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Paul Beesleyd2fcc4e2019-05-29 13:59:40 +01001Build 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
johpow01fa59c6f2020-10-02 13:41:11 -050025- ``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
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +010029- ``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
Alexei Fedorov132e6652020-12-07 16:38:53 +000033- ``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
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +010039- ``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
Balint Dobszay719ba9c2021-03-26 16:23:18 +010058- ``BL2_ENABLE_SP_LOAD``: Boolean option to enable loading SP packages from the
59 FIP. Automatically enabled if ``SP_LAYOUT_FILE`` is provided.
60
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +010061- ``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
Alexei Fedorove039e482020-06-19 14:33:49 +0100104- 4: Turn on branch target identification mechanism
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100105
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 +-------+--------------+-------+-----+
Alexei Fedorove039e482020-06-19 14:33:49 +0100120 | 4 | bti | N | Y |
121 +-------+--------------+-------+-----+
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100122
Manish Pandey34a305e2021-10-21 21:53:49 +0100123 This option defaults to 0.
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100124 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
Grant Likely388248a2020-07-30 08:50:10 +0100135- ``BUILD_BASE``: Output directory for the build. Defaults to ``./build``
136
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100137- ``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
Sandrine Bailleuxd4c1d442020-01-15 10:23:25 +0100149- ``COT``: When Trusted Boot is enabled, selects the desired chain of trust.
150 Defaults to ``tbbr``.
151
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100152- ``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
Olivier Deprez7efa3f12020-03-26 16:09:21 +0100167- ``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
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100173- ``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
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000177- ``CTX_INCLUDE_MTE_REGS``: Numeric value to include Memory Tagging Extension
178 registers in cpu context. This must be enabled, if the platform wants to use
179 this feature in the Secure world and MTE is enabled at ELX. This flag can
180 take values 0 to 2, to align with the ``FEATURE_DETECTION`` mechanism.
181 Default value is 0.
Arunachalam Ganapathydd3ec7e2020-05-28 11:57:09 +0100182
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000183- ``CTX_INCLUDE_NEVE_REGS``: Numeric value, when set will cause the Armv8.4-NV
184 registers to be saved/restored when entering/exiting an EL2 execution
185 context. This flag can take values 0 to 2, to align with the
186 ``FEATURE_DETECTION`` mechanism. Default value is 0.
187
188- ``CTX_INCLUDE_PAUTH_REGS``: Numeric value to enable the Pointer
189 Authentication for Secure world. This will cause the ARMv8.3-PAuth registers
190 to be included when saving and restoring the CPU context as part of world
191 switch. This flag can take values 0 to 2, to align with ``FEATURE_DETECTION``
192 mechanism. Default value is 0.
193
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100194 Note that Pointer Authentication is enabled for Non-secure world irrespective
195 of the value of this flag if the CPU supports it.
196
197- ``DEBUG``: Chooses between a debug and release build. It can take either 0
198 (release) or 1 (debug) as values. 0 is the default.
199
Sumit Garg392e4df2019-11-15 10:43:00 +0530200- ``DECRYPTION_SUPPORT``: This build flag enables the user to select the
201 authenticated decryption algorithm to be used to decrypt firmware/s during
202 boot. It accepts 2 values: ``aes_gcm`` and ``none``. The default value of
203 this flag is ``none`` to disable firmware decryption which is an optional
Manish Pandey34a305e2021-10-21 21:53:49 +0100204 feature as per TBBR.
Sumit Garg392e4df2019-11-15 10:43:00 +0530205
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100206- ``DISABLE_BIN_GENERATION``: Boolean option to disable the generation
207 of the binary image. If set to 1, then only the ELF image is built.
208 0 is the default.
209
Javier Almansa Sobrinof3a4c542020-11-23 18:38:15 +0000210- ``DISABLE_MTPMU``: Boolean option to disable FEAT_MTPMU if implemented
211 (Armv8.6 onwards). Its default value is 0 to keep consistency with platforms
212 that do not implement FEAT_MTPMU. For more information on FEAT_MTPMU,
213 check the latest Arm ARM.
214
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100215- ``DYN_DISABLE_AUTH``: Provides the capability to dynamically disable Trusted
216 Board Boot authentication at runtime. This option is meant to be enabled only
217 for development platforms. ``TRUSTED_BOARD_BOOT`` flag must be set if this
218 flag has to be enabled. 0 is the default.
219
220- ``E``: Boolean option to make warnings into errors. Default is 1.
221
222- ``EL3_PAYLOAD_BASE``: This option enables booting an EL3 payload instead of
223 the normal boot flow. It must specify the entry point address of the EL3
224 payload. Please refer to the "Booting an EL3 payload" section for more
225 details.
226
227- ``ENABLE_AMU``: Boolean option to enable Activity Monitor Unit extensions.
228 This is an optional architectural feature available on v8.4 onwards. Some
229 v8.2 implementations also implement an AMU and this option can be used to
230 enable this feature on those systems as well. Default is 0.
231
Chris Kay925fda42021-05-25 10:42:56 +0100232- ``ENABLE_AMU_AUXILIARY_COUNTERS``: Enables support for AMU auxiliary counters
233 (also known as group 1 counters). These are implementation-defined counters,
234 and as such require additional platform configuration. Default is 0.
235
Chris Kayf11909f2021-08-19 11:21:52 +0100236- ``ENABLE_AMU_FCONF``: Enables configuration of the AMU through FCONF, which
237 allows platforms with auxiliary counters to describe them via the
238 ``HW_CONFIG`` device tree blob. Default is 0.
239
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100240- ``ENABLE_ASSERTIONS``: This option controls whether or not calls to ``assert()``
241 are compiled out. For debug builds, this option defaults to 1, and calls to
242 ``assert()`` are left in place. For release builds, this option defaults to 0
243 and calls to ``assert()`` function are compiled out. This option can be set
244 independently of ``DEBUG``. It can also be used to hide any auxiliary code
245 that is only required for the assertion and does not fit in the assertion
246 itself.
247
Alexei Fedorovb8f26e92020-02-06 17:11:03 +0000248- ``ENABLE_BACKTRACE``: This option controls whether to enable backtrace
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100249 dumps or not. It is supported in both AArch64 and AArch32. However, in
250 AArch32 the format of the frame records are not defined in the AAPCS and they
251 are defined by the implementation. This implementation of backtrace only
252 supports the format used by GCC when T32 interworking is disabled. For this
253 reason enabling this option in AArch32 will force the compiler to only
254 generate A32 code. This option is enabled by default only in AArch64 debug
255 builds, but this behaviour can be overridden in each platform's Makefile or
256 in the build command line.
257
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000258- ``ENABLE_FEAT_AMUv1``: Numeric value to enable access to the HAFGRTR_EL2
Jayanth Dodderi Chidanand76ff3632021-12-05 19:21:14 +0000259 (Hypervisor Activity Monitors Fine-Grained Read Trap Register) during EL2
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000260 to EL3 context save/restore operations. This flag can take the values 0 to 2,
261 to align with the ``FEATURE_DETECTION`` mechanism. It is an optional feature
262 available on v8.4 and onwards and must be set to either 1 or 2 alongside
263 ``ENABLE_FEAT_FGT``, to access the HAFGRTR_EL2 register.
264 Default value is ``0``.
265
266- ``ENABLE_FEAT_AMUv1p1``: Numeric value to enable the ``FEAT_AMUv1p1``
267 extension. ``FEAT_AMUv1p1`` is an optional feature available on Arm v8.6
268 onwards. This flag can take the values 0 to 2, to align with the
269 ``FEATURE_DETECTION`` mechanism. Default value is ``0``.
270
271- ``ENABLE_FEAT_CSV2_2``: Numeric value to enable the ``FEAT_CSV2_2``
272 extension. It allows access to the SCXTNUM_EL2 (Software Context Number)
273 register during EL2 context save/restore operations. ``FEAT_CSV2_2`` is an
274 optional feature available on Arm v8.0 onwards. This flag can take values
275 0 to 2, to align with the ``FEATURE_DETECTION`` mechanism.
276 Default value is ``0``.
277
278- ``ENABLE_FEAT_DIT``: Numeric value to enable ``FEAT_DIT`` (Data Independent
279 Timing) extension. It allows setting the ``DIT`` bit of PSTATE in EL3.
280 ``FEAT_DIT`` is a mandatory architectural feature and is enabled from v8.4
281 and upwards. This flag can take the values 0 to 2, to align with the
282 ``FEATURE_DETECTION`` mechanism. Default value is ``0``.
Jayanth Dodderi Chidanand76ff3632021-12-05 19:21:14 +0000283
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000284- ``ENABLE_FEAT_ECV``: Numeric value to enable support for the Enhanced Counter
Jayanth Dodderi Chidanand76ff3632021-12-05 19:21:14 +0000285 Virtualization feature, allowing for access to the CNTPOFF_EL2 (Counter-timer
286 Physical Offset register) during EL2 to EL3 context save/restore operations.
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000287 Its a mandatory architectural feature and is enabled from v8.6 and upwards.
288 This flag can take the values 0 to 2, to align with the ``FEATURE_DETECTION``
289 mechanism. Default value is ``0``.
Jayanth Dodderi Chidanand76ff3632021-12-05 19:21:14 +0000290
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000291- ``ENABLE_FEAT_FGT``: Numeric value to enable support for FGT (Fine Grain Traps)
Jayanth Dodderi Chidanand76ff3632021-12-05 19:21:14 +0000292 feature allowing for access to the HDFGRTR_EL2 (Hypervisor Debug Fine-Grained
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000293 Read Trap Register) during EL2 to EL3 context save/restore operations.
294 Its a mandatory architectural feature and is enabled from v8.6 and upwards.
295 This flag can take the values 0 to 2, to align with the ``FEATURE_DETECTION``
296 mechanism. Default value is ``0``.
297
298- ``ENABLE_FEAT_HCX``: Numeric value to set the bit SCR_EL3.HXEn in EL3 to
299 allow access to HCRX_EL2 (extended hypervisor control register) from EL2 as
300 well as adding HCRX_EL2 to the EL2 context save/restore operations. Its a
301 mandatory architectural feature and is enabled from v8.7 and upwards. This
302 flag can take the values 0 to 2, to align with the ``FEATURE_DETECTION``
303 mechanism. Default value is ``0``.
304
305- ``ENABLE_FEAT_PAN``: Numeric value to enable the ``FEAT_PAN`` (Privileged
306 Access Never) extension. ``FEAT_PAN`` adds a bit to PSTATE, generating a
307 permission fault for any privileged data access from EL1/EL2 to virtual
308 memory address, accessible at EL0, provided (HCR_EL2.E2H=1). It is a
309 mandatory architectural feature and is enabled from v8.1 and upwards. This
310 flag can take values 0 to 2, to align with the ``FEATURE_DETECTION``
311 mechanism. Default value is ``0``.
312
313- ``ENABLE_FEAT_RNG``: Numeric value to enable the ``FEAT_RNG`` extension.
314 ``FEAT_RNG`` is an optional feature available on Arm v8.5 onwards. This
315 flag can take the values 0 to 2, to align with the ``FEATURE_DETECTION``
316 mechanism. Default is ``0``.
317
318- ``ENABLE_FEAT_SB``: Numeric value to enable the ``FEAT_SB`` (Speculation
319 Barrier) extension allowing access to ``sb`` instruction. ``FEAT_SB`` is an
320 optional feature and defaults to ``0`` for pre-Armv8.5 CPUs but are mandatory
321 for Armv8.5 or later CPUs. This flag can take values 0 to 2, to align with
322 ``FEATURE_DETECTION`` mechanism. It is enabled from v8.5 and upwards and if
323 needed could be overidden from platforms explicitly. Default value is ``0``.
324
325- ``ENABLE_FEAT_SEL2``: Numeric value to enable the ``FEAT_SEL2`` (Secure EL2)
326 extension. ``FEAT_SEL2`` is a mandatory feature available on Arm v8.4.
327 This flag can take values 0 to 2, to align with the ``FEATURE_DETECTION``
328 mechanism. Default is ``0``.
Jayanth Dodderi Chidanand76ff3632021-12-05 19:21:14 +0000329
Jayanth Dodderi Chidanand4b5489c2022-03-28 15:28:55 +0100330- ``ENABLE_FEAT_TWED``: Numeric value to enable the ``FEAT_TWED`` (Delayed
331 trapping of WFE Instruction) extension. ``FEAT_TWED`` is a optional feature
332 available on Arm v8.6. This flag can take values 0 to 2, to align with the
333 ``FEATURE_DETECTION`` mechanism. Default is ``0``.
334
335 When ``ENABLE_FEAT_TWED`` is set to ``1``, WFE instruction trapping gets
336 delayed by the amount of value in ``TWED_DELAY``.
337
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000338- ``ENABLE_FEAT_VHE``: Numeric value to enable the ``FEAT_VHE`` (Virtualization
339 Host Extensions) extension. It allows access to CONTEXTIDR_EL2 register
340 during EL2 context save/restore operations.``FEAT_VHE`` is a mandatory
341 architectural feature and is enabled from v8.1 and upwards. It can take
342 values 0 to 2, to align with the ``FEATURE_DETECTION`` mechanism.
343 Default value is ``0``.
johpow01f91e59f2021-08-04 19:38:18 -0500344
Sandrine Bailleux11427302019-12-17 09:38:08 +0100345- ``ENABLE_LTO``: Boolean option to enable Link Time Optimization (LTO)
zelalem-aweked5f45272019-11-12 16:20:17 -0600346 support in GCC for TF-A. This option is currently only supported for
347 AArch64. Default is 0.
348
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000349- ``ENABLE_MPAM_FOR_LOWER_ELS``: Numeric value to enable lower ELs to use MPAM
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100350 feature. MPAM is an optional Armv8.4 extension that enables various memory
351 system components and resources to define partitions; software running at
352 various ELs can assign themselves to desired partition to control their
353 performance aspects.
354
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000355 This flag can take values 0 to 2, to align with the ``FEATURE_DETECTION``
356 mechanism. When this option is set to ``1`` or ``2``, EL3 allows lower ELs to
357 access their own MPAM registers without trapping into EL3. This option
358 doesn't make use of partitioning in EL3, however. Platform initialisation
359 code should configure and use partitions in EL3 as required. This option
360 defaults to ``0``.
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100361
Chris Kay03be39d2021-05-05 13:38:30 +0100362- ``ENABLE_MPMM``: Boolean option to enable support for the Maximum Power
363 Mitigation Mechanism supported by certain Arm cores, which allows the SoC
364 firmware to detect and limit high activity events to assist in SoC processor
365 power domain dynamic power budgeting and limit the triggering of whole-rail
366 (i.e. clock chopping) responses to overcurrent conditions. Defaults to ``0``.
367
368- ``ENABLE_MPMM_FCONF``: Enables configuration of MPMM through FCONF, which
369 allows platforms with cores supporting MPMM to describe them via the
370 ``HW_CONFIG`` device tree blob. Default is 0.
371
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100372- ``ENABLE_PIE``: Boolean option to enable Position Independent Executable(PIE)
373 support within generic code in TF-A. This option is currently only supported
Yann Gautier514e59c2020-10-05 11:02:54 +0200374 in BL2_AT_EL3, BL31, and BL32 (TSP) for AARCH64 binaries, and in BL32
375 (SP_min) for AARCH32. Default is 0.
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100376
377- ``ENABLE_PMF``: Boolean option to enable support for optional Performance
378 Measurement Framework(PMF). Default is 0.
379
380- ``ENABLE_PSCI_STAT``: Boolean option to enable support for optional PSCI
381 functions ``PSCI_STAT_RESIDENCY`` and ``PSCI_STAT_COUNT``. Default is 0.
382 In the absence of an alternate stat collection backend, ``ENABLE_PMF`` must
383 be enabled. If ``ENABLE_PMF`` is set, the residency statistics are tracked in
384 software.
385
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000386- ``ENABLE_RME``: Numeric value to enable support for the ARMv9 Realm
387 Management Extension. This flag can take the values 0 to 2, to align with
388 the ``FEATURE_DETECTION`` mechanism. Default value is 0. This is currently
389 an experimental feature.
Zelalem Aweke4d37db82021-07-11 18:33:20 -0500390
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100391- ``ENABLE_RUNTIME_INSTRUMENTATION``: Boolean option to enable runtime
392 instrumentation which injects timestamp collection points into TF-A to
393 allow runtime performance to be measured. Currently, only PSCI is
394 instrumented. Enabling this option enables the ``ENABLE_PMF`` build option
395 as well. Default is 0.
396
johpow019baade32021-07-08 14:14:00 -0500397- ``ENABLE_SME_FOR_NS``: Boolean option to enable Scalable Matrix Extension
398 (SME), SVE, and FPU/SIMD for the non-secure world only. These features share
399 registers so are enabled together. Using this option without
400 ENABLE_SME_FOR_SWD=1 will cause SME, SVE, and FPU/SIMD instructions in secure
401 world to trap to EL3. SME is an optional architectural feature for AArch64
402 and TF-A support is experimental. At this time, this build option cannot be
Manish Pandey247e5c32021-11-15 15:29:08 +0000403 used on systems that have SPD=spmd/SPM_MM or ENABLE_RME, and attempting to
404 build with these options will fail. Default is 0.
johpow019baade32021-07-08 14:14:00 -0500405
406- ``ENABLE_SME_FOR_SWD``: Boolean option to enable the Scalable Matrix
407 Extension for secure world use along with SVE and FPU/SIMD, ENABLE_SME_FOR_NS
408 must also be set to use this. If enabling this, the secure world MUST
409 handle context switching for SME, SVE, and FPU/SIMD registers to ensure that
410 no data is leaked to non-secure world. This is experimental. Default is 0.
411
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100412- ``ENABLE_SPE_FOR_LOWER_ELS`` : Boolean option to enable Statistical Profiling
413 extensions. This is an optional architectural feature for AArch64.
414 The default is 1 but is automatically disabled when the target architecture
415 is AArch32.
416
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100417- ``ENABLE_SVE_FOR_NS``: Boolean option to enable Scalable Vector Extension
418 (SVE) for the Non-secure world only. SVE is an optional architectural feature
419 for AArch64. Note that when SVE is enabled for the Non-secure world, access
Max Shvetsovc4502772021-03-22 11:59:37 +0000420 to SIMD and floating-point functionality from the Secure world is disabled by
421 default and controlled with ENABLE_SVE_FOR_SWD.
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100422 This is to avoid corruption of the Non-secure world data in the Z-registers
423 which are aliased by the SIMD and FP registers. The build option is not
424 compatible with the ``CTX_INCLUDE_FPREGS`` build option, and will raise an
425 assert on platforms where SVE is implemented and ``ENABLE_SVE_FOR_NS`` set to
johpow019baade32021-07-08 14:14:00 -0500426 1. The default is 1 but is automatically disabled when ENABLE_SME_FOR_NS=1
Manish Pandey247e5c32021-11-15 15:29:08 +0000427 since SME encompasses SVE. At this time, this build option cannot be used on
428 systems that have SPM_MM enabled.
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100429
Max Shvetsovc4502772021-03-22 11:59:37 +0000430- ``ENABLE_SVE_FOR_SWD``: Boolean option to enable SVE for the Secure world.
431 SVE is an optional architectural feature for AArch64. Note that this option
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000432 requires ENABLE_SVE_FOR_NS to be enabled. The default is 0 and it
433 is automatically disabled when the target architecture is AArch32.
Max Shvetsovc4502772021-03-22 11:59:37 +0000434
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100435- ``ENABLE_STACK_PROTECTOR``: String option to enable the stack protection
436 checks in GCC. Allowed values are "all", "strong", "default" and "none". The
437 default value is set to "none". "strong" is the recommended stack protection
438 level if this feature is desired. "none" disables the stack protection. For
439 all values other than "none", the ``plat_get_stack_protector_canary()``
440 platform hook needs to be implemented. The value is passed as the last
441 component of the option ``-fstack-protector-$ENABLE_STACK_PROTECTOR``.
442
Sumit Gargc0c369c2019-11-15 18:47:53 +0530443- ``ENCRYPT_BL31``: Binary flag to enable encryption of BL31 firmware. This
Manish Pandey34a305e2021-10-21 21:53:49 +0100444 flag depends on ``DECRYPTION_SUPPORT`` build flag.
Sumit Gargc0c369c2019-11-15 18:47:53 +0530445
446- ``ENCRYPT_BL32``: Binary flag to enable encryption of Secure BL32 payload.
Manish Pandey34a305e2021-10-21 21:53:49 +0100447 This flag depends on ``DECRYPTION_SUPPORT`` build flag.
Sumit Gargc0c369c2019-11-15 18:47:53 +0530448
449- ``ENC_KEY``: A 32-byte (256-bit) symmetric key in hex string format. It could
450 either be SSK or BSSK depending on ``FW_ENC_STATUS`` flag. This value depends
Manish Pandey34a305e2021-10-21 21:53:49 +0100451 on ``DECRYPTION_SUPPORT`` build flag.
Sumit Gargc0c369c2019-11-15 18:47:53 +0530452
453- ``ENC_NONCE``: A 12-byte (96-bit) encryption nonce or Initialization Vector
454 (IV) in hex string format. This value depends on ``DECRYPTION_SUPPORT``
Manish Pandey34a305e2021-10-21 21:53:49 +0100455 build flag.
Sumit Gargc0c369c2019-11-15 18:47:53 +0530456
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100457- ``ERROR_DEPRECATED``: This option decides whether to treat the usage of
458 deprecated platform APIs, helper functions or drivers within Trusted
459 Firmware as error. It can take the value 1 (flag the use of deprecated
460 APIs as error) or 0. The default is 0.
461
462- ``EL3_EXCEPTION_HANDLING``: When set to ``1``, enable handling of exceptions
463 targeted at EL3. When set ``0`` (default), no exceptions are expected or
464 handled at EL3, and a panic will result. This is supported only for AArch64
465 builds.
466
Javier Almansa Sobrino0d1f6b12020-09-18 16:47:07 +0100467- ``EVENT_LOG_LEVEL``: Chooses the log level to use for Measured Boot when
468 ``MEASURED_BOOT`` is enabled. For a list of valid values, see ``LOG_LEVEL``.
469 Default value is 40 (LOG_LEVEL_INFO).
470
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100471- ``FAULT_INJECTION_SUPPORT``: ARMv8.4 extensions introduced support for fault
472 injection from lower ELs, and this build option enables lower ELs to use
473 Error Records accessed via System Registers to inject faults. This is
474 applicable only to AArch64 builds.
475
476 This feature is intended for testing purposes only, and is advisable to keep
477 disabled for production images.
478
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000479- ``FEATURE_DETECTION``: Boolean option to enable the architectural features
480 detection mechanism. It detects whether the Architectural features enabled
481 through feature specific build flags are supported by the PE or not by
482 validating them either at boot phase or at runtime based on the value
483 possessed by the feature flag (0 to 2) and report error messages at an early
484 stage.
485
486 This prevents and benefits us from EL3 runtime exceptions during context save
487 and restore routines guarded by these build flags. Henceforth validating them
488 before their usage provides more control on the actions taken under them.
489
490 The mechanism permits the build flags to take values 0, 1 or 2 and
491 evaluates them accordingly.
492
493 Lets consider ``ENABLE_FEAT_HCX``, build flag for ``FEAT_HCX`` as an example:
494
495 ::
496
497 ENABLE_FEAT_HCX = 0: Feature disabled statically at compile time.
498 ENABLE_FEAT_HCX = 1: Feature Enabled and the flag is validated at boottime.
499 ENABLE_FEAT_HCX = 2: Feature Enabled and the flag is validated at runtime.
500
501 In the above example, if the feature build flag, ``ENABLE_FEAT_HCX`` set to
502 0, feature is disabled statically during compilation. If it is defined as 1,
503 feature is validated, wherein FEAT_HCX is detected at boot time. In case not
504 implemented by the PE, a hard panic is generated. Finally, if the flag is set
505 to 2, feature is validated at runtime.
506
507 Note that the entire implementation is divided into two phases, wherein as
508 as part of phase-1 we are supporting the values 0,1. Value 2 is currently not
509 supported and is planned to be handled explicilty in phase-2 implementation.
510
511 FEATURE_DETECTION macro is disabled by default, and is currently an
512 experimental procedure. Platforms can explicitly make use of this by
513 mechanism, by enabling it to validate whether they have set their build flags
514 properly at an early phase.
515
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100516- ``FIP_NAME``: This is an optional build option which specifies the FIP
517 filename for the ``fip`` target. Default is ``fip.bin``.
518
519- ``FWU_FIP_NAME``: This is an optional build option which specifies the FWU
520 FIP filename for the ``fwu_fip`` target. Default is ``fwu_fip.bin``.
521
Sumit Gargc0c369c2019-11-15 18:47:53 +0530522- ``FW_ENC_STATUS``: Top level firmware's encryption numeric flag, values:
523
524 ::
525
526 0: Encryption is done with Secret Symmetric Key (SSK) which is common
527 for a class of devices.
528 1: Encryption is done with Binding Secret Symmetric Key (BSSK) which is
529 unique per device.
530
Manish Pandey34a305e2021-10-21 21:53:49 +0100531 This flag depends on ``DECRYPTION_SUPPORT`` build flag.
Sumit Gargc0c369c2019-11-15 18:47:53 +0530532
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100533- ``GENERATE_COT``: Boolean flag used to build and execute the ``cert_create``
534 tool to create certificates as per the Chain of Trust described in
535 :ref:`Trusted Board Boot`. The build system then calls ``fiptool`` to
536 include the certificates in the FIP and FWU_FIP. Default value is '0'.
537
538 Specify both ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=1`` to include support
539 for the Trusted Board Boot feature in the BL1 and BL2 images, to generate
540 the corresponding certificates, and to include those certificates in the
541 FIP and FWU_FIP.
542
543 Note that if ``TRUSTED_BOARD_BOOT=0`` and ``GENERATE_COT=1``, the BL1 and BL2
544 images will not include support for Trusted Board Boot. The FIP will still
545 include the corresponding certificates. This FIP can be used to verify the
546 Chain of Trust on the host machine through other mechanisms.
547
548 Note that if ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=0``, the BL1 and BL2
549 images will include support for Trusted Board Boot, but the FIP and FWU_FIP
550 will not include the corresponding certificates, causing a boot failure.
551
552- ``GICV2_G0_FOR_EL3``: Unlike GICv3, the GICv2 architecture doesn't have
553 inherent support for specific EL3 type interrupts. Setting this build option
554 to ``1`` assumes GICv2 *Group 0* interrupts are expected to target EL3, both
Madhukar Pappireddy86350ae2020-07-29 09:37:25 -0500555 by :ref:`platform abstraction layer<platform Interrupt Controller API>` and
556 :ref:`Interrupt Management Framework<Interrupt Management Framework>`.
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100557 This allows GICv2 platforms to enable features requiring EL3 interrupt type.
558 This also means that all GICv2 Group 0 interrupts are delivered to EL3, and
559 the Secure Payload interrupts needs to be synchronously handed over to Secure
560 EL1 for handling. The default value of this option is ``0``, which means the
561 Group 0 interrupts are assumed to be handled by Secure EL1.
562
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100563- ``HANDLE_EA_EL3_FIRST``: When set to ``1``, External Aborts and SError
564 Interrupts will be always trapped in EL3 i.e. in BL31 at runtime. When set to
565 ``0`` (default), these exceptions will be trapped in the current exception
566 level (or in EL1 if the current exception level is EL0).
567
568- ``HW_ASSISTED_COHERENCY``: On most Arm systems to-date, platform-specific
569 software operations are required for CPUs to enter and exit coherency.
570 However, newer systems exist where CPUs' entry to and exit from coherency
571 is managed in hardware. Such systems require software to only initiate these
572 operations, and the rest is managed in hardware, minimizing active software
573 management. In such systems, this boolean option enables TF-A to carry out
574 build and run-time optimizations during boot and power management operations.
575 This option defaults to 0 and if it is enabled, then it implies
576 ``WARMBOOT_ENABLE_DCACHE_EARLY`` is also enabled.
577
578 If this flag is disabled while the platform which TF-A is compiled for
579 includes cores that manage coherency in hardware, then a compilation error is
580 generated. This is based on the fact that a system cannot have, at the same
581 time, cores that manage coherency in hardware and cores that don't. In other
582 words, a platform cannot have, at the same time, cores that require
583 ``HW_ASSISTED_COHERENCY=1`` and cores that require
584 ``HW_ASSISTED_COHERENCY=0``.
585
586 Note that, when ``HW_ASSISTED_COHERENCY`` is enabled, version 2 of
587 translation library (xlat tables v2) must be used; version 1 of translation
588 library is not supported.
589
Louis Mayencourtc1c2bf72020-02-13 08:21:34 +0000590- ``INVERTED_MEMMAP``: memmap tool print by default lower addresses at the
David Horstmannb2cc35f2021-01-21 12:29:59 +0000591 bottom, higher addresses at the top. This build flag can be set to '1' to
Louis Mayencourtc1c2bf72020-02-13 08:21:34 +0000592 invert this behavior. Lower addresses will be printed at the top and higher
593 addresses at the bottom.
594
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100595- ``JUNO_AARCH32_EL3_RUNTIME``: This build flag enables you to execute EL3
596 runtime software in AArch32 mode, which is required to run AArch32 on Juno.
597 By default this flag is set to '0'. Enabling this flag builds BL1 and BL2 in
598 AArch64 and facilitates the loading of ``SP_MIN`` and BL33 as AArch32 executable
599 images.
600
601- ``KEY_ALG``: This build flag enables the user to select the algorithm to be
602 used for generating the PKCS keys and subsequent signing of the certificate.
603 It accepts 3 values: ``rsa``, ``rsa_1_5`` and ``ecdsa``. The option
604 ``rsa_1_5`` is the legacy PKCS#1 RSA 1.5 algorithm which is not TBBR
605 compliant and is retained only for compatibility. The default value of this
606 flag is ``rsa`` which is the TBBR compliant PKCS#1 RSA 2.1 scheme.
607
Gilad Ben-Yossefa6e53422019-09-15 13:29:29 +0300608- ``KEY_SIZE``: This build flag enables the user to select the key size for
609 the algorithm specified by ``KEY_ALG``. The valid values for ``KEY_SIZE``
610 depend on the chosen algorithm and the cryptographic module.
611
612 +-----------+------------------------------------+
613 | KEY_ALG | Possible key sizes |
614 +===========+====================================+
615 | rsa | 1024 , 2048 (default), 3072, 4096* |
616 +-----------+------------------------------------+
617 | ecdsa | unavailable |
618 +-----------+------------------------------------+
619
620 * Only 2048 bits size is available with CryptoCell 712 SBROM release 1.
621 Only 3072 bits size is available with CryptoCell 712 SBROM release 2.
622
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100623- ``HASH_ALG``: This build flag enables the user to select the secure hash
624 algorithm. It accepts 3 values: ``sha256``, ``sha384`` and ``sha512``.
625 The default value of this flag is ``sha256``.
626
627- ``LDFLAGS``: Extra user options appended to the linkers' command line in
628 addition to the one set by the build system.
629
630- ``LOG_LEVEL``: Chooses the log level, which controls the amount of console log
631 output compiled into the build. This should be one of the following:
632
633 ::
634
635 0 (LOG_LEVEL_NONE)
636 10 (LOG_LEVEL_ERROR)
637 20 (LOG_LEVEL_NOTICE)
638 30 (LOG_LEVEL_WARNING)
639 40 (LOG_LEVEL_INFO)
640 50 (LOG_LEVEL_VERBOSE)
641
642 All log output up to and including the selected log level is compiled into
643 the build. The default value is 40 in debug builds and 20 in release builds.
644
Alexei Fedorov913cb7e2020-01-23 14:27:38 +0000645- ``MEASURED_BOOT``: Boolean flag to include support for the Measured Boot
Manish V Badarkhe92de80a2021-12-16 10:41:47 +0000646 feature. This flag can be enabled with ``TRUSTED_BOARD_BOOT`` in order to
647 provide trust that the code taking the measurements and recording them has
648 not been tampered with.
Sandrine Bailleux533d8b32021-06-10 11:18:04 +0200649
Manish Pandey34a305e2021-10-21 21:53:49 +0100650 This option defaults to 0.
Alexei Fedorov913cb7e2020-01-23 14:27:38 +0000651
Manish V Badarkhe8564f772022-02-14 18:31:16 +0000652- ``DRTM_SUPPORT``: Boolean flag to enable support for Dynamic Root of Trust
653 for Measurement (DRTM). This feature has trust dependency on BL31 for taking
654 the measurements and recording them as per `PSA DRTM specification`_. For
655 platforms which use BL2 to load/authenticate BL31 ``TRUSTED_BOARD_BOOT`` can
656 be used and for the platforms which use ``RESET_TO_BL31`` platform owners
657 should have mechanism to authenticate BL31.
658
659 This option defaults to 0.
660
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100661- ``NON_TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It
662 specifies the file that contains the Non-Trusted World private key in PEM
663 format. If ``SAVE_KEYS=1``, this file name will be used to save the key.
664
665- ``NS_BL2U``: Path to NS_BL2U image in the host file system. This image is
666 optional. It is only needed if the platform makefile specifies that it
667 is required in order to build the ``fwu_fip`` target.
668
669- ``NS_TIMER_SWITCH``: Enable save and restore for non-secure timer register
670 contents upon world switch. It can take either 0 (don't save and restore) or
671 1 (do save and restore). 0 is the default. An SPD may set this to 1 if it
672 wants the timer registers to be saved and restored.
673
674- ``OVERRIDE_LIBC``: This option allows platforms to override the default libc
675 for the BL image. It can be either 0 (include) or 1 (remove). The default
676 value is 0.
677
678- ``PL011_GENERIC_UART``: Boolean option to indicate the PL011 driver that
679 the underlying hardware is not a full PL011 UART but a minimally compliant
680 generic UART, which is a subset of the PL011. The driver will not access
681 any register that is not part of the SBSA generic UART specification.
682 Default value is 0 (a full PL011 compliant UART is present).
683
684- ``PLAT``: Choose a platform to build TF-A for. The chosen platform name
685 must be subdirectory of any depth under ``plat/``, and must contain a
686 platform makefile named ``platform.mk``. For example, to build TF-A for the
687 Arm Juno board, select PLAT=juno.
688
689- ``PRELOADED_BL33_BASE``: This option enables booting a preloaded BL33 image
690 instead of the normal boot flow. When defined, it must specify the entry
691 point address for the preloaded BL33 image. This option is incompatible with
692 ``EL3_PAYLOAD_BASE``. If both are defined, ``EL3_PAYLOAD_BASE`` has priority
693 over ``PRELOADED_BL33_BASE``.
694
695- ``PROGRAMMABLE_RESET_ADDRESS``: This option indicates whether the reset
696 vector address can be programmed or is fixed on the platform. It can take
697 either 0 (fixed) or 1 (programmable). Default is 0. If the platform has a
698 programmable reset address, it is expected that a CPU will start executing
699 code directly at the right address, both on a cold and warm reset. In this
700 case, there is no need to identify the entrypoint on boot and the boot path
701 can be optimised. The ``plat_get_my_entrypoint()`` platform porting interface
702 does not need to be implemented in this case.
703
704- ``PSCI_EXTENDED_STATE_ID``: As per PSCI1.0 Specification, there are 2 formats
705 possible for the PSCI power-state parameter: original and extended State-ID
706 formats. This flag if set to 1, configures the generic PSCI layer to use the
707 extended format. The default value of this flag is 0, which means by default
708 the original power-state format is used by the PSCI implementation. This flag
709 should be specified by the platform makefile and it governs the return value
710 of PSCI_FEATURES API for CPU_SUSPEND smc function id. When this option is
711 enabled on Arm platforms, the option ``ARM_RECOM_STATE_ID_ENC`` needs to be
712 set to 1 as well.
713
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000714- ``RAS_EXTENSION``: Numeric value to enable Armv8.2 RAS features. RAS features
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100715 are an optional extension for pre-Armv8.2 CPUs, but are mandatory for Armv8.2
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000716 or later CPUs. This flag can take the values 0 to 2, to align with the
717 ``FEATURE_DETECTION`` mechanism.
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100718
719 When ``RAS_EXTENSION`` is set to ``1``, ``HANDLE_EA_EL3_FIRST`` must also be
720 set to ``1``.
721
722 This option is disabled by default.
723
724- ``RESET_TO_BL31``: Enable BL31 entrypoint as the CPU reset vector instead
725 of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1
726 entrypoint) or 1 (CPU reset to BL31 entrypoint).
727 The default value is 0.
728
Jorge Ramirez-Ortiz598db322022-04-15 11:51:03 +0200729- ``RESET_TO_BL31_WITH_PARAMS``: If ``RESET_TO_BL31`` has been enabled, setting
730 this additional option guarantees that the input registers are not cleared
731 therefore allowing parameters to be passed to the BL31 entrypoint.
732 The default value is 0.
733
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100734- ``RESET_TO_SP_MIN``: SP_MIN is the minimal AArch32 Secure Payload provided
735 in TF-A. This flag configures SP_MIN entrypoint as the CPU reset vector
736 instead of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1
737 entrypoint) or 1 (CPU reset to SP_MIN entrypoint). The default value is 0.
738
739- ``ROT_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the
Max Shvetsov06dba292019-12-06 11:50:12 +0000740 file that contains the ROT private key in PEM format and enforces public key
741 hash generation. If ``SAVE_KEYS=1``, this
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100742 file name will be used to save the key.
743
744- ``SAVE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the
745 certificate generation tool to save the keys used to establish the Chain of
746 Trust. Allowed options are '0' or '1'. Default is '0' (do not save).
747
748- ``SCP_BL2``: Path to SCP_BL2 image in the host file system. This image is optional.
749 If a SCP_BL2 image is present then this option must be passed for the ``fip``
750 target.
751
752- ``SCP_BL2_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the
753 file that contains the SCP_BL2 private key in PEM format. If ``SAVE_KEYS=1``,
754 this file name will be used to save the key.
755
756- ``SCP_BL2U``: Path to SCP_BL2U image in the host file system. This image is
757 optional. It is only needed if the platform makefile specifies that it
758 is required in order to build the ``fwu_fip`` target.
759
760- ``SDEI_SUPPORT``: Setting this to ``1`` enables support for Software
761 Delegated Exception Interface to BL31 image. This defaults to ``0``.
762
763 When set to ``1``, the build option ``EL3_EXCEPTION_HANDLING`` must also be
764 set to ``1``.
765
766- ``SEPARATE_CODE_AND_RODATA``: Whether code and read-only data should be
767 isolated on separate memory pages. This is a trade-off between security and
768 memory usage. See "Isolating code and read-only data on separate memory
Olivier Deprez7efa3f12020-03-26 16:09:21 +0100769 pages" section in :ref:`Firmware Design`. This flag is disabled by default
770 and affects all BL images.
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100771
Samuel Holland31a14e12018-10-17 21:40:18 -0500772- ``SEPARATE_NOBITS_REGION``: Setting this option to ``1`` allows the NOBITS
773 sections of BL31 (.bss, stacks, page tables, and coherent memory) to be
774 allocated in RAM discontiguous from the loaded firmware image. When set, the
David Horstmannb2cc35f2021-01-21 12:29:59 +0000775 platform is expected to provide definitions for ``BL31_NOBITS_BASE`` and
Samuel Holland31a14e12018-10-17 21:40:18 -0500776 ``BL31_NOBITS_LIMIT``. When the option is ``0`` (the default), NOBITS
777 sections are placed in RAM immediately following the loaded firmware image.
778
Jiafei Pan0824b452022-02-24 10:47:33 +0800779- ``SEPARATE_BL2_NOLOAD_REGION``: Setting this option to ``1`` allows the
780 NOLOAD sections of BL2 (.bss, stacks, page tables) to be allocated in RAM
781 discontiguous from loaded firmware images. When set, the platform need to
782 provide definitions of ``BL2_NOLOAD_START`` and ``BL2_NOLOAD_LIMIT``. This
783 flag is disabled by default and NOLOAD sections are placed in RAM immediately
784 following the loaded firmware image.
785
Jeremy Linton684a0792021-01-26 22:42:03 -0600786- ``SMC_PCI_SUPPORT``: This option allows platforms to handle PCI configuration
787 access requests via a standard SMCCC defined in `DEN0115`_. When combined with
788 UEFI+ACPI this can provide a certain amount of OS forward compatibility
789 with newer platforms that aren't ECAM compliant.
790
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100791- ``SPD``: Choose a Secure Payload Dispatcher component to be built into TF-A.
792 This build option is only valid if ``ARCH=aarch64``. The value should be
793 the path to the directory containing the SPD source, relative to
794 ``services/spd/``; the directory is expected to contain a makefile called
Olivier Deprez7efa3f12020-03-26 16:09:21 +0100795 ``<spd-value>.mk``. The SPM Dispatcher standard service is located in
796 services/std_svc/spmd and enabled by ``SPD=spmd``. The SPM Dispatcher
797 cannot be enabled when the ``SPM_MM`` option is enabled.
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100798
799- ``SPIN_ON_BL1_EXIT``: This option introduces an infinite loop in BL1. It can
800 take either 0 (no loop) or 1 (add a loop). 0 is the default. This loop stops
801 execution in BL1 just before handing over to BL31. At this point, all
802 firmware images have been loaded in memory, and the MMU and caches are
803 turned off. Refer to the "Debugging options" section for more details.
804
Marc Bonniciabaac162021-12-01 18:00:40 +0000805- ``SPMC_AT_EL3`` : This boolean option is used jointly with the SPM
806 Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC
807 component runs at the EL3 exception level. The default value is ``0`` (
808 disabled). This configuration supports pre-Armv8.4 platforms (aka not
809 implementing the ``FEAT_SEL2`` extension). This is an experimental feature.
810
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +0000811- ``SPMD_SPM_AT_SEL2`` : This boolean option is used jointly with the SPM
Olivier Deprez7efa3f12020-03-26 16:09:21 +0100812 Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC
Marc Bonniciabaac162021-12-01 18:00:40 +0000813 component runs at the S-EL2 exception level provided by the ``FEAT_SEL2``
Olivier Deprez7efa3f12020-03-26 16:09:21 +0100814 extension. This is the default when enabling the SPM Dispatcher. When
815 disabled (0) it indicates the SPMC component runs at the S-EL1 execution
Marc Bonniciabaac162021-12-01 18:00:40 +0000816 state or at EL3 if ``SPMC_AT_EL3`` is enabled. The latter configurations
817 support pre-Armv8.4 platforms (aka not implementing the ``FEAT_SEL2``
818 extension).
Olivier Deprez7efa3f12020-03-26 16:09:21 +0100819
Paul Beesleyfe975b42019-09-16 11:29:03 +0000820- ``SPM_MM`` : Boolean option to enable the Management Mode (MM)-based Secure
Olivier Deprez7efa3f12020-03-26 16:09:21 +0100821 Partition Manager (SPM) implementation. The default value is ``0``
822 (disabled). This option cannot be enabled (``1``) when SPM Dispatcher is
823 enabled (``SPD=spmd``).
Paul Beesleyfe975b42019-09-16 11:29:03 +0000824
Manish Pandey3f90ad72020-01-14 11:52:05 +0000825- ``SP_LAYOUT_FILE``: Platform provided path to JSON file containing the
Olivier Deprez7efa3f12020-03-26 16:09:21 +0100826 description of secure partitions. The build system will parse this file and
827 package all secure partition blobs into the FIP. This file is not
828 necessarily part of TF-A tree. Only available when ``SPD=spmd``.
Manish Pandey3f90ad72020-01-14 11:52:05 +0000829
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100830- ``SP_MIN_WITH_SECURE_FIQ``: Boolean flag to indicate the SP_MIN handles
831 secure interrupts (caught through the FIQ line). Platforms can enable
832 this directive if they need to handle such interruption. When enabled,
833 the FIQ are handled in monitor mode and non secure world is not allowed
834 to mask these events. Platforms that enable FIQ handling in SP_MIN shall
835 implement the api ``sp_min_plat_fiq_handler()``. The default value is 0.
836
Mark Brown64869972022-04-20 18:14:32 +0100837- ``SVE_VECTOR_LEN``: SVE vector length to configure in ZCR_EL3.
838 Platforms can configure this if they need to lower the hardware
839 limit, for example due to asymmetric configuration or limitations of
840 software run at lower ELs. The default is the architectural maximum
841 of 2048 which should be suitable for most configurations, the
842 hardware will limit the effective VL to the maximum physically supported
843 VL.
844
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100845- ``TRUSTED_BOARD_BOOT``: Boolean flag to include support for the Trusted Board
846 Boot feature. When set to '1', BL1 and BL2 images include support to load
847 and verify the certificates and images in a FIP, and BL1 includes support
848 for the Firmware Update. The default value is '0'. Generation and inclusion
849 of certificates in the FIP and FWU_FIP depends upon the value of the
850 ``GENERATE_COT`` option.
851
852 .. warning::
853 This option depends on ``CREATE_KEYS`` to be enabled. If the keys
854 already exist in disk, they will be overwritten without further notice.
855
856- ``TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It
857 specifies the file that contains the Trusted World private key in PEM
858 format. If ``SAVE_KEYS=1``, this file name will be used to save the key.
859
860- ``TSP_INIT_ASYNC``: Choose BL32 initialization method as asynchronous or
861 synchronous, (see "Initializing a BL32 Image" section in
862 :ref:`Firmware Design`). It can take the value 0 (BL32 is initialized using
863 synchronous method) or 1 (BL32 is initialized using asynchronous method).
864 Default is 0.
865
866- ``TSP_NS_INTR_ASYNC_PREEMPT``: A non zero value enables the interrupt
867 routing model which routes non-secure interrupts asynchronously from TSP
868 to EL3 causing immediate preemption of TSP. The EL3 is responsible
869 for saving and restoring the TSP context in this routing model. The
870 default routing model (when the value is 0) is to route non-secure
871 interrupts to TSP allowing it to save its context and hand over
872 synchronously to EL3 via an SMC.
873
874 .. note::
875 When ``EL3_EXCEPTION_HANDLING`` is ``1``, ``TSP_NS_INTR_ASYNC_PREEMPT``
876 must also be set to ``1``.
877
Jayanth Dodderi Chidanand4b5489c2022-03-28 15:28:55 +0100878- ``TWED_DELAY``: Numeric value to be set in order to delay the trapping of
879 WFE instruction. ``ENABLE_FEAT_TWED`` build option must be enabled to set
880 this delay. It can take values in the range (0-15). Default value is ``0``
881 and based on this value, 2^(TWED_DELAY + 8) cycles will be delayed.
882 Platforms need to explicitly update this value based on their requirements.
883
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100884- ``USE_ARM_LINK``: This flag determines whether to enable support for ARM
885 linker. When the ``LINKER`` build variable points to the armlink linker,
886 this flag is enabled automatically. To enable support for armlink, platforms
887 will have to provide a scatter file for the BL image. Currently, Tegra
888 platforms use the armlink support to compile BL3-1 images.
889
890- ``USE_COHERENT_MEM``: This flag determines whether to include the coherent
891 memory region in the BL memory map or not (see "Use of Coherent memory in
892 TF-A" section in :ref:`Firmware Design`). It can take the value 1
893 (Coherent memory region is included) or 0 (Coherent memory region is
894 excluded). Default is 1.
895
Ambroise Vincent9660dc12019-07-12 13:47:03 +0100896- ``USE_DEBUGFS``: When set to 1 this option activates an EXPERIMENTAL feature
897 exposing a virtual filesystem interface through BL31 as a SiP SMC function.
898 Default is 0.
899
Louis Mayencourt6b232d92020-02-28 16:57:30 +0000900- ``ARM_IO_IN_DTB``: This flag determines whether to use IO based on the
901 firmware configuration framework. This will move the io_policies into a
Louis Mayencourtbadcac82019-10-24 15:18:46 +0100902 configuration device tree, instead of static structure in the code base.
903
Manish V Badarkhead339892020-06-29 10:32:53 +0100904- ``COT_DESC_IN_DTB``: This flag determines whether to create COT descriptors
905 at runtime using fconf. If this flag is enabled, COT descriptors are
906 statically captured in tb_fw_config file in the form of device tree nodes
907 and properties. Currently, COT descriptors used by BL2 are moved to the
908 device tree and COT descriptors used by BL1 are retained in the code
Manish Pandey34a305e2021-10-21 21:53:49 +0100909 base statically.
Manish V Badarkhead339892020-06-29 10:32:53 +0100910
Balint Dobszayd0dbd5e2019-12-18 15:28:00 +0100911- ``SDEI_IN_FCONF``: This flag determines whether to configure SDEI setup in
912 runtime using firmware configuration framework. The platform specific SDEI
913 shared and private events configuration is retrieved from device tree rather
Manish Pandey34a305e2021-10-21 21:53:49 +0100914 than static C structures at compile time. This is only supported if
915 SDEI_SUPPORT build flag is enabled.
Louis Mayencourtbadcac82019-10-24 15:18:46 +0100916
Madhukar Pappireddy02cc3ff2020-06-02 09:26:30 -0500917- ``SEC_INT_DESC_IN_FCONF``: This flag determines whether to configure Group 0
918 and Group1 secure interrupts using the firmware configuration framework. The
919 platform specific secure interrupt property descriptor is retrieved from
920 device tree in runtime rather than depending on static C structure at compile
Manish Pandey34a305e2021-10-21 21:53:49 +0100921 time.
Madhukar Pappireddy02cc3ff2020-06-02 09:26:30 -0500922
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +0100923- ``USE_ROMLIB``: This flag determines whether library at ROM will be used.
924 This feature creates a library of functions to be placed in ROM and thus
925 reduces SRAM usage. Refer to :ref:`Library at ROM` for further details. Default
926 is 0.
927
928- ``V``: Verbose build. If assigned anything other than 0, the build commands
929 are printed. Default is 0.
930
931- ``VERSION_STRING``: String used in the log output for each TF-A image.
932 Defaults to a string formed by concatenating the version number, build type
933 and build string.
934
935- ``W``: Warning level. Some compiler warning options of interest have been
936 regrouped and put in the root Makefile. This flag can take the values 0 to 3,
937 each level enabling more warning options. Default is 0.
938
939- ``WARMBOOT_ENABLE_DCACHE_EARLY`` : Boolean option to enable D-cache early on
940 the CPU after warm boot. This is applicable for platforms which do not
941 require interconnect programming to enable cache coherency (eg: single
942 cluster platforms). If this option is enabled, then warm boot path
943 enables D-caches immediately after enabling MMU. This option defaults to 0.
944
Manish V Badarkhe75c972a2020-03-22 05:06:38 +0000945- ``SUPPORT_STACK_MEMTAG``: This flag determines whether to enable memory
946 tagging for stack or not. It accepts 2 values: ``yes`` and ``no``. The
947 default value of this flag is ``no``. Note this option must be enabled only
948 for ARM architecture greater than Armv8.5-A.
949
Manish V Badarkhea59fa012020-07-31 08:38:49 +0100950- ``ERRATA_SPECULATIVE_AT``: This flag determines whether to enable ``AT``
951 speculative errata workaround or not. It accepts 2 values: ``1`` and ``0``.
952 The default value of this flag is ``0``.
953
954 ``AT`` speculative errata workaround disables stage1 page table walk for
955 lower ELs (EL1 and EL0) in EL3 so that ``AT`` speculative fetch at any point
956 produces either the correct result or failure without TLB allocation.
Manish V Badarkhe2801ed42020-04-28 04:53:32 +0100957
958 This boolean option enables errata for all below CPUs.
959
Manish V Badarkhea59fa012020-07-31 08:38:49 +0100960 +---------+--------------+-------------------------+
961 | Errata | CPU | Workaround Define |
962 +=========+==============+=========================+
963 | 1165522 | Cortex-A76 | ``ERRATA_A76_1165522`` |
964 +---------+--------------+-------------------------+
965 | 1319367 | Cortex-A72 | ``ERRATA_A72_1319367`` |
966 +---------+--------------+-------------------------+
967 | 1319537 | Cortex-A57 | ``ERRATA_A57_1319537`` |
968 +---------+--------------+-------------------------+
969 | 1530923 | Cortex-A55 | ``ERRATA_A55_1530923`` |
970 +---------+--------------+-------------------------+
971 | 1530924 | Cortex-A53 | ``ERRATA_A53_1530924`` |
972 +---------+--------------+-------------------------+
973
974 .. note::
975 This option is enabled by build only if platform sets any of above defines
976 mentioned in ’Workaround Define' column in the table.
977 If this option is enabled for the EL3 software then EL2 software also must
978 implement this workaround due to the behaviour of the errata mentioned
979 in new SDEN document which will get published soon.
Manish V Badarkhe2801ed42020-04-28 04:53:32 +0100980
Varun Wadekar92234852020-06-12 10:11:28 -0700981- ``RAS_TRAP_LOWER_EL_ERR_ACCESS``: This flag enables/disables the SCR_EL3.TERR
982 bit, to trap access to the RAS ERR and RAS ERX registers from lower ELs.
983 This flag is disabled by default.
984
Juan Pablo Conde52865522022-06-28 16:56:32 -0400985- ``OPENSSL_DIR``: This option is used to provide the path to a directory on the
986 host machine where a custom installation of OpenSSL is located, which is used
987 to build the certificate generation, firmware encryption and FIP tools. If
988 this option is not set, the default OS installation will be used.
Manish V Badarkhe3589b702020-07-29 10:58:44 +0100989
Madhukar Pappireddy7a554a12020-08-12 13:18:19 -0500990- ``USE_SP804_TIMER``: Use the SP804 timer instead of the Generic Timer for
991 functions that wait for an arbitrary time length (udelay and mdelay). The
992 default value is 0.
993
Jayanth Dodderi Chidanand69316752022-05-09 12:33:03 +0100994- ``ENABLE_BRBE_FOR_NS``: Numeric value to enable access to the branch record
995 buffer registers from NS ELs when FEAT_BRBE is implemented. BRBE is an
996 optional architectural feature for AArch64. This flag can take the values
997 0 to 2, to align with the ``FEATURE_DETECTION`` mechanism. The default is 0
998 and it is automatically disabled when the target architecture is AArch32.
johpow0181865962022-01-28 17:06:20 -0600999
Jayanth Dodderi Chidananda793ccc2022-05-19 14:08:28 +01001000- ``ENABLE_TRBE_FOR_NS``: Numeric value to enable access of trace buffer
Manish V Badarkhe20df29c2021-07-02 09:10:56 +01001001 control registers from NS ELs, NS-EL2 or NS-EL1(when NS-EL2 is implemented
1002 but unused) when FEAT_TRBE is implemented. TRBE is an optional architectural
Jayanth Dodderi Chidananda793ccc2022-05-19 14:08:28 +01001003 feature for AArch64. This flag can take the values 0 to 2, to align with the
1004 ``FEATURE_DETECTION`` mechanism. The default is 0 and it is automatically
1005 disabled when the target architecture is AArch32.
Manish V Badarkhe20df29c2021-07-02 09:10:56 +01001006
Manish V Badarkhef356f7e2021-06-29 11:44:20 +01001007- ``ENABLE_SYS_REG_TRACE_FOR_NS``: Boolean option to enable trace system
1008 registers access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented
1009 but unused). This feature is available if trace unit such as ETMv4.x, and
1010 ETE(extending ETM feature) is implemented. This flag is disabled by default.
1011
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +00001012- ``ENABLE_TRF_FOR_NS``: Numeric value to enable trace filter control registers
Manish V Badarkhe51a97112021-07-08 09:33:18 +01001013 access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented but unused),
Jayanth Dodderi Chidanand38b461a2022-02-28 23:41:41 +00001014 if FEAT_TRF is implemented. This flag can take the values 0 to 2, to align
1015 with the ``FEATURE_DETECTION`` mechanism. This flag is disabled by default.
Manish V Badarkhe51a97112021-07-08 09:33:18 +01001016
Tamas Banc9ccc272022-01-18 16:20:47 +01001017- ``PLAT_RSS_NOT_SUPPORTED``: Boolean option to enable the usage of the PSA
1018 APIs on platforms that doesn't support RSS (providing Arm CCA HES
1019 functionalities). When enabled (``1``), a mocked version of the APIs are used.
1020 The default value is 0.
1021
Alexei Fedorov84f1b5d2020-03-23 18:45:17 +00001022GICv3 driver options
1023--------------------
1024
1025GICv3 driver files are included using directive:
1026
1027``include drivers/arm/gic/v3/gicv3.mk``
1028
1029The driver can be configured with the following options set in the platform
1030makefile:
1031
Andre Przywarae1cc1302020-03-25 15:50:38 +00001032- ``GICV3_SUPPORT_GIC600``: Add support for the GIC-600 variants of GICv3.
1033 Enabling this option will add runtime detection support for the
1034 GIC-600, so is safe to select even for a GIC500 implementation.
1035 This option defaults to 0.
Alexei Fedorov84f1b5d2020-03-23 18:45:17 +00001036
Varun Wadekareea6dc12021-05-04 16:14:09 -07001037- ``GICV3_SUPPORT_GIC600AE_FMU``: Add support for the Fault Management Unit
1038 for GIC-600 AE. Enabling this option will introduce support to initialize
1039 the FMU. Platforms should call the init function during boot to enable the
1040 FMU and its safety mechanisms. This option defaults to 0.
1041
Alexei Fedorov84f1b5d2020-03-23 18:45:17 +00001042- ``GICV3_IMPL_GIC600_MULTICHIP``: Selects GIC-600 variant with multichip
1043 functionality. This option defaults to 0
1044
1045- ``GICV3_OVERRIDE_DISTIF_PWR_OPS``: Allows override of default implementation
1046 of ``arm_gicv3_distif_pre_save`` and ``arm_gicv3_distif_post_restore``
1047 functions. This is required for FVP platform which need to simulate GIC save
1048 and restore during SYSTEM_SUSPEND without powering down GIC. Default is 0.
1049
Alexei Fedorov19705932020-04-06 19:00:35 +01001050- ``GIC_ENABLE_V4_EXTN`` : Enables GICv4 related changes in GICv3 driver.
1051 This option defaults to 0.
1052
Alexei Fedorova6e6ae02020-04-06 16:27:54 +01001053- ``GIC_EXT_INTID``: When set to ``1``, GICv3 driver will support extended
1054 PPI (1056-1119) and SPI (4096-5119) range. This option defaults to 0.
1055
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +01001056Debugging options
1057-----------------
1058
1059To compile a debug version and make the build more verbose use
1060
1061.. code:: shell
1062
1063 make PLAT=<platform> DEBUG=1 V=1 all
1064
Daniel Boulbydf83a832022-05-03 16:46:16 +01001065AArch64 GCC 11 uses DWARF version 5 debugging symbols by default. Some tools
1066(for example Arm-DS) might not support this and may need an older version of
1067DWARF symbols to be emitted by GCC. This can be achieved by using the
1068``-gdwarf-<version>`` flag, with the version being set to 2, 3, 4 or 5. Setting
1069the version to 4 is recommended for Arm-DS.
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +01001070
1071When debugging logic problems it might also be useful to disable all compiler
1072optimizations by using ``-O0``.
1073
1074.. warning::
1075 Using ``-O0`` could cause output images to be larger and base addresses
1076 might need to be recalculated (see the **Memory layout on Arm development
1077 platforms** section in the :ref:`Firmware Design`).
1078
1079Extra debug options can be passed to the build system by setting ``CFLAGS`` or
1080``LDFLAGS``:
1081
1082.. code:: shell
1083
1084 CFLAGS='-O0 -gdwarf-2' \
1085 make PLAT=<platform> DEBUG=1 V=1 all
1086
1087Note that using ``-Wl,`` style compilation driver options in ``CFLAGS`` will be
1088ignored as the linker is called directly.
1089
1090It is also possible to introduce an infinite loop to help in debugging the
1091post-BL2 phase of TF-A. This can be done by rebuilding BL1 with the
1092``SPIN_ON_BL1_EXIT=1`` build flag. Refer to the :ref:`build_options_common`
1093section. In this case, the developer may take control of the target using a
Daniel Boulbydf83a832022-05-03 16:46:16 +01001094debugger when indicated by the console output. When using Arm-DS, the following
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +01001095commands can be used:
1096
1097::
1098
1099 # Stop target execution
1100 interrupt
1101
1102 #
1103 # Prepare your debugging environment, e.g. set breakpoints
1104 #
1105
1106 # Jump over the debug loop
1107 set var $AARCH64::$Core::$PC = $AARCH64::$Core::$PC + 4
1108
1109 # Resume execution
1110 continue
1111
Manish V Badarkhe5c101ae2021-03-16 11:14:19 +00001112Firmware update options
1113-----------------------
1114
1115- ``NR_OF_FW_BANKS``: Define the number of firmware banks. This flag is used
1116 in defining the firmware update metadata structure. This flag is by default
1117 set to '2'.
1118
1119- ``NR_OF_IMAGES_IN_FW_BANK``: Define the number of firmware images in each
1120 firmware bank. Each firmware bank must have the same number of images as per
1121 the `PSA FW update specification`_.
1122 This flag is used in defining the firmware update metadata structure. This
1123 flag is by default set to '1'.
1124
Manish V Badarkheda87af12021-06-20 21:14:46 +01001125- ``PSA_FWU_SUPPORT``: Enable the firmware update mechanism as per the
1126 `PSA FW update specification`_. The default value is 0, and this is an
1127 experimental feature.
1128 PSA firmware update implementation has some limitations, such as BL2 is
1129 not part of the protocol-updatable images, if BL2 needs to be updated, then
1130 it should be done through another platform-defined mechanism, and it assumes
1131 that the platform's hardware supports CRC32 instructions.
1132
Paul Beesleyd2fcc4e2019-05-29 13:59:40 +01001133--------------
1134
Jiafei Pan0824b452022-02-24 10:47:33 +08001135*Copyright (c) 2019-2022, Arm Limited. All rights reserved.*
Jeremy Linton684a0792021-01-26 22:42:03 -06001136
1137.. _DEN0115: https://developer.arm.com/docs/den0115/latest
Manish V Badarkhe5c101ae2021-03-16 11:14:19 +00001138.. _PSA FW update specification: https://developer.arm.com/documentation/den0118/a/
Manish V Badarkhe8564f772022-02-14 18:31:16 +00001139.. _PSA DRTM specification: https://developer.arm.com/documentation/den0113/a