xref: /rk3399_ARM-atf/docs/getting_started/build-options.rst (revision 46789a7c711d650ae9b2bad0c2b817c4ba4a214a)
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_LTO``: Boolean option to enable Link Time Optimization (LTO)
242   support in GCC for TF-A. This option is currently only supported for
243   AArch64. Default is 0.
244
245-  ``ENABLE_MPAM_FOR_LOWER_ELS``: Boolean option to enable lower ELs to use MPAM
246   feature. MPAM is an optional Armv8.4 extension that enables various memory
247   system components and resources to define partitions; software running at
248   various ELs can assign themselves to desired partition to control their
249   performance aspects.
250
251   When this option is set to ``1``, EL3 allows lower ELs to access their own
252   MPAM registers without trapping into EL3. This option doesn't make use of
253   partitioning in EL3, however. Platform initialisation code should configure
254   and use partitions in EL3 as required. This option defaults to ``0``.
255
256-  ``ENABLE_PIE``: Boolean option to enable Position Independent Executable(PIE)
257   support within generic code in TF-A. This option is currently only supported
258   in BL2_AT_EL3, BL31, and BL32 (TSP) for AARCH64 binaries, and in BL32
259   (SP_min) for AARCH32. Default is 0.
260
261-  ``ENABLE_PMF``: Boolean option to enable support for optional Performance
262   Measurement Framework(PMF). Default is 0.
263
264-  ``ENABLE_PSCI_STAT``: Boolean option to enable support for optional PSCI
265   functions ``PSCI_STAT_RESIDENCY`` and ``PSCI_STAT_COUNT``. Default is 0.
266   In the absence of an alternate stat collection backend, ``ENABLE_PMF`` must
267   be enabled. If ``ENABLE_PMF`` is set, the residency statistics are tracked in
268   software.
269
270-  ``ENABLE_RUNTIME_INSTRUMENTATION``: Boolean option to enable runtime
271   instrumentation which injects timestamp collection points into TF-A to
272   allow runtime performance to be measured. Currently, only PSCI is
273   instrumented. Enabling this option enables the ``ENABLE_PMF`` build option
274   as well. Default is 0.
275
276-  ``ENABLE_SPE_FOR_LOWER_ELS`` : Boolean option to enable Statistical Profiling
277   extensions. This is an optional architectural feature for AArch64.
278   The default is 1 but is automatically disabled when the target architecture
279   is AArch32.
280
281-  ``ENABLE_SVE_FOR_NS``: Boolean option to enable Scalable Vector Extension
282   (SVE) for the Non-secure world only. SVE is an optional architectural feature
283   for AArch64. Note that when SVE is enabled for the Non-secure world, access
284   to SIMD and floating-point functionality from the Secure world is disabled by
285   default and controlled with ENABLE_SVE_FOR_SWD.
286   This is to avoid corruption of the Non-secure world data in the Z-registers
287   which are aliased by the SIMD and FP registers. The build option is not
288   compatible with the ``CTX_INCLUDE_FPREGS`` build option, and will raise an
289   assert on platforms where SVE is implemented and ``ENABLE_SVE_FOR_NS`` set to
290   1. The default is 1 but is automatically disabled when the target
291   architecture is AArch32.
292
293-  ``ENABLE_SVE_FOR_SWD``: Boolean option to enable SVE for the Secure world.
294   SVE is an optional architectural feature for AArch64. Note that this option
295   requires ENABLE_SVE_FOR_NS to be enabled.  The default is 0 and it is
296   automatically disabled when the target architecture is AArch32.
297
298-  ``ENABLE_STACK_PROTECTOR``: String option to enable the stack protection
299   checks in GCC. Allowed values are "all", "strong", "default" and "none". The
300   default value is set to "none". "strong" is the recommended stack protection
301   level if this feature is desired. "none" disables the stack protection. For
302   all values other than "none", the ``plat_get_stack_protector_canary()``
303   platform hook needs to be implemented. The value is passed as the last
304   component of the option ``-fstack-protector-$ENABLE_STACK_PROTECTOR``.
305
306-  ``ENCRYPT_BL31``: Binary flag to enable encryption of BL31 firmware. This
307   flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as
308   experimental.
309
310-  ``ENCRYPT_BL32``: Binary flag to enable encryption of Secure BL32 payload.
311   This flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as
312   experimental.
313
314-  ``ENC_KEY``: A 32-byte (256-bit) symmetric key in hex string format. It could
315   either be SSK or BSSK depending on ``FW_ENC_STATUS`` flag. This value depends
316   on ``DECRYPTION_SUPPORT`` build flag which is marked as experimental.
317
318-  ``ENC_NONCE``: A 12-byte (96-bit) encryption nonce or Initialization Vector
319   (IV) in hex string format. This value depends on ``DECRYPTION_SUPPORT``
320   build flag which is marked as experimental.
321
322-  ``ERROR_DEPRECATED``: This option decides whether to treat the usage of
323   deprecated platform APIs, helper functions or drivers within Trusted
324   Firmware as error. It can take the value 1 (flag the use of deprecated
325   APIs as error) or 0. The default is 0.
326
327-  ``EL3_EXCEPTION_HANDLING``: When set to ``1``, enable handling of exceptions
328   targeted at EL3. When set ``0`` (default), no exceptions are expected or
329   handled at EL3, and a panic will result. This is supported only for AArch64
330   builds.
331
332-  ``EVENT_LOG_LEVEL``: Chooses the log level to use for Measured Boot when
333   ``MEASURED_BOOT`` is enabled. For a list of valid values, see ``LOG_LEVEL``.
334   Default value is 40 (LOG_LEVEL_INFO).
335
336-  ``FAULT_INJECTION_SUPPORT``: ARMv8.4 extensions introduced support for fault
337   injection from lower ELs, and this build option enables lower ELs to use
338   Error Records accessed via System Registers to inject faults. This is
339   applicable only to AArch64 builds.
340
341   This feature is intended for testing purposes only, and is advisable to keep
342   disabled for production images.
343
344-  ``FIP_NAME``: This is an optional build option which specifies the FIP
345   filename for the ``fip`` target. Default is ``fip.bin``.
346
347-  ``FWU_FIP_NAME``: This is an optional build option which specifies the FWU
348   FIP filename for the ``fwu_fip`` target. Default is ``fwu_fip.bin``.
349
350-  ``FW_ENC_STATUS``: Top level firmware's encryption numeric flag, values:
351
352   ::
353
354     0: Encryption is done with Secret Symmetric Key (SSK) which is common
355        for a class of devices.
356     1: Encryption is done with Binding Secret Symmetric Key (BSSK) which is
357        unique per device.
358
359   This flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as
360   experimental.
361
362-  ``GENERATE_COT``: Boolean flag used to build and execute the ``cert_create``
363   tool to create certificates as per the Chain of Trust described in
364   :ref:`Trusted Board Boot`. The build system then calls ``fiptool`` to
365   include the certificates in the FIP and FWU_FIP. Default value is '0'.
366
367   Specify both ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=1`` to include support
368   for the Trusted Board Boot feature in the BL1 and BL2 images, to generate
369   the corresponding certificates, and to include those certificates in the
370   FIP and FWU_FIP.
371
372   Note that if ``TRUSTED_BOARD_BOOT=0`` and ``GENERATE_COT=1``, the BL1 and BL2
373   images will not include support for Trusted Board Boot. The FIP will still
374   include the corresponding certificates. This FIP can be used to verify the
375   Chain of Trust on the host machine through other mechanisms.
376
377   Note that if ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=0``, the BL1 and BL2
378   images will include support for Trusted Board Boot, but the FIP and FWU_FIP
379   will not include the corresponding certificates, causing a boot failure.
380
381-  ``GICV2_G0_FOR_EL3``: Unlike GICv3, the GICv2 architecture doesn't have
382   inherent support for specific EL3 type interrupts. Setting this build option
383   to ``1`` assumes GICv2 *Group 0* interrupts are expected to target EL3, both
384   by :ref:`platform abstraction layer<platform Interrupt Controller API>` and
385   :ref:`Interrupt Management Framework<Interrupt Management Framework>`.
386   This allows GICv2 platforms to enable features requiring EL3 interrupt type.
387   This also means that all GICv2 Group 0 interrupts are delivered to EL3, and
388   the Secure Payload interrupts needs to be synchronously handed over to Secure
389   EL1 for handling. The default value of this option is ``0``, which means the
390   Group 0 interrupts are assumed to be handled by Secure EL1.
391
392-  ``HANDLE_EA_EL3_FIRST``: When set to ``1``, External Aborts and SError
393   Interrupts will be always trapped in EL3 i.e. in BL31 at runtime. When set to
394   ``0`` (default), these exceptions will be trapped in the current exception
395   level (or in EL1 if the current exception level is EL0).
396
397-  ``HW_ASSISTED_COHERENCY``: On most Arm systems to-date, platform-specific
398   software operations are required for CPUs to enter and exit coherency.
399   However, newer systems exist where CPUs' entry to and exit from coherency
400   is managed in hardware. Such systems require software to only initiate these
401   operations, and the rest is managed in hardware, minimizing active software
402   management. In such systems, this boolean option enables TF-A to carry out
403   build and run-time optimizations during boot and power management operations.
404   This option defaults to 0 and if it is enabled, then it implies
405   ``WARMBOOT_ENABLE_DCACHE_EARLY`` is also enabled.
406
407   If this flag is disabled while the platform which TF-A is compiled for
408   includes cores that manage coherency in hardware, then a compilation error is
409   generated. This is based on the fact that a system cannot have, at the same
410   time, cores that manage coherency in hardware and cores that don't. In other
411   words, a platform cannot have, at the same time, cores that require
412   ``HW_ASSISTED_COHERENCY=1`` and cores that require
413   ``HW_ASSISTED_COHERENCY=0``.
414
415   Note that, when ``HW_ASSISTED_COHERENCY`` is enabled, version 2 of
416   translation library (xlat tables v2) must be used; version 1 of translation
417   library is not supported.
418
419-  ``INVERTED_MEMMAP``: memmap tool print by default lower addresses at the
420   bottom, higher addresses at the top. This build flag can be set to '1' to
421   invert this behavior. Lower addresses will be printed at the top and higher
422   addresses at the bottom.
423
424-  ``JUNO_AARCH32_EL3_RUNTIME``: This build flag enables you to execute EL3
425   runtime software in AArch32 mode, which is required to run AArch32 on Juno.
426   By default this flag is set to '0'. Enabling this flag builds BL1 and BL2 in
427   AArch64 and facilitates the loading of ``SP_MIN`` and BL33 as AArch32 executable
428   images.
429
430-  ``KEY_ALG``: This build flag enables the user to select the algorithm to be
431   used for generating the PKCS keys and subsequent signing of the certificate.
432   It accepts 3 values: ``rsa``, ``rsa_1_5`` and ``ecdsa``. The option
433   ``rsa_1_5`` is the legacy PKCS#1 RSA 1.5 algorithm which is not TBBR
434   compliant and is retained only for compatibility. The default value of this
435   flag is ``rsa`` which is the TBBR compliant PKCS#1 RSA 2.1 scheme.
436
437-  ``KEY_SIZE``: This build flag enables the user to select the key size for
438   the algorithm specified by ``KEY_ALG``. The valid values for ``KEY_SIZE``
439   depend on the chosen algorithm and the cryptographic module.
440
441   +-----------+------------------------------------+
442   |  KEY_ALG  |        Possible key sizes          |
443   +===========+====================================+
444   |    rsa    | 1024 , 2048 (default), 3072, 4096* |
445   +-----------+------------------------------------+
446   |   ecdsa   |            unavailable             |
447   +-----------+------------------------------------+
448
449   * Only 2048 bits size is available with CryptoCell 712 SBROM release 1.
450     Only 3072 bits size is available with CryptoCell 712 SBROM release 2.
451
452-  ``HASH_ALG``: This build flag enables the user to select the secure hash
453   algorithm. It accepts 3 values: ``sha256``, ``sha384`` and ``sha512``.
454   The default value of this flag is ``sha256``.
455
456-  ``LDFLAGS``: Extra user options appended to the linkers' command line in
457   addition to the one set by the build system.
458
459-  ``LOG_LEVEL``: Chooses the log level, which controls the amount of console log
460   output compiled into the build. This should be one of the following:
461
462   ::
463
464       0  (LOG_LEVEL_NONE)
465       10 (LOG_LEVEL_ERROR)
466       20 (LOG_LEVEL_NOTICE)
467       30 (LOG_LEVEL_WARNING)
468       40 (LOG_LEVEL_INFO)
469       50 (LOG_LEVEL_VERBOSE)
470
471   All log output up to and including the selected log level is compiled into
472   the build. The default value is 40 in debug builds and 20 in release builds.
473
474-  ``MEASURED_BOOT``: Boolean flag to include support for the Measured Boot
475   feature. If this flag is enabled ``TRUSTED_BOARD_BOOT`` must be set as well
476   in order to provide trust that the code taking the measurements and recording
477   them has not been tampered with.
478
479   This option defaults to 0 and is an experimental feature in the stage of
480   development.
481
482-  ``NON_TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It
483   specifies the file that contains the Non-Trusted World private key in PEM
484   format. If ``SAVE_KEYS=1``, this file name will be used to save the key.
485
486-  ``NS_BL2U``: Path to NS_BL2U image in the host file system. This image is
487   optional. It is only needed if the platform makefile specifies that it
488   is required in order to build the ``fwu_fip`` target.
489
490-  ``NS_TIMER_SWITCH``: Enable save and restore for non-secure timer register
491   contents upon world switch. It can take either 0 (don't save and restore) or
492   1 (do save and restore). 0 is the default. An SPD may set this to 1 if it
493   wants the timer registers to be saved and restored.
494
495-  ``OVERRIDE_LIBC``: This option allows platforms to override the default libc
496   for the BL image. It can be either 0 (include) or 1 (remove). The default
497   value is 0.
498
499-  ``PL011_GENERIC_UART``: Boolean option to indicate the PL011 driver that
500   the underlying hardware is not a full PL011 UART but a minimally compliant
501   generic UART, which is a subset of the PL011. The driver will not access
502   any register that is not part of the SBSA generic UART specification.
503   Default value is 0 (a full PL011 compliant UART is present).
504
505-  ``PLAT``: Choose a platform to build TF-A for. The chosen platform name
506   must be subdirectory of any depth under ``plat/``, and must contain a
507   platform makefile named ``platform.mk``. For example, to build TF-A for the
508   Arm Juno board, select PLAT=juno.
509
510-  ``PRELOADED_BL33_BASE``: This option enables booting a preloaded BL33 image
511   instead of the normal boot flow. When defined, it must specify the entry
512   point address for the preloaded BL33 image. This option is incompatible with
513   ``EL3_PAYLOAD_BASE``. If both are defined, ``EL3_PAYLOAD_BASE`` has priority
514   over ``PRELOADED_BL33_BASE``.
515
516-  ``PROGRAMMABLE_RESET_ADDRESS``: This option indicates whether the reset
517   vector address can be programmed or is fixed on the platform. It can take
518   either 0 (fixed) or 1 (programmable). Default is 0. If the platform has a
519   programmable reset address, it is expected that a CPU will start executing
520   code directly at the right address, both on a cold and warm reset. In this
521   case, there is no need to identify the entrypoint on boot and the boot path
522   can be optimised. The ``plat_get_my_entrypoint()`` platform porting interface
523   does not need to be implemented in this case.
524
525-  ``PSCI_EXTENDED_STATE_ID``: As per PSCI1.0 Specification, there are 2 formats
526   possible for the PSCI power-state parameter: original and extended State-ID
527   formats. This flag if set to 1, configures the generic PSCI layer to use the
528   extended format. The default value of this flag is 0, which means by default
529   the original power-state format is used by the PSCI implementation. This flag
530   should be specified by the platform makefile and it governs the return value
531   of PSCI_FEATURES API for CPU_SUSPEND smc function id. When this option is
532   enabled on Arm platforms, the option ``ARM_RECOM_STATE_ID_ENC`` needs to be
533   set to 1 as well.
534
535-  ``RAS_EXTENSION``: When set to ``1``, enable Armv8.2 RAS features. RAS features
536   are an optional extension for pre-Armv8.2 CPUs, but are mandatory for Armv8.2
537   or later CPUs.
538
539   When ``RAS_EXTENSION`` is set to ``1``, ``HANDLE_EA_EL3_FIRST`` must also be
540   set to ``1``.
541
542   This option is disabled by default.
543
544-  ``RESET_TO_BL31``: Enable BL31 entrypoint as the CPU reset vector instead
545   of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1
546   entrypoint) or 1 (CPU reset to BL31 entrypoint).
547   The default value is 0.
548
549-  ``RESET_TO_SP_MIN``: SP_MIN is the minimal AArch32 Secure Payload provided
550   in TF-A. This flag configures SP_MIN entrypoint as the CPU reset vector
551   instead of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1
552   entrypoint) or 1 (CPU reset to SP_MIN entrypoint). The default value is 0.
553
554-  ``ROT_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the
555   file that contains the ROT private key in PEM format and enforces public key
556   hash generation. If ``SAVE_KEYS=1``, this
557   file name will be used to save the key.
558
559-  ``SAVE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the
560   certificate generation tool to save the keys used to establish the Chain of
561   Trust. Allowed options are '0' or '1'. Default is '0' (do not save).
562
563-  ``SCP_BL2``: Path to SCP_BL2 image in the host file system. This image is optional.
564   If a SCP_BL2 image is present then this option must be passed for the ``fip``
565   target.
566
567-  ``SCP_BL2_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the
568   file that contains the SCP_BL2 private key in PEM format. If ``SAVE_KEYS=1``,
569   this file name will be used to save the key.
570
571-  ``SCP_BL2U``: Path to SCP_BL2U image in the host file system. This image is
572   optional. It is only needed if the platform makefile specifies that it
573   is required in order to build the ``fwu_fip`` target.
574
575-  ``SDEI_SUPPORT``: Setting this to ``1`` enables support for Software
576   Delegated Exception Interface to BL31 image. This defaults to ``0``.
577
578   When set to ``1``, the build option ``EL3_EXCEPTION_HANDLING`` must also be
579   set to ``1``.
580
581-  ``SEPARATE_CODE_AND_RODATA``: Whether code and read-only data should be
582   isolated on separate memory pages. This is a trade-off between security and
583   memory usage. See "Isolating code and read-only data on separate memory
584   pages" section in :ref:`Firmware Design`. This flag is disabled by default
585   and affects all BL images.
586
587-  ``SEPARATE_NOBITS_REGION``: Setting this option to ``1`` allows the NOBITS
588   sections of BL31 (.bss, stacks, page tables, and coherent memory) to be
589   allocated in RAM discontiguous from the loaded firmware image. When set, the
590   platform is expected to provide definitions for ``BL31_NOBITS_BASE`` and
591   ``BL31_NOBITS_LIMIT``. When the option is ``0`` (the default), NOBITS
592   sections are placed in RAM immediately following the loaded firmware image.
593
594-  ``SMC_PCI_SUPPORT``: This option allows platforms to handle PCI configuration
595   access requests via a standard SMCCC defined in `DEN0115`_. When combined with
596   UEFI+ACPI this can provide a certain amount of OS forward compatibility
597   with newer platforms that aren't ECAM compliant.
598
599-  ``SPD``: Choose a Secure Payload Dispatcher component to be built into TF-A.
600   This build option is only valid if ``ARCH=aarch64``. The value should be
601   the path to the directory containing the SPD source, relative to
602   ``services/spd/``; the directory is expected to contain a makefile called
603   ``<spd-value>.mk``. The SPM Dispatcher standard service is located in
604   services/std_svc/spmd and enabled by ``SPD=spmd``. The SPM Dispatcher
605   cannot be enabled when the ``SPM_MM`` option is enabled.
606
607-  ``SPIN_ON_BL1_EXIT``: This option introduces an infinite loop in BL1. It can
608   take either 0 (no loop) or 1 (add a loop). 0 is the default. This loop stops
609   execution in BL1 just before handing over to BL31. At this point, all
610   firmware images have been loaded in memory, and the MMU and caches are
611   turned off. Refer to the "Debugging options" section for more details.
612
613-  ``SPMD_SPM_AT_SEL2`` : this boolean option is used jointly with the SPM
614   Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC
615   component runs at the S-EL2 execution state provided by the Armv8.4-SecEL2
616   extension. This is the default when enabling the SPM Dispatcher. When
617   disabled (0) it indicates the SPMC component runs at the S-EL1 execution
618   state. This latter configuration supports pre-Armv8.4 platforms (aka not
619   implementing the Armv8.4-SecEL2 extension).
620
621-  ``SPM_MM`` : Boolean option to enable the Management Mode (MM)-based Secure
622   Partition Manager (SPM) implementation. The default value is ``0``
623   (disabled). This option cannot be enabled (``1``) when SPM Dispatcher is
624   enabled (``SPD=spmd``).
625
626-  ``SP_LAYOUT_FILE``: Platform provided path to JSON file containing the
627   description of secure partitions. The build system will parse this file and
628   package all secure partition blobs into the FIP. This file is not
629   necessarily part of TF-A tree. Only available when ``SPD=spmd``.
630
631-  ``SP_MIN_WITH_SECURE_FIQ``: Boolean flag to indicate the SP_MIN handles
632   secure interrupts (caught through the FIQ line). Platforms can enable
633   this directive if they need to handle such interruption. When enabled,
634   the FIQ are handled in monitor mode and non secure world is not allowed
635   to mask these events. Platforms that enable FIQ handling in SP_MIN shall
636   implement the api ``sp_min_plat_fiq_handler()``. The default value is 0.
637
638-  ``TRUSTED_BOARD_BOOT``: Boolean flag to include support for the Trusted Board
639   Boot feature. When set to '1', BL1 and BL2 images include support to load
640   and verify the certificates and images in a FIP, and BL1 includes support
641   for the Firmware Update. The default value is '0'. Generation and inclusion
642   of certificates in the FIP and FWU_FIP depends upon the value of the
643   ``GENERATE_COT`` option.
644
645   .. warning::
646      This option depends on ``CREATE_KEYS`` to be enabled. If the keys
647      already exist in disk, they will be overwritten without further notice.
648
649-  ``TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It
650   specifies the file that contains the Trusted World private key in PEM
651   format. If ``SAVE_KEYS=1``, this file name will be used to save the key.
652
653-  ``TSP_INIT_ASYNC``: Choose BL32 initialization method as asynchronous or
654   synchronous, (see "Initializing a BL32 Image" section in
655   :ref:`Firmware Design`). It can take the value 0 (BL32 is initialized using
656   synchronous method) or 1 (BL32 is initialized using asynchronous method).
657   Default is 0.
658
659-  ``TSP_NS_INTR_ASYNC_PREEMPT``: A non zero value enables the interrupt
660   routing model which routes non-secure interrupts asynchronously from TSP
661   to EL3 causing immediate preemption of TSP. The EL3 is responsible
662   for saving and restoring the TSP context in this routing model. The
663   default routing model (when the value is 0) is to route non-secure
664   interrupts to TSP allowing it to save its context and hand over
665   synchronously to EL3 via an SMC.
666
667   .. note::
668      When ``EL3_EXCEPTION_HANDLING`` is ``1``, ``TSP_NS_INTR_ASYNC_PREEMPT``
669      must also be set to ``1``.
670
671-  ``USE_ARM_LINK``: This flag determines whether to enable support for ARM
672   linker. When the ``LINKER`` build variable points to the armlink linker,
673   this flag is enabled automatically. To enable support for armlink, platforms
674   will have to provide a scatter file for the BL image. Currently, Tegra
675   platforms use the armlink support to compile BL3-1 images.
676
677-  ``USE_COHERENT_MEM``: This flag determines whether to include the coherent
678   memory region in the BL memory map or not (see "Use of Coherent memory in
679   TF-A" section in :ref:`Firmware Design`). It can take the value 1
680   (Coherent memory region is included) or 0 (Coherent memory region is
681   excluded). Default is 1.
682
683-  ``USE_DEBUGFS``: When set to 1 this option activates an EXPERIMENTAL feature
684   exposing a virtual filesystem interface through BL31 as a SiP SMC function.
685   Default is 0.
686
687-  ``ARM_IO_IN_DTB``: This flag determines whether to use IO based on the
688   firmware configuration framework. This will move the io_policies into a
689   configuration device tree, instead of static structure in the code base.
690   This is currently an experimental feature.
691
692-  ``COT_DESC_IN_DTB``: This flag determines whether to create COT descriptors
693   at runtime using fconf. If this flag is enabled, COT descriptors are
694   statically captured in tb_fw_config file in the form of device tree nodes
695   and properties. Currently, COT descriptors used by BL2 are moved to the
696   device tree and COT descriptors used by BL1 are retained in the code
697   base statically. This is currently an experimental feature.
698
699-  ``SDEI_IN_FCONF``: This flag determines whether to configure SDEI setup in
700   runtime using firmware configuration framework. The platform specific SDEI
701   shared and private events configuration is retrieved from device tree rather
702   than static C structures at compile time. This is currently an experimental
703   feature and is only supported if SDEI_SUPPORT build flag is enabled.
704
705-  ``SEC_INT_DESC_IN_FCONF``: This flag determines whether to configure Group 0
706   and Group1 secure interrupts using the firmware configuration framework. The
707   platform specific secure interrupt property descriptor is retrieved from
708   device tree in runtime rather than depending on static C structure at compile
709   time. This is currently an experimental feature.
710
711-  ``USE_ROMLIB``: This flag determines whether library at ROM will be used.
712   This feature creates a library of functions to be placed in ROM and thus
713   reduces SRAM usage. Refer to :ref:`Library at ROM` for further details. Default
714   is 0.
715
716-  ``V``: Verbose build. If assigned anything other than 0, the build commands
717   are printed. Default is 0.
718
719-  ``VERSION_STRING``: String used in the log output for each TF-A image.
720   Defaults to a string formed by concatenating the version number, build type
721   and build string.
722
723-  ``W``: Warning level. Some compiler warning options of interest have been
724   regrouped and put in the root Makefile. This flag can take the values 0 to 3,
725   each level enabling more warning options. Default is 0.
726
727-  ``WARMBOOT_ENABLE_DCACHE_EARLY`` : Boolean option to enable D-cache early on
728   the CPU after warm boot. This is applicable for platforms which do not
729   require interconnect programming to enable cache coherency (eg: single
730   cluster platforms). If this option is enabled, then warm boot path
731   enables D-caches immediately after enabling MMU. This option defaults to 0.
732
733-  ``SUPPORT_STACK_MEMTAG``: This flag determines whether to enable memory
734   tagging for stack or not. It accepts 2 values: ``yes`` and ``no``. The
735   default value of this flag is ``no``. Note this option must be enabled only
736   for ARM architecture greater than Armv8.5-A.
737
738-  ``ERRATA_SPECULATIVE_AT``: This flag determines whether to enable ``AT``
739   speculative errata workaround or not. It accepts 2 values: ``1`` and ``0``.
740   The default value of this flag is ``0``.
741
742   ``AT`` speculative errata workaround disables stage1 page table walk for
743   lower ELs (EL1 and EL0) in EL3 so that ``AT`` speculative fetch at any point
744   produces either the correct result or failure without TLB allocation.
745
746   This boolean option enables errata for all below CPUs.
747
748   +---------+--------------+-------------------------+
749   | Errata  |      CPU     |     Workaround Define   |
750   +=========+==============+=========================+
751   | 1165522 |  Cortex-A76  |  ``ERRATA_A76_1165522`` |
752   +---------+--------------+-------------------------+
753   | 1319367 |  Cortex-A72  |  ``ERRATA_A72_1319367`` |
754   +---------+--------------+-------------------------+
755   | 1319537 |  Cortex-A57  |  ``ERRATA_A57_1319537`` |
756   +---------+--------------+-------------------------+
757   | 1530923 |  Cortex-A55  |  ``ERRATA_A55_1530923`` |
758   +---------+--------------+-------------------------+
759   | 1530924 |  Cortex-A53  |  ``ERRATA_A53_1530924`` |
760   +---------+--------------+-------------------------+
761
762   .. note::
763      This option is enabled by build only if platform sets any of above defines
764      mentioned in ’Workaround Define' column in the table.
765      If this option is enabled for the EL3 software then EL2 software also must
766      implement this workaround due to the behaviour of the errata mentioned
767      in new SDEN document which will get published soon.
768
769- ``RAS_TRAP_LOWER_EL_ERR_ACCESS``: This flag enables/disables the SCR_EL3.TERR
770  bit, to trap access to the RAS ERR and RAS ERX registers from lower ELs.
771  This flag is disabled by default.
772
773- ``OPENSSL_DIR``: This flag is used to provide the installed openssl directory
774  path on the host machine which is used to build certificate generation and
775  firmware encryption tool.
776
777- ``USE_SP804_TIMER``: Use the SP804 timer instead of the Generic Timer for
778  functions that wait for an arbitrary time length (udelay and mdelay). The
779  default value is 0.
780
781- ``ENABLE_TRBE_FOR_NS``: This flag is used to enable access of trace buffer
782  control registers from NS ELs, NS-EL2 or NS-EL1(when NS-EL2 is implemented
783  but unused) when FEAT_TRBE is implemented. TRBE is an optional architectural
784  feature for AArch64. The default is 0 and it is automatically disabled when
785  the target architecture is AArch32.
786
787- ``ENABLE_SYS_REG_TRACE_FOR_NS``: Boolean option to enable trace system
788  registers access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented
789  but unused). This feature is available if trace unit such as ETMv4.x, and
790  ETE(extending ETM feature) is implemented. This flag is disabled by default.
791
792- ``ENABLE_TRF_FOR_NS``: Boolean option to enable trace filter control registers
793  access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented but unused),
794  if FEAT_TRF is implemented. This flag is disabled by default.
795
796GICv3 driver options
797--------------------
798
799GICv3 driver files are included using directive:
800
801``include drivers/arm/gic/v3/gicv3.mk``
802
803The driver can be configured with the following options set in the platform
804makefile:
805
806-  ``GICV3_SUPPORT_GIC600``: Add support for the GIC-600 variants of GICv3.
807   Enabling this option will add runtime detection support for the
808   GIC-600, so is safe to select even for a GIC500 implementation.
809   This option defaults to 0.
810
811- ``GICV3_SUPPORT_GIC600AE_FMU``: Add support for the Fault Management Unit
812   for GIC-600 AE. Enabling this option will introduce support to initialize
813   the FMU. Platforms should call the init function during boot to enable the
814   FMU and its safety mechanisms. This option defaults to 0.
815
816-  ``GICV3_IMPL_GIC600_MULTICHIP``: Selects GIC-600 variant with multichip
817   functionality. This option defaults to 0
818
819-  ``GICV3_OVERRIDE_DISTIF_PWR_OPS``: Allows override of default implementation
820   of ``arm_gicv3_distif_pre_save`` and ``arm_gicv3_distif_post_restore``
821   functions. This is required for FVP platform which need to simulate GIC save
822   and restore during SYSTEM_SUSPEND without powering down GIC. Default is 0.
823
824-  ``GIC_ENABLE_V4_EXTN`` : Enables GICv4 related changes in GICv3 driver.
825   This option defaults to 0.
826
827-  ``GIC_EXT_INTID``: When set to ``1``, GICv3 driver will support extended
828   PPI (1056-1119) and SPI (4096-5119) range. This option defaults to 0.
829
830Debugging options
831-----------------
832
833To compile a debug version and make the build more verbose use
834
835.. code:: shell
836
837    make PLAT=<platform> DEBUG=1 V=1 all
838
839AArch64 GCC uses DWARF version 4 debugging symbols by default. Some tools (for
840example DS-5) might not support this and may need an older version of DWARF
841symbols to be emitted by GCC. This can be achieved by using the
842``-gdwarf-<version>`` flag, with the version being set to 2 or 3. Setting the
843version to 2 is recommended for DS-5 versions older than 5.16.
844
845When debugging logic problems it might also be useful to disable all compiler
846optimizations by using ``-O0``.
847
848.. warning::
849   Using ``-O0`` could cause output images to be larger and base addresses
850   might need to be recalculated (see the **Memory layout on Arm development
851   platforms** section in the :ref:`Firmware Design`).
852
853Extra debug options can be passed to the build system by setting ``CFLAGS`` or
854``LDFLAGS``:
855
856.. code:: shell
857
858    CFLAGS='-O0 -gdwarf-2'                                     \
859    make PLAT=<platform> DEBUG=1 V=1 all
860
861Note that using ``-Wl,`` style compilation driver options in ``CFLAGS`` will be
862ignored as the linker is called directly.
863
864It is also possible to introduce an infinite loop to help in debugging the
865post-BL2 phase of TF-A. This can be done by rebuilding BL1 with the
866``SPIN_ON_BL1_EXIT=1`` build flag. Refer to the :ref:`build_options_common`
867section. In this case, the developer may take control of the target using a
868debugger when indicated by the console output. When using DS-5, the following
869commands can be used:
870
871::
872
873    # Stop target execution
874    interrupt
875
876    #
877    # Prepare your debugging environment, e.g. set breakpoints
878    #
879
880    # Jump over the debug loop
881    set var $AARCH64::$Core::$PC = $AARCH64::$Core::$PC + 4
882
883    # Resume execution
884    continue
885
886Firmware update options
887-----------------------
888
889-  ``NR_OF_FW_BANKS``: Define the number of firmware banks. This flag is used
890   in defining the firmware update metadata structure. This flag is by default
891   set to '2'.
892
893-  ``NR_OF_IMAGES_IN_FW_BANK``: Define the number of firmware images in each
894   firmware bank. Each firmware bank must have the same number of images as per
895   the `PSA FW update specification`_.
896   This flag is used in defining the firmware update metadata structure. This
897   flag is by default set to '1'.
898
899-  ``PSA_FWU_SUPPORT``: Enable the firmware update mechanism as per the
900   `PSA FW update specification`_. The default value is 0, and this is an
901   experimental feature.
902   PSA firmware update implementation has some limitations, such as BL2 is
903   not part of the protocol-updatable images, if BL2 needs to be updated, then
904   it should be done through another platform-defined mechanism, and it assumes
905   that the platform's hardware supports CRC32 instructions.
906
907--------------
908
909*Copyright (c) 2019-2021, Arm Limited. All rights reserved.*
910
911.. _DEN0115: https://developer.arm.com/docs/den0115/latest
912.. _PSA FW update specification: https://developer.arm.com/documentation/den0118/a/
913
914