiyun	depends on CPU_SUP_INTEL && MICROCODE
1323*4882a593Smuzhiyun	default MICROCODE
1324*4882a593Smuzhiyun	help
1325*4882a593Smuzhiyun	  This options enables microcode patch loading support for Intel
1326*4882a593Smuzhiyun	  processors.
1327*4882a593Smuzhiyun
1328*4882a593Smuzhiyun	  For the current Intel microcode data package go to
1329*4882a593Smuzhiyun	  <https://downloadcenter.intel.com> and search for
1330*4882a593Smuzhiyun	  'Linux Processor Microcode Data File'.
1331*4882a593Smuzhiyun
1332*4882a593Smuzhiyunconfig MICROCODE_AMD
1333*4882a593Smuzhiyun	bool "AMD microcode loading support"
1334*4882a593Smuzhiyun	depends on CPU_SUP_AMD && MICROCODE
1335*4882a593Smuzhiyun	help
1336*4882a593Smuzhiyun	  If you select this option, microcode patch loading support for AMD
1337*4882a593Smuzhiyun	  processors will be enabled.
1338*4882a593Smuzhiyun
1339*4882a593Smuzhiyunconfig MICROCODE_OLD_INTERFACE
1340*4882a593Smuzhiyun	bool "Ancient loading interface (DEPRECATED)"
1341*4882a593Smuzhiyun	default n
1342*4882a593Smuzhiyun	depends on MICROCODE
1343*4882a593Smuzhiyun	help
1344*4882a593Smuzhiyun	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1345*4882a593Smuzhiyun	  which was used by userspace tools like iucode_tool and microcode.ctl.
1346*4882a593Smuzhiyun	  It is inadequate because it runs too late to be able to properly
1347*4882a593Smuzhiyun	  load microcode on a machine and it needs special tools. Instead, you
1348*4882a593Smuzhiyun	  should've switched to the early loading method with the initrd or
1349*4882a593Smuzhiyun	  builtin microcode by now: Documentation/x86/microcode.rst
1350*4882a593Smuzhiyun
1351*4882a593Smuzhiyunconfig X86_MSR
1352*4882a593Smuzhiyun	tristate "/dev/cpu/*/msr - Model-specific register support"
1353*4882a593Smuzhiyun	help
1354*4882a593Smuzhiyun	  This device gives privileged processes access to the x86
1355*4882a593Smuzhiyun	  Model-Specific Registers (MSRs).  It is a character device with
1356*4882a593Smuzhiyun	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1357*4882a593Smuzhiyun	  MSR accesses are directed to a specific CPU on multi-processor
1358*4882a593Smuzhiyun	  systems.
1359*4882a593Smuzhiyun
1360*4882a593Smuzhiyunconfig X86_CPUID
1361*4882a593Smuzhiyun	tristate "/dev/cpu/*/cpuid - CPU information support"
1362*4882a593Smuzhiyun	help
1363*4882a593Smuzhiyun	  This device gives processes access to the x86 CPUID instruction to
1364*4882a593Smuzhiyun	  be executed on a specific processor.  It is a character device
1365*4882a593Smuzhiyun	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1366*4882a593Smuzhiyun	  /dev/cpu/31/cpuid.
1367*4882a593Smuzhiyun
1368*4882a593Smuzhiyunchoice
1369*4882a593Smuzhiyun	prompt "High Memory Support"
1370*4882a593Smuzhiyun	default HIGHMEM4G
1371*4882a593Smuzhiyun	depends on X86_32
1372*4882a593Smuzhiyun
1373*4882a593Smuzhiyunconfig NOHIGHMEM
1374*4882a593Smuzhiyun	bool "off"
1375*4882a593Smuzhiyun	help
1376*4882a593Smuzhiyun	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1377*4882a593Smuzhiyun	  However, the address space of 32-bit x86 processors is only 4
1378*4882a593Smuzhiyun	  Gigabytes large. That means that, if you have a large amount of
1379*4882a593Smuzhiyun	  physical memory, not all of it can be "permanently mapped" by the
1380*4882a593Smuzhiyun	  kernel. The physical memory that's not permanently mapped is called
1381*4882a593Smuzhiyun	  "high memory".
1382*4882a593Smuzhiyun
1383*4882a593Smuzhiyun	  If you are compiling a kernel which will never run on a machine with
1384*4882a593Smuzhiyun	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1385*4882a593Smuzhiyun	  choice and suitable for most users). This will result in a "3GB/1GB"
1386*4882a593Smuzhiyun	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1387*4882a593Smuzhiyun	  space and the remaining part of the 4GB virtual memory space is used
1388*4882a593Smuzhiyun	  by the kernel to permanently map as much physical memory as
1389*4882a593Smuzhiyun	  possible.
1390*4882a593Smuzhiyun
1391*4882a593Smuzhiyun	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1392*4882a593Smuzhiyun	  answer "4GB" here.
1393*4882a593Smuzhiyun
1394*4882a593Smuzhiyun	  If more than 4 Gigabytes is used then answer "64GB" here. This
1395*4882a593Smuzhiyun	  selection turns Intel PAE (Physical Address Extension) mode on.
1396*4882a593Smuzhiyun	  PAE implements 3-level paging on IA32 processors. PAE is fully
1397*4882a593Smuzhiyun	  supported by Linux, PAE mode is implemented on all recent Intel
1398*4882a593Smuzhiyun	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1399*4882a593Smuzhiyun	  then the kernel will not boot on CPUs that don't support PAE!
1400*4882a593Smuzhiyun
1401*4882a593Smuzhiyun	  The actual amount of total physical memory will either be
1402*4882a593Smuzhiyun	  auto detected or can be forced by using a kernel command line option
1403*4882a593Smuzhiyun	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1404*4882a593Smuzhiyun	  your boot loader (lilo or loadlin) about how to pass options to the
1405*4882a593Smuzhiyun	  kernel at boot time.)
1406*4882a593Smuzhiyun
1407*4882a593Smuzhiyun	  If unsure, say "off".
1408*4882a593Smuzhiyun
1409*4882a593Smuzhiyunconfig HIGHMEM4G
1410*4882a593Smuzhiyun	bool "4GB"
1411*4882a593Smuzhiyun	help
1412*4882a593Smuzhiyun	  Select this if you have a 32-bit processor and between 1 and 4
1413*4882a593Smuzhiyun	  gigabytes of physical RAM.
1414*4882a593Smuzhiyun
1415*4882a593Smuzhiyunconfig HIGHMEM64G
1416*4882a593Smuzhiyun	bool "64GB"
1417*4882a593Smuzhiyun	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1418*4882a593Smuzhiyun	select X86_PAE
1419*4882a593Smuzhiyun	help
1420*4882a593Smuzhiyun	  Select this if you have a 32-bit processor and more than 4
1421*4882a593Smuzhiyun	  gigabytes of physical RAM.
1422*4882a593Smuzhiyun
1423*4882a593Smuzhiyunendchoice
1424*4882a593Smuzhiyun
1425*4882a593Smuzhiyunchoice
1426*4882a593Smuzhiyun	prompt "Memory split" if EXPERT
1427*4882a593Smuzhiyun	default VMSPLIT_3G
1428*4882a593Smuzhiyun	depends on X86_32
1429*4882a593Smuzhiyun	help
1430*4882a593Smuzhiyun	  Select the desired split between kernel and user memory.
1431*4882a593Smuzhiyun
1432*4882a593Smuzhiyun	  If the address range available to the kernel is less than the
1433*4882a593Smuzhiyun	  physical memory installed, the remaining memory will be available
1434*4882a593Smuzhiyun	  as "high memory". Accessing high memory is a little more costly
1435*4882a593Smuzhiyun	  than low memory, as it needs to be mapped into the kernel first.
1436*4882a593Smuzhiyun	  Note that increasing the kernel address space limits the range
1437*4882a593Smuzhiyun	  available to user programs, making the address space there
1438*4882a593Smuzhiyun	  tighter.  Selecting anything other than the default 3G/1G split
1439*4882a593Smuzhiyun	  will also likely make your kernel incompatible with binary-only
1440*4882a593Smuzhiyun	  kernel modules.
1441*4882a593Smuzhiyun
1442*4882a593Smuzhiyun	  If you are not absolutely sure what you are doing, leave this
1443*4882a593Smuzhiyun	  option alone!
1444*4882a593Smuzhiyun
1445*4882a593Smuzhiyun	config VMSPLIT_3G
1446*4882a593Smuzhiyun		bool "3G/1G user/kernel split"
1447*4882a593Smuzhiyun	config VMSPLIT_3G_OPT
1448*4882a593Smuzhiyun		depends on !X86_PAE
1449*4882a593Smuzhiyun		bool "3G/1G user/kernel split (for full 1G low memory)"
1450*4882a593Smuzhiyun	config VMSPLIT_2G
1451*4882a593Smuzhiyun		bool "2G/2G user/kernel split"
1452*4882a593Smuzhiyun	config VMSPLIT_2G_OPT
1453*4882a593Smuzhiyun		depends on !X86_PAE
1454*4882a593Smuzhiyun		bool "2G/2G user/kernel split (for full 2G low memory)"
1455*4882a593Smuzhiyun	config VMSPLIT_1G
1456*4882a593Smuzhiyun		bool "1G/3G user/kernel split"
1457*4882a593Smuzhiyunendchoice
1458*4882a593Smuzhiyun
1459*4882a593Smuzhiyunconfig PAGE_OFFSET
1460*4882a593Smuzhiyun	hex
1461*4882a593Smuzhiyun	default 0xB0000000 if VMSPLIT_3G_OPT
1462*4882a593Smuzhiyun	default 0x80000000 if VMSPLIT_2G
1463*4882a593Smuzhiyun	default 0x78000000 if VMSPLIT_2G_OPT
1464*4882a593Smuzhiyun	default 0x40000000 if VMSPLIT_1G
1465*4882a593Smuzhiyun	default 0xC0000000
1466*4882a593Smuzhiyun	depends on X86_32
1467*4882a593Smuzhiyun
1468*4882a593Smuzhiyunconfig HIGHMEM
1469*4882a593Smuzhiyun	def_bool y
1470*4882a593Smuzhiyun	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1471*4882a593Smuzhiyun
1472*4882a593Smuzhiyunconfig X86_PAE
1473*4882a593Smuzhiyun	bool "PAE (Physical Address Extension) Support"
1474*4882a593Smuzhiyun	depends on X86_32 && !HIGHMEM4G
1475*4882a593Smuzhiyun	select PHYS_ADDR_T_64BIT
1476*4882a593Smuzhiyun	select SWIOTLB
1477*4882a593Smuzhiyun	help
1478*4882a593Smuzhiyun	  PAE is required for NX support, and furthermore enables
1479*4882a593Smuzhiyun	  larger swapspace support for non-overcommit purposes. It
1480*4882a593Smuzhiyun	  has the cost of more pagetable lookup overhead, and also
1481*4882a593Smuzhiyun	  consumes more pagetable space per process.
1482*4882a593Smuzhiyun
1483*4882a593Smuzhiyunconfig X86_5LEVEL
1484*4882a593Smuzhiyun	bool "Enable 5-level page tables support"
1485*4882a593Smuzhiyun	default y
1486*4882a593Smuzhiyun	select DYNAMIC_MEMORY_LAYOUT
1487*4882a593Smuzhiyun	select SPARSEMEM_VMEMMAP
1488*4882a593Smuzhiyun	depends on X86_64
1489*4882a593Smuzhiyun	help
1490*4882a593Smuzhiyun	  5-level paging enables access to larger address space:
1491*4882a593Smuzhiyun	  upto 128 PiB of virtual address space and 4 PiB of
1492*4882a593Smuzhiyun	  physical address space.
1493*4882a593Smuzhiyun
1494*4882a593Smuzhiyun	  It will be supported by future Intel CPUs.
1495*4882a593Smuzhiyun
1496*4882a593Smuzhiyun	  A kernel with the option enabled can be booted on machines that
1497*4882a593Smuzhiyun	  support 4- or 5-level paging.
1498*4882a593Smuzhiyun
1499*4882a593Smuzhiyun	  See Documentation/x86/x86_64/5level-paging.rst for more
1500*4882a593Smuzhiyun	  information.
1501*4882a593Smuzhiyun
1502*4882a593Smuzhiyun	  Say N if unsure.
1503*4882a593Smuzhiyun
1504*4882a593Smuzhiyunconfig X86_DIRECT_GBPAGES
1505*4882a593Smuzhiyun	def_bool y
1506*4882a593Smuzhiyun	depends on X86_64
1507*4882a593Smuzhiyun	help
1508*4882a593Smuzhiyun	  Certain kernel features effectively disable kernel
1509*4882a593Smuzhiyun	  linear 1 GB mappings (even if the CPU otherwise
1510*4882a593Smuzhiyun	  supports them), so don't confuse the user by printing
1511*4882a593Smuzhiyun	  that we have them enabled.
1512*4882a593Smuzhiyun
1513*4882a593Smuzhiyunconfig X86_CPA_STATISTICS
1514*4882a593Smuzhiyun	bool "Enable statistic for Change Page Attribute"
1515*4882a593Smuzhiyun	depends on DEBUG_FS
1516*4882a593Smuzhiyun	help
1517*4882a593Smuzhiyun	  Expose statistics about the Change Page Attribute mechanism, which
1518*4882a593Smuzhiyun	  helps to determine the effectiveness of preserving large and huge
1519*4882a593Smuzhiyun	  page mappings when mapping protections are changed.
1520*4882a593Smuzhiyun
1521*4882a593Smuzhiyunconfig AMD_MEM_ENCRYPT
1522*4882a593Smuzhiyun	bool "AMD Secure Memory Encryption (SME) support"
1523*4882a593Smuzhiyun	depends on X86_64 && CPU_SUP_AMD
1524*4882a593Smuzhiyun	select DMA_COHERENT_POOL
1525*4882a593Smuzhiyun	select DYNAMIC_PHYSICAL_MASK
1526*4882a593Smuzhiyun	select ARCH_USE_MEMREMAP_PROT
1527*4882a593Smuzhiyun	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1528*4882a593Smuzhiyun	select INSTRUCTION_DECODER
1529*4882a593Smuzhiyun	select ARCH_HAS_CC_PLATFORM
1530*4882a593Smuzhiyun	help
1531*4882a593Smuzhiyun	  Say yes to enable support for the encryption of system memory.
1532*4882a593Smuzhiyun	  This requires an AMD processor that supports Secure Memory
1533*4882a593Smuzhiyun	  Encryption (SME).
1534*4882a593Smuzhiyun
1535*4882a593Smuzhiyunconfig AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1536*4882a593Smuzhiyun	bool "Activate AMD Secure Memory Encryption (SME) by default"
1537*4882a593Smuzhiyun	depends on AMD_MEM_ENCRYPT
1538*4882a593Smuzhiyun	help
1539*4882a593Smuzhiyun	  Say yes to have system memory encrypted by default if running on
1540*4882a593Smuzhiyun	  an AMD processor that supports Secure Memory Encryption (SME).
1541*4882a593Smuzhiyun
1542*4882a593Smuzhiyun	  If set to Y, then the encryption of system memory can be
1543*4882a593Smuzhiyun	  deactivated with the mem_encrypt=off command line option.
1544*4882a593Smuzhiyun
1545*4882a593Smuzhiyun	  If set to N, then the encryption of system memory can be
1546*4882a593Smuzhiyun	  activated with the mem_encrypt=on command line option.
1547*4882a593Smuzhiyun
1548*4882a593Smuzhiyun# Common NUMA Features
1549*4882a593Smuzhiyunconfig NUMA
1550*4882a593Smuzhiyun	bool "NUMA Memory Allocation and Scheduler Support"
1551*4882a593Smuzhiyun	depends on SMP
1552*4882a593Smuzhiyun	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1553*4882a593Smuzhiyun	default y if X86_BIGSMP
1554*4882a593Smuzhiyun	help
1555*4882a593Smuzhiyun	  Enable NUMA (Non-Uniform Memory Access) support.
1556*4882a593Smuzhiyun
1557*4882a593Smuzhiyun	  The kernel will try to allocate memory used by a CPU on the
1558*4882a593Smuzhiyun	  local memory controller of the CPU and add some more
1559*4882a593Smuzhiyun	  NUMA awareness to the kernel.
1560*4882a593Smuzhiyun
1561*4882a593Smuzhiyun	  For 64-bit this is recommended if the system is Intel Core i7
1562*4882a593Smuzhiyun	  (or later), AMD Opteron, or EM64T NUMA.
1563*4882a593Smuzhiyun
1564*4882a593Smuzhiyun	  For 32-bit this is only needed if you boot a 32-bit
1565*4882a593Smuzhiyun	  kernel on a 64-bit NUMA platform.
1566*4882a593Smuzhiyun
1567*4882a593Smuzhiyun	  Otherwise, you should say N.
1568*4882a593Smuzhiyun
1569*4882a593Smuzhiyunconfig AMD_NUMA
1570*4882a593Smuzhiyun	def_bool y
1571*4882a593Smuzhiyun	prompt "Old style AMD Opteron NUMA detection"
1572*4882a593Smuzhiyun	depends on X86_64 && NUMA && PCI
1573*4882a593Smuzhiyun	help
1574*4882a593Smuzhiyun	  Enable AMD NUMA node topology detection.  You should say Y here if
1575*4882a593Smuzhiyun	  you have a multi processor AMD system. This uses an old method to
1576*4882a593Smuzhiyun	  read the NUMA configuration directly from the builtin Northbridge
1577*4882a593Smuzhiyun	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1578*4882a593Smuzhiyun	  which also takes priority if both are compiled in.
1579*4882a593Smuzhiyun
1580*4882a593Smuzhiyunconfig X86_64_ACPI_NUMA
1581*4882a593Smuzhiyun	def_bool y
1582*4882a593Smuzhiyun	prompt "ACPI NUMA detection"
1583*4882a593Smuzhiyun	depends on X86_64 && NUMA && ACPI && PCI
1584*4882a593Smuzhiyun	select ACPI_NUMA
1585*4882a593Smuzhiyun	help
1586*4882a593Smuzhiyun	  Enable ACPI SRAT based node topology detection.
1587*4882a593Smuzhiyun
1588*4882a593Smuzhiyunconfig NUMA_EMU
1589*4882a593Smuzhiyun	bool "NUMA emulation"
1590*4882a593Smuzhiyun	depends on NUMA
1591*4882a593Smuzhiyun	help
1592*4882a593Smuzhiyun	  Enable NUMA emulation. A flat machine will be split
1593*4882a593Smuzhiyun	  into virtual nodes when booted with "numa=fake=N", where N is the
1594*4882a593Smuzhiyun	  number of nodes. This is only useful for debugging.
1595*4882a593Smuzhiyun
1596*4882a593Smuzhiyunconfig NODES_SHIFT
1597*4882a593Smuzhiyun	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1598*4882a593Smuzhiyun	range 1 10
1599*4882a593Smuzhiyun	default "10" if MAXSMP
1600*4882a593Smuzhiyun	default "6" if X86_64
1601*4882a593Smuzhiyun	default "3"
1602*4882a593Smuzhiyun	depends on NEED_MULTIPLE_NODES
1603*4882a593Smuzhiyun	help
1604*4882a593Smuzhiyun	  Specify the maximum number of NUMA Nodes available on the target
1605*4882a593Smuzhiyun	  system.  Increases memory reserved to accommodate various tables.
1606*4882a593Smuzhiyun
1607*4882a593Smuzhiyunconfig ARCH_FLATMEM_ENABLE
1608*4882a593Smuzhiyun	def_bool y
1609*4882a593Smuzhiyun	depends on X86_32 && !NUMA
1610*4882a593Smuzhiyun
1611*4882a593Smuzhiyunconfig ARCH_SPARSEMEM_ENABLE
1612*4882a593Smuzhiyun	def_bool y
1613*4882a593Smuzhiyun	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1614*4882a593Smuzhiyun	select SPARSEMEM_STATIC if X86_32
1615*4882a593Smuzhiyun	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1616*4882a593Smuzhiyun
1617*4882a593Smuzhiyunconfig ARCH_SPARSEMEM_DEFAULT
1618*4882a593Smuzhiyun	def_bool X86_64 || (NUMA && X86_32)
1619*4882a593Smuzhiyun
1620*4882a593Smuzhiyunconfig ARCH_SELECT_MEMORY_MODEL
1621*4882a593Smuzhiyun	def_bool y
1622*4882a593Smuzhiyun	depends on ARCH_SPARSEMEM_ENABLE
1623*4882a593Smuzhiyun
1624*4882a593Smuzhiyunconfig ARCH_MEMORY_PROBE
1625*4882a593Smuzhiyun	bool "Enable sysfs memory/probe interface"
1626*4882a593Smuzhiyun	depends on X86_64 && MEMORY_HOTPLUG
1627*4882a593Smuzhiyun	help
1628*4882a593Smuzhiyun	  This option enables a sysfs memory/probe interface for testing.
1629*4882a593Smuzhiyun	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1630*4882a593Smuzhiyun	  If you are unsure how to answer this question, answer N.
1631*4882a593Smuzhiyun
1632*4882a593Smuzhiyunconfig ARCH_PROC_KCORE_TEXT
1633*4882a593Smuzhiyun	def_bool y
1634*4882a593Smuzhiyun	depends on X86_64 && PROC_KCORE
1635*4882a593Smuzhiyun
1636*4882a593Smuzhiyunconfig ILLEGAL_POINTER_VALUE
1637*4882a593Smuzhiyun	hex
1638*4882a593Smuzhiyun	default 0 if X86_32
1639*4882a593Smuzhiyun	default 0xdead000000000000 if X86_64
1640*4882a593Smuzhiyun
1641*4882a593Smuzhiyunconfig X86_PMEM_LEGACY_DEVICE
1642*4882a593Smuzhiyun	bool
1643*4882a593Smuzhiyun
1644*4882a593Smuzhiyunconfig X86_PMEM_LEGACY
1645*4882a593Smuzhiyun	tristate "Support non-standard NVDIMMs and ADR protected memory"
1646*4882a593Smuzhiyun	depends on PHYS_ADDR_T_64BIT
1647*4882a593Smuzhiyun	depends on BLK_DEV
1648*4882a593Smuzhiyun	select X86_PMEM_LEGACY_DEVICE
1649*4882a593Smuzhiyun	select NUMA_KEEP_MEMINFO if NUMA
1650*4882a593Smuzhiyun	select LIBNVDIMM
1651*4882a593Smuzhiyun	help
1652*4882a593Smuzhiyun	  Treat memory marked using the non-standard e820 type of 12 as used
1653*4882a593Smuzhiyun	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1654*4882a593Smuzhiyun	  The kernel will offer these regions to the 'pmem' driver so
1655*4882a593Smuzhiyun	  they can be used for persistent storage.
1656*4882a593Smuzhiyun
1657*4882a593Smuzhiyun	  Say Y if unsure.
1658*4882a593Smuzhiyun
1659*4882a593Smuzhiyunconfig HIGHPTE
1660*4882a593Smuzhiyun	bool "Allocate 3rd-level pagetables from highmem"
1661*4882a593Smuzhiyun	depends on HIGHMEM
1662*4882a593Smuzhiyun	help
1663*4882a593Smuzhiyun	  The VM uses one page table entry for each page of physical memory.
1664*4882a593Smuzhiyun	  For systems with a lot of RAM, this can be wasteful of precious
1665*4882a593Smuzhiyun	  low memory.  Setting this option will put user-space page table
1666*4882a593Smuzhiyun	  entries in high memory.
1667*4882a593Smuzhiyun
1668*4882a593Smuzhiyunconfig X86_CHECK_BIOS_CORRUPTION
1669*4882a593Smuzhiyun	bool "Check for low memory corruption"
1670*4882a593Smuzhiyun	help
1671*4882a593Smuzhiyun	  Periodically check for memory corruption in low memory, which
1672*4882a593Smuzhiyun	  is suspected to be caused by BIOS.  Even when enabled in the
1673*4882a593Smuzhiyun	  configuration, it is disabled at runtime.  Enable it by
1674*4882a593Smuzhiyun	  setting "memory_corruption_check=1" on the kernel command
1675*4882a593Smuzhiyun	  line.  By default it scans the low 64k of memory every 60
1676*4882a593Smuzhiyun	  seconds; see the memory_corruption_check_size and
1677*4882a593Smuzhiyun	  memory_corruption_check_period parameters in
1678*4882a593Smuzhiyun	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1679*4882a593Smuzhiyun
1680*4882a593Smuzhiyun	  When enabled with the default parameters, this option has
1681*4882a593Smuzhiyun	  almost no overhead, as it reserves a relatively small amount
1682*4882a593Smuzhiyun	  of memory and scans it infrequently.  It both detects corruption
1683*4882a593Smuzhiyun	  and prevents it from affecting the running system.
1684*4882a593Smuzhiyun
1685*4882a593Smuzhiyun	  It is, however, intended as a diagnostic tool; if repeatable
1686*4882a593Smuzhiyun	  BIOS-originated corruption always affects the same memory,
1687*4882a593Smuzhiyun	  you can use memmap= to prevent the kernel from using that
1688*4882a593Smuzhiyun	  memory.
1689*4882a593Smuzhiyun
1690*4882a593Smuzhiyunconfig X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1691*4882a593Smuzhiyun	bool "Set the default setting of memory_corruption_check"
1692*4882a593Smuzhiyun	depends on X86_CHECK_BIOS_CORRUPTION
1693*4882a593Smuzhiyun	default y
1694*4882a593Smuzhiyun	help
1695*4882a593Smuzhiyun	  Set whether the default state of memory_corruption_check is
1696*4882a593Smuzhiyun	  on or off.
1697*4882a593Smuzhiyun
1698*4882a593Smuzhiyunconfig X86_RESERVE_LOW
1699*4882a593Smuzhiyun	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1700*4882a593Smuzhiyun	default 64
1701*4882a593Smuzhiyun	range 4 640
1702*4882a593Smuzhiyun	help
1703*4882a593Smuzhiyun	  Specify the amount of low memory to reserve for the BIOS.
1704*4882a593Smuzhiyun
1705*4882a593Smuzhiyun	  The first page contains BIOS data structures that the kernel
1706*4882a593Smuzhiyun	  must not use, so that page must always be reserved.
1707*4882a593Smuzhiyun
1708*4882a593Smuzhiyun	  By default we reserve the first 64K of physical RAM, as a
1709*4882a593Smuzhiyun	  number of BIOSes are known to corrupt that memory range
1710*4882a593Smuzhiyun	  during events such as suspend/resume or monitor cable
1711*4882a593Smuzhiyun	  insertion, so it must not be used by the kernel.
1712*4882a593Smuzhiyun
1713*4882a593Smuzhiyun	  You can set this to 4 if you are absolutely sure that you
1714*4882a593Smuzhiyun	  trust the BIOS to get all its memory reservations and usages
1715*4882a593Smuzhiyun	  right.  If you know your BIOS have problems beyond the
1716*4882a593Smuzhiyun	  default 64K area, you can set this to 640 to avoid using the
1717*4882a593Smuzhiyun	  entire low memory range.
1718*4882a593Smuzhiyun
1719*4882a593Smuzhiyun	  If you have doubts about the BIOS (e.g. suspend/resume does
1720*4882a593Smuzhiyun	  not work or there's kernel crashes after certain hardware
1721*4882a593Smuzhiyun	  hotplug events) then you might want to enable
1722*4882a593Smuzhiyun	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1723*4882a593Smuzhiyun	  typical corruption patterns.
1724*4882a593Smuzhiyun
1725*4882a593Smuzhiyun	  Leave this to the default value of 64 if you are unsure.
1726*4882a593Smuzhiyun
1727*4882a593Smuzhiyunconfig MATH_EMULATION
1728*4882a593Smuzhiyun	bool
1729*4882a593Smuzhiyun	depends on MODIFY_LDT_SYSCALL
1730*4882a593Smuzhiyun	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1731*4882a593Smuzhiyun	help
1732*4882a593Smuzhiyun	  Linux can emulate a math coprocessor (used for floating point
1733*4882a593Smuzhiyun	  operations) if you don't have one. 486DX and Pentium processors have
1734*4882a593Smuzhiyun	  a math coprocessor built in, 486SX and 386 do not, unless you added
1735*4882a593Smuzhiyun	  a 487DX or 387, respectively. (The messages during boot time can
1736*4882a593Smuzhiyun	  give you some hints here ["man dmesg"].) Everyone needs either a
1737*4882a593Smuzhiyun	  coprocessor or this emulation.
1738*4882a593Smuzhiyun
1739*4882a593Smuzhiyun	  If you don't have a math coprocessor, you need to say Y here; if you
1740*4882a593Smuzhiyun	  say Y here even though you have a coprocessor, the coprocessor will
1741*4882a593Smuzhiyun	  be used nevertheless. (This behavior can be changed with the kernel
1742*4882a593Smuzhiyun	  command line option "no387", which comes handy if your coprocessor
1743*4882a593Smuzhiyun	  is broken. Try "man bootparam" or see the documentation of your boot
1744*4882a593Smuzhiyun	  loader (lilo or loadlin) about how to pass options to the kernel at
1745*4882a593Smuzhiyun	  boot time.) This means that it is a good idea to say Y here if you
1746*4882a593Smuzhiyun	  intend to use this kernel on different machines.
1747*4882a593Smuzhiyun
1748*4882a593Smuzhiyun	  More information about the internals of the Linux math coprocessor
1749*4882a593Smuzhiyun	  emulation can be found in <file:arch/x86/math-emu/README>.
1750*4882a593Smuzhiyun
1751*4882a593Smuzhiyun	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1752*4882a593Smuzhiyun	  kernel, it won't hurt.
1753*4882a593Smuzhiyun
1754*4882a593Smuzhiyunconfig MTRR
1755*4882a593Smuzhiyun	def_bool y
1756*4882a593Smuzhiyun	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1757*4882a593Smuzhiyun	help
1758*4882a593Smuzhiyun	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1759*4882a593Smuzhiyun	  the Memory Type Range Registers (MTRRs) may be used to control
1760*4882a593Smuzhiyun	  processor access to memory ranges. This is most useful if you have
1761*4882a593Smuzhiyun	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1762*4882a593Smuzhiyun	  allows bus write transfers to be combined into a larger transfer
1763*4882a593Smuzhiyun	  before bursting over the PCI/AGP bus. This can increase performance
1764*4882a593Smuzhiyun	  of image write operations 2.5 times or more. Saying Y here creates a
1765*4882a593Smuzhiyun	  /proc/mtrr file which may be used to manipulate your processor's
1766*4882a593Smuzhiyun	  MTRRs. Typically the X server should use this.
1767*4882a593Smuzhiyun
1768*4882a593Smuzhiyun	  This code has a reasonably generic interface so that similar
1769*4882a593Smuzhiyun	  control registers on other processors can be easily supported
1770*4882a593Smuzhiyun	  as well:
1771*4882a593Smuzhiyun
1772*4882a593Smuzhiyun	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1773*4882a593Smuzhiyun	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1774*4882a593Smuzhiyun	  these, the ARRs are used to emulate the MTRRs.
1775*4882a593Smuzhiyun	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1776*4882a593Smuzhiyun	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1777*4882a593Smuzhiyun	  write-combining. All of these processors are supported by this code
1778*4882a593Smuzhiyun	  and it makes sense to say Y here if you have one of them.
1779*4882a593Smuzhiyun
1780*4882a593Smuzhiyun	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1781*4882a593Smuzhiyun	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1782*4882a593Smuzhiyun	  can lead to all sorts of problems, so it's good to say Y here.
1783*4882a593Smuzhiyun
1784*4882a593Smuzhiyun	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1785*4882a593Smuzhiyun	  just add about 9 KB to your kernel.
1786*4882a593Smuzhiyun
1787*4882a593Smuzhiyun	  See <file:Documentation/x86/mtrr.rst> for more information.
1788*4882a593Smuzhiyun
1789*4882a593Smuzhiyunconfig MTRR_SANITIZER
1790*4882a593Smuzhiyun	def_bool y
1791*4882a593Smuzhiyun	prompt "MTRR cleanup support"
1792*4882a593Smuzhiyun	depends on MTRR
1793*4882a593Smuzhiyun	help
1794*4882a593Smuzhiyun	  Convert MTRR layout from continuous to discrete, so X drivers can
1795*4882a593Smuzhiyun	  add writeback entries.
1796*4882a593Smuzhiyun
1797*4882a593Smuzhiyun	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1798*4882a593Smuzhiyun	  The largest mtrr entry size for a continuous block can be set with
1799*4882a593Smuzhiyun	  mtrr_chunk_size.
1800*4882a593Smuzhiyun
1801*4882a593Smuzhiyun	  If unsure, say Y.
1802*4882a593Smuzhiyun
1803*4882a593Smuzhiyunconfig MTRR_SANITIZER_ENABLE_DEFAULT
1804*4882a593Smuzhiyun	int "MTRR cleanup enable value (0-1)"
1805*4882a593Smuzhiyun	range 0 1
1806*4882a593Smuzhiyun	default "0"
1807*4882a593Smuzhiyun	depends on MTRR_SANITIZER
1808*4882a593Smuzhiyun	help
1809*4882a593Smuzhiyun	  Enable mtrr cleanup default value
1810*4882a593Smuzhiyun
1811*4882a593Smuzhiyunconfig MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1812*4882a593Smuzhiyun	int "MTRR cleanup spare reg num (0-7)"
1813*4882a593Smuzhiyun	range 0 7
1814*4882a593Smuzhiyun	default "1"
1815*4882a593Smuzhiyun	depends on MTRR_SANITIZER
1816*4882a593Smuzhiyun	help
1817*4882a593Smuzhiyun	  mtrr cleanup spare entries default, it can be changed via
1818*4882a593Smuzhiyun	  mtrr_spare_reg_nr=N on the kernel command line.
1819*4882a593Smuzhiyun
1820*4882a593Smuzhiyunconfig X86_PAT
1821*4882a593Smuzhiyun	def_bool y
1822*4882a593Smuzhiyun	prompt "x86 PAT support" if EXPERT
1823*4882a593Smuzhiyun	depends on MTRR
1824*4882a593Smuzhiyun	help
1825*4882a593Smuzhiyun	  Use PAT attributes to setup page level cache control.
1826*4882a593Smuzhiyun
1827*4882a593Smuzhiyun	  PATs are the modern equivalents of MTRRs and are much more
1828*4882a593Smuzhiyun	  flexible than MTRRs.
1829*4882a593Smuzhiyun
1830*4882a593Smuzhiyun	  Say N here if you see bootup problems (boot crash, boot hang,
1831*4882a593Smuzhiyun	  spontaneous reboots) or a non-working video driver.
1832*4882a593Smuzhiyun
1833*4882a593Smuzhiyun	  If unsure, say Y.
1834*4882a593Smuzhiyun
1835*4882a593Smuzhiyunconfig ARCH_USES_PG_UNCACHED
1836*4882a593Smuzhiyun	def_bool y
1837*4882a593Smuzhiyun	depends on X86_PAT
1838*4882a593Smuzhiyun
1839*4882a593Smuzhiyunconfig ARCH_RANDOM
1840*4882a593Smuzhiyun	def_bool y
1841*4882a593Smuzhiyun	prompt "x86 architectural random number generator" if EXPERT
1842*4882a593Smuzhiyun	help
1843*4882a593Smuzhiyun	  Enable the x86 architectural RDRAND instruction
1844*4882a593Smuzhiyun	  (Intel Bull Mountain technology) to generate random numbers.
1845*4882a593Smuzhiyun	  If supported, this is a high bandwidth, cryptographically
1846*4882a593Smuzhiyun	  secure hardware random number generator.
1847*4882a593Smuzhiyun
1848*4882a593Smuzhiyunconfig X86_SMAP
1849*4882a593Smuzhiyun	def_bool y
1850*4882a593Smuzhiyun	prompt "Supervisor Mode Access Prevention" if EXPERT
1851*4882a593Smuzhiyun	help
1852*4882a593Smuzhiyun	  Supervisor Mode Access Prevention (SMAP) is a security
1853*4882a593Smuzhiyun	  feature in newer Intel processors.  There is a small
1854*4882a593Smuzhiyun	  performance cost if this enabled and turned on; there is
1855*4882a593Smuzhiyun	  also a small increase in the kernel size if this is enabled.
1856*4882a593Smuzhiyun
1857*4882a593Smuzhiyun	  If unsure, say Y.
1858*4882a593Smuzhiyun
1859*4882a593Smuzhiyunconfig X86_UMIP
1860*4882a593Smuzhiyun	def_bool y
1861*4882a593Smuzhiyun	prompt "User Mode Instruction Prevention" if EXPERT
1862*4882a593Smuzhiyun	help
1863*4882a593Smuzhiyun	  User Mode Instruction Prevention (UMIP) is a security feature in
1864*4882a593Smuzhiyun	  some x86 processors. If enabled, a general protection fault is
1865*4882a593Smuzhiyun	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1866*4882a593Smuzhiyun	  executed in user mode. These instructions unnecessarily expose
1867*4882a593Smuzhiyun	  information about the hardware state.
1868*4882a593Smuzhiyun
1869*4882a593Smuzhiyun	  The vast majority of applications do not use these instructions.
1870*4882a593Smuzhiyun	  For the very few that do, software emulation is provided in
1871*4882a593Smuzhiyun	  specific cases in protected and virtual-8086 modes. Emulated
1872*4882a593Smuzhiyun	  results are dummy.
1873*4882a593Smuzhiyun
1874*4882a593Smuzhiyunconfig X86_INTEL_MEMORY_PROTECTION_KEYS
1875*4882a593Smuzhiyun	prompt "Memory Protection Keys"
1876*4882a593Smuzhiyun	def_bool y
1877*4882a593Smuzhiyun	# Note: only available in 64-bit mode
1878*4882a593Smuzhiyun	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1879*4882a593Smuzhiyun	select ARCH_USES_HIGH_VMA_FLAGS
1880*4882a593Smuzhiyun	select ARCH_HAS_PKEYS
1881*4882a593Smuzhiyun	help
1882*4882a593Smuzhiyun	  Memory Protection Keys provides a mechanism for enforcing
1883*4882a593Smuzhiyun	  page-based protections, but without requiring modification of the
1884*4882a593Smuzhiyun	  page tables when an application changes protection domains.
1885*4882a593Smuzhiyun
1886*4882a593Smuzhiyun	  For details, see Documentation/core-api/protection-keys.rst
1887*4882a593Smuzhiyun
1888*4882a593Smuzhiyun	  If unsure, say y.
1889*4882a593Smuzhiyun
1890*4882a593Smuzhiyunchoice
1891*4882a593Smuzhiyun	prompt "TSX enable mode"
1892*4882a593Smuzhiyun	depends on CPU_SUP_INTEL
1893*4882a593Smuzhiyun	default X86_INTEL_TSX_MODE_OFF
1894*4882a593Smuzhiyun	help
1895*4882a593Smuzhiyun	  Intel's TSX (Transactional Synchronization Extensions) feature
1896*4882a593Smuzhiyun	  allows to optimize locking protocols through lock elision which
1897*4882a593Smuzhiyun	  can lead to a noticeable performance boost.
1898*4882a593Smuzhiyun
1899*4882a593Smuzhiyun	  On the other hand it has been shown that TSX can be exploited
1900*4882a593Smuzhiyun	  to form side channel attacks (e.g. TAA) and chances are there
1901*4882a593Smuzhiyun	  will be more of those attacks discovered in the future.
1902*4882a593Smuzhiyun
1903*4882a593Smuzhiyun	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1904*4882a593Smuzhiyun	  might override this decision by tsx=on the command line parameter.
1905*4882a593Smuzhiyun	  Even with TSX enabled, the kernel will attempt to enable the best
1906*4882a593Smuzhiyun	  possible TAA mitigation setting depending on the microcode available
1907*4882a593Smuzhiyun	  for the particular machine.
1908*4882a593Smuzhiyun
1909*4882a593Smuzhiyun	  This option allows to set the default tsx mode between tsx=on, =off
1910*4882a593Smuzhiyun	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1911*4882a593Smuzhiyun	  details.
1912*4882a593Smuzhiyun
1913*4882a593Smuzhiyun	  Say off if not sure, auto if TSX is in use but it should be used on safe
1914*4882a593Smuzhiyun	  platforms or on if TSX is in use and the security aspect of tsx is not
1915*4882a593Smuzhiyun	  relevant.
1916*4882a593Smuzhiyun
1917*4882a593Smuzhiyunconfig X86_INTEL_TSX_MODE_OFF
1918*4882a593Smuzhiyun	bool "off"
1919*4882a593Smuzhiyun	help
1920*4882a593Smuzhiyun	  TSX is disabled if possible - equals to tsx=off command line parameter.
1921*4882a593Smuzhiyun
1922*4882a593Smuzhiyunconfig X86_INTEL_TSX_MODE_ON
1923*4882a593Smuzhiyun	bool "on"
1924*4882a593Smuzhiyun	help
1925*4882a593Smuzhiyun	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1926*4882a593Smuzhiyun	  line parameter.
1927*4882a593Smuzhiyun
1928*4882a593Smuzhiyunconfig X86_INTEL_TSX_MODE_AUTO
1929*4882a593Smuzhiyun	bool "auto"
1930*4882a593Smuzhiyun	help
1931*4882a593Smuzhiyun	  TSX is enabled on TSX capable HW that is believed to be safe against
1932*4882a593Smuzhiyun	  side channel attacks- equals the tsx=auto command line parameter.
1933*4882a593Smuzhiyunendchoice
1934*4882a593Smuzhiyun
1935*4882a593Smuzhiyunconfig EFI
1936*4882a593Smuzhiyun	bool "EFI runtime service support"
1937*4882a593Smuzhiyun	depends on ACPI
1938*4882a593Smuzhiyun	select UCS2_STRING
1939*4882a593Smuzhiyun	select EFI_RUNTIME_WRAPPERS
1940*4882a593Smuzhiyun	select ARCH_USE_MEMREMAP_PROT
1941*4882a593Smuzhiyun	help
1942*4882a593Smuzhiyun	  This enables the kernel to use EFI runtime services that are
1943*4882a593Smuzhiyun	  available (such as the EFI variable services).
1944*4882a593Smuzhiyun
1945*4882a593Smuzhiyun	  This option is only useful on systems that have EFI firmware.
1946*4882a593Smuzhiyun	  In addition, you should use the latest ELILO loader available
1947*4882a593Smuzhiyun	  at <http://elilo.sourceforge.net> in order to take advantage
1948*4882a593Smuzhiyun	  of EFI runtime services. However, even with this option, the
1949*4882a593Smuzhiyun	  resultant kernel should continue to boot on existing non-EFI
1950*4882a593Smuzhiyun	  platforms.
1951*4882a593Smuzhiyun
1952*4882a593Smuzhiyunconfig EFI_STUB
1953*4882a593Smuzhiyun	bool "EFI stub support"
1954*4882a593Smuzhiyun	depends on EFI && !X86_USE_3DNOW
1955*4882a593Smuzhiyun	select RELOCATABLE
1956*4882a593Smuzhiyun	help
1957*4882a593Smuzhiyun	  This kernel feature allows a bzImage to be loaded directly
1958*4882a593Smuzhiyun	  by EFI firmware without the use of a bootloader.
1959*4882a593Smuzhiyun
1960*4882a593Smuzhiyun	  See Documentation/admin-guide/efi-stub.rst for more information.
1961*4882a593Smuzhiyun
1962*4882a593Smuzhiyunconfig EFI_MIXED
1963*4882a593Smuzhiyun	bool "EFI mixed-mode support"
1964*4882a593Smuzhiyun	depends on EFI_STUB && X86_64
1965*4882a593Smuzhiyun	help
1966*4882a593Smuzhiyun	   Enabling this feature allows a 64-bit kernel to be booted
1967*4882a593Smuzhiyun	   on a 32-bit firmware, provided that your CPU supports 64-bit
1968*4882a593Smuzhiyun	   mode.
1969*4882a593Smuzhiyun
1970*4882a593Smuzhiyun	   Note that it is not possible to boot a mixed-mode enabled
1971*4882a593Smuzhiyun	   kernel via the EFI boot stub - a bootloader that supports
1972*4882a593Smuzhiyun	   the EFI handover protocol must be used.
1973*4882a593Smuzhiyun
1974*4882a593Smuzhiyun	   If unsure, say N.
1975*4882a593Smuzhiyun
1976*4882a593Smuzhiyunsource "kernel/Kconfig.hz"
1977*4882a593Smuzhiyun
1978*4882a593Smuzhiyunconfig KEXEC
1979*4882a593Smuzhiyun	bool "kexec system call"
1980*4882a593Smuzhiyun	select KEXEC_CORE
1981*4882a593Smuzhiyun	help
1982*4882a593Smuzhiyun	  kexec is a system call that implements the ability to shutdown your
1983*4882a593Smuzhiyun	  current kernel, and to start another kernel.  It is like a reboot
1984*4882a593Smuzhiyun	  but it is independent of the system firmware.   And like a reboot
1985*4882a593Smuzhiyun	  you can start any kernel with it, not just Linux.
1986*4882a593Smuzhiyun
1987*4882a593Smuzhiyun	  The name comes from the similarity to the exec system call.
1988*4882a593Smuzhiyun
1989*4882a593Smuzhiyun	  It is an ongoing process to be certain the hardware in a machine
1990*4882a593Smuzhiyun	  is properly shutdown, so do not be surprised if this code does not
1991*4882a593Smuzhiyun	  initially work for you.  As of this writing the exact hardware
1992*4882a593Smuzhiyun	  interface is strongly in flux, so no good recommendation can be
1993*4882a593Smuzhiyun	  made.
1994*4882a593Smuzhiyun
1995*4882a593Smuzhiyunconfig KEXEC_FILE
1996*4882a593Smuzhiyun	bool "kexec file based system call"
1997*4882a593Smuzhiyun	select KEXEC_CORE
1998*4882a593Smuzhiyun	select BUILD_BIN2C
1999*4882a593Smuzhiyun	depends on X86_64
2000*4882a593Smuzhiyun	depends on CRYPTO=y
2001*4882a593Smuzhiyun	depends on CRYPTO_SHA256=y
2002*4882a593Smuzhiyun	help
2003*4882a593Smuzhiyun	  This is new version of kexec system call. This system call is
2004*4882a593Smuzhiyun	  file based and takes file descriptors as system call argument
2005*4882a593Smuzhiyun	  for kernel and initramfs as opposed to list of segments as
2006*4882a593Smuzhiyun	  accepted by previous system call.
2007*4882a593Smuzhiyun
2008*4882a593Smuzhiyunconfig ARCH_HAS_KEXEC_PURGATORY
2009*4882a593Smuzhiyun	def_bool KEXEC_FILE
2010*4882a593Smuzhiyun
2011*4882a593Smuzhiyunconfig KEXEC_SIG
2012*4882a593Smuzhiyun	bool "Verify kernel signature during kexec_file_load() syscall"
2013*4882a593Smuzhiyun	depends on KEXEC_FILE
2014*4882a593Smuzhiyun	help
2015*4882a593Smuzhiyun
2016*4882a593Smuzhiyun	  This option makes the kexec_file_load() syscall check for a valid
2017*4882a593Smuzhiyun	  signature of the kernel image.  The image can still be loaded without
2018*4882a593Smuzhiyun	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2019*4882a593Smuzhiyun	  there's a signature that we can check, then it must be valid.
2020*4882a593Smuzhiyun
2021*4882a593Smuzhiyun	  In addition to this option, you need to enable signature
2022*4882a593Smuzhiyun	  verification for the corresponding kernel image type being
2023*4882a593Smuzhiyun	  loaded in order for this to work.
2024*4882a593Smuzhiyun
2025*4882a593Smuzhiyunconfig KEXEC_SIG_FORCE
2026*4882a593Smuzhiyun	bool "Require a valid signature in kexec_file_load() syscall"
2027*4882a593Smuzhiyun	depends on KEXEC_SIG
2028*4882a593Smuzhiyun	help
2029*4882a593Smuzhiyun	  This option makes kernel signature verification mandatory for
2030*4882a593Smuzhiyun	  the kexec_file_load() syscall.
2031*4882a593Smuzhiyun
2032*4882a593Smuzhiyunconfig KEXEC_BZIMAGE_VERIFY_SIG
2033*4882a593Smuzhiyun	bool "Enable bzImage signature verification support"
2034*4882a593Smuzhiyun	depends on KEXEC_SIG
2035*4882a593Smuzhiyun	depends on SIGNED_PE_FILE_VERIFICATION
2036*4882a593Smuzhiyun	select SYSTEM_TRUSTED_KEYRING
2037*4882a593Smuzhiyun	help
2038*4882a593Smuzhiyun	  Enable bzImage signature verification support.
2039*4882a593Smuzhiyun
2040*4882a593Smuzhiyunconfig CRASH_DUMP
2041*4882a593Smuzhiyun	bool "kernel crash dumps"
2042*4882a593Smuzhiyun	depends on X86_64 || (X86_32 && HIGHMEM)
2043*4882a593Smuzhiyun	help
2044*4882a593Smuzhiyun	  Generate crash dump after being started by kexec.
2045*4882a593Smuzhiyun	  This should be normally only set in special crash dump kernels
2046*4882a593Smuzhiyun	  which are loaded in the main kernel with kexec-tools into
2047*4882a593Smuzhiyun	  a specially reserved region and then later executed after
2048*4882a593Smuzhiyun	  a crash by kdump/kexec. The crash dump kernel must be compiled
2049*4882a593Smuzhiyun	  to a memory address not used by the main kernel or BIOS using
2050*4882a593Smuzhiyun	  PHYSICAL_START, or it must be built as a relocatable image
2051*4882a593Smuzhiyun	  (CONFIG_RELOCATABLE=y).
2052*4882a593Smuzhiyun	  For more details see Documentation/admin-guide/kdump/kdump.rst
2053*4882a593Smuzhiyun
2054*4882a593Smuzhiyunconfig KEXEC_JUMP
2055*4882a593Smuzhiyun	bool "kexec jump"
2056*4882a593Smuzhiyun	depends on KEXEC && HIBERNATION
2057*4882a593Smuzhiyun	help
2058*4882a593Smuzhiyun	  Jump between original kernel and kexeced kernel and invoke
2059*4882a593Smuzhiyun	  code in physical address mode via KEXEC
2060*4882a593Smuzhiyun
2061*4882a593Smuzhiyunconfig PHYSICAL_START
2062*4882a593Smuzhiyun	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2063*4882a593Smuzhiyun	default "0x1000000"
2064*4882a593Smuzhiyun	help
2065*4882a593Smuzhiyun	  This gives the physical address where the kernel is loaded.
2066*4882a593Smuzhiyun
2067*4882a593Smuzhiyun	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2068*4882a593Smuzhiyun	  bzImage will decompress itself to above physical address and
2069*4882a593Smuzhiyun	  run from there. Otherwise, bzImage will run from the address where
2070*4882a593Smuzhiyun	  it has been loaded by the boot loader and will ignore above physical
2071*4882a593Smuzhiyun	  address.
2072*4882a593Smuzhiyun
2073*4882a593Smuzhiyun	  In normal kdump cases one does not have to set/change this option
2074*4882a593Smuzhiyun	  as now bzImage can be compiled as a completely relocatable image
2075*4882a593Smuzhiyun	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2076*4882a593Smuzhiyun	  address. This option is mainly useful for the folks who don't want
2077*4882a593Smuzhiyun	  to use a bzImage for capturing the crash dump and want to use a
2078*4882a593Smuzhiyun	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2079*4882a593Smuzhiyun	  to be specifically compiled to run from a specific memory area
2080*4882a593Smuzhiyun	  (normally a reserved region) and this option comes handy.
2081*4882a593Smuzhiyun
2082*4882a593Smuzhiyun	  So if you are using bzImage for capturing the crash dump,
2083*4882a593Smuzhiyun	  leave the value here unchanged to 0x1000000 and set
2084*4882a593Smuzhiyun	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2085*4882a593Smuzhiyun	  for capturing the crash dump change this value to start of
2086*4882a593Smuzhiyun	  the reserved region.  In other words, it can be set based on
2087*4882a593Smuzhiyun	  the "X" value as specified in the "crashkernel=YM@XM"
2088*4882a593Smuzhiyun	  command line boot parameter passed to the panic-ed
2089*4882a593Smuzhiyun	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2090*4882a593Smuzhiyun	  for more details about crash dumps.
2091*4882a593Smuzhiyun
2092*4882a593Smuzhiyun	  Usage of bzImage for capturing the crash dump is recommended as
2093*4882a593Smuzhiyun	  one does not have to build two kernels. Same kernel can be used
2094*4882a593Smuzhiyun	  as production kernel and capture kernel. Above option should have
2095*4882a593Smuzhiyun	  gone away after relocatable bzImage support is introduced. But it
2096*4882a593Smuzhiyun	  is present because there are users out there who continue to use
2097*4882a593Smuzhiyun	  vmlinux for dump capture. This option should go away down the
2098*4882a593Smuzhiyun	  line.
2099*4882a593Smuzhiyun
2100*4882a593Smuzhiyun	  Don't change this unless you know what you are doing.
2101*4882a593Smuzhiyun
2102*4882a593Smuzhiyunconfig RELOCATABLE
2103*4882a593Smuzhiyun	bool "Build a relocatable kernel"
2104*4882a593Smuzhiyun	default y
2105*4882a593Smuzhiyun	help
2106*4882a593Smuzhiyun	  This builds a kernel image that retains relocation information
2107*4882a593Smuzhiyun	  so it can be loaded someplace besides the default 1MB.
2108*4882a593Smuzhiyun	  The relocations tend to make the kernel binary about 10% larger,
2109*4882a593Smuzhiyun	  but are discarded at runtime.
2110*4882a593Smuzhiyun
2111*4882a593Smuzhiyun	  One use is for the kexec on panic case where the recovery kernel
2112*4882a593Smuzhiyun	  must live at a different physical address than the primary
2113*4882a593Smuzhiyun	  kernel.
2114*4882a593Smuzhiyun
2115*4882a593Smuzhiyun	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2116*4882a593Smuzhiyun	  it has been loaded at and the compile time physical address
2117*4882a593Smuzhiyun	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2118*4882a593Smuzhiyun
2119*4882a593Smuzhiyunconfig RANDOMIZE_BASE
2120*4882a593Smuzhiyun	bool "Randomize the address of the kernel image (KASLR)"
2121*4882a593Smuzhiyun	depends on RELOCATABLE
2122*4882a593Smuzhiyun	default y
2123*4882a593Smuzhiyun	help
2124*4882a593Smuzhiyun	  In support of Kernel Address Space Layout Randomization (KASLR),
2125*4882a593Smuzhiyun	  this randomizes the physical address at which the kernel image
2126*4882a593Smuzhiyun	  is decompressed and the virtual address where the kernel
2127*4882a593Smuzhiyun	  image is mapped, as a security feature that deters exploit
2128*4882a593Smuzhiyun	  attempts relying on knowledge of the location of kernel
2129*4882a593Smuzhiyun	  code internals.
2130*4882a593Smuzhiyun
2131*4882a593Smuzhiyun	  On 64-bit, the kernel physical and virtual addresses are
2132*4882a593Smuzhiyun	  randomized separately. The physical address will be anywhere
2133*4882a593Smuzhiyun	  between 16MB and the top of physical memory (up to 64TB). The
2134*4882a593Smuzhiyun	  virtual address will be randomized from 16MB up to 1GB (9 bits
2135*4882a593Smuzhiyun	  of entropy). Note that this also reduces the memory space
2136*4882a593Smuzhiyun	  available to kernel modules from 1.5GB to 1GB.
2137*4882a593Smuzhiyun
2138*4882a593Smuzhiyun	  On 32-bit, the kernel physical and virtual addresses are
2139*4882a593Smuzhiyun	  randomized together. They will be randomized from 16MB up to
2140*4882a593Smuzhiyun	  512MB (8 bits of entropy).
2141*4882a593Smuzhiyun
2142*4882a593Smuzhiyun	  Entropy is generated using the RDRAND instruction if it is
2143*4882a593Smuzhiyun	  supported. If RDTSC is supported, its value is mixed into
2144*4882a593Smuzhiyun	  the entropy pool as well. If neither RDRAND nor RDTSC are
2145*4882a593Smuzhiyun	  supported, then entropy is read from the i8254 timer. The
2146*4882a593Smuzhiyun	  usable entropy is limited by the kernel being built using
2147*4882a593Smuzhiyun	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2148*4882a593Smuzhiyun	  minimum of 2MB. As a result, only 10 bits of entropy are
2149*4882a593Smuzhiyun	  theoretically possible, but the implementations are further
2150*4882a593Smuzhiyun	  limited due to memory layouts.
2151*4882a593Smuzhiyun
2152*4882a593Smuzhiyun	  If unsure, say Y.
2153*4882a593Smuzhiyun
2154*4882a593Smuzhiyun# Relocation on x86 needs some additional build support
2155*4882a593Smuzhiyunconfig X86_NEED_RELOCS
2156*4882a593Smuzhiyun	def_bool y
2157*4882a593Smuzhiyun	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2158*4882a593Smuzhiyun
2159*4882a593Smuzhiyunconfig PHYSICAL_ALIGN
2160*4882a593Smuzhiyun	hex "Alignment value to which kernel should be aligned"
2161*4882a593Smuzhiyun	default "0x200000"
2162*4882a593Smuzhiyun	range 0x2000 0x1000000 if X86_32
2163*4882a593Smuzhiyun	range 0x200000 0x1000000 if X86_64
2164*4882a593Smuzhiyun	help
2165*4882a593Smuzhiyun	  This value puts the alignment restrictions on physical address
2166*4882a593Smuzhiyun	  where kernel is loaded and run from. Kernel is compiled for an
2167*4882a593Smuzhiyun	  address which meets above alignment restriction.
2168*4882a593Smuzhiyun
2169*4882a593Smuzhiyun	  If bootloader loads the kernel at a non-aligned address and
2170*4882a593Smuzhiyun	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2171*4882a593Smuzhiyun	  address aligned to above value and run from there.
2172*4882a593Smuzhiyun
2173*4882a593Smuzhiyun	  If bootloader loads the kernel at a non-aligned address and
2174*4882a593Smuzhiyun	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2175*4882a593Smuzhiyun	  load address and decompress itself to the address it has been
2176*4882a593Smuzhiyun	  compiled for and run from there. The address for which kernel is
2177*4882a593Smuzhiyun	  compiled already meets above alignment restrictions. Hence the
2178*4882a593Smuzhiyun	  end result is that kernel runs from a physical address meeting
2179*4882a593Smuzhiyun	  above alignment restrictions.
2180*4882a593Smuzhiyun
2181*4882a593Smuzhiyun	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2182*4882a593Smuzhiyun	  this value must be a multiple of 0x200000.
2183*4882a593Smuzhiyun
2184*4882a593Smuzhiyun	  Don't change this unless you know what you are doing.
2185*4882a593Smuzhiyun
2186*4882a593Smuzhiyunconfig DYNAMIC_MEMORY_LAYOUT
2187*4882a593Smuzhiyun	bool
2188*4882a593Smuzhiyun	help
2189*4882a593Smuzhiyun	  This option makes base addresses of vmalloc and vmemmap as well as
2190*4882a593Smuzhiyun	  __PAGE_OFFSET movable during boot.
2191*4882a593Smuzhiyun
2192*4882a593Smuzhiyunconfig RANDOMIZE_MEMORY
2193*4882a593Smuzhiyun	bool "Randomize the kernel memory sections"
2194*4882a593Smuzhiyun	depends on X86_64
2195*4882a593Smuzhiyun	depends on RANDOMIZE_BASE
2196*4882a593Smuzhiyun	select DYNAMIC_MEMORY_LAYOUT
2197*4882a593Smuzhiyun	default RANDOMIZE_BASE
2198*4882a593Smuzhiyun	help
2199*4882a593Smuzhiyun	   Randomizes the base virtual address of kernel memory sections
2200*4882a593Smuzhiyun	   (physical memory mapping, vmalloc & vmemmap). This security feature
2201*4882a593Smuzhiyun	   makes exploits relying on predictable memory locations less reliable.
2202*4882a593Smuzhiyun
2203*4882a593Smuzhiyun	   The order of allocations remains unchanged. Entropy is generated in
2204*4882a593Smuzhiyun	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2205*4882a593Smuzhiyun	   configuration have in average 30,000 different possible virtual
2206*4882a593Smuzhiyun	   addresses for each memory section.
2207*4882a593Smuzhiyun
2208*4882a593Smuzhiyun	   If unsure, say Y.
2209*4882a593Smuzhiyun
2210*4882a593Smuzhiyunconfig RANDOMIZE_MEMORY_PHYSICAL_PADDING
2211*4882a593Smuzhiyun	hex "Physical memory mapping padding" if EXPERT
2212*4882a593Smuzhiyun	depends on RANDOMIZE_MEMORY
2213*4882a593Smuzhiyun	default "0xa" if MEMORY_HOTPLUG
2214*4882a593Smuzhiyun	default "0x0"
2215*4882a593Smuzhiyun	range 0x1 0x40 if MEMORY_HOTPLUG
2216*4882a593Smuzhiyun	range 0x0 0x40
2217*4882a593Smuzhiyun	help
2218*4882a593Smuzhiyun	   Define the padding in terabytes added to the existing physical
2219*4882a593Smuzhiyun	   memory size during kernel memory randomization. It is useful
2220*4882a593Smuzhiyun	   for memory hotplug support but reduces the entropy available for
2221*4882a593Smuzhiyun	   address randomization.
2222*4882a593Smuzhiyun
2223*4882a593Smuzhiyun	   If unsure, leave at the default value.
2224*4882a593Smuzhiyun
2225*4882a593Smuzhiyunconfig HOTPLUG_CPU
2226*4882a593Smuzhiyun	def_bool y
2227*4882a593Smuzhiyun	depends on SMP
2228*4882a593Smuzhiyun
2229*4882a593Smuzhiyunconfig BOOTPARAM_HOTPLUG_CPU0
2230*4882a593Smuzhiyun	bool "Set default setting of cpu0_hotpluggable"
2231*4882a593Smuzhiyun	depends on HOTPLUG_CPU
2232*4882a593Smuzhiyun	help
2233*4882a593Smuzhiyun	  Set whether default state of cpu0_hotpluggable is on or off.
2234*4882a593Smuzhiyun
2235*4882a593Smuzhiyun	  Say Y here to enable CPU0 hotplug by default. If this switch
2236*4882a593Smuzhiyun	  is turned on, there is no need to give cpu0_hotplug kernel
2237*4882a593Smuzhiyun	  parameter and the CPU0 hotplug feature is enabled by default.
2238*4882a593Smuzhiyun
2239*4882a593Smuzhiyun	  Please note: there are two known CPU0 dependencies if you want
2240*4882a593Smuzhiyun	  to enable the CPU0 hotplug feature either by this switch or by
2241*4882a593Smuzhiyun	  cpu0_hotplug kernel parameter.
2242*4882a593Smuzhiyun
2243*4882a593Smuzhiyun	  First, resume from hibernate or suspend always starts from CPU0.
2244*4882a593Smuzhiyun	  So hibernate and suspend are prevented if CPU0 is offline.
2245*4882a593Smuzhiyun
2246*4882a593Smuzhiyun	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2247*4882a593Smuzhiyun	  offline if any interrupt can not migrate out of CPU0. There may
2248*4882a593Smuzhiyun	  be other CPU0 dependencies.
2249*4882a593Smuzhiyun
2250*4882a593Smuzhiyun	  Please make sure the dependencies are under your control before
2251*4882a593Smuzhiyun	  you enable this feature.
2252*4882a593Smuzhiyun
2253*4882a593Smuzhiyun	  Say N if you don't want to enable CPU0 hotplug feature by default.
2254*4882a593Smuzhiyun	  You still can enable the CPU0 hotplug feature at boot by kernel
2255*4882a593Smuzhiyun	  parameter cpu0_hotplug.
2256*4882a593Smuzhiyun
2257*4882a593Smuzhiyunconfig DEBUG_HOTPLUG_CPU0
2258*4882a593Smuzhiyun	def_bool n
2259*4882a593Smuzhiyun	prompt "Debug CPU0 hotplug"
2260*4882a593Smuzhiyun	depends on HOTPLUG_CPU
2261*4882a593Smuzhiyun	help
2262*4882a593Smuzhiyun	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2263*4882a593Smuzhiyun	  soon as possible and boots up userspace with CPU0 offlined. User
2264*4882a593Smuzhiyun	  can online CPU0 back after boot time.
2265*4882a593Smuzhiyun
2266*4882a593Smuzhiyun	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2267*4882a593Smuzhiyun	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2268*4882a593Smuzhiyun	  compilation or giving cpu0_hotplug kernel parameter at boot.
2269*4882a593Smuzhiyun
2270*4882a593Smuzhiyun	  If unsure, say N.
2271*4882a593Smuzhiyun
2272*4882a593Smuzhiyunconfig COMPAT_VDSO
2273*4882a593Smuzhiyun	def_bool n
2274*4882a593Smuzhiyun	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2275*4882a593Smuzhiyun	depends on COMPAT_32
2276*4882a593Smuzhiyun	help
2277*4882a593Smuzhiyun	  Certain buggy versions of glibc will crash if they are
2278*4882a593Smuzhiyun	  presented with a 32-bit vDSO that is not mapped at the address
2279*4882a593Smuzhiyun	  indicated in its segment table.
2280*4882a593Smuzhiyun
2281*4882a593Smuzhiyun	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2282*4882a593Smuzhiyun	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2283*4882a593Smuzhiyun	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2284*4882a593Smuzhiyun	  the only released version with the bug, but OpenSUSE 9
2285*4882a593Smuzhiyun	  contains a buggy "glibc 2.3.2".
2286*4882a593Smuzhiyun
2287*4882a593Smuzhiyun	  The symptom of the bug is that everything crashes on startup, saying:
2288*4882a593Smuzhiyun	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2289*4882a593Smuzhiyun
2290*4882a593Smuzhiyun	  Saying Y here changes the default value of the vdso32 boot
2291*4882a593Smuzhiyun	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2292*4882a593Smuzhiyun	  This works around the glibc bug but hurts performance.
2293*4882a593Smuzhiyun
2294*4882a593Smuzhiyun	  If unsure, say N: if you are compiling your own kernel, you
2295*4882a593Smuzhiyun	  are unlikely to be using a buggy version of glibc.
2296*4882a593Smuzhiyun
2297*4882a593Smuzhiyunchoice
2298*4882a593Smuzhiyun	prompt "vsyscall table for legacy applications"
2299*4882a593Smuzhiyun	depends on X86_64
2300*4882a593Smuzhiyun	default LEGACY_VSYSCALL_XONLY
2301*4882a593Smuzhiyun	help
2302*4882a593Smuzhiyun	  Legacy user code that does not know how to find the vDSO expects
2303*4882a593Smuzhiyun	  to be able to issue three syscalls by calling fixed addresses in
2304*4882a593Smuzhiyun	  kernel space. Since this location is not randomized with ASLR,
2305*4882a593Smuzhiyun	  it can be used to assist security vulnerability exploitation.
2306*4882a593Smuzhiyun
2307*4882a593Smuzhiyun	  This setting can be changed at boot time via the kernel command
2308*4882a593Smuzhiyun	  line parameter vsyscall=[emulate|xonly|none].
2309*4882a593Smuzhiyun
2310*4882a593Smuzhiyun	  On a system with recent enough glibc (2.14 or newer) and no
2311*4882a593Smuzhiyun	  static binaries, you can say None without a performance penalty
2312*4882a593Smuzhiyun	  to improve security.
2313*4882a593Smuzhiyun
2314*4882a593Smuzhiyun	  If unsure, select "Emulate execution only".
2315*4882a593Smuzhiyun
2316*4882a593Smuzhiyun	config LEGACY_VSYSCALL_EMULATE
2317*4882a593Smuzhiyun		bool "Full emulation"
2318*4882a593Smuzhiyun		help
2319*4882a593Smuzhiyun		  The kernel traps and emulates calls into the fixed vsyscall
2320*4882a593Smuzhiyun		  address mapping. This makes the mapping non-executable, but
2321*4882a593Smuzhiyun		  it still contains readable known contents, which could be
2322*4882a593Smuzhiyun		  used in certain rare security vulnerability exploits. This
2323*4882a593Smuzhiyun		  configuration is recommended when using legacy userspace
2324*4882a593Smuzhiyun		  that still uses vsyscalls along with legacy binary
2325*4882a593Smuzhiyun		  instrumentation tools that require code to be readable.
2326*4882a593Smuzhiyun
2327*4882a593Smuzhiyun		  An example of this type of legacy userspace is running
2328*4882a593Smuzhiyun		  Pin on an old binary that still uses vsyscalls.
2329*4882a593Smuzhiyun
2330*4882a593Smuzhiyun	config LEGACY_VSYSCALL_XONLY
2331*4882a593Smuzhiyun		bool "Emulate execution only"
2332*4882a593Smuzhiyun		help
2333*4882a593Smuzhiyun		  The kernel traps and emulates calls into the fixed vsyscall
2334*4882a593Smuzhiyun		  address mapping and does not allow reads.  This
2335*4882a593Smuzhiyun		  configuration is recommended when userspace might use the
2336*4882a593Smuzhiyun		  legacy vsyscall area but support for legacy binary
2337*4882a593Smuzhiyun		  instrumentation of legacy code is not needed.  It mitigates
2338*4882a593Smuzhiyun		  certain uses of the vsyscall area as an ASLR-bypassing
2339*4882a593Smuzhiyun		  buffer.
2340*4882a593Smuzhiyun
2341*4882a593Smuzhiyun	config LEGACY_VSYSCALL_NONE
2342*4882a593Smuzhiyun		bool "None"
2343*4882a593Smuzhiyun		help
2344*4882a593Smuzhiyun		  There will be no vsyscall mapping at all. This will
2345*4882a593Smuzhiyun		  eliminate any risk of ASLR bypass due to the vsyscall
2346*4882a593Smuzhiyun		  fixed address mapping. Attempts to use the vsyscalls
2347*4882a593Smuzhiyun		  will be reported to dmesg, so that either old or
2348*4882a593Smuzhiyun		  malicious userspace programs can be identified.
2349*4882a593Smuzhiyun
2350*4882a593Smuzhiyunendchoice
2351*4882a593Smuzhiyun
2352*4882a593Smuzhiyunconfig CMDLINE_BOOL
2353*4882a593Smuzhiyun	bool "Built-in kernel command line"
2354*4882a593Smuzhiyun	help
2355*4882a593Smuzhiyun	  Allow for specifying boot arguments to the kernel at
2356*4882a593Smuzhiyun	  build time.  On some systems (e.g. embedded ones), it is
2357*4882a593Smuzhiyun	  necessary or convenient to provide some or all of the
2358*4882a593Smuzhiyun	  kernel boot arguments with the kernel itself (that is,
2359*4882a593Smuzhiyun	  to not rely on the boot loader to provide them.)
2360*4882a593Smuzhiyun
2361*4882a593Smuzhiyun	  To compile command line arguments into the kernel,
2362*4882a593Smuzhiyun	  set this option to 'Y', then fill in the
2363*4882a593Smuzhiyun	  boot arguments in CONFIG_CMDLINE.
2364*4882a593Smuzhiyun
2365*4882a593Smuzhiyun	  Systems with fully functional boot loaders (i.e. non-embedded)
2366*4882a593Smuzhiyun	  should leave this option set to 'N'.
2367*4882a593Smuzhiyun
2368*4882a593Smuzhiyunconfig CMDLINE
2369*4882a593Smuzhiyun	string "Built-in kernel command string"
2370*4882a593Smuzhiyun	depends on CMDLINE_BOOL
2371*4882a593Smuzhiyun	default ""
2372*4882a593Smuzhiyun	help
2373*4882a593Smuzhiyun	  Enter arguments here that should be compiled into the kernel
2374*4882a593Smuzhiyun	  image and used at boot time.  If the boot loader provides a
2375*4882a593Smuzhiyun	  command line at boot time, it is appended to this string to
2376*4882a593Smuzhiyun	  form the full kernel command line, when the system boots.
2377*4882a593Smuzhiyun
2378*4882a593Smuzhiyun	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2379*4882a593Smuzhiyun	  change this behavior.
2380*4882a593Smuzhiyun
2381*4882a593Smuzhiyun	  In most cases, the command line (whether built-in or provided
2382*4882a593Smuzhiyun	  by the boot loader) should specify the device for the root
2383*4882a593Smuzhiyun	  file system.
2384*4882a593Smuzhiyun
2385*4882a593Smuzhiyunconfig CMDLINE_OVERRIDE
2386*4882a593Smuzhiyun	bool "Built-in command line overrides boot loader arguments"
2387*4882a593Smuzhiyun	depends on CMDLINE_BOOL && CMDLINE != ""
2388*4882a593Smuzhiyun	help
2389*4882a593Smuzhiyun	  Set this option to 'Y' to have the kernel ignore the boot loader
2390*4882a593Smuzhiyun	  command line, and use ONLY the built-in command line.
2391*4882a593Smuzhiyun
2392*4882a593Smuzhiyun	  This is used to work around broken boot loaders.  This should
2393*4882a593Smuzhiyun	  be set to 'N' under normal conditions.
2394*4882a593Smuzhiyun
2395*4882a593Smuzhiyunconfig MODIFY_LDT_SYSCALL
2396*4882a593Smuzhiyun	bool "Enable the LDT (local descriptor table)" if EXPERT
2397*4882a593Smuzhiyun	default y
2398*4882a593Smuzhiyun	help
2399*4882a593Smuzhiyun	  Linux can allow user programs to install a per-process x86
2400*4882a593Smuzhiyun	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2401*4882a593Smuzhiyun	  call.  This is required to run 16-bit or segmented code such as
2402*4882a593Smuzhiyun	  DOSEMU or some Wine programs.  It is also used by some very old
2403*4882a593Smuzhiyun	  threading libraries.
2404*4882a593Smuzhiyun
2405*4882a593Smuzhiyun	  Enabling this feature adds a small amount of overhead to
2406*4882a593Smuzhiyun	  context switches and increases the low-level kernel attack
2407*4882a593Smuzhiyun	  surface.  Disabling it removes the modify_ldt(2) system call.
2408*4882a593Smuzhiyun
2409*4882a593Smuzhiyun	  Saying 'N' here may make sense for embedded or server kernels.
2410*4882a593Smuzhiyun
2411*4882a593Smuzhiyunsource "kernel/livepatch/Kconfig"
2412*4882a593Smuzhiyun
2413*4882a593Smuzhiyunendmenu
2414*4882a593Smuzhiyun
2415*4882a593Smuzhiyunconfig CC_HAS_SLS
2416*4882a593Smuzhiyun	def_bool $(cc-option,-mharden-sls=all)
2417*4882a593Smuzhiyun
2418*4882a593Smuzhiyunconfig CC_HAS_RETURN_THUNK
2419*4882a593Smuzhiyun	def_bool $(cc-option,-mfunction-return=thunk-extern)
2420*4882a593Smuzhiyun
2421*4882a593Smuzhiyunmenuconfig SPECULATION_MITIGATIONS
2422*4882a593Smuzhiyun	bool "Mitigations for speculative execution vulnerabilities"
2423*4882a593Smuzhiyun	default y
2424*4882a593Smuzhiyun	help
2425*4882a593Smuzhiyun	  Say Y here to enable options which enable mitigations for
2426*4882a593Smuzhiyun	  speculative execution hardware vulnerabilities.
2427*4882a593Smuzhiyun
2428*4882a593Smuzhiyun	  If you say N, all mitigations will be disabled. You really
2429*4882a593Smuzhiyun	  should know what you are doing to say so.
2430*4882a593Smuzhiyun
2431*4882a593Smuzhiyunif SPECULATION_MITIGATIONS
2432*4882a593Smuzhiyun
2433*4882a593Smuzhiyunconfig PAGE_TABLE_ISOLATION
2434*4882a593Smuzhiyun	bool "Remove the kernel mapping in user mode"
2435*4882a593Smuzhiyun	default y
2436*4882a593Smuzhiyun	depends on (X86_64 || X86_PAE)
2437*4882a593Smuzhiyun	help
2438*4882a593Smuzhiyun	  This feature reduces the number of hardware side channels by
2439*4882a593Smuzhiyun	  ensuring that the majority of kernel addresses are not mapped
2440*4882a593Smuzhiyun	  into userspace.
2441*4882a593Smuzhiyun
2442*4882a593Smuzhiyun	  See Documentation/x86/pti.rst for more details.
2443*4882a593Smuzhiyun
2444*4882a593Smuzhiyunconfig RETPOLINE
2445*4882a593Smuzhiyun	bool "Avoid speculative indirect branches in kernel"
2446*4882a593Smuzhiyun	default y
2447*4882a593Smuzhiyun	help
2448*4882a593Smuzhiyun	  Compile kernel with the retpoline compiler options to guard against
2449*4882a593Smuzhiyun	  kernel-to-user data leaks by avoiding speculative indirect
2450*4882a593Smuzhiyun	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2451*4882a593Smuzhiyun	  support for full protection. The kernel may run slower.
2452*4882a593Smuzhiyun
2453*4882a593Smuzhiyunconfig RETHUNK
2454*4882a593Smuzhiyun	bool "Enable return-thunks"
2455*4882a593Smuzhiyun	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2456*4882a593Smuzhiyun	default y if X86_64
2457*4882a593Smuzhiyun	help
2458*4882a593Smuzhiyun	  Compile the kernel with the return-thunks compiler option to guard
2459*4882a593Smuzhiyun	  against kernel-to-user data leaks by avoiding return speculation.
2460*4882a593Smuzhiyun	  Requires a compiler with -mfunction-return=thunk-extern
2461*4882a593Smuzhiyun	  support for full protection. The kernel may run slower.
2462*4882a593Smuzhiyun
2463*4882a593Smuzhiyunconfig CPU_UNRET_ENTRY
2464*4882a593Smuzhiyun	bool "Enable UNRET on kernel entry"
2465*4882a593Smuzhiyun	depends on CPU_SUP_AMD && RETHUNK && X86_64
2466*4882a593Smuzhiyun	default y
2467*4882a593Smuzhiyun	help
2468*4882a593Smuzhiyun	  Compile the kernel with support for the retbleed=unret mitigation.
2469*4882a593Smuzhiyun
2470*4882a593Smuzhiyunconfig CPU_IBPB_ENTRY
2471*4882a593Smuzhiyun	bool "Enable IBPB on kernel entry"
2472*4882a593Smuzhiyun	depends on CPU_SUP_AMD && X86_64
2473*4882a593Smuzhiyun	default y
2474*4882a593Smuzhiyun	help
2475*4882a593Smuzhiyun	  Compile the kernel with support for the retbleed=ibpb mitigation.
2476*4882a593Smuzhiyun
2477*4882a593Smuzhiyunconfig CPU_IBRS_ENTRY
2478*4882a593Smuzhiyun	bool "Enable IBRS on kernel entry"
2479*4882a593Smuzhiyun	depends on CPU_SUP_INTEL && X86_64
2480*4882a593Smuzhiyun	default y
2481*4882a593Smuzhiyun	help
2482*4882a593Smuzhiyun	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2483*4882a593Smuzhiyun	  This mitigates both spectre_v2 and retbleed at great cost to
2484*4882a593Smuzhiyun	  performance.
2485*4882a593Smuzhiyun
2486*4882a593Smuzhiyunconfig SLS
2487*4882a593Smuzhiyun	bool "Mitigate Straight-Line-Speculation"
2488*4882a593Smuzhiyun	depends on CC_HAS_SLS && X86_64
2489*4882a593Smuzhiyun	default n
2490*4882a593Smuzhiyun	help
2491*4882a593Smuzhiyun	  Compile the kernel with straight-line-speculation options to guard
2492*4882a593Smuzhiyun	  against straight line speculation. The kernel image might be slightly
2493*4882a593Smuzhiyun	  larger.
2494*4882a593Smuzhiyun
2495*4882a593Smuzhiyunendif
2496*4882a593Smuzhiyun
2497*4882a593Smuzhiyunconfig ARCH_HAS_ADD_PAGES
2498*4882a593Smuzhiyun	def_bool y
2499*4882a593Smuzhiyun	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2500*4882a593Smuzhiyun
2501*4882a593Smuzhiyunconfig ARCH_ENABLE_MEMORY_HOTPLUG
2502*4882a593Smuzhiyun	def_bool y
2503*4882a593Smuzhiyun	depends on X86_64 || (X86_32 && HIGHMEM)
2504*4882a593Smuzhiyun
2505*4882a593Smuzhiyunconfig ARCH_ENABLE_MEMORY_HOTREMOVE
2506*4882a593Smuzhiyun	def_bool y
2507*4882a593Smuzhiyun	depends on MEMORY_HOTPLUG
2508*4882a593Smuzhiyun
2509*4882a593Smuzhiyunconfig USE_PERCPU_NUMA_NODE_ID
2510*4882a593Smuzhiyun	def_bool y
2511*4882a593Smuzhiyun	depends on NUMA
2512*4882a593Smuzhiyun
2513*4882a593Smuzhiyunconfig ARCH_ENABLE_SPLIT_PMD_PTLOCK
2514*4882a593Smuzhiyun	def_bool y
2515*4882a593Smuzhiyun	depends on X86_64 || X86_PAE
2516*4882a593Smuzhiyun
2517*4882a593Smuzhiyunconfig ARCH_ENABLE_HUGEPAGE_MIGRATION
2518*4882a593Smuzhiyun	def_bool y
2519*4882a593Smuzhiyun	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2520*4882a593Smuzhiyun
2521*4882a593Smuzhiyunconfig ARCH_ENABLE_THP_MIGRATION
2522*4882a593Smuzhiyun	def_bool y
2523*4882a593Smuzhiyun	depends on X86_64 && TRANSPARENT_HUGEPAGE
2524*4882a593Smuzhiyun
2525*4882a593Smuzhiyunmenu "Power management and ACPI options"
2526*4882a593Smuzhiyun
2527*4882a593Smuzhiyunconfig ARCH_HIBERNATION_HEADER
2528*4882a593Smuzhiyun	def_bool y
2529*4882a593Smuzhiyun	depends on HIBERNATION
2530*4882a593Smuzhiyun
2531*4882a593Smuzhiyunsource "kernel/power/Kconfig"
2532*4882a593Smuzhiyun
2533*4882a593Smuzhiyunsource "drivers/acpi/Kconfig"
2534*4882a593Smuzhiyun
2535*4882a593Smuzhiyunsource "drivers/sfi/Kconfig"
2536*4882a593Smuzhiyun
2537*4882a593Smuzhiyunconfig X86_APM_BOOT
2538*4882a593Smuzhiyun	def_bool y
2539*4882a593Smuzhiyun	depends on APM
2540*4882a593Smuzhiyun
2541*4882a593Smuzhiyunmenuconfig APM
2542*4882a593Smuzhiyun	tristate "APM (Advanced Power Management) BIOS support"
2543*4882a593Smuzhiyun	depends on X86_32 && PM_SLEEP
2544*4882a593Smuzhiyun	help
2545*4882a593Smuzhiyun	  APM is a BIOS specification for saving power using several different
2546*4882a593Smuzhiyun	  techniques. This is mostly useful for battery powered laptops with
2547*4882a593Smuzhiyun	  APM compliant BIOSes. If you say Y here, the system time will be
2548*4882a593Smuzhiyun	  reset after a RESUME operation, the /proc/apm device will provide
2549*4882a593Smuzhiyun	  battery status information, and user-space programs will receive
2550*4882a593Smuzhiyun	  notification of APM "events" (e.g. battery status change).
2551*4882a593Smuzhiyun
2552*4882a593Smuzhiyun	  If you select "Y" here, you can disable actual use of the APM
2553*4882a593Smuzhiyun	  BIOS by passing the "apm=off" option to the kernel at boot time.
2554*4882a593Smuzhiyun
2555*4882a593Smuzhiyun	  Note that the APM support is almost completely disabled for
2556*4882a593Smuzhiyun	  machines with more than one CPU.
2557*4882a593Smuzhiyun
2558*4882a593Smuzhiyun	  In order to use APM, you will need supporting software. For location
2559*4882a593Smuzhiyun	  and more information, read <file:Documentation/power/apm-acpi.rst>
2560*4882a593Smuzhiyun	  and the Battery Powered Linux mini-HOWTO, available from
2561*4882a593Smuzhiyun	  <http://www.tldp.org/docs.html#howto>.
2562*4882a593Smuzhiyun
2563*4882a593Smuzhiyun	  This driver does not spin down disk drives (see the hdparm(8)
2564*4882a593Smuzhiyun	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2565*4882a593Smuzhiyun	  VESA-compliant "green" monitors.
2566*4882a593Smuzhiyun
2567*4882a593Smuzhiyun	  This driver does not support the TI 4000M TravelMate and the ACER
2568*4882a593Smuzhiyun	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2569*4882a593Smuzhiyun	  desktop machines also don't have compliant BIOSes, and this driver
2570*4882a593Smuzhiyun	  may cause those machines to panic during the boot phase.
2571*4882a593Smuzhiyun
2572*4882a593Smuzhiyun	  Generally, if you don't have a battery in your machine, there isn't
2573*4882a593Smuzhiyun	  much point in using this driver and you should say N. If you get
2574*4882a593Smuzhiyun	  random kernel OOPSes or reboots that don't seem to be related to
2575*4882a593Smuzhiyun	  anything, try disabling/enabling this option (or disabling/enabling
2576*4882a593Smuzhiyun	  APM in your BIOS).
2577*4882a593Smuzhiyun
2578*4882a593Smuzhiyun	  Some other things you should try when experiencing seemingly random,
2579*4882a593Smuzhiyun	  "weird" problems:
2580*4882a593Smuzhiyun
2581*4882a593Smuzhiyun	  1) make sure that you have enough swap space and that it is
2582*4882a593Smuzhiyun	  enabled.
2583*4882a593Smuzhiyun	  2) pass the "no-hlt" option to the kernel
2584*4882a593Smuzhiyun	  3) switch on floating point emulation in the kernel and pass
2585*4882a593Smuzhiyun	  the "no387" option to the kernel
2586*4882a593Smuzhiyun	  4) pass the "floppy=nodma" option to the kernel
2587*4882a593Smuzhiyun	  5) pass the "mem=4M" option to the kernel (thereby disabling
2588*4882a593Smuzhiyun	  all but the first 4 MB of RAM)
2589*4882a593Smuzhiyun	  6) make sure that the CPU is not over clocked.
2590*4882a593Smuzhiyun	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2591*4882a593Smuzhiyun	  8) disable the cache from your BIOS settings
2592*4882a593Smuzhiyun	  9) install a fan for the video card or exchange video RAM
2593*4882a593Smuzhiyun	  10) install a better fan for the CPU
2594*4882a593Smuzhiyun	  11) exchange RAM chips
2595*4882a593Smuzhiyun	  12) exchange the motherboard.
2596*4882a593Smuzhiyun
2597*4882a593Smuzhiyun	  To compile this driver as a module, choose M here: the
2598*4882a593Smuzhiyun	  module will be called apm.
2599*4882a593Smuzhiyun
2600*4882a593Smuzhiyunif APM
2601*4882a593Smuzhiyun
2602*4882a593Smuzhiyunconfig APM_IGNORE_USER_SUSPEND
2603*4882a593Smuzhiyun	bool "Ignore USER SUSPEND"
2604*4882a593Smuzhiyun	help
2605*4882a593Smuzhiyun	  This option will ignore USER SUSPEND requests. On machines with a
2606*4882a593Smuzhiyun	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2607*4882a593Smuzhiyun	  series notebooks, it is necessary to say Y because of a BIOS bug.
2608*4882a593Smuzhiyun
2609*4882a593Smuzhiyunconfig APM_DO_ENABLE
2610*4882a593Smuzhiyun	bool "Enable PM at boot time"
2611*4882a593Smuzhiyun	help
2612*4882a593Smuzhiyun	  Enable APM features at boot time. From page 36 of the APM BIOS
2613*4882a593Smuzhiyun	  specification: "When disabled, the APM BIOS does not automatically
2614*4882a593Smuzhiyun	  power manage devices, enter the Standby State, enter the Suspend
2615*4882a593Smuzhiyun	  State, or take power saving steps in response to CPU Idle calls."
2616*4882a593Smuzhiyun	  This driver will make CPU Idle calls when Linux is idle (unless this
2617*4882a593Smuzhiyun	  feature is turned off -- see "Do CPU IDLE calls", below). This
2618*4882a593Smuzhiyun	  should always save battery power, but more complicated APM features
2619*4882a593Smuzhiyun	  will be dependent on your BIOS implementation. You may need to turn
2620*4882a593Smuzhiyun	  this option off if your computer hangs at boot time when using APM
2621*4882a593Smuzhiyun	  support, or if it beeps continuously instead of suspending. Turn
2622*4882a593Smuzhiyun	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2623*4882a593Smuzhiyun	  T400CDT. This is off by default since most machines do fine without
2624*4882a593Smuzhiyun	  this feature.
2625*4882a593Smuzhiyun
2626*4882a593Smuzhiyunconfig APM_CPU_IDLE
2627*4882a593Smuzhiyun	depends on CPU_IDLE
2628*4882a593Smuzhiyun	bool "Make CPU Idle calls when idle"
2629*4882a593Smuzhiyun	help
2630*4882a593Smuzhiyun	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2631*4882a593Smuzhiyun	  On some machines, this can activate improved power savings, such as
2632*4882a593Smuzhiyun	  a slowed CPU clock rate, when the machine is idle. These idle calls
2633*4882a593Smuzhiyun	  are made after the idle loop has run for some length of time (e.g.,
2634*4882a593Smuzhiyun	  333 mS). On some machines, this will cause a hang at boot time or
2635*4882a593Smuzhiyun	  whenever the CPU becomes idle. (On machines with more than one CPU,
2636*4882a593Smuzhiyun	  this option does nothing.)
2637*4882a593Smuzhiyun
2638*4882a593Smuzhiyunconfig APM_DISPLAY_BLANK
2639*4882a593Smuzhiyun	bool "Enable console blanking using APM"
2640*4882a593Smuzhiyun	help
2641*4882a593Smuzhiyun	  Enable console blanking using the APM. Some laptops can use this to
2642*4882a593Smuzhiyun	  turn off the LCD backlight when the screen blanker of the Linux
2643*4882a593Smuzhiyun	  virtual console blanks the screen. Note that this is only used by
2644*4882a593Smuzhiyun	  the virtual console screen blanker, and won't turn off the backlight
2645*4882a593Smuzhiyun	  when using the X Window system. This also doesn't have anything to
2646*4882a593Smuzhiyun	  do with your VESA-compliant power-saving monitor. Further, this
2647*4882a593Smuzhiyun	  option doesn't work for all laptops -- it might not turn off your
2648*4882a593Smuzhiyun	  backlight at all, or it might print a lot of errors to the console,
2649*4882a593Smuzhiyun	  especially if you are using gpm.
2650*4882a593Smuzhiyun
2651*4882a593Smuzhiyunconfig APM_ALLOW_INTS
2652*4882a593Smuzhiyun	bool "Allow interrupts during APM BIOS calls"
2653*4882a593Smuzhiyun	help
2654*4882a593Smuzhiyun	  Normally we disable external interrupts while we are making calls to
2655*4882a593Smuzhiyun	  the APM BIOS as a measure to lessen the effects of a badly behaving
2656*4882a593Smuzhiyun	  BIOS implementation.  The BIOS should reenable interrupts if it
2657*4882a593Smuzhiyun	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2658*4882a593Smuzhiyun	  many of the newer IBM Thinkpads.  If you experience hangs when you
2659*4882a593Smuzhiyun	  suspend, try setting this to Y.  Otherwise, say N.
2660*4882a593Smuzhiyun
2661*4882a593Smuzhiyunendif # APM
2662*4882a593Smuzhiyun
2663*4882a593Smuzhiyunsource "drivers/cpufreq/Kconfig"
2664*4882a593Smuzhiyun
2665*4882a593Smuzhiyunsource "drivers/cpuidle/Kconfig"
2666*4882a593Smuzhiyun
2667*4882a593Smuzhiyunsource "drivers/idle/Kconfig"
2668*4882a593Smuzhiyun
2669*4882a593Smuzhiyunendmenu
2670*4882a593Smuzhiyun
2671*4882a593Smuzhiyun
2672*4882a593Smuzhiyunmenu "Bus options (PCI etc.)"
2673*4882a593Smuzhiyun
2674*4882a593Smuzhiyunchoice
2675*4882a593Smuzhiyun	prompt "PCI access mode"
2676*4882a593Smuzhiyun	depends on X86_32 && PCI
2677*4882a593Smuzhiyun	default PCI_GOANY
2678*4882a593Smuzhiyun	help
2679*4882a593Smuzhiyun	  On PCI systems, the BIOS can be used to detect the PCI devices and
2680*4882a593Smuzhiyun	  determine their configuration. However, some old PCI motherboards
2681*4882a593Smuzhiyun	  have BIOS bugs and may crash if this is done. Also, some embedded
2682*4882a593Smuzhiyun	  PCI-based systems don't have any BIOS at all. Linux can also try to
2683*4882a593Smuzhiyun	  detect the PCI hardware directly without using the BIOS.
2684*4882a593Smuzhiyun
2685*4882a593Smuzhiyun	  With this option, you can specify how Linux should detect the
2686*4882a593Smuzhiyun	  PCI devices. If you choose "BIOS", the BIOS will be used,
2687*4882a593Smuzhiyun	  if you choose "Direct", the BIOS won't be used, and if you
2688*4882a593Smuzhiyun	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2689*4882a593Smuzhiyun	  If you choose "Any", the kernel will try MMCONFIG, then the
2690*4882a593Smuzhiyun	  direct access method and falls back to the BIOS if that doesn't
2691*4882a593Smuzhiyun	  work. If unsure, go with the default, which is "Any".
2692*4882a593Smuzhiyun
2693*4882a593Smuzhiyunconfig PCI_GOBIOS
2694*4882a593Smuzhiyun	bool "BIOS"
2695*4882a593Smuzhiyun
2696*4882a593Smuzhiyunconfig PCI_GOMMCONFIG
2697*4882a593Smuzhiyun	bool "MMConfig"
2698*4882a593Smuzhiyun
2699*4882a593Smuzhiyunconfig PCI_GODIRECT
2700*4882a593Smuzhiyun	bool "Direct"
2701*4882a593Smuzhiyun
2702*4882a593Smuzhiyunconfig PCI_GOOLPC
2703*4882a593Smuzhiyun	bool "OLPC XO-1"
2704*4882a593Smuzhiyun	depends on OLPC
2705*4882a593Smuzhiyun
2706*4882a593Smuzhiyunconfig PCI_GOANY
2707*4882a593Smuzhiyun	bool "Any"
2708*4882a593Smuzhiyun
2709*4882a593Smuzhiyunendchoice
2710*4882a593Smuzhiyun
2711*4882a593Smuzhiyunconfig PCI_BIOS
2712*4882a593Smuzhiyun	def_bool y
2713*4882a593Smuzhiyun	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2714*4882a593Smuzhiyun
2715*4882a593Smuzhiyun# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2716*4882a593Smuzhiyunconfig PCI_DIRECT
2717*4882a593Smuzhiyun	def_bool y
2718*4882a593Smuzhiyun	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2719*4882a593Smuzhiyun
2720*4882a593Smuzhiyunconfig PCI_MMCONFIG
2721*4882a593Smuzhiyun	bool "Support mmconfig PCI config space access" if X86_64
2722*4882a593Smuzhiyun	default y
2723*4882a593Smuzhiyun	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2724*4882a593Smuzhiyun	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2725*4882a593Smuzhiyun
2726*4882a593Smuzhiyunconfig PCI_OLPC
2727*4882a593Smuzhiyun	def_bool y
2728*4882a593Smuzhiyun	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2729*4882a593Smuzhiyun
2730*4882a593Smuzhiyunconfig PCI_XEN
2731*4882a593Smuzhiyun	def_bool y
2732*4882a593Smuzhiyun	depends on PCI && XEN
2733*4882a593Smuzhiyun	select SWIOTLB_XEN
2734*4882a593Smuzhiyun
2735*4882a593Smuzhiyunconfig MMCONF_FAM10H
2736*4882a593Smuzhiyun	def_bool y
2737*4882a593Smuzhiyun	depends on X86_64 && PCI_MMCONFIG && ACPI
2738*4882a593Smuzhiyun
2739*4882a593Smuzhiyunconfig PCI_CNB20LE_QUIRK
2740*4882a593Smuzhiyun	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2741*4882a593Smuzhiyun	depends on PCI
2742*4882a593Smuzhiyun	help
2743*4882a593Smuzhiyun	  Read the PCI windows out of the CNB20LE host bridge. This allows
2744*4882a593Smuzhiyun	  PCI hotplug to work on systems with the CNB20LE chipset which do
2745*4882a593Smuzhiyun	  not have ACPI.
2746*4882a593Smuzhiyun
2747*4882a593Smuzhiyun	  There's no public spec for this chipset, and this functionality
2748*4882a593Smuzhiyun	  is known to be incomplete.
2749*4882a593Smuzhiyun
2750*4882a593Smuzhiyun	  You should say N unless you know you need this.
2751*4882a593Smuzhiyun
2752*4882a593Smuzhiyunconfig ISA_BUS
2753*4882a593Smuzhiyun	bool "ISA bus support on modern systems" if EXPERT
2754*4882a593Smuzhiyun	help
2755*4882a593Smuzhiyun	  Expose ISA bus device drivers and options available for selection and
2756*4882a593Smuzhiyun	  configuration. Enable this option if your target machine has an ISA
2757*4882a593Smuzhiyun	  bus. ISA is an older system, displaced by PCI and newer bus
2758*4882a593Smuzhiyun	  architectures -- if your target machine is modern, it probably does
2759*4882a593Smuzhiyun	  not have an ISA bus.
2760*4882a593Smuzhiyun
2761*4882a593Smuzhiyun	  If unsure, say N.
2762*4882a593Smuzhiyun
2763*4882a593Smuzhiyun# x86_64 have no ISA slots, but can have ISA-style DMA.
2764*4882a593Smuzhiyunconfig ISA_DMA_API
2765*4882a593Smuzhiyun	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2766*4882a593Smuzhiyun	default y
2767*4882a593Smuzhiyun	help
2768*4882a593Smuzhiyun	  Enables ISA-style DMA support for devices requiring such controllers.
2769*4882a593Smuzhiyun	  If unsure, say Y.
2770*4882a593Smuzhiyun
2771*4882a593Smuzhiyunif X86_32
2772*4882a593Smuzhiyun
2773*4882a593Smuzhiyunconfig ISA
2774*4882a593Smuzhiyun	bool "ISA support"
2775*4882a593Smuzhiyun	help
2776*4882a593Smuzhiyun	  Find out whether you have ISA slots on your motherboard.  ISA is the
2777*4882a593Smuzhiyun	  name of a bus system, i.e. the way the CPU talks to the other stuff
2778*4882a593Smuzhiyun	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2779*4882a593Smuzhiyun	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2780*4882a593Smuzhiyun	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2781*4882a593Smuzhiyun
2782*4882a593Smuzhiyunconfig SCx200
2783*4882a593Smuzhiyun	tristate "NatSemi SCx200 support"
2784*4882a593Smuzhiyun	help
2785*4882a593Smuzhiyun	  This provides basic support for National Semiconductor's
2786*4882a593Smuzhiyun	  (now AMD's) Geode processors.  The driver probes for the
2787*4882a593Smuzhiyun	  PCI-IDs of several on-chip devices, so its a good dependency
2788*4882a593Smuzhiyun	  for other scx200_* drivers.
2789*4882a593Smuzhiyun
2790*4882a593Smuzhiyun	  If compiled as a module, the driver is named scx200.
2791*4882a593Smuzhiyun
2792*4882a593Smuzhiyunconfig SCx200HR_TIMER
2793*4882a593Smuzhiyun	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2794*4882a593Smuzhiyun	depends on SCx200
2795*4882a593Smuzhiyun	default y
2796*4882a593Smuzhiyun	help
2797*4882a593Smuzhiyun	  This driver provides a clocksource built upon the on-chip
2798*4882a593Smuzhiyun	  27MHz high-resolution timer.  Its also a workaround for
2799*4882a593Smuzhiyun	  NSC Geode SC-1100's buggy TSC, which loses time when the
2800*4882a593Smuzhiyun	  processor goes idle (as is done by the scheduler).  The
2801*4882a593Smuzhiyun	  other workaround is idle=poll boot option.
2802*4882a593Smuzhiyun
2803*4882a593Smuzhiyunconfig OLPC
2804*4882a593Smuzhiyun	bool "One Laptop Per Child support"
2805*4882a593Smuzhiyun	depends on !X86_PAE
2806*4882a593Smuzhiyun	select GPIOLIB
2807*4882a593Smuzhiyun	select OF
2808*4882a593Smuzhiyun	select OF_PROMTREE
2809*4882a593Smuzhiyun	select IRQ_DOMAIN
2810*4882a593Smuzhiyun	select OLPC_EC
2811*4882a593Smuzhiyun	help
2812*4882a593Smuzhiyun	  Add support for detecting the unique features of the OLPC
2813*4882a593Smuzhiyun	  XO hardware.
2814*4882a593Smuzhiyun
2815*4882a593Smuzhiyunconfig OLPC_XO1_PM
2816*4882a593Smuzhiyun	bool "OLPC XO-1 Power Management"
2817*4882a593Smuzhiyun	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2818*4882a593Smuzhiyun	help
2819*4882a593Smuzhiyun	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2820*4882a593Smuzhiyun
2821*4882a593Smuzhiyunconfig OLPC_XO1_RTC
2822*4882a593Smuzhiyun	bool "OLPC XO-1 Real Time Clock"
2823*4882a593Smuzhiyun	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2824*4882a593Smuzhiyun	help
2825*4882a593Smuzhiyun	  Add support for the XO-1 real time clock, which can be used as a
2826*4882a593Smuzhiyun	  programmable wakeup source.
2827*4882a593Smuzhiyun
2828*4882a593Smuzhiyunconfig OLPC_XO1_SCI
2829*4882a593Smuzhiyun	bool "OLPC XO-1 SCI extras"
2830*4882a593Smuzhiyun	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2831*4882a593Smuzhiyun	depends on INPUT=y
2832*4882a593Smuzhiyun	select POWER_SUPPLY
2833*4882a593Smuzhiyun	help
2834*4882a593Smuzhiyun	  Add support for SCI-based features of the OLPC XO-1 laptop:
2835*4882a593Smuzhiyun	   - EC-driven system wakeups
2836*4882a593Smuzhiyun	   - Power button
2837*4882a593Smuzhiyun	   - Ebook switch
2838*4882a593Smuzhiyun	   - Lid switch
2839*4882a593Smuzhiyun	   - AC adapter status updates
2840*4882a593Smuzhiyun	   - Battery status updates
2841*4882a593Smuzhiyun
2842*4882a593Smuzhiyunconfig OLPC_XO15_SCI
2843*4882a593Smuzhiyun	bool "OLPC XO-1.5 SCI extras"
2844*4882a593Smuzhiyun	depends on OLPC && ACPI
2845*4882a593Smuzhiyun	select POWER_SUPPLY
2846*4882a593Smuzhiyun	help
2847*4882a593Smuzhiyun	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2848*4882a593Smuzhiyun	   - EC-driven system wakeups
2849*4882a593Smuzhiyun	   - AC adapter status updates
2850*4882a593Smuzhiyun	   - Battery status updates
2851*4882a593Smuzhiyun
2852*4882a593Smuzhiyunconfig ALIX
2853*4882a593Smuzhiyun	bool "PCEngines ALIX System Support (LED setup)"
2854*4882a593Smuzhiyun	select GPIOLIB
2855*4882a593Smuzhiyun	help
2856*4882a593Smuzhiyun	  This option enables system support for the PCEngines ALIX.
2857*4882a593Smuzhiyun	  At present this just sets up LEDs for GPIO control on
2858*4882a593Smuzhiyun	  ALIX2/3/6 boards.  However, other system specific setup should
2859*4882a593Smuzhiyun	  get added here.
2860*4882a593Smuzhiyun
2861*4882a593Smuzhiyun	  Note: You must still enable the drivers for GPIO and LED support
2862*4882a593Smuzhiyun	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2863*4882a593Smuzhiyun
2864*4882a593Smuzhiyun	  Note: You have to set alix.force=1 for boards with Award BIOS.
2865*4882a593Smuzhiyun
2866*4882a593Smuzhiyunconfig NET5501
2867*4882a593Smuzhiyun	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2868*4882a593Smuzhiyun	select GPIOLIB
2869*4882a593Smuzhiyun	help
2870*4882a593Smuzhiyun	  This option enables system support for the Soekris Engineering net5501.
2871*4882a593Smuzhiyun
2872*4882a593Smuzhiyunconfig GEOS
2873*4882a593Smuzhiyun	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2874*4882a593Smuzhiyun	select GPIOLIB
2875*4882a593Smuzhiyun	depends on DMI
2876*4882a593Smuzhiyun	help
2877*4882a593Smuzhiyun	  This option enables system support for the Traverse Technologies GEOS.
2878*4882a593Smuzhiyun
2879*4882a593Smuzhiyunconfig TS5500
2880*4882a593Smuzhiyun	bool "Technologic Systems TS-5500 platform support"
2881*4882a593Smuzhiyun	depends on MELAN
2882*4882a593Smuzhiyun	select CHECK_SIGNATURE
2883*4882a593Smuzhiyun	select NEW_LEDS
2884*4882a593Smuzhiyun	select LEDS_CLASS
2885*4882a593Smuzhiyun	help
2886*4882a593Smuzhiyun	  This option enables system support for the Technologic Systems TS-5500.
2887*4882a593Smuzhiyun
2888*4882a593Smuzhiyunendif # X86_32
2889*4882a593Smuzhiyun
2890*4882a593Smuzhiyunconfig AMD_NB
2891*4882a593Smuzhiyun	def_bool y
2892*4882a593Smuzhiyun	depends on CPU_SUP_AMD && PCI
2893*4882a593Smuzhiyun
2894*4882a593Smuzhiyunconfig X86_SYSFB
2895*4882a593Smuzhiyun	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2896*4882a593Smuzhiyun	help
2897*4882a593Smuzhiyun	  Firmwares often provide initial graphics framebuffers so the BIOS,
2898*4882a593Smuzhiyun	  bootloader or kernel can show basic video-output during boot for
2899*4882a593Smuzhiyun	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2900*4882a593Smuzhiyun	  Extensions and EFI-framebuffers for this, which are mostly limited
2901*4882a593Smuzhiyun	  to x86.
2902*4882a593Smuzhiyun	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2903*4882a593Smuzhiyun	  framebuffers so the new generic system-framebuffer drivers can be
2904*4882a593Smuzhiyun	  used on x86. If the framebuffer is not compatible with the generic
2905*4882a593Smuzhiyun	  modes, it is advertised as fallback platform framebuffer so legacy
2906*4882a593Smuzhiyun	  drivers like efifb, vesafb and uvesafb can pick it up.
2907*4882a593Smuzhiyun	  If this option is not selected, all system framebuffers are always
2908*4882a593Smuzhiyun	  marked as fallback platform framebuffers as usual.
2909*4882a593Smuzhiyun
2910*4882a593Smuzhiyun	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2911*4882a593Smuzhiyun	  not be able to pick up generic system framebuffers if this option
2912*4882a593Smuzhiyun	  is selected. You are highly encouraged to enable simplefb as
2913*4882a593Smuzhiyun	  replacement if you select this option. simplefb can correctly deal
2914*4882a593Smuzhiyun	  with generic system framebuffers. But you should still keep vesafb
2915*4882a593Smuzhiyun	  and others enabled as fallback if a system framebuffer is
2916*4882a593Smuzhiyun	  incompatible with simplefb.
2917*4882a593Smuzhiyun
2918*4882a593Smuzhiyun	  If unsure, say Y.
2919*4882a593Smuzhiyun
2920*4882a593Smuzhiyunendmenu
2921*4882a593Smuzhiyun
2922*4882a593Smuzhiyun
2923*4882a593Smuzhiyunmenu "Binary Emulations"
2924*4882a593Smuzhiyun
2925*4882a593Smuzhiyunconfig IA32_EMULATION
2926*4882a593Smuzhiyun	bool "IA32 Emulation"
2927*4882a593Smuzhiyun	depends on X86_64
2928*4882a593Smuzhiyun	select ARCH_WANT_OLD_COMPAT_IPC
2929*4882a593Smuzhiyun	select BINFMT_ELF
2930*4882a593Smuzhiyun	select COMPAT_BINFMT_ELF
2931*4882a593Smuzhiyun	select COMPAT_OLD_SIGACTION
2932*4882a593Smuzhiyun	help
2933*4882a593Smuzhiyun	  Include code to run legacy 32-bit programs under a
2934*4882a593Smuzhiyun	  64-bit kernel. You should likely turn this on, unless you're
2935*4882a593Smuzhiyun	  100% sure that you don't have any 32-bit programs left.
2936*4882a593Smuzhiyun
2937*4882a593Smuzhiyunconfig IA32_AOUT
2938*4882a593Smuzhiyun	tristate "IA32 a.out support"
2939*4882a593Smuzhiyun	depends on IA32_EMULATION
2940*4882a593Smuzhiyun	depends on BROKEN
2941*4882a593Smuzhiyun	help
2942*4882a593Smuzhiyun	  Support old a.out binaries in the 32bit emulation.
2943*4882a593Smuzhiyun
2944*4882a593Smuzhiyunconfig X86_X32
2945*4882a593Smuzhiyun	bool "x32 ABI for 64-bit mode"
2946*4882a593Smuzhiyun	depends on X86_64
2947*4882a593Smuzhiyun	# llvm-objcopy does not convert x86_64 .note.gnu.property or
2948*4882a593Smuzhiyun	# compressed debug sections to x86_x32 properly:
2949*4882a593Smuzhiyun	# https://github.com/ClangBuiltLinux/linux/issues/514
2950*4882a593Smuzhiyun	# https://github.com/ClangBuiltLinux/linux/issues/1141
2951*4882a593Smuzhiyun	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
2952*4882a593Smuzhiyun	help
2953*4882a593Smuzhiyun	  Include code to run binaries for the x32 native 32-bit ABI
2954*4882a593Smuzhiyun	  for 64-bit processors.  An x32 process gets access to the
2955*4882a593Smuzhiyun	  full 64-bit register file and wide data path while leaving
2956*4882a593Smuzhiyun	  pointers at 32 bits for smaller memory footprint.
2957*4882a593Smuzhiyun
2958*4882a593Smuzhiyun	  You will need a recent binutils (2.22 or later) with
2959*4882a593Smuzhiyun	  elf32_x86_64 support enabled to compile a kernel with this
2960*4882a593Smuzhiyun	  option set.
2961*4882a593Smuzhiyun
2962*4882a593Smuzhiyunconfig COMPAT_32
2963*4882a593Smuzhiyun	def_bool y
2964*4882a593Smuzhiyun	depends on IA32_EMULATION || X86_32
2965*4882a593Smuzhiyun	select HAVE_UID16
2966*4882a593Smuzhiyun	select OLD_SIGSUSPEND3
2967*4882a593Smuzhiyun
2968*4882a593Smuzhiyunconfig COMPAT
2969*4882a593Smuzhiyun	def_bool y
2970*4882a593Smuzhiyun	depends on IA32_EMULATION || X86_X32
2971*4882a593Smuzhiyun
2972*4882a593Smuzhiyunif COMPAT
2973*4882a593Smuzhiyunconfig COMPAT_FOR_U64_ALIGNMENT
2974*4882a593Smuzhiyun	def_bool y
2975*4882a593Smuzhiyun
2976*4882a593Smuzhiyunconfig SYSVIPC_COMPAT
2977*4882a593Smuzhiyun	def_bool y
2978*4882a593Smuzhiyun	depends on SYSVIPC
2979*4882a593Smuzhiyunendif
2980*4882a593Smuzhiyun
2981*4882a593Smuzhiyunendmenu
2982*4882a593Smuzhiyun
2983*4882a593Smuzhiyun
2984*4882a593Smuzhiyunconfig HAVE_ATOMIC_IOMAP
2985*4882a593Smuzhiyun	def_bool y
2986*4882a593Smuzhiyun	depends on X86_32
2987*4882a593Smuzhiyun
2988*4882a593Smuzhiyunsource "drivers/firmware/Kconfig"
2989*4882a593Smuzhiyun
2990*4882a593Smuzhiyunsource "arch/x86/kvm/Kconfig"
2991*4882a593Smuzhiyun
2992*4882a593Smuzhiyunsource "arch/x86/Kconfig.assembler"
2993