xref: /rk3399_ARM-atf/docs/getting_started/build-options.rst (revision 5b18de09e80f87963df9a2e451c47e2321b8643a)
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 and this is an experimental feature.
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 and this is an experimental feature.
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. Also, it is an experimental feature.
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_ASSERTIONS``: This option controls whether or not calls to ``assert()``
224   are compiled out. For debug builds, this option defaults to 1, and calls to
225   ``assert()`` are left in place. For release builds, this option defaults to 0
226   and calls to ``assert()`` function are compiled out. This option can be set
227   independently of ``DEBUG``. It can also be used to hide any auxiliary code
228   that is only required for the assertion and does not fit in the assertion
229   itself.
230
231-  ``ENABLE_BACKTRACE``: This option controls whether to enable backtrace
232   dumps or not. It is supported in both AArch64 and AArch32. However, in
233   AArch32 the format of the frame records are not defined in the AAPCS and they
234   are defined by the implementation. This implementation of backtrace only
235   supports the format used by GCC when T32 interworking is disabled. For this
236   reason enabling this option in AArch32 will force the compiler to only
237   generate A32 code. This option is enabled by default only in AArch64 debug
238   builds, but this behaviour can be overridden in each platform's Makefile or
239   in the build command line.
240
241-  ``ENABLE_FEAT_HCX``: This option sets the bit SCR_EL3.HXEn in EL3 to allow
242   access to HCRX_EL2 (extended hypervisor control register) from EL2 as well as
243   adding HCRX_EL2 to the EL2 context save/restore operations.
244
245-  ``ENABLE_LTO``: Boolean option to enable Link Time Optimization (LTO)
246   support in GCC for TF-A. This option is currently only supported for
247   AArch64. Default is 0.
248
249-  ``ENABLE_MPAM_FOR_LOWER_ELS``: Boolean option to enable lower ELs to use MPAM
250   feature. MPAM is an optional Armv8.4 extension that enables various memory
251   system components and resources to define partitions; software running at
252   various ELs can assign themselves to desired partition to control their
253   performance aspects.
254
255   When this option is set to ``1``, EL3 allows lower ELs to access their own
256   MPAM registers without trapping into EL3. This option doesn't make use of
257   partitioning in EL3, however. Platform initialisation code should configure
258   and use partitions in EL3 as required. This option defaults to ``0``.
259
260-  ``ENABLE_PIE``: Boolean option to enable Position Independent Executable(PIE)
261   support within generic code in TF-A. This option is currently only supported
262   in BL2_AT_EL3, BL31, and BL32 (TSP) for AARCH64 binaries, and in BL32
263   (SP_min) for AARCH32. Default is 0.
264
265-  ``ENABLE_PMF``: Boolean option to enable support for optional Performance
266   Measurement Framework(PMF). Default is 0.
267
268-  ``ENABLE_PSCI_STAT``: Boolean option to enable support for optional PSCI
269   functions ``PSCI_STAT_RESIDENCY`` and ``PSCI_STAT_COUNT``. Default is 0.
270   In the absence of an alternate stat collection backend, ``ENABLE_PMF`` must
271   be enabled. If ``ENABLE_PMF`` is set, the residency statistics are tracked in
272   software.
273
274- ``ENABLE_RME``: Boolean option to enable support for the ARMv9 Realm
275   Management Extension. Default value is 0. This is currently an experimental
276   feature.
277
278-  ``ENABLE_RUNTIME_INSTRUMENTATION``: Boolean option to enable runtime
279   instrumentation which injects timestamp collection points into TF-A to
280   allow runtime performance to be measured. Currently, only PSCI is
281   instrumented. Enabling this option enables the ``ENABLE_PMF`` build option
282   as well. Default is 0.
283
284-  ``ENABLE_SPE_FOR_LOWER_ELS`` : Boolean option to enable Statistical Profiling
285   extensions. This is an optional architectural feature for AArch64.
286   The default is 1 but is automatically disabled when the target architecture
287   is AArch32.
288
289-  ``ENABLE_SVE_FOR_NS``: Boolean option to enable Scalable Vector Extension
290   (SVE) for the Non-secure world only. SVE is an optional architectural feature
291   for AArch64. Note that when SVE is enabled for the Non-secure world, access
292   to SIMD and floating-point functionality from the Secure world is disabled by
293   default and controlled with ENABLE_SVE_FOR_SWD.
294   This is to avoid corruption of the Non-secure world data in the Z-registers
295   which are aliased by the SIMD and FP registers. The build option is not
296   compatible with the ``CTX_INCLUDE_FPREGS`` build option, and will raise an
297   assert on platforms where SVE is implemented and ``ENABLE_SVE_FOR_NS`` set to
298   1. The default is 1 but is automatically disabled when the target
299   architecture is AArch32.
300
301-  ``ENABLE_SVE_FOR_SWD``: Boolean option to enable SVE for the Secure world.
302   SVE is an optional architectural feature for AArch64. Note that this option
303   requires ENABLE_SVE_FOR_NS to be enabled.  The default is 0 and it is
304   automatically disabled when the target architecture is AArch32.
305
306-  ``ENABLE_STACK_PROTECTOR``: String option to enable the stack protection
307   checks in GCC. Allowed values are "all", "strong", "default" and "none". The
308   default value is set to "none". "strong" is the recommended stack protection
309   level if this feature is desired. "none" disables the stack protection. For
310   all values other than "none", the ``plat_get_stack_protector_canary()``
311   platform hook needs to be implemented. The value is passed as the last
312   component of the option ``-fstack-protector-$ENABLE_STACK_PROTECTOR``.
313
314-  ``ENCRYPT_BL31``: Binary flag to enable encryption of BL31 firmware. This
315   flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as
316   experimental.
317
318-  ``ENCRYPT_BL32``: Binary flag to enable encryption of Secure BL32 payload.
319   This flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as
320   experimental.
321
322-  ``ENC_KEY``: A 32-byte (256-bit) symmetric key in hex string format. It could
323   either be SSK or BSSK depending on ``FW_ENC_STATUS`` flag. This value depends
324   on ``DECRYPTION_SUPPORT`` build flag which is marked as experimental.
325
326-  ``ENC_NONCE``: A 12-byte (96-bit) encryption nonce or Initialization Vector
327   (IV) in hex string format. This value depends on ``DECRYPTION_SUPPORT``
328   build flag which is marked as experimental.
329
330-  ``ERROR_DEPRECATED``: This option decides whether to treat the usage of
331   deprecated platform APIs, helper functions or drivers within Trusted
332   Firmware as error. It can take the value 1 (flag the use of deprecated
333   APIs as error) or 0. The default is 0.
334
335-  ``EL3_EXCEPTION_HANDLING``: When set to ``1``, enable handling of exceptions
336   targeted at EL3. When set ``0`` (default), no exceptions are expected or
337   handled at EL3, and a panic will result. This is supported only for AArch64
338   builds.
339
340-  ``EVENT_LOG_LEVEL``: Chooses the log level to use for Measured Boot when
341   ``MEASURED_BOOT`` is enabled. For a list of valid values, see ``LOG_LEVEL``.
342   Default value is 40 (LOG_LEVEL_INFO).
343
344-  ``FAULT_INJECTION_SUPPORT``: ARMv8.4 extensions introduced support for fault
345   injection from lower ELs, and this build option enables lower ELs to use
346   Error Records accessed via System Registers to inject faults. This is
347   applicable only to AArch64 builds.
348
349   This feature is intended for testing purposes only, and is advisable to keep
350   disabled for production images.
351
352-  ``FIP_NAME``: This is an optional build option which specifies the FIP
353   filename for the ``fip`` target. Default is ``fip.bin``.
354
355-  ``FWU_FIP_NAME``: This is an optional build option which specifies the FWU
356   FIP filename for the ``fwu_fip`` target. Default is ``fwu_fip.bin``.
357
358-  ``FW_ENC_STATUS``: Top level firmware's encryption numeric flag, values:
359
360   ::
361
362     0: Encryption is done with Secret Symmetric Key (SSK) which is common
363        for a class of devices.
364     1: Encryption is done with Binding Secret Symmetric Key (BSSK) which is
365        unique per device.
366
367   This flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as
368   experimental.
369
370-  ``GENERATE_COT``: Boolean flag used to build and execute the ``cert_create``
371   tool to create certificates as per the Chain of Trust described in
372   :ref:`Trusted Board Boot`. The build system then calls ``fiptool`` to
373   include the certificates in the FIP and FWU_FIP. Default value is '0'.
374
375   Specify both ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=1`` to include support
376   for the Trusted Board Boot feature in the BL1 and BL2 images, to generate
377   the corresponding certificates, and to include those certificates in the
378   FIP and FWU_FIP.
379
380   Note that if ``TRUSTED_BOARD_BOOT=0`` and ``GENERATE_COT=1``, the BL1 and BL2
381   images will not include support for Trusted Board Boot. The FIP will still
382   include the corresponding certificates. This FIP can be used to verify the
383   Chain of Trust on the host machine through other mechanisms.
384
385   Note that if ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=0``, the BL1 and BL2
386   images will include support for Trusted Board Boot, but the FIP and FWU_FIP
387   will not include the corresponding certificates, causing a boot failure.
388
389-  ``GICV2_G0_FOR_EL3``: Unlike GICv3, the GICv2 architecture doesn't have
390   inherent support for specific EL3 type interrupts. Setting this build option
391   to ``1`` assumes GICv2 *Group 0* interrupts are expected to target EL3, both
392   by :ref:`platform abstraction layer<platform Interrupt Controller API>` and
393   :ref:`Interrupt Management Framework<Interrupt Management Framework>`.
394   This allows GICv2 platforms to enable features requiring EL3 interrupt type.
395   This also means that all GICv2 Group 0 interrupts are delivered to EL3, and
396   the Secure Payload interrupts needs to be synchronously handed over to Secure
397   EL1 for handling. The default value of this option is ``0``, which means the
398   Group 0 interrupts are assumed to be handled by Secure EL1.
399
400-  ``HANDLE_EA_EL3_FIRST``: When set to ``1``, External Aborts and SError
401   Interrupts will be always trapped in EL3 i.e. in BL31 at runtime. When set to
402   ``0`` (default), these exceptions will be trapped in the current exception
403   level (or in EL1 if the current exception level is EL0).
404
405-  ``HW_ASSISTED_COHERENCY``: On most Arm systems to-date, platform-specific
406   software operations are required for CPUs to enter and exit coherency.
407   However, newer systems exist where CPUs' entry to and exit from coherency
408   is managed in hardware. Such systems require software to only initiate these
409   operations, and the rest is managed in hardware, minimizing active software
410   management. In such systems, this boolean option enables TF-A to carry out
411   build and run-time optimizations during boot and power management operations.
412   This option defaults to 0 and if it is enabled, then it implies
413   ``WARMBOOT_ENABLE_DCACHE_EARLY`` is also enabled.
414
415   If this flag is disabled while the platform which TF-A is compiled for
416   includes cores that manage coherency in hardware, then a compilation error is
417   generated. This is based on the fact that a system cannot have, at the same
418   time, cores that manage coherency in hardware and cores that don't. In other
419   words, a platform cannot have, at the same time, cores that require
420   ``HW_ASSISTED_COHERENCY=1`` and cores that require
421   ``HW_ASSISTED_COHERENCY=0``.
422
423   Note that, when ``HW_ASSISTED_COHERENCY`` is enabled, version 2 of
424   translation library (xlat tables v2) must be used; version 1 of translation
425   library is not supported.
426
427-  ``INVERTED_MEMMAP``: memmap tool print by default lower addresses at the
428   bottom, higher addresses at the top. This build flag can be set to '1' to
429   invert this behavior. Lower addresses will be printed at the top and higher
430   addresses at the bottom.
431
432-  ``JUNO_AARCH32_EL3_RUNTIME``: This build flag enables you to execute EL3
433   runtime software in AArch32 mode, which is required to run AArch32 on Juno.
434   By default this flag is set to '0'. Enabling this flag builds BL1 and BL2 in
435   AArch64 and facilitates the loading of ``SP_MIN`` and BL33 as AArch32 executable
436   images.
437
438-  ``KEY_ALG``: This build flag enables the user to select the algorithm to be
439   used for generating the PKCS keys and subsequent signing of the certificate.
440   It accepts 3 values: ``rsa``, ``rsa_1_5`` and ``ecdsa``. The option
441   ``rsa_1_5`` is the legacy PKCS#1 RSA 1.5 algorithm which is not TBBR
442   compliant and is retained only for compatibility. The default value of this
443   flag is ``rsa`` which is the TBBR compliant PKCS#1 RSA 2.1 scheme.
444
445-  ``KEY_SIZE``: This build flag enables the user to select the key size for
446   the algorithm specified by ``KEY_ALG``. The valid values for ``KEY_SIZE``
447   depend on the chosen algorithm and the cryptographic module.
448
449   +-----------+------------------------------------+
450   |  KEY_ALG  |        Possible key sizes          |
451   +===========+====================================+
452   |    rsa    | 1024 , 2048 (default), 3072, 4096* |
453   +-----------+------------------------------------+
454   |   ecdsa   |            unavailable             |
455   +-----------+------------------------------------+
456
457   * Only 2048 bits size is available with CryptoCell 712 SBROM release 1.
458     Only 3072 bits size is available with CryptoCell 712 SBROM release 2.
459
460-  ``HASH_ALG``: This build flag enables the user to select the secure hash
461   algorithm. It accepts 3 values: ``sha256``, ``sha384`` and ``sha512``.
462   The default value of this flag is ``sha256``.
463
464-  ``LDFLAGS``: Extra user options appended to the linkers' command line in
465   addition to the one set by the build system.
466
467-  ``LOG_LEVEL``: Chooses the log level, which controls the amount of console log
468   output compiled into the build. This should be one of the following:
469
470   ::
471
472       0  (LOG_LEVEL_NONE)
473       10 (LOG_LEVEL_ERROR)
474       20 (LOG_LEVEL_NOTICE)
475       30 (LOG_LEVEL_WARNING)
476       40 (LOG_LEVEL_INFO)
477       50 (LOG_LEVEL_VERBOSE)
478
479   All log output up to and including the selected log level is compiled into
480   the build. The default value is 40 in debug builds and 20 in release builds.
481
482-  ``MEASURED_BOOT``: Boolean flag to include support for the Measured Boot
483   feature. If this flag is enabled ``TRUSTED_BOARD_BOOT`` must be set as well
484   in order to provide trust that the code taking the measurements and recording
485   them has not been tampered with.
486
487   This option defaults to 0 and is an experimental feature in the stage of
488   development.
489
490-  ``NON_TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It
491   specifies the file that contains the Non-Trusted World private key in PEM
492   format. If ``SAVE_KEYS=1``, this file name will be used to save the key.
493
494-  ``NS_BL2U``: Path to NS_BL2U image in the host file system. This image is
495   optional. It is only needed if the platform makefile specifies that it
496   is required in order to build the ``fwu_fip`` target.
497
498-  ``NS_TIMER_SWITCH``: Enable save and restore for non-secure timer register
499   contents upon world switch. It can take either 0 (don't save and restore) or
500   1 (do save and restore). 0 is the default. An SPD may set this to 1 if it
501   wants the timer registers to be saved and restored.
502
503-  ``OVERRIDE_LIBC``: This option allows platforms to override the default libc
504   for the BL image. It can be either 0 (include) or 1 (remove). The default
505   value is 0.
506
507-  ``PL011_GENERIC_UART``: Boolean option to indicate the PL011 driver that
508   the underlying hardware is not a full PL011 UART but a minimally compliant
509   generic UART, which is a subset of the PL011. The driver will not access
510   any register that is not part of the SBSA generic UART specification.
511   Default value is 0 (a full PL011 compliant UART is present).
512
513-  ``PLAT``: Choose a platform to build TF-A for. The chosen platform name
514   must be subdirectory of any depth under ``plat/``, and must contain a
515   platform makefile named ``platform.mk``. For example, to build TF-A for the
516   Arm Juno board, select PLAT=juno.
517
518-  ``PRELOADED_BL33_BASE``: This option enables booting a preloaded BL33 image
519   instead of the normal boot flow. When defined, it must specify the entry
520   point address for the preloaded BL33 image. This option is incompatible with
521   ``EL3_PAYLOAD_BASE``. If both are defined, ``EL3_PAYLOAD_BASE`` has priority
522   over ``PRELOADED_BL33_BASE``.
523
524-  ``PROGRAMMABLE_RESET_ADDRESS``: This option indicates whether the reset
525   vector address can be programmed or is fixed on the platform. It can take
526   either 0 (fixed) or 1 (programmable). Default is 0. If the platform has a
527   programmable reset address, it is expected that a CPU will start executing
528   code directly at the right address, both on a cold and warm reset. In this
529   case, there is no need to identify the entrypoint on boot and the boot path
530   can be optimised. The ``plat_get_my_entrypoint()`` platform porting interface
531   does not need to be implemented in this case.
532
533-  ``PSCI_EXTENDED_STATE_ID``: As per PSCI1.0 Specification, there are 2 formats
534   possible for the PSCI power-state parameter: original and extended State-ID
535   formats. This flag if set to 1, configures the generic PSCI layer to use the
536   extended format. The default value of this flag is 0, which means by default
537   the original power-state format is used by the PSCI implementation. This flag
538   should be specified by the platform makefile and it governs the return value
539   of PSCI_FEATURES API for CPU_SUSPEND smc function id. When this option is
540   enabled on Arm platforms, the option ``ARM_RECOM_STATE_ID_ENC`` needs to be
541   set to 1 as well.
542
543-  ``RAS_EXTENSION``: When set to ``1``, enable Armv8.2 RAS features. RAS features
544   are an optional extension for pre-Armv8.2 CPUs, but are mandatory for Armv8.2
545   or later CPUs.
546
547   When ``RAS_EXTENSION`` is set to ``1``, ``HANDLE_EA_EL3_FIRST`` must also be
548   set to ``1``.
549
550   This option is disabled by default.
551
552-  ``RESET_TO_BL31``: Enable BL31 entrypoint as the CPU reset vector instead
553   of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1
554   entrypoint) or 1 (CPU reset to BL31 entrypoint).
555   The default value is 0.
556
557-  ``RESET_TO_SP_MIN``: SP_MIN is the minimal AArch32 Secure Payload provided
558   in TF-A. This flag configures SP_MIN entrypoint as the CPU reset vector
559   instead of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1
560   entrypoint) or 1 (CPU reset to SP_MIN entrypoint). The default value is 0.
561
562-  ``ROT_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the
563   file that contains the ROT private key in PEM format and enforces public key
564   hash generation. If ``SAVE_KEYS=1``, this
565   file name will be used to save the key.
566
567-  ``SAVE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the
568   certificate generation tool to save the keys used to establish the Chain of
569   Trust. Allowed options are '0' or '1'. Default is '0' (do not save).
570
571-  ``SCP_BL2``: Path to SCP_BL2 image in the host file system. This image is optional.
572   If a SCP_BL2 image is present then this option must be passed for the ``fip``
573   target.
574
575-  ``SCP_BL2_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the
576   file that contains the SCP_BL2 private key in PEM format. If ``SAVE_KEYS=1``,
577   this file name will be used to save the key.
578
579-  ``SCP_BL2U``: Path to SCP_BL2U image in the host file system. This image is
580   optional. It is only needed if the platform makefile specifies that it
581   is required in order to build the ``fwu_fip`` target.
582
583-  ``SDEI_SUPPORT``: Setting this to ``1`` enables support for Software
584   Delegated Exception Interface to BL31 image. This defaults to ``0``.
585
586   When set to ``1``, the build option ``EL3_EXCEPTION_HANDLING`` must also be
587   set to ``1``.
588
589-  ``SEPARATE_CODE_AND_RODATA``: Whether code and read-only data should be
590   isolated on separate memory pages. This is a trade-off between security and
591   memory usage. See "Isolating code and read-only data on separate memory
592   pages" section in :ref:`Firmware Design`. This flag is disabled by default
593   and affects all BL images.
594
595-  ``SEPARATE_NOBITS_REGION``: Setting this option to ``1`` allows the NOBITS
596   sections of BL31 (.bss, stacks, page tables, and coherent memory) to be
597   allocated in RAM discontiguous from the loaded firmware image. When set, the
598   platform is expected to provide definitions for ``BL31_NOBITS_BASE`` and
599   ``BL31_NOBITS_LIMIT``. When the option is ``0`` (the default), NOBITS
600   sections are placed in RAM immediately following the loaded firmware image.
601
602-  ``SMC_PCI_SUPPORT``: This option allows platforms to handle PCI configuration
603   access requests via a standard SMCCC defined in `DEN0115`_. When combined with
604   UEFI+ACPI this can provide a certain amount of OS forward compatibility
605   with newer platforms that aren't ECAM compliant.
606
607-  ``SPD``: Choose a Secure Payload Dispatcher component to be built into TF-A.
608   This build option is only valid if ``ARCH=aarch64``. The value should be
609   the path to the directory containing the SPD source, relative to
610   ``services/spd/``; the directory is expected to contain a makefile called
611   ``<spd-value>.mk``. The SPM Dispatcher standard service is located in
612   services/std_svc/spmd and enabled by ``SPD=spmd``. The SPM Dispatcher
613   cannot be enabled when the ``SPM_MM`` option is enabled.
614
615-  ``SPIN_ON_BL1_EXIT``: This option introduces an infinite loop in BL1. It can
616   take either 0 (no loop) or 1 (add a loop). 0 is the default. This loop stops
617   execution in BL1 just before handing over to BL31. At this point, all
618   firmware images have been loaded in memory, and the MMU and caches are
619   turned off. Refer to the "Debugging options" section for more details.
620
621-  ``SPMD_SPM_AT_SEL2`` : this boolean option is used jointly with the SPM
622   Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC
623   component runs at the S-EL2 execution state provided by the Armv8.4-SecEL2
624   extension. This is the default when enabling the SPM Dispatcher. When
625   disabled (0) it indicates the SPMC component runs at the S-EL1 execution
626   state. This latter configuration supports pre-Armv8.4 platforms (aka not
627   implementing the Armv8.4-SecEL2 extension).
628
629-  ``SPM_MM`` : Boolean option to enable the Management Mode (MM)-based Secure
630   Partition Manager (SPM) implementation. The default value is ``0``
631   (disabled). This option cannot be enabled (``1``) when SPM Dispatcher is
632   enabled (``SPD=spmd``).
633
634-  ``SP_LAYOUT_FILE``: Platform provided path to JSON file containing the
635   description of secure partitions. The build system will parse this file and
636   package all secure partition blobs into the FIP. This file is not
637   necessarily part of TF-A tree. Only available when ``SPD=spmd``.
638
639-  ``SP_MIN_WITH_SECURE_FIQ``: Boolean flag to indicate the SP_MIN handles
640   secure interrupts (caught through the FIQ line). Platforms can enable
641   this directive if they need to handle such interruption. When enabled,
642   the FIQ are handled in monitor mode and non secure world is not allowed
643   to mask these events. Platforms that enable FIQ handling in SP_MIN shall
644   implement the api ``sp_min_plat_fiq_handler()``. The default value is 0.
645
646-  ``TRUSTED_BOARD_BOOT``: Boolean flag to include support for the Trusted Board
647   Boot feature. When set to '1', BL1 and BL2 images include support to load
648   and verify the certificates and images in a FIP, and BL1 includes support
649   for the Firmware Update. The default value is '0'. Generation and inclusion
650   of certificates in the FIP and FWU_FIP depends upon the value of the
651   ``GENERATE_COT`` option.
652
653   .. warning::
654      This option depends on ``CREATE_KEYS`` to be enabled. If the keys
655      already exist in disk, they will be overwritten without further notice.
656
657-  ``TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It
658   specifies the file that contains the Trusted World private key in PEM
659   format. If ``SAVE_KEYS=1``, this file name will be used to save the key.
660
661-  ``TSP_INIT_ASYNC``: Choose BL32 initialization method as asynchronous or
662   synchronous, (see "Initializing a BL32 Image" section in
663   :ref:`Firmware Design`). It can take the value 0 (BL32 is initialized using
664   synchronous method) or 1 (BL32 is initialized using asynchronous method).
665   Default is 0.
666
667-  ``TSP_NS_INTR_ASYNC_PREEMPT``: A non zero value enables the interrupt
668   routing model which routes non-secure interrupts asynchronously from TSP
669   to EL3 causing immediate preemption of TSP. The EL3 is responsible
670   for saving and restoring the TSP context in this routing model. The
671   default routing model (when the value is 0) is to route non-secure
672   interrupts to TSP allowing it to save its context and hand over
673   synchronously to EL3 via an SMC.
674
675   .. note::
676      When ``EL3_EXCEPTION_HANDLING`` is ``1``, ``TSP_NS_INTR_ASYNC_PREEMPT``
677      must also be set to ``1``.
678
679-  ``USE_ARM_LINK``: This flag determines whether to enable support for ARM
680   linker. When the ``LINKER`` build variable points to the armlink linker,
681   this flag is enabled automatically. To enable support for armlink, platforms
682   will have to provide a scatter file for the BL image. Currently, Tegra
683   platforms use the armlink support to compile BL3-1 images.
684
685-  ``USE_COHERENT_MEM``: This flag determines whether to include the coherent
686   memory region in the BL memory map or not (see "Use of Coherent memory in
687   TF-A" section in :ref:`Firmware Design`). It can take the value 1
688   (Coherent memory region is included) or 0 (Coherent memory region is
689   excluded). Default is 1.
690
691-  ``USE_DEBUGFS``: When set to 1 this option activates an EXPERIMENTAL feature
692   exposing a virtual filesystem interface through BL31 as a SiP SMC function.
693   Default is 0.
694
695-  ``ARM_IO_IN_DTB``: This flag determines whether to use IO based on the
696   firmware configuration framework. This will move the io_policies into a
697   configuration device tree, instead of static structure in the code base.
698   This is currently an experimental feature.
699
700-  ``COT_DESC_IN_DTB``: This flag determines whether to create COT descriptors
701   at runtime using fconf. If this flag is enabled, COT descriptors are
702   statically captured in tb_fw_config file in the form of device tree nodes
703   and properties. Currently, COT descriptors used by BL2 are moved to the
704   device tree and COT descriptors used by BL1 are retained in the code
705   base statically. This is currently an experimental feature.
706
707-  ``SDEI_IN_FCONF``: This flag determines whether to configure SDEI setup in
708   runtime using firmware configuration framework. The platform specific SDEI
709   shared and private events configuration is retrieved from device tree rather
710   than static C structures at compile time. This is currently an experimental
711   feature and is only supported if SDEI_SUPPORT build flag is enabled.
712
713-  ``SEC_INT_DESC_IN_FCONF``: This flag determines whether to configure Group 0
714   and Group1 secure interrupts using the firmware configuration framework. The
715   platform specific secure interrupt property descriptor is retrieved from
716   device tree in runtime rather than depending on static C structure at compile
717   time. This is currently an experimental feature.
718
719-  ``USE_ROMLIB``: This flag determines whether library at ROM will be used.
720   This feature creates a library of functions to be placed in ROM and thus
721   reduces SRAM usage. Refer to :ref:`Library at ROM` for further details. Default
722   is 0.
723
724-  ``V``: Verbose build. If assigned anything other than 0, the build commands
725   are printed. Default is 0.
726
727-  ``VERSION_STRING``: String used in the log output for each TF-A image.
728   Defaults to a string formed by concatenating the version number, build type
729   and build string.
730
731-  ``W``: Warning level. Some compiler warning options of interest have been
732   regrouped and put in the root Makefile. This flag can take the values 0 to 3,
733   each level enabling more warning options. Default is 0.
734
735-  ``WARMBOOT_ENABLE_DCACHE_EARLY`` : Boolean option to enable D-cache early on
736   the CPU after warm boot. This is applicable for platforms which do not
737   require interconnect programming to enable cache coherency (eg: single
738   cluster platforms). If this option is enabled, then warm boot path
739   enables D-caches immediately after enabling MMU. This option defaults to 0.
740
741-  ``SUPPORT_STACK_MEMTAG``: This flag determines whether to enable memory
742   tagging for stack or not. It accepts 2 values: ``yes`` and ``no``. The
743   default value of this flag is ``no``. Note this option must be enabled only
744   for ARM architecture greater than Armv8.5-A.
745
746-  ``ERRATA_SPECULATIVE_AT``: This flag determines whether to enable ``AT``
747   speculative errata workaround or not. It accepts 2 values: ``1`` and ``0``.
748   The default value of this flag is ``0``.
749
750   ``AT`` speculative errata workaround disables stage1 page table walk for
751   lower ELs (EL1 and EL0) in EL3 so that ``AT`` speculative fetch at any point
752   produces either the correct result or failure without TLB allocation.
753
754   This boolean option enables errata for all below CPUs.
755
756   +---------+--------------+-------------------------+
757   | Errata  |      CPU     |     Workaround Define   |
758   +=========+==============+=========================+
759   | 1165522 |  Cortex-A76  |  ``ERRATA_A76_1165522`` |
760   +---------+--------------+-------------------------+
761   | 1319367 |  Cortex-A72  |  ``ERRATA_A72_1319367`` |
762   +---------+--------------+-------------------------+
763   | 1319537 |  Cortex-A57  |  ``ERRATA_A57_1319537`` |
764   +---------+--------------+-------------------------+
765   | 1530923 |  Cortex-A55  |  ``ERRATA_A55_1530923`` |
766   +---------+--------------+-------------------------+
767   | 1530924 |  Cortex-A53  |  ``ERRATA_A53_1530924`` |
768   +---------+--------------+-------------------------+
769
770   .. note::
771      This option is enabled by build only if platform sets any of above defines
772      mentioned in ’Workaround Define' column in the table.
773      If this option is enabled for the EL3 software then EL2 software also must
774      implement this workaround due to the behaviour of the errata mentioned
775      in new SDEN document which will get published soon.
776
777- ``RAS_TRAP_LOWER_EL_ERR_ACCESS``: This flag enables/disables the SCR_EL3.TERR
778  bit, to trap access to the RAS ERR and RAS ERX registers from lower ELs.
779  This flag is disabled by default.
780
781- ``OPENSSL_DIR``: This flag is used to provide the installed openssl directory
782  path on the host machine which is used to build certificate generation and
783  firmware encryption tool.
784
785- ``USE_SP804_TIMER``: Use the SP804 timer instead of the Generic Timer for
786  functions that wait for an arbitrary time length (udelay and mdelay). The
787  default value is 0.
788
789- ``ENABLE_TRBE_FOR_NS``: This flag is used to enable access of trace buffer
790  control registers from NS ELs, NS-EL2 or NS-EL1(when NS-EL2 is implemented
791  but unused) when FEAT_TRBE is implemented. TRBE is an optional architectural
792  feature for AArch64. The default is 0 and it is automatically disabled when
793  the target architecture is AArch32.
794
795- ``ENABLE_SYS_REG_TRACE_FOR_NS``: Boolean option to enable trace system
796  registers access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented
797  but unused). This feature is available if trace unit such as ETMv4.x, and
798  ETE(extending ETM feature) is implemented. This flag is disabled by default.
799
800- ``ENABLE_TRF_FOR_NS``: Boolean option to enable trace filter control registers
801  access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented but unused),
802  if FEAT_TRF is implemented. This flag is disabled by default.
803
804GICv3 driver options
805--------------------
806
807GICv3 driver files are included using directive:
808
809``include drivers/arm/gic/v3/gicv3.mk``
810
811The driver can be configured with the following options set in the platform
812makefile:
813
814-  ``GICV3_SUPPORT_GIC600``: Add support for the GIC-600 variants of GICv3.
815   Enabling this option will add runtime detection support for the
816   GIC-600, so is safe to select even for a GIC500 implementation.
817   This option defaults to 0.
818
819- ``GICV3_SUPPORT_GIC600AE_FMU``: Add support for the Fault Management Unit
820   for GIC-600 AE. Enabling this option will introduce support to initialize
821   the FMU. Platforms should call the init function during boot to enable the
822   FMU and its safety mechanisms. This option defaults to 0.
823
824-  ``GICV3_IMPL_GIC600_MULTICHIP``: Selects GIC-600 variant with multichip
825   functionality. This option defaults to 0
826
827-  ``GICV3_OVERRIDE_DISTIF_PWR_OPS``: Allows override of default implementation
828   of ``arm_gicv3_distif_pre_save`` and ``arm_gicv3_distif_post_restore``
829   functions. This is required for FVP platform which need to simulate GIC save
830   and restore during SYSTEM_SUSPEND without powering down GIC. Default is 0.
831
832-  ``GIC_ENABLE_V4_EXTN`` : Enables GICv4 related changes in GICv3 driver.
833   This option defaults to 0.
834
835-  ``GIC_EXT_INTID``: When set to ``1``, GICv3 driver will support extended
836   PPI (1056-1119) and SPI (4096-5119) range. This option defaults to 0.
837
838Debugging options
839-----------------
840
841To compile a debug version and make the build more verbose use
842
843.. code:: shell
844
845    make PLAT=<platform> DEBUG=1 V=1 all
846
847AArch64 GCC uses DWARF version 4 debugging symbols by default. Some tools (for
848example DS-5) might not support this and may need an older version of DWARF
849symbols to be emitted by GCC. This can be achieved by using the
850``-gdwarf-<version>`` flag, with the version being set to 2 or 3. Setting the
851version to 2 is recommended for DS-5 versions older than 5.16.
852
853When debugging logic problems it might also be useful to disable all compiler
854optimizations by using ``-O0``.
855
856.. warning::
857   Using ``-O0`` could cause output images to be larger and base addresses
858   might need to be recalculated (see the **Memory layout on Arm development
859   platforms** section in the :ref:`Firmware Design`).
860
861Extra debug options can be passed to the build system by setting ``CFLAGS`` or
862``LDFLAGS``:
863
864.. code:: shell
865
866    CFLAGS='-O0 -gdwarf-2'                                     \
867    make PLAT=<platform> DEBUG=1 V=1 all
868
869Note that using ``-Wl,`` style compilation driver options in ``CFLAGS`` will be
870ignored as the linker is called directly.
871
872It is also possible to introduce an infinite loop to help in debugging the
873post-BL2 phase of TF-A. This can be done by rebuilding BL1 with the
874``SPIN_ON_BL1_EXIT=1`` build flag. Refer to the :ref:`build_options_common`
875section. In this case, the developer may take control of the target using a
876debugger when indicated by the console output. When using DS-5, the following
877commands can be used:
878
879::
880
881    # Stop target execution
882    interrupt
883
884    #
885    # Prepare your debugging environment, e.g. set breakpoints
886    #
887
888    # Jump over the debug loop
889    set var $AARCH64::$Core::$PC = $AARCH64::$Core::$PC + 4
890
891    # Resume execution
892    continue
893
894Firmware update options
895-----------------------
896
897-  ``NR_OF_FW_BANKS``: Define the number of firmware banks. This flag is used
898   in defining the firmware update metadata structure. This flag is by default
899   set to '2'.
900
901-  ``NR_OF_IMAGES_IN_FW_BANK``: Define the number of firmware images in each
902   firmware bank. Each firmware bank must have the same number of images as per
903   the `PSA FW update specification`_.
904   This flag is used in defining the firmware update metadata structure. This
905   flag is by default set to '1'.
906
907-  ``PSA_FWU_SUPPORT``: Enable the firmware update mechanism as per the
908   `PSA FW update specification`_. The default value is 0, and this is an
909   experimental feature.
910   PSA firmware update implementation has some limitations, such as BL2 is
911   not part of the protocol-updatable images, if BL2 needs to be updated, then
912   it should be done through another platform-defined mechanism, and it assumes
913   that the platform's hardware supports CRC32 instructions.
914
915--------------
916
917*Copyright (c) 2019-2021, Arm Limited. All rights reserved.*
918
919.. _DEN0115: https://developer.arm.com/docs/den0115/latest
920.. _PSA FW update specification: https://developer.arm.com/documentation/den0118/a/
921
922