xref: /rk3399_ARM-atf/docs/getting_started/build-options.rst (revision 4ce3e99a336b74611349595ea7fd5ed0277c3eeb)
1Build Options
2=============
3
4The TF-A build system supports the following build options. Unless mentioned
5otherwise, these options are expected to be specified at the build command
6line and are not to be modified in any component makefiles. Note that the
7build system doesn't track dependency for build options. Therefore, if any of
8the build options are changed from a previous build, a clean build must be
9performed.
10
11.. _build_options_common:
12
13Common build options
14--------------------
15
16-  ``AARCH32_INSTRUCTION_SET``: Choose the AArch32 instruction set that the
17   compiler should use. Valid values are T32 and A32. It defaults to T32 due to
18   code having a smaller resulting size.
19
20-  ``AARCH32_SP`` : Choose the AArch32 Secure Payload component to be built as
21   as the BL32 image when ``ARCH=aarch32``. The value should be the path to the
22   directory containing the SP source, relative to the ``bl32/``; the directory
23   is expected to contain a makefile called ``<aarch32_sp-value>.mk``.
24
25-  ``AMU_RESTRICT_COUNTERS``: Register reads to the group 1 counters will return
26   zero at all but the highest implemented exception level.  Reads from the
27   memory mapped view are unaffected by this control.
28
29-  ``ARCH`` : Choose the target build architecture for TF-A. It can take either
30   ``aarch64`` or ``aarch32`` as values. By default, it is defined to
31   ``aarch64``.
32
33-  ``ARM_ARCH_FEATURE``: Optional Arm Architecture build option which specifies
34   one or more feature modifiers. This option has the form ``[no]feature+...``
35   and defaults to ``none``. It translates into compiler option
36   ``-march=armvX[.Y]-a+[no]feature+...``. See compiler's documentation for the
37   list of supported feature modifiers.
38
39-  ``ARM_ARCH_MAJOR``: The major version of Arm Architecture to target when
40   compiling TF-A. Its value must be numeric, and defaults to 8 . See also,
41   *Armv8 Architecture Extensions* and *Armv7 Architecture Extensions* in
42   :ref:`Firmware Design`.
43
44-  ``ARM_ARCH_MINOR``: The minor version of Arm Architecture to target when
45   compiling TF-A. Its value must be a numeric, and defaults to 0. See also,
46   *Armv8 Architecture Extensions* in :ref:`Firmware Design`.
47
48-  ``BL2``: This is an optional build option which specifies the path to BL2
49   image for the ``fip`` target. In this case, the BL2 in the TF-A will not be
50   built.
51
52-  ``BL2U``: This is an optional build option which specifies the path to
53   BL2U image. In this case, the BL2U in TF-A will not be built.
54
55-  ``BL2_AT_EL3``: This is an optional build option that enables the use of
56   BL2 at EL3 execution level.
57
58-  ``BL2_ENABLE_SP_LOAD``: Boolean option to enable loading SP packages from the
59   FIP. Automatically enabled if ``SP_LAYOUT_FILE`` is provided.
60
61-  ``BL2_IN_XIP_MEM``: In some use-cases BL2 will be stored in eXecute In Place
62   (XIP) memory, like BL1. In these use-cases, it is necessary to initialize
63   the RW sections in RAM, while leaving the RO sections in place. This option
64   enable this use-case. For now, this option is only supported when BL2_AT_EL3
65   is set to '1'.
66
67-  ``BL31``: This is an optional build option which specifies the path to
68   BL31 image for the ``fip`` target. In this case, the BL31 in TF-A will not
69   be built.
70
71-  ``BL31_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the
72   file that contains the BL31 private key in PEM format. If ``SAVE_KEYS=1``,
73   this file name will be used to save the key.
74
75-  ``BL32``: This is an optional build option which specifies the path to
76   BL32 image for the ``fip`` target. In this case, the BL32 in TF-A will not
77   be built.
78
79-  ``BL32_EXTRA1``: This is an optional build option which specifies the path to
80   Trusted OS Extra1 image for the  ``fip`` target.
81
82-  ``BL32_EXTRA2``: This is an optional build option which specifies the path to
83   Trusted OS Extra2 image for the ``fip`` target.
84
85-  ``BL32_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the
86   file that contains the BL32 private key in PEM format. If ``SAVE_KEYS=1``,
87   this file name will be used to save the key.
88
89-  ``BL33``: Path to BL33 image in the host file system. This is mandatory for
90   ``fip`` target in case TF-A BL2 is used.
91
92-  ``BL33_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the
93   file that contains the BL33 private key in PEM format. If ``SAVE_KEYS=1``,
94   this file name will be used to save the key.
95
96-  ``BRANCH_PROTECTION``: Numeric value to enable ARMv8.3 Pointer Authentication
97   and ARMv8.5 Branch Target Identification support for TF-A BL images themselves.
98   If enabled, it is needed to use a compiler that supports the option
99   ``-mbranch-protection``. Selects the branch protection features to use:
100-  0: Default value turns off all types of branch protection
101-  1: Enables all types of branch protection features
102-  2: Return address signing to its standard level
103-  3: Extend the signing to include leaf functions
104-  4: Turn on branch target identification mechanism
105
106   The table below summarizes ``BRANCH_PROTECTION`` values, GCC compilation options
107   and resulting PAuth/BTI features.
108
109   +-------+--------------+-------+-----+
110   | Value |  GCC option  | PAuth | BTI |
111   +=======+==============+=======+=====+
112   |   0   |     none     |   N   |  N  |
113   +-------+--------------+-------+-----+
114   |   1   |   standard   |   Y   |  Y  |
115   +-------+--------------+-------+-----+
116   |   2   |   pac-ret    |   Y   |  N  |
117   +-------+--------------+-------+-----+
118   |   3   | pac-ret+leaf |   Y   |  N  |
119   +-------+--------------+-------+-----+
120   |   4   |     bti      |   N   |  Y  |
121   +-------+--------------+-------+-----+
122
123   This option defaults to 0.
124   Note that Pointer Authentication is enabled for Non-secure world
125   irrespective of the value of this option if the CPU supports it.
126
127-  ``BUILD_MESSAGE_TIMESTAMP``: String used to identify the time and date of the
128   compilation of each build. It must be set to a C string (including quotes
129   where applicable). Defaults to a string that contains the time and date of
130   the compilation.
131
132-  ``BUILD_STRING``: Input string for VERSION_STRING, which allows the TF-A
133   build to be uniquely identified. Defaults to the current git commit id.
134
135-  ``BUILD_BASE``: Output directory for the build. Defaults to ``./build``
136
137-  ``CFLAGS``: Extra user options appended on the compiler's command line in
138   addition to the options set by the build system.
139
140-  ``COLD_BOOT_SINGLE_CPU``: This option indicates whether the platform may
141   release several CPUs out of reset. It can take either 0 (several CPUs may be
142   brought up) or 1 (only one CPU will ever be brought up during cold reset).
143   Default is 0. If the platform always brings up a single CPU, there is no
144   need to distinguish between primary and secondary CPUs and the boot path can
145   be optimised. The ``plat_is_my_cpu_primary()`` and
146   ``plat_secondary_cold_boot_setup()`` platform porting interfaces do not need
147   to be implemented in this case.
148
149-  ``COT``: When Trusted Boot is enabled, selects the desired chain of trust.
150   Defaults to ``tbbr``.
151
152-  ``CRASH_REPORTING``: A non-zero value enables a console dump of processor
153   register state when an unexpected exception occurs during execution of
154   BL31. This option defaults to the value of ``DEBUG`` - i.e. by default
155   this is only enabled for a debug build of the firmware.
156
157-  ``CREATE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the
158   certificate generation tool to create new keys in case no valid keys are
159   present or specified. Allowed options are '0' or '1'. Default is '1'.
160
161-  ``CTX_INCLUDE_AARCH32_REGS`` : Boolean option that, when set to 1, will cause
162   the AArch32 system registers to be included when saving and restoring the
163   CPU context. The option must be set to 0 for AArch64-only platforms (that
164   is on hardware that does not implement AArch32, or at least not at EL1 and
165   higher ELs). Default value is 1.
166
167-  ``CTX_INCLUDE_EL2_REGS`` : This boolean option provides context save/restore
168   operations when entering/exiting an EL2 execution context. This is of primary
169   interest when Armv8.4-SecEL2 extension is implemented. Default is 0 (disabled).
170   This option must be equal to 1 (enabled) when ``SPD=spmd`` and
171   ``SPMD_SPM_AT_SEL2`` is set.
172
173-  ``CTX_INCLUDE_FPREGS``: Boolean option that, when set to 1, will cause the FP
174   registers to be included when saving and restoring the CPU context. Default
175   is 0.
176
177-  ``CTX_INCLUDE_NEVE_REGS``: Boolean option that, when set to 1, will cause the
178   Armv8.4-NV registers to be saved/restored when entering/exiting an EL2
179   execution context. Default value is 0.
180
181-  ``CTX_INCLUDE_PAUTH_REGS``: Boolean option that, when set to 1, enables
182   Pointer Authentication for Secure world. This will cause the ARMv8.3-PAuth
183   registers to be included when saving and restoring the CPU context as
184   part of world switch. Default value is 0.
185   Note that Pointer Authentication is enabled for Non-secure world irrespective
186   of the value of this flag if the CPU supports it.
187
188-  ``DEBUG``: Chooses between a debug and release build. It can take either 0
189   (release) or 1 (debug) as values. 0 is the default.
190
191-  ``DECRYPTION_SUPPORT``: This build flag enables the user to select the
192   authenticated decryption algorithm to be used to decrypt firmware/s during
193   boot. It accepts 2 values: ``aes_gcm`` and ``none``. The default value of
194   this flag is ``none`` to disable firmware decryption which is an optional
195   feature as per TBBR.
196
197-  ``DISABLE_BIN_GENERATION``: Boolean option to disable the generation
198   of the binary image. If set to 1, then only the ELF image is built.
199   0 is the default.
200
201-  ``DISABLE_MTPMU``: Boolean option to disable FEAT_MTPMU if implemented
202   (Armv8.6 onwards). Its default value is 0 to keep consistency with platforms
203   that do not implement FEAT_MTPMU. For more information on FEAT_MTPMU,
204   check the latest Arm ARM.
205
206-  ``DYN_DISABLE_AUTH``: Provides the capability to dynamically disable Trusted
207   Board Boot authentication at runtime. This option is meant to be enabled only
208   for development platforms. ``TRUSTED_BOARD_BOOT`` flag must be set if this
209   flag has to be enabled. 0 is the default.
210
211-  ``E``: Boolean option to make warnings into errors. Default is 1.
212
213-  ``EL3_PAYLOAD_BASE``: This option enables booting an EL3 payload instead of
214   the normal boot flow. It must specify the entry point address of the EL3
215   payload. Please refer to the "Booting an EL3 payload" section for more
216   details.
217
218-  ``ENABLE_AMU``: Boolean option to enable Activity Monitor Unit extensions.
219   This is an optional architectural feature available on v8.4 onwards. Some
220   v8.2 implementations also implement an AMU and this option can be used to
221   enable this feature on those systems as well. Default is 0.
222
223-  ``ENABLE_AMU_AUXILIARY_COUNTERS``: Enables support for AMU auxiliary counters
224   (also known as group 1 counters). These are implementation-defined counters,
225   and as such require additional platform configuration. Default is 0.
226
227-  ``ENABLE_AMU_FCONF``: Enables configuration of the AMU through FCONF, which
228   allows platforms with auxiliary counters to describe them via the
229   ``HW_CONFIG`` device tree blob. Default is 0.
230
231-  ``ENABLE_ASSERTIONS``: This option controls whether or not calls to ``assert()``
232   are compiled out. For debug builds, this option defaults to 1, and calls to
233   ``assert()`` are left in place. For release builds, this option defaults to 0
234   and calls to ``assert()`` function are compiled out. This option can be set
235   independently of ``DEBUG``. It can also be used to hide any auxiliary code
236   that is only required for the assertion and does not fit in the assertion
237   itself.
238
239-  ``ENABLE_BACKTRACE``: This option controls whether to enable backtrace
240   dumps or not. It is supported in both AArch64 and AArch32. However, in
241   AArch32 the format of the frame records are not defined in the AAPCS and they
242   are defined by the implementation. This implementation of backtrace only
243   supports the format used by GCC when T32 interworking is disabled. For this
244   reason enabling this option in AArch32 will force the compiler to only
245   generate A32 code. This option is enabled by default only in AArch64 debug
246   builds, but this behaviour can be overridden in each platform's Makefile or
247   in the build command line.
248
249-  ``ENABLE_FEAT_HCX``: This option sets the bit SCR_EL3.HXEn in EL3 to allow
250   access to HCRX_EL2 (extended hypervisor control register) from EL2 as well as
251   adding HCRX_EL2 to the EL2 context save/restore operations.
252
253-  ``ENABLE_LTO``: Boolean option to enable Link Time Optimization (LTO)
254   support in GCC for TF-A. This option is currently only supported for
255   AArch64. Default is 0.
256
257-  ``ENABLE_MPAM_FOR_LOWER_ELS``: Boolean option to enable lower ELs to use MPAM
258   feature. MPAM is an optional Armv8.4 extension that enables various memory
259   system components and resources to define partitions; software running at
260   various ELs can assign themselves to desired partition to control their
261   performance aspects.
262
263   When this option is set to ``1``, EL3 allows lower ELs to access their own
264   MPAM registers without trapping into EL3. This option doesn't make use of
265   partitioning in EL3, however. Platform initialisation code should configure
266   and use partitions in EL3 as required. This option defaults to ``0``.
267
268-  ``ENABLE_MPMM``: Boolean option to enable support for the Maximum Power
269   Mitigation Mechanism supported by certain Arm cores, which allows the SoC
270   firmware to detect and limit high activity events to assist in SoC processor
271   power domain dynamic power budgeting and limit the triggering of whole-rail
272   (i.e. clock chopping) responses to overcurrent conditions. Defaults to ``0``.
273
274-  ``ENABLE_MPMM_FCONF``: Enables configuration of MPMM through FCONF, which
275   allows platforms with cores supporting MPMM to describe them via the
276   ``HW_CONFIG`` device tree blob. Default is 0.
277
278-  ``ENABLE_PIE``: Boolean option to enable Position Independent Executable(PIE)
279   support within generic code in TF-A. This option is currently only supported
280   in BL2_AT_EL3, BL31, and BL32 (TSP) for AARCH64 binaries, and in BL32
281   (SP_min) for AARCH32. Default is 0.
282
283-  ``ENABLE_PMF``: Boolean option to enable support for optional Performance
284   Measurement Framework(PMF). Default is 0.
285
286-  ``ENABLE_PSCI_STAT``: Boolean option to enable support for optional PSCI
287   functions ``PSCI_STAT_RESIDENCY`` and ``PSCI_STAT_COUNT``. Default is 0.
288   In the absence of an alternate stat collection backend, ``ENABLE_PMF`` must
289   be enabled. If ``ENABLE_PMF`` is set, the residency statistics are tracked in
290   software.
291
292- ``ENABLE_RME``: Boolean option to enable support for the ARMv9 Realm
293   Management Extension. Default value is 0. This is currently an experimental
294   feature.
295
296-  ``ENABLE_RUNTIME_INSTRUMENTATION``: Boolean option to enable runtime
297   instrumentation which injects timestamp collection points into TF-A to
298   allow runtime performance to be measured. Currently, only PSCI is
299   instrumented. Enabling this option enables the ``ENABLE_PMF`` build option
300   as well. Default is 0.
301
302-  ``ENABLE_SPE_FOR_LOWER_ELS`` : Boolean option to enable Statistical Profiling
303   extensions. This is an optional architectural feature for AArch64.
304   The default is 1 but is automatically disabled when the target architecture
305   is AArch32.
306
307-  ``ENABLE_SVE_FOR_NS``: Boolean option to enable Scalable Vector Extension
308   (SVE) for the Non-secure world only. SVE is an optional architectural feature
309   for AArch64. Note that when SVE is enabled for the Non-secure world, access
310   to SIMD and floating-point functionality from the Secure world is disabled by
311   default and controlled with ENABLE_SVE_FOR_SWD.
312   This is to avoid corruption of the Non-secure world data in the Z-registers
313   which are aliased by the SIMD and FP registers. The build option is not
314   compatible with the ``CTX_INCLUDE_FPREGS`` build option, and will raise an
315   assert on platforms where SVE is implemented and ``ENABLE_SVE_FOR_NS`` set to
316   1. The default is 1 but is automatically disabled when the target
317   architecture is AArch32.
318
319-  ``ENABLE_SVE_FOR_SWD``: Boolean option to enable SVE for the Secure world.
320   SVE is an optional architectural feature for AArch64. Note that this option
321   requires ENABLE_SVE_FOR_NS to be enabled.  The default is 0 and it is
322   automatically disabled when the target architecture is AArch32.
323
324-  ``ENABLE_STACK_PROTECTOR``: String option to enable the stack protection
325   checks in GCC. Allowed values are "all", "strong", "default" and "none". The
326   default value is set to "none". "strong" is the recommended stack protection
327   level if this feature is desired. "none" disables the stack protection. For
328   all values other than "none", the ``plat_get_stack_protector_canary()``
329   platform hook needs to be implemented. The value is passed as the last
330   component of the option ``-fstack-protector-$ENABLE_STACK_PROTECTOR``.
331
332-  ``ENCRYPT_BL31``: Binary flag to enable encryption of BL31 firmware. This
333   flag depends on ``DECRYPTION_SUPPORT`` build flag.
334
335-  ``ENCRYPT_BL32``: Binary flag to enable encryption of Secure BL32 payload.
336   This flag depends on ``DECRYPTION_SUPPORT`` build flag.
337
338-  ``ENC_KEY``: A 32-byte (256-bit) symmetric key in hex string format. It could
339   either be SSK or BSSK depending on ``FW_ENC_STATUS`` flag. This value depends
340   on ``DECRYPTION_SUPPORT`` build flag.
341
342-  ``ENC_NONCE``: A 12-byte (96-bit) encryption nonce or Initialization Vector
343   (IV) in hex string format. This value depends on ``DECRYPTION_SUPPORT``
344   build flag.
345
346-  ``ERROR_DEPRECATED``: This option decides whether to treat the usage of
347   deprecated platform APIs, helper functions or drivers within Trusted
348   Firmware as error. It can take the value 1 (flag the use of deprecated
349   APIs as error) or 0. The default is 0.
350
351-  ``EL3_EXCEPTION_HANDLING``: When set to ``1``, enable handling of exceptions
352   targeted at EL3. When set ``0`` (default), no exceptions are expected or
353   handled at EL3, and a panic will result. This is supported only for AArch64
354   builds.
355
356-  ``EVENT_LOG_LEVEL``: Chooses the log level to use for Measured Boot when
357   ``MEASURED_BOOT`` is enabled. For a list of valid values, see ``LOG_LEVEL``.
358   Default value is 40 (LOG_LEVEL_INFO).
359
360-  ``FAULT_INJECTION_SUPPORT``: ARMv8.4 extensions introduced support for fault
361   injection from lower ELs, and this build option enables lower ELs to use
362   Error Records accessed via System Registers to inject faults. This is
363   applicable only to AArch64 builds.
364
365   This feature is intended for testing purposes only, and is advisable to keep
366   disabled for production images.
367
368-  ``FIP_NAME``: This is an optional build option which specifies the FIP
369   filename for the ``fip`` target. Default is ``fip.bin``.
370
371-  ``FWU_FIP_NAME``: This is an optional build option which specifies the FWU
372   FIP filename for the ``fwu_fip`` target. Default is ``fwu_fip.bin``.
373
374-  ``FW_ENC_STATUS``: Top level firmware's encryption numeric flag, values:
375
376   ::
377
378     0: Encryption is done with Secret Symmetric Key (SSK) which is common
379        for a class of devices.
380     1: Encryption is done with Binding Secret Symmetric Key (BSSK) which is
381        unique per device.
382
383   This flag depends on ``DECRYPTION_SUPPORT`` build flag.
384
385-  ``GENERATE_COT``: Boolean flag used to build and execute the ``cert_create``
386   tool to create certificates as per the Chain of Trust described in
387   :ref:`Trusted Board Boot`. The build system then calls ``fiptool`` to
388   include the certificates in the FIP and FWU_FIP. Default value is '0'.
389
390   Specify both ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=1`` to include support
391   for the Trusted Board Boot feature in the BL1 and BL2 images, to generate
392   the corresponding certificates, and to include those certificates in the
393   FIP and FWU_FIP.
394
395   Note that if ``TRUSTED_BOARD_BOOT=0`` and ``GENERATE_COT=1``, the BL1 and BL2
396   images will not include support for Trusted Board Boot. The FIP will still
397   include the corresponding certificates. This FIP can be used to verify the
398   Chain of Trust on the host machine through other mechanisms.
399
400   Note that if ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=0``, the BL1 and BL2
401   images will include support for Trusted Board Boot, but the FIP and FWU_FIP
402   will not include the corresponding certificates, causing a boot failure.
403
404-  ``GICV2_G0_FOR_EL3``: Unlike GICv3, the GICv2 architecture doesn't have
405   inherent support for specific EL3 type interrupts. Setting this build option
406   to ``1`` assumes GICv2 *Group 0* interrupts are expected to target EL3, both
407   by :ref:`platform abstraction layer<platform Interrupt Controller API>` and
408   :ref:`Interrupt Management Framework<Interrupt Management Framework>`.
409   This allows GICv2 platforms to enable features requiring EL3 interrupt type.
410   This also means that all GICv2 Group 0 interrupts are delivered to EL3, and
411   the Secure Payload interrupts needs to be synchronously handed over to Secure
412   EL1 for handling. The default value of this option is ``0``, which means the
413   Group 0 interrupts are assumed to be handled by Secure EL1.
414
415-  ``HANDLE_EA_EL3_FIRST``: When set to ``1``, External Aborts and SError
416   Interrupts will be always trapped in EL3 i.e. in BL31 at runtime. When set to
417   ``0`` (default), these exceptions will be trapped in the current exception
418   level (or in EL1 if the current exception level is EL0).
419
420-  ``HW_ASSISTED_COHERENCY``: On most Arm systems to-date, platform-specific
421   software operations are required for CPUs to enter and exit coherency.
422   However, newer systems exist where CPUs' entry to and exit from coherency
423   is managed in hardware. Such systems require software to only initiate these
424   operations, and the rest is managed in hardware, minimizing active software
425   management. In such systems, this boolean option enables TF-A to carry out
426   build and run-time optimizations during boot and power management operations.
427   This option defaults to 0 and if it is enabled, then it implies
428   ``WARMBOOT_ENABLE_DCACHE_EARLY`` is also enabled.
429
430   If this flag is disabled while the platform which TF-A is compiled for
431   includes cores that manage coherency in hardware, then a compilation error is
432   generated. This is based on the fact that a system cannot have, at the same
433   time, cores that manage coherency in hardware and cores that don't. In other
434   words, a platform cannot have, at the same time, cores that require
435   ``HW_ASSISTED_COHERENCY=1`` and cores that require
436   ``HW_ASSISTED_COHERENCY=0``.
437
438   Note that, when ``HW_ASSISTED_COHERENCY`` is enabled, version 2 of
439   translation library (xlat tables v2) must be used; version 1 of translation
440   library is not supported.
441
442-  ``INVERTED_MEMMAP``: memmap tool print by default lower addresses at the
443   bottom, higher addresses at the top. This build flag can be set to '1' to
444   invert this behavior. Lower addresses will be printed at the top and higher
445   addresses at the bottom.
446
447-  ``JUNO_AARCH32_EL3_RUNTIME``: This build flag enables you to execute EL3
448   runtime software in AArch32 mode, which is required to run AArch32 on Juno.
449   By default this flag is set to '0'. Enabling this flag builds BL1 and BL2 in
450   AArch64 and facilitates the loading of ``SP_MIN`` and BL33 as AArch32 executable
451   images.
452
453-  ``KEY_ALG``: This build flag enables the user to select the algorithm to be
454   used for generating the PKCS keys and subsequent signing of the certificate.
455   It accepts 3 values: ``rsa``, ``rsa_1_5`` and ``ecdsa``. The option
456   ``rsa_1_5`` is the legacy PKCS#1 RSA 1.5 algorithm which is not TBBR
457   compliant and is retained only for compatibility. The default value of this
458   flag is ``rsa`` which is the TBBR compliant PKCS#1 RSA 2.1 scheme.
459
460-  ``KEY_SIZE``: This build flag enables the user to select the key size for
461   the algorithm specified by ``KEY_ALG``. The valid values for ``KEY_SIZE``
462   depend on the chosen algorithm and the cryptographic module.
463
464   +-----------+------------------------------------+
465   |  KEY_ALG  |        Possible key sizes          |
466   +===========+====================================+
467   |    rsa    | 1024 , 2048 (default), 3072, 4096* |
468   +-----------+------------------------------------+
469   |   ecdsa   |            unavailable             |
470   +-----------+------------------------------------+
471
472   * Only 2048 bits size is available with CryptoCell 712 SBROM release 1.
473     Only 3072 bits size is available with CryptoCell 712 SBROM release 2.
474
475-  ``HASH_ALG``: This build flag enables the user to select the secure hash
476   algorithm. It accepts 3 values: ``sha256``, ``sha384`` and ``sha512``.
477   The default value of this flag is ``sha256``.
478
479-  ``LDFLAGS``: Extra user options appended to the linkers' command line in
480   addition to the one set by the build system.
481
482-  ``LOG_LEVEL``: Chooses the log level, which controls the amount of console log
483   output compiled into the build. This should be one of the following:
484
485   ::
486
487       0  (LOG_LEVEL_NONE)
488       10 (LOG_LEVEL_ERROR)
489       20 (LOG_LEVEL_NOTICE)
490       30 (LOG_LEVEL_WARNING)
491       40 (LOG_LEVEL_INFO)
492       50 (LOG_LEVEL_VERBOSE)
493
494   All log output up to and including the selected log level is compiled into
495   the build. The default value is 40 in debug builds and 20 in release builds.
496
497-  ``MEASURED_BOOT``: Boolean flag to include support for the Measured Boot
498   feature. If this flag is enabled ``TRUSTED_BOARD_BOOT`` must be set as well
499   in order to provide trust that the code taking the measurements and recording
500   them has not been tampered with.
501
502   This option defaults to 0.
503
504-  ``NON_TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It
505   specifies the file that contains the Non-Trusted World private key in PEM
506   format. If ``SAVE_KEYS=1``, this file name will be used to save the key.
507
508-  ``NS_BL2U``: Path to NS_BL2U image in the host file system. This image is
509   optional. It is only needed if the platform makefile specifies that it
510   is required in order to build the ``fwu_fip`` target.
511
512-  ``NS_TIMER_SWITCH``: Enable save and restore for non-secure timer register
513   contents upon world switch. It can take either 0 (don't save and restore) or
514   1 (do save and restore). 0 is the default. An SPD may set this to 1 if it
515   wants the timer registers to be saved and restored.
516
517-  ``OVERRIDE_LIBC``: This option allows platforms to override the default libc
518   for the BL image. It can be either 0 (include) or 1 (remove). The default
519   value is 0.
520
521-  ``PL011_GENERIC_UART``: Boolean option to indicate the PL011 driver that
522   the underlying hardware is not a full PL011 UART but a minimally compliant
523   generic UART, which is a subset of the PL011. The driver will not access
524   any register that is not part of the SBSA generic UART specification.
525   Default value is 0 (a full PL011 compliant UART is present).
526
527-  ``PLAT``: Choose a platform to build TF-A for. The chosen platform name
528   must be subdirectory of any depth under ``plat/``, and must contain a
529   platform makefile named ``platform.mk``. For example, to build TF-A for the
530   Arm Juno board, select PLAT=juno.
531
532-  ``PRELOADED_BL33_BASE``: This option enables booting a preloaded BL33 image
533   instead of the normal boot flow. When defined, it must specify the entry
534   point address for the preloaded BL33 image. This option is incompatible with
535   ``EL3_PAYLOAD_BASE``. If both are defined, ``EL3_PAYLOAD_BASE`` has priority
536   over ``PRELOADED_BL33_BASE``.
537
538-  ``PROGRAMMABLE_RESET_ADDRESS``: This option indicates whether the reset
539   vector address can be programmed or is fixed on the platform. It can take
540   either 0 (fixed) or 1 (programmable). Default is 0. If the platform has a
541   programmable reset address, it is expected that a CPU will start executing
542   code directly at the right address, both on a cold and warm reset. In this
543   case, there is no need to identify the entrypoint on boot and the boot path
544   can be optimised. The ``plat_get_my_entrypoint()`` platform porting interface
545   does not need to be implemented in this case.
546
547-  ``PSCI_EXTENDED_STATE_ID``: As per PSCI1.0 Specification, there are 2 formats
548   possible for the PSCI power-state parameter: original and extended State-ID
549   formats. This flag if set to 1, configures the generic PSCI layer to use the
550   extended format. The default value of this flag is 0, which means by default
551   the original power-state format is used by the PSCI implementation. This flag
552   should be specified by the platform makefile and it governs the return value
553   of PSCI_FEATURES API for CPU_SUSPEND smc function id. When this option is
554   enabled on Arm platforms, the option ``ARM_RECOM_STATE_ID_ENC`` needs to be
555   set to 1 as well.
556
557-  ``RAS_EXTENSION``: When set to ``1``, enable Armv8.2 RAS features. RAS features
558   are an optional extension for pre-Armv8.2 CPUs, but are mandatory for Armv8.2
559   or later CPUs.
560
561   When ``RAS_EXTENSION`` is set to ``1``, ``HANDLE_EA_EL3_FIRST`` must also be
562   set to ``1``.
563
564   This option is disabled by default.
565
566-  ``RESET_TO_BL31``: Enable BL31 entrypoint as the CPU reset vector instead
567   of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1
568   entrypoint) or 1 (CPU reset to BL31 entrypoint).
569   The default value is 0.
570
571-  ``RESET_TO_SP_MIN``: SP_MIN is the minimal AArch32 Secure Payload provided
572   in TF-A. This flag configures SP_MIN entrypoint as the CPU reset vector
573   instead of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1
574   entrypoint) or 1 (CPU reset to SP_MIN entrypoint). The default value is 0.
575
576-  ``ROT_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the
577   file that contains the ROT private key in PEM format and enforces public key
578   hash generation. If ``SAVE_KEYS=1``, this
579   file name will be used to save the key.
580
581-  ``SAVE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the
582   certificate generation tool to save the keys used to establish the Chain of
583   Trust. Allowed options are '0' or '1'. Default is '0' (do not save).
584
585-  ``SCP_BL2``: Path to SCP_BL2 image in the host file system. This image is optional.
586   If a SCP_BL2 image is present then this option must be passed for the ``fip``
587   target.
588
589-  ``SCP_BL2_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the
590   file that contains the SCP_BL2 private key in PEM format. If ``SAVE_KEYS=1``,
591   this file name will be used to save the key.
592
593-  ``SCP_BL2U``: Path to SCP_BL2U image in the host file system. This image is
594   optional. It is only needed if the platform makefile specifies that it
595   is required in order to build the ``fwu_fip`` target.
596
597-  ``SDEI_SUPPORT``: Setting this to ``1`` enables support for Software
598   Delegated Exception Interface to BL31 image. This defaults to ``0``.
599
600   When set to ``1``, the build option ``EL3_EXCEPTION_HANDLING`` must also be
601   set to ``1``.
602
603-  ``SEPARATE_CODE_AND_RODATA``: Whether code and read-only data should be
604   isolated on separate memory pages. This is a trade-off between security and
605   memory usage. See "Isolating code and read-only data on separate memory
606   pages" section in :ref:`Firmware Design`. This flag is disabled by default
607   and affects all BL images.
608
609-  ``SEPARATE_NOBITS_REGION``: Setting this option to ``1`` allows the NOBITS
610   sections of BL31 (.bss, stacks, page tables, and coherent memory) to be
611   allocated in RAM discontiguous from the loaded firmware image. When set, the
612   platform is expected to provide definitions for ``BL31_NOBITS_BASE`` and
613   ``BL31_NOBITS_LIMIT``. When the option is ``0`` (the default), NOBITS
614   sections are placed in RAM immediately following the loaded firmware image.
615
616-  ``SMC_PCI_SUPPORT``: This option allows platforms to handle PCI configuration
617   access requests via a standard SMCCC defined in `DEN0115`_. When combined with
618   UEFI+ACPI this can provide a certain amount of OS forward compatibility
619   with newer platforms that aren't ECAM compliant.
620
621-  ``SPD``: Choose a Secure Payload Dispatcher component to be built into TF-A.
622   This build option is only valid if ``ARCH=aarch64``. The value should be
623   the path to the directory containing the SPD source, relative to
624   ``services/spd/``; the directory is expected to contain a makefile called
625   ``<spd-value>.mk``. The SPM Dispatcher standard service is located in
626   services/std_svc/spmd and enabled by ``SPD=spmd``. The SPM Dispatcher
627   cannot be enabled when the ``SPM_MM`` option is enabled.
628
629-  ``SPIN_ON_BL1_EXIT``: This option introduces an infinite loop in BL1. It can
630   take either 0 (no loop) or 1 (add a loop). 0 is the default. This loop stops
631   execution in BL1 just before handing over to BL31. At this point, all
632   firmware images have been loaded in memory, and the MMU and caches are
633   turned off. Refer to the "Debugging options" section for more details.
634
635-  ``SPMD_SPM_AT_SEL2`` : this boolean option is used jointly with the SPM
636   Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC
637   component runs at the S-EL2 execution state provided by the Armv8.4-SecEL2
638   extension. This is the default when enabling the SPM Dispatcher. When
639   disabled (0) it indicates the SPMC component runs at the S-EL1 execution
640   state. This latter configuration supports pre-Armv8.4 platforms (aka not
641   implementing the Armv8.4-SecEL2 extension).
642
643-  ``SPM_MM`` : Boolean option to enable the Management Mode (MM)-based Secure
644   Partition Manager (SPM) implementation. The default value is ``0``
645   (disabled). This option cannot be enabled (``1``) when SPM Dispatcher is
646   enabled (``SPD=spmd``).
647
648-  ``SP_LAYOUT_FILE``: Platform provided path to JSON file containing the
649   description of secure partitions. The build system will parse this file and
650   package all secure partition blobs into the FIP. This file is not
651   necessarily part of TF-A tree. Only available when ``SPD=spmd``.
652
653-  ``SP_MIN_WITH_SECURE_FIQ``: Boolean flag to indicate the SP_MIN handles
654   secure interrupts (caught through the FIQ line). Platforms can enable
655   this directive if they need to handle such interruption. When enabled,
656   the FIQ are handled in monitor mode and non secure world is not allowed
657   to mask these events. Platforms that enable FIQ handling in SP_MIN shall
658   implement the api ``sp_min_plat_fiq_handler()``. The default value is 0.
659
660-  ``TRUSTED_BOARD_BOOT``: Boolean flag to include support for the Trusted Board
661   Boot feature. When set to '1', BL1 and BL2 images include support to load
662   and verify the certificates and images in a FIP, and BL1 includes support
663   for the Firmware Update. The default value is '0'. Generation and inclusion
664   of certificates in the FIP and FWU_FIP depends upon the value of the
665   ``GENERATE_COT`` option.
666
667   .. warning::
668      This option depends on ``CREATE_KEYS`` to be enabled. If the keys
669      already exist in disk, they will be overwritten without further notice.
670
671-  ``TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It
672   specifies the file that contains the Trusted World private key in PEM
673   format. If ``SAVE_KEYS=1``, this file name will be used to save the key.
674
675-  ``TSP_INIT_ASYNC``: Choose BL32 initialization method as asynchronous or
676   synchronous, (see "Initializing a BL32 Image" section in
677   :ref:`Firmware Design`). It can take the value 0 (BL32 is initialized using
678   synchronous method) or 1 (BL32 is initialized using asynchronous method).
679   Default is 0.
680
681-  ``TSP_NS_INTR_ASYNC_PREEMPT``: A non zero value enables the interrupt
682   routing model which routes non-secure interrupts asynchronously from TSP
683   to EL3 causing immediate preemption of TSP. The EL3 is responsible
684   for saving and restoring the TSP context in this routing model. The
685   default routing model (when the value is 0) is to route non-secure
686   interrupts to TSP allowing it to save its context and hand over
687   synchronously to EL3 via an SMC.
688
689   .. note::
690      When ``EL3_EXCEPTION_HANDLING`` is ``1``, ``TSP_NS_INTR_ASYNC_PREEMPT``
691      must also be set to ``1``.
692
693-  ``USE_ARM_LINK``: This flag determines whether to enable support for ARM
694   linker. When the ``LINKER`` build variable points to the armlink linker,
695   this flag is enabled automatically. To enable support for armlink, platforms
696   will have to provide a scatter file for the BL image. Currently, Tegra
697   platforms use the armlink support to compile BL3-1 images.
698
699-  ``USE_COHERENT_MEM``: This flag determines whether to include the coherent
700   memory region in the BL memory map or not (see "Use of Coherent memory in
701   TF-A" section in :ref:`Firmware Design`). It can take the value 1
702   (Coherent memory region is included) or 0 (Coherent memory region is
703   excluded). Default is 1.
704
705-  ``USE_DEBUGFS``: When set to 1 this option activates an EXPERIMENTAL feature
706   exposing a virtual filesystem interface through BL31 as a SiP SMC function.
707   Default is 0.
708
709-  ``ARM_IO_IN_DTB``: This flag determines whether to use IO based on the
710   firmware configuration framework. This will move the io_policies into a
711   configuration device tree, instead of static structure in the code base.
712
713-  ``COT_DESC_IN_DTB``: This flag determines whether to create COT descriptors
714   at runtime using fconf. If this flag is enabled, COT descriptors are
715   statically captured in tb_fw_config file in the form of device tree nodes
716   and properties. Currently, COT descriptors used by BL2 are moved to the
717   device tree and COT descriptors used by BL1 are retained in the code
718   base statically.
719
720-  ``SDEI_IN_FCONF``: This flag determines whether to configure SDEI setup in
721   runtime using firmware configuration framework. The platform specific SDEI
722   shared and private events configuration is retrieved from device tree rather
723   than static C structures at compile time. This is only supported if
724   SDEI_SUPPORT build flag is enabled.
725
726-  ``SEC_INT_DESC_IN_FCONF``: This flag determines whether to configure Group 0
727   and Group1 secure interrupts using the firmware configuration framework. The
728   platform specific secure interrupt property descriptor is retrieved from
729   device tree in runtime rather than depending on static C structure at compile
730   time.
731
732-  ``USE_ROMLIB``: This flag determines whether library at ROM will be used.
733   This feature creates a library of functions to be placed in ROM and thus
734   reduces SRAM usage. Refer to :ref:`Library at ROM` for further details. Default
735   is 0.
736
737-  ``V``: Verbose build. If assigned anything other than 0, the build commands
738   are printed. Default is 0.
739
740-  ``VERSION_STRING``: String used in the log output for each TF-A image.
741   Defaults to a string formed by concatenating the version number, build type
742   and build string.
743
744-  ``W``: Warning level. Some compiler warning options of interest have been
745   regrouped and put in the root Makefile. This flag can take the values 0 to 3,
746   each level enabling more warning options. Default is 0.
747
748-  ``WARMBOOT_ENABLE_DCACHE_EARLY`` : Boolean option to enable D-cache early on
749   the CPU after warm boot. This is applicable for platforms which do not
750   require interconnect programming to enable cache coherency (eg: single
751   cluster platforms). If this option is enabled, then warm boot path
752   enables D-caches immediately after enabling MMU. This option defaults to 0.
753
754-  ``SUPPORT_STACK_MEMTAG``: This flag determines whether to enable memory
755   tagging for stack or not. It accepts 2 values: ``yes`` and ``no``. The
756   default value of this flag is ``no``. Note this option must be enabled only
757   for ARM architecture greater than Armv8.5-A.
758
759-  ``ERRATA_SPECULATIVE_AT``: This flag determines whether to enable ``AT``
760   speculative errata workaround or not. It accepts 2 values: ``1`` and ``0``.
761   The default value of this flag is ``0``.
762
763   ``AT`` speculative errata workaround disables stage1 page table walk for
764   lower ELs (EL1 and EL0) in EL3 so that ``AT`` speculative fetch at any point
765   produces either the correct result or failure without TLB allocation.
766
767   This boolean option enables errata for all below CPUs.
768
769   +---------+--------------+-------------------------+
770   | Errata  |      CPU     |     Workaround Define   |
771   +=========+==============+=========================+
772   | 1165522 |  Cortex-A76  |  ``ERRATA_A76_1165522`` |
773   +---------+--------------+-------------------------+
774   | 1319367 |  Cortex-A72  |  ``ERRATA_A72_1319367`` |
775   +---------+--------------+-------------------------+
776   | 1319537 |  Cortex-A57  |  ``ERRATA_A57_1319537`` |
777   +---------+--------------+-------------------------+
778   | 1530923 |  Cortex-A55  |  ``ERRATA_A55_1530923`` |
779   +---------+--------------+-------------------------+
780   | 1530924 |  Cortex-A53  |  ``ERRATA_A53_1530924`` |
781   +---------+--------------+-------------------------+
782
783   .. note::
784      This option is enabled by build only if platform sets any of above defines
785      mentioned in ’Workaround Define' column in the table.
786      If this option is enabled for the EL3 software then EL2 software also must
787      implement this workaround due to the behaviour of the errata mentioned
788      in new SDEN document which will get published soon.
789
790- ``RAS_TRAP_LOWER_EL_ERR_ACCESS``: This flag enables/disables the SCR_EL3.TERR
791  bit, to trap access to the RAS ERR and RAS ERX registers from lower ELs.
792  This flag is disabled by default.
793
794- ``OPENSSL_DIR``: This flag is used to provide the installed openssl directory
795  path on the host machine which is used to build certificate generation and
796  firmware encryption tool.
797
798- ``USE_SP804_TIMER``: Use the SP804 timer instead of the Generic Timer for
799  functions that wait for an arbitrary time length (udelay and mdelay). The
800  default value is 0.
801
802- ``ENABLE_TRBE_FOR_NS``: This flag is used to enable access of trace buffer
803  control registers from NS ELs, NS-EL2 or NS-EL1(when NS-EL2 is implemented
804  but unused) when FEAT_TRBE is implemented. TRBE is an optional architectural
805  feature for AArch64. The default is 0 and it is automatically disabled when
806  the target architecture is AArch32.
807
808- ``ENABLE_SYS_REG_TRACE_FOR_NS``: Boolean option to enable trace system
809  registers access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented
810  but unused). This feature is available if trace unit such as ETMv4.x, and
811  ETE(extending ETM feature) is implemented. This flag is disabled by default.
812
813- ``ENABLE_TRF_FOR_NS``: Boolean option to enable trace filter control registers
814  access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented but unused),
815  if FEAT_TRF is implemented. This flag is disabled by default.
816
817GICv3 driver options
818--------------------
819
820GICv3 driver files are included using directive:
821
822``include drivers/arm/gic/v3/gicv3.mk``
823
824The driver can be configured with the following options set in the platform
825makefile:
826
827-  ``GICV3_SUPPORT_GIC600``: Add support for the GIC-600 variants of GICv3.
828   Enabling this option will add runtime detection support for the
829   GIC-600, so is safe to select even for a GIC500 implementation.
830   This option defaults to 0.
831
832- ``GICV3_SUPPORT_GIC600AE_FMU``: Add support for the Fault Management Unit
833   for GIC-600 AE. Enabling this option will introduce support to initialize
834   the FMU. Platforms should call the init function during boot to enable the
835   FMU and its safety mechanisms. This option defaults to 0.
836
837-  ``GICV3_IMPL_GIC600_MULTICHIP``: Selects GIC-600 variant with multichip
838   functionality. This option defaults to 0
839
840-  ``GICV3_OVERRIDE_DISTIF_PWR_OPS``: Allows override of default implementation
841   of ``arm_gicv3_distif_pre_save`` and ``arm_gicv3_distif_post_restore``
842   functions. This is required for FVP platform which need to simulate GIC save
843   and restore during SYSTEM_SUSPEND without powering down GIC. Default is 0.
844
845-  ``GIC_ENABLE_V4_EXTN`` : Enables GICv4 related changes in GICv3 driver.
846   This option defaults to 0.
847
848-  ``GIC_EXT_INTID``: When set to ``1``, GICv3 driver will support extended
849   PPI (1056-1119) and SPI (4096-5119) range. This option defaults to 0.
850
851Debugging options
852-----------------
853
854To compile a debug version and make the build more verbose use
855
856.. code:: shell
857
858    make PLAT=<platform> DEBUG=1 V=1 all
859
860AArch64 GCC uses DWARF version 4 debugging symbols by default. Some tools (for
861example DS-5) might not support this and may need an older version of DWARF
862symbols to be emitted by GCC. This can be achieved by using the
863``-gdwarf-<version>`` flag, with the version being set to 2 or 3. Setting the
864version to 2 is recommended for DS-5 versions older than 5.16.
865
866When debugging logic problems it might also be useful to disable all compiler
867optimizations by using ``-O0``.
868
869.. warning::
870   Using ``-O0`` could cause output images to be larger and base addresses
871   might need to be recalculated (see the **Memory layout on Arm development
872   platforms** section in the :ref:`Firmware Design`).
873
874Extra debug options can be passed to the build system by setting ``CFLAGS`` or
875``LDFLAGS``:
876
877.. code:: shell
878
879    CFLAGS='-O0 -gdwarf-2'                                     \
880    make PLAT=<platform> DEBUG=1 V=1 all
881
882Note that using ``-Wl,`` style compilation driver options in ``CFLAGS`` will be
883ignored as the linker is called directly.
884
885It is also possible to introduce an infinite loop to help in debugging the
886post-BL2 phase of TF-A. This can be done by rebuilding BL1 with the
887``SPIN_ON_BL1_EXIT=1`` build flag. Refer to the :ref:`build_options_common`
888section. In this case, the developer may take control of the target using a
889debugger when indicated by the console output. When using DS-5, the following
890commands can be used:
891
892::
893
894    # Stop target execution
895    interrupt
896
897    #
898    # Prepare your debugging environment, e.g. set breakpoints
899    #
900
901    # Jump over the debug loop
902    set var $AARCH64::$Core::$PC = $AARCH64::$Core::$PC + 4
903
904    # Resume execution
905    continue
906
907Firmware update options
908-----------------------
909
910-  ``NR_OF_FW_BANKS``: Define the number of firmware banks. This flag is used
911   in defining the firmware update metadata structure. This flag is by default
912   set to '2'.
913
914-  ``NR_OF_IMAGES_IN_FW_BANK``: Define the number of firmware images in each
915   firmware bank. Each firmware bank must have the same number of images as per
916   the `PSA FW update specification`_.
917   This flag is used in defining the firmware update metadata structure. This
918   flag is by default set to '1'.
919
920-  ``PSA_FWU_SUPPORT``: Enable the firmware update mechanism as per the
921   `PSA FW update specification`_. The default value is 0, and this is an
922   experimental feature.
923   PSA firmware update implementation has some limitations, such as BL2 is
924   not part of the protocol-updatable images, if BL2 needs to be updated, then
925   it should be done through another platform-defined mechanism, and it assumes
926   that the platform's hardware supports CRC32 instructions.
927
928--------------
929
930*Copyright (c) 2019-2021, Arm Limited. All rights reserved.*
931
932.. _DEN0115: https://developer.arm.com/docs/den0115/latest
933.. _PSA FW update specification: https://developer.arm.com/documentation/den0118/a/
934