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- ``ARM_BL2_SP_LIST_DTS``: Path to DTS file snippet to override the hardcoded 49 SP nodes in tb_fw_config. 50 51- ``ARM_SPMC_MANIFEST_DTS`` : path to an alternate manifest file used as the 52 SPMC Core manifest. Valid when ``SPD=spmd`` is selected. 53 54- ``BL2``: This is an optional build option which specifies the path to BL2 55 image for the ``fip`` target. In this case, the BL2 in the TF-A will not be 56 built. 57 58- ``BL2U``: This is an optional build option which specifies the path to 59 BL2U image. In this case, the BL2U in TF-A will not be built. 60 61- ``RESET_TO_BL2``: Boolean option to enable BL2 entrypoint as the CPU reset 62 vector instead of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1 63 entrypoint) or 1 (CPU reset to BL2 entrypoint). 64 The default value is 0. 65 66- ``BL2_RUNS_AT_EL3``: This is an implicit flag to denote that BL2 runs at EL3. 67 While it is explicitly set to 1 when RESET_TO_BL2 is set to 1 it can also be 68 true in a 4-world system where RESET_TO_BL2 is 0. 69 70- ``BL2_ENABLE_SP_LOAD``: Boolean option to enable loading SP packages from the 71 FIP. Automatically enabled if ``SP_LAYOUT_FILE`` is provided. 72 73- ``BL2_IN_XIP_MEM``: In some use-cases BL2 will be stored in eXecute In Place 74 (XIP) memory, like BL1. In these use-cases, it is necessary to initialize 75 the RW sections in RAM, while leaving the RO sections in place. This option 76 enable this use-case. For now, this option is only supported 77 when RESET_TO_BL2 is set to '1'. 78 79- ``BL31``: This is an optional build option which specifies the path to 80 BL31 image for the ``fip`` target. In this case, the BL31 in TF-A will not 81 be built. 82 83- ``BL31_KEY``: This option is used when ``GENERATE_COT=1``. It specifies a 84 file that contains the BL31 private key in PEM format or a PKCS11 URI. If 85 ``SAVE_KEYS=1``, only a file is accepted and it will be used to save the key. 86 87- ``BL32``: This is an optional build option which specifies the path to 88 BL32 image for the ``fip`` target. In this case, the BL32 in TF-A will not 89 be built. 90 91- ``BL32_EXTRA1``: This is an optional build option which specifies the path to 92 Trusted OS Extra1 image for the ``fip`` target. 93 94- ``BL32_EXTRA2``: This is an optional build option which specifies the path to 95 Trusted OS Extra2 image for the ``fip`` target. 96 97- ``BL32_KEY``: This option is used when ``GENERATE_COT=1``. It specifies a 98 file that contains the BL32 private key in PEM format or a PKCS11 URI. If 99 ``SAVE_KEYS=1``, only a file is accepted and it will be used to save the key. 100 101- ``BL33``: Path to BL33 image in the host file system. This is mandatory for 102 ``fip`` target in case TF-A BL2 is used. 103 104- ``BL33_KEY``: This option is used when ``GENERATE_COT=1``. It specifies a 105 file that contains the BL33 private key in PEM format or a PKCS11 URI. If 106 ``SAVE_KEYS=1``, only a file is accepted and it will be used to save the key. 107 108- ``BRANCH_PROTECTION``: Numeric value to enable ARMv8.3 Pointer Authentication 109 and ARMv8.5 Branch Target Identification support for TF-A BL images themselves. 110 If enabled, it is needed to use a compiler that supports the option 111 ``-mbranch-protection``. Selects the branch protection features to use: 112- 0: Default value turns off all types of branch protection 113- 1: Enables all types of branch protection features 114- 2: Return address signing to its standard level 115- 3: Extend the signing to include leaf functions 116- 4: Turn on branch target identification mechanism 117 118 The table below summarizes ``BRANCH_PROTECTION`` values, GCC compilation options 119 and resulting PAuth/BTI features. 120 121 +-------+--------------+-------+-----+ 122 | Value | GCC option | PAuth | BTI | 123 +=======+==============+=======+=====+ 124 | 0 | none | N | N | 125 +-------+--------------+-------+-----+ 126 | 1 | standard | Y | Y | 127 +-------+--------------+-------+-----+ 128 | 2 | pac-ret | Y | N | 129 +-------+--------------+-------+-----+ 130 | 3 | pac-ret+leaf | Y | N | 131 +-------+--------------+-------+-----+ 132 | 4 | bti | N | Y | 133 +-------+--------------+-------+-----+ 134 135 This option defaults to 0. 136 Note that Pointer Authentication is enabled for Non-secure world 137 irrespective of the value of this option if the CPU supports it. 138 139- ``BUILD_MESSAGE_TIMESTAMP``: String used to identify the time and date of the 140 compilation of each build. It must be set to a C string (including quotes 141 where applicable). Defaults to a string that contains the time and date of 142 the compilation. 143 144- ``BUILD_STRING``: Input string for VERSION_STRING, which allows the TF-A 145 build to be uniquely identified. Defaults to the current git commit id. 146 147- ``BUILD_BASE``: Output directory for the build. Defaults to ``./build`` 148 149- ``CFLAGS``: Extra user options appended on the compiler's command line in 150 addition to the options set by the build system. 151 152- ``COLD_BOOT_SINGLE_CPU``: This option indicates whether the platform may 153 release several CPUs out of reset. It can take either 0 (several CPUs may be 154 brought up) or 1 (only one CPU will ever be brought up during cold reset). 155 Default is 0. If the platform always brings up a single CPU, there is no 156 need to distinguish between primary and secondary CPUs and the boot path can 157 be optimised. The ``plat_is_my_cpu_primary()`` and 158 ``plat_secondary_cold_boot_setup()`` platform porting interfaces do not need 159 to be implemented in this case. 160 161- ``COT``: When Trusted Boot is enabled, selects the desired chain of trust. 162 Defaults to ``tbbr``. 163 164- ``CRASH_REPORTING``: A non-zero value enables a console dump of processor 165 register state when an unexpected exception occurs during execution of 166 BL31. This option defaults to the value of ``DEBUG`` - i.e. by default 167 this is only enabled for a debug build of the firmware. 168 169- ``CREATE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the 170 certificate generation tool to create new keys in case no valid keys are 171 present or specified. Allowed options are '0' or '1'. Default is '1'. 172 173- ``CTX_INCLUDE_AARCH32_REGS`` : Boolean option that, when set to 1, will cause 174 the AArch32 system registers to be included when saving and restoring the 175 CPU context. The option must be set to 0 for AArch64-only platforms (that 176 is on hardware that does not implement AArch32, or at least not at EL1 and 177 higher ELs). Default value is 1. 178 179- ``CTX_INCLUDE_FPREGS``: Boolean option that, when set to 1, will cause the FP 180 registers to be included when saving and restoring the CPU context. Default 181 is 0. 182 183- ``CTX_INCLUDE_MPAM_REGS``: Boolean option that, when set to 1, will cause the 184 Memory System Resource Partitioning and Monitoring (MPAM) 185 registers to be included when saving and restoring the CPU context. 186 Default is '0'. 187 188- ``CTX_INCLUDE_NEVE_REGS``: Numeric value, when set will cause the Armv8.4-NV 189 registers to be saved/restored when entering/exiting an EL2 execution 190 context. This flag can take values 0 to 2, to align with the 191 ``ENABLE_FEAT`` mechanism. Default value is 0. 192 193- ``CTX_INCLUDE_PAUTH_REGS``: Numeric value to enable the Pointer 194 Authentication for Secure world. This will cause the ARMv8.3-PAuth registers 195 to be included when saving and restoring the CPU context as part of world 196 switch. This flag can take values 0 to 2, to align with ``ENABLE_FEAT`` 197 mechanism. Default value is 0. 198 199 Note that Pointer Authentication is enabled for Non-secure world irrespective 200 of the value of this flag if the CPU supports it. 201 202- ``DEBUG``: Chooses between a debug and release build. It can take either 0 203 (release) or 1 (debug) as values. 0 is the default. 204 205- ``DECRYPTION_SUPPORT``: This build flag enables the user to select the 206 authenticated decryption algorithm to be used to decrypt firmware/s during 207 boot. It accepts 2 values: ``aes_gcm`` and ``none``. The default value of 208 this flag is ``none`` to disable firmware decryption which is an optional 209 feature as per TBBR. 210 211- ``DISABLE_BIN_GENERATION``: Boolean option to disable the generation 212 of the binary image. If set to 1, then only the ELF image is built. 213 0 is the default. 214 215- ``DISABLE_MTPMU``: Numeric option to disable ``FEAT_MTPMU`` (Multi Threaded 216 PMU). ``FEAT_MTPMU`` is an optional feature available on Armv8.6 onwards. 217 This flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` 218 mechanism. Default is ``0``. 219 220- ``DYN_DISABLE_AUTH``: Provides the capability to dynamically disable Trusted 221 Board Boot authentication at runtime. This option is meant to be enabled only 222 for development platforms. ``TRUSTED_BOARD_BOOT`` flag must be set if this 223 flag has to be enabled. 0 is the default. 224 225- ``E``: Boolean option to make warnings into errors. Default is 1. 226 227 When specifying higher warnings levels (``W=1`` and higher), this option 228 defaults to 0. This is done to encourage contributors to use them, as they 229 are expected to produce warnings that would otherwise fail the build. New 230 contributions are still expected to build with ``W=0`` and ``E=1`` (the 231 default). 232 233- ``EL3_PAYLOAD_BASE``: This option enables booting an EL3 payload instead of 234 the normal boot flow. It must specify the entry point address of the EL3 235 payload. Please refer to the "Booting an EL3 payload" section for more 236 details. 237 238- ``ENABLE_AMU_AUXILIARY_COUNTERS``: Enables support for AMU auxiliary counters 239 (also known as group 1 counters). These are implementation-defined counters, 240 and as such require additional platform configuration. Default is 0. 241 242- ``ENABLE_AMU_FCONF``: Enables configuration of the AMU through FCONF, which 243 allows platforms with auxiliary counters to describe them via the 244 ``HW_CONFIG`` device tree blob. Default is 0. 245 246- ``ENABLE_ASSERTIONS``: This option controls whether or not calls to ``assert()`` 247 are compiled out. For debug builds, this option defaults to 1, and calls to 248 ``assert()`` are left in place. For release builds, this option defaults to 0 249 and calls to ``assert()`` function are compiled out. This option can be set 250 independently of ``DEBUG``. It can also be used to hide any auxiliary code 251 that is only required for the assertion and does not fit in the assertion 252 itself. 253 254- ``ENABLE_BACKTRACE``: This option controls whether to enable backtrace 255 dumps or not. It is supported in both AArch64 and AArch32. However, in 256 AArch32 the format of the frame records are not defined in the AAPCS and they 257 are defined by the implementation. This implementation of backtrace only 258 supports the format used by GCC when T32 interworking is disabled. For this 259 reason enabling this option in AArch32 will force the compiler to only 260 generate A32 code. This option is enabled by default only in AArch64 debug 261 builds, but this behaviour can be overridden in each platform's Makefile or 262 in the build command line. 263 264- ``ENABLE_FEAT`` 265 The Arm architecture defines several architecture extension features, 266 named FEAT_xxx in the architecure manual. Some of those features require 267 setup code in higher exception levels, other features might be used by TF-A 268 code itself. 269 Most of the feature flags defined in the TF-A build system permit to take 270 the values 0, 1 or 2, with the following meaning: 271 272 :: 273 274 ENABLE_FEAT_* = 0: Feature is disabled statically at compile time. 275 ENABLE_FEAT_* = 1: Feature is enabled unconditionally at compile time. 276 ENABLE_FEAT_* = 2: Feature is enabled, but checked at runtime. 277 278 When setting the flag to 0, the feature is disabled during compilation, 279 and the compiler's optimisation stage and the linker will try to remove 280 as much of this code as possible. 281 If it is defined to 1, the code will use the feature unconditionally, so the 282 CPU is expected to support that feature. The FEATURE_DETECTION debug 283 feature, if enabled, will verify this. 284 If the feature flag is set to 2, support for the feature will be compiled 285 in, but its existence will be checked at runtime, so it works on CPUs with 286 or without the feature. This is mostly useful for platforms which either 287 support multiple different CPUs, or where the CPU is configured at runtime, 288 like in emulators. 289 290- ``ENABLE_FEAT_AMU``: Numeric value to enable Activity Monitor Unit 291 extensions. This flag can take the values 0 to 2, to align with the 292 ``ENABLE_FEAT`` mechanism. This is an optional architectural feature 293 available on v8.4 onwards. Some v8.2 implementations also implement an AMU 294 and this option can be used to enable this feature on those systems as well. 295 This flag can take the values 0 to 2, the default is 0. 296 297- ``ENABLE_FEAT_AMUv1p1``: Numeric value to enable the ``FEAT_AMUv1p1`` 298 extension. ``FEAT_AMUv1p1`` is an optional feature available on Arm v8.6 299 onwards. This flag can take the values 0 to 2, to align with the 300 ``ENABLE_FEAT`` mechanism. Default value is ``0``. 301 302- ``ENABLE_FEAT_CSV2_2``: Numeric value to enable the ``FEAT_CSV2_2`` 303 extension. It allows access to the SCXTNUM_EL2 (Software Context Number) 304 register during EL2 context save/restore operations. ``FEAT_CSV2_2`` is an 305 optional feature available on Arm v8.0 onwards. This flag can take values 306 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. 307 Default value is ``0``. 308 309- ``ENABLE_FEAT_CSV2_3``: Numeric value to enable support for ``FEAT_CSV2_3`` 310 extension. This feature is supported in AArch64 state only and is an optional 311 feature available in Arm v8.0 implementations. 312 ``FEAT_CSV2_3`` implies the implementation of ``FEAT_CSV2_2``. 313 The flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` 314 mechanism. Default value is ``0``. 315 316- ``ENABLE_FEAT_DIT``: Numeric value to enable ``FEAT_DIT`` (Data Independent 317 Timing) extension. It allows setting the ``DIT`` bit of PSTATE in EL3. 318 ``FEAT_DIT`` is a mandatory architectural feature and is enabled from v8.4 319 and upwards. This flag can take the values 0 to 2, to align with the 320 ``ENABLE_FEAT`` mechanism. Default value is ``0``. 321 322- ``ENABLE_FEAT_ECV``: Numeric value to enable support for the Enhanced Counter 323 Virtualization feature, allowing for access to the CNTPOFF_EL2 (Counter-timer 324 Physical Offset register) during EL2 to EL3 context save/restore operations. 325 Its a mandatory architectural feature and is enabled from v8.6 and upwards. 326 This flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` 327 mechanism. Default value is ``0``. 328 329- ``ENABLE_FEAT_FGT``: Numeric value to enable support for FGT (Fine Grain Traps) 330 feature allowing for access to the HDFGRTR_EL2 (Hypervisor Debug Fine-Grained 331 Read Trap Register) during EL2 to EL3 context save/restore operations. 332 Its a mandatory architectural feature and is enabled from v8.6 and upwards. 333 This flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` 334 mechanism. Default value is ``0``. 335 336- ``ENABLE_FEAT_HCX``: Numeric value to set the bit SCR_EL3.HXEn in EL3 to 337 allow access to HCRX_EL2 (extended hypervisor control register) from EL2 as 338 well as adding HCRX_EL2 to the EL2 context save/restore operations. Its a 339 mandatory architectural feature and is enabled from v8.7 and upwards. This 340 flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` 341 mechanism. Default value is ``0``. 342 343- ``ENABLE_FEAT_MTE``: Numeric value to enable Memory Tagging Extension 344 if the platform wants to use this feature at EL0 ``ENABLE_FEAT_MTE`` is 345 required. This flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` 346 feature detection mechanism. Default value is ``0``. 347 348- ``ENABLE_FEAT_MTE2``: Numeric value to enable Memory Tagging Extension2 349 if the platform wants to use this feature and MTE2 is enabled at ELX. 350 This flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` 351 mechanism. Default value is ``0``. 352 353- ``ENABLE_FEAT_MTE_PERM``: Numeric value to enable support for 354 ``FEAT_MTE_PERM``, which introduces Allocation tag access permission to 355 memory region attributes. ``FEAT_MTE_PERM`` is a optional architectural 356 feature available from v8.9 and upwards. This flag can take the values 0 to 357 2, to align with the ``ENABLE_FEAT`` mechanism. Default value is 358 ``0``. 359 360- ``ENABLE_FEAT_PAN``: Numeric value to enable the ``FEAT_PAN`` (Privileged 361 Access Never) extension. ``FEAT_PAN`` adds a bit to PSTATE, generating a 362 permission fault for any privileged data access from EL1/EL2 to virtual 363 memory address, accessible at EL0, provided (HCR_EL2.E2H=1). It is a 364 mandatory architectural feature and is enabled from v8.1 and upwards. This 365 flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` 366 mechanism. Default value is ``0``. 367 368- ``ENABLE_FEAT_RNG``: Numeric value to enable the ``FEAT_RNG`` extension. 369 ``FEAT_RNG`` is an optional feature available on Arm v8.5 onwards. This 370 flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` 371 mechanism. Default value is ``0``. 372 373- ``ENABLE_FEAT_RNG_TRAP``: Numeric value to enable the ``FEAT_RNG_TRAP`` 374 extension. This feature is only supported in AArch64 state. This flag can 375 take values 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. 376 Default value is ``0``. ``FEAT_RNG_TRAP`` is an optional feature from 377 Armv8.5 onwards. 378 379- ``ENABLE_FEAT_SB``: Boolean option to let the TF-A code use the ``FEAT_SB`` 380 (Speculation Barrier) instruction ``FEAT_SB`` is an optional feature and 381 defaults to ``0`` for pre-Armv8.5 CPUs, but is mandatory for Armv8.5 or 382 later CPUs. It is enabled from v8.5 and upwards and if needed can be 383 overidden from platforms explicitly. 384 385- ``ENABLE_FEAT_SEL2``: Numeric value to enable the ``FEAT_SEL2`` (Secure EL2) 386 extension. ``FEAT_SEL2`` is a mandatory feature available on Arm v8.4. 387 This flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` 388 mechanism. Default is ``0``. 389 390- ``ENABLE_FEAT_TWED``: Numeric value to enable the ``FEAT_TWED`` (Delayed 391 trapping of WFE Instruction) extension. ``FEAT_TWED`` is a optional feature 392 available on Arm v8.6. This flag can take values 0 to 2, to align with the 393 ``ENABLE_FEAT`` mechanism. Default is ``0``. 394 395 When ``ENABLE_FEAT_TWED`` is set to ``1``, WFE instruction trapping gets 396 delayed by the amount of value in ``TWED_DELAY``. 397 398- ``ENABLE_FEAT_VHE``: Numeric value to enable the ``FEAT_VHE`` (Virtualization 399 Host Extensions) extension. It allows access to CONTEXTIDR_EL2 register 400 during EL2 context save/restore operations.``FEAT_VHE`` is a mandatory 401 architectural feature and is enabled from v8.1 and upwards. It can take 402 values 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. 403 Default value is ``0``. 404 405- ``ENABLE_FEAT_TCR2``: Numeric value to set the bit SCR_EL3.ENTCR2 in EL3 to 406 allow access to TCR2_EL2 (extended translation control) from EL2 as 407 well as adding TCR2_EL2 to the EL2 context save/restore operations. Its a 408 mandatory architectural feature and is enabled from v8.9 and upwards. This 409 flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` 410 mechanism. Default value is ``0``. 411 412- ``ENABLE_FEAT_S2PIE``: Numeric value to enable support for FEAT_S2PIE 413 at EL2 and below, and context switch relevant registers. This flag 414 can take the values 0 to 2, to align with the ``ENABLE_FEAT`` 415 mechanism. Default value is ``0``. 416 417- ``ENABLE_FEAT_S1PIE``: Numeric value to enable support for FEAT_S1PIE 418 at EL2 and below, and context switch relevant registers. This flag 419 can take the values 0 to 2, to align with the ``ENABLE_FEAT`` 420 mechanism. Default value is ``0``. 421 422- ``ENABLE_FEAT_S2POE``: Numeric value to enable support for FEAT_S2POE 423 at EL2 and below, and context switch relevant registers. This flag 424 can take the values 0 to 2, to align with the ``ENABLE_FEAT`` 425 mechanism. Default value is ``0``. 426 427- ``ENABLE_FEAT_S1POE``: Numeric value to enable support for FEAT_S1POE 428 at EL2 and below, and context switch relevant registers. This flag 429 can take the values 0 to 2, to align with the ``ENABLE_FEAT`` 430 mechanism. Default value is ``0``. 431 432- ``ENABLE_FEAT_GCS``: Numeric value to set the bit SCR_EL3.GCSEn in EL3 to 433 allow use of Guarded Control Stack from EL2 as well as adding the GCS 434 registers to the EL2 context save/restore operations. This flag can take 435 the values 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. 436 Default value is ``0``. 437 438- ``ENABLE_LTO``: Boolean option to enable Link Time Optimization (LTO) 439 support in GCC for TF-A. This option is currently only supported for 440 AArch64. Default is 0. 441 442- ``ENABLE_FEAT_MPAM``: Numeric value to enable lower ELs to use MPAM 443 feature. MPAM is an optional Armv8.4 extension that enables various memory 444 system components and resources to define partitions; software running at 445 various ELs can assign themselves to desired partition to control their 446 performance aspects. 447 448 This flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` 449 mechanism. When this option is set to ``1`` or ``2``, EL3 allows lower ELs to 450 access their own MPAM registers without trapping into EL3. This option 451 doesn't make use of partitioning in EL3, however. Platform initialisation 452 code should configure and use partitions in EL3 as required. This option 453 defaults to ``2`` since MPAM is enabled by default for NS world only. 454 The flag is automatically disabled when the target 455 architecture is AArch32. 456 457- ``ENABLE_MPMM``: Boolean option to enable support for the Maximum Power 458 Mitigation Mechanism supported by certain Arm cores, which allows the SoC 459 firmware to detect and limit high activity events to assist in SoC processor 460 power domain dynamic power budgeting and limit the triggering of whole-rail 461 (i.e. clock chopping) responses to overcurrent conditions. Defaults to ``0``. 462 463- ``ENABLE_MPMM_FCONF``: Enables configuration of MPMM through FCONF, which 464 allows platforms with cores supporting MPMM to describe them via the 465 ``HW_CONFIG`` device tree blob. Default is 0. 466 467- ``ENABLE_PIE``: Boolean option to enable Position Independent Executable(PIE) 468 support within generic code in TF-A. This option is currently only supported 469 in BL2, BL31, and BL32 (TSP) for AARCH64 binaries, and 470 in BL32 (SP_min) for AARCH32. Default is 0. 471 472- ``ENABLE_PMF``: Boolean option to enable support for optional Performance 473 Measurement Framework(PMF). Default is 0. 474 475- ``ENABLE_PSCI_STAT``: Boolean option to enable support for optional PSCI 476 functions ``PSCI_STAT_RESIDENCY`` and ``PSCI_STAT_COUNT``. Default is 0. 477 In the absence of an alternate stat collection backend, ``ENABLE_PMF`` must 478 be enabled. If ``ENABLE_PMF`` is set, the residency statistics are tracked in 479 software. 480 481- ``ENABLE_RUNTIME_INSTRUMENTATION``: Boolean option to enable runtime 482 instrumentation which injects timestamp collection points into TF-A to 483 allow runtime performance to be measured. Currently, only PSCI is 484 instrumented. Enabling this option enables the ``ENABLE_PMF`` build option 485 as well. Default is 0. 486 487- ``ENABLE_SPE_FOR_NS`` : Numeric value to enable Statistical Profiling 488 extensions. This is an optional architectural feature for AArch64. 489 This flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` 490 mechanism. The default is 2 but is automatically disabled when the target 491 architecture is AArch32. 492 493- ``ENABLE_SVE_FOR_NS``: Numeric value to enable Scalable Vector Extension 494 (SVE) for the Non-secure world only. SVE is an optional architectural feature 495 for AArch64. Note that when SVE is enabled for the Non-secure world, access 496 to SIMD and floating-point functionality from the Secure world is disabled by 497 default and controlled with ENABLE_SVE_FOR_SWD. 498 This is to avoid corruption of the Non-secure world data in the Z-registers 499 which are aliased by the SIMD and FP registers. The build option is not 500 compatible with the ``CTX_INCLUDE_FPREGS`` build option, and will raise an 501 assert on platforms where SVE is implemented and ``ENABLE_SVE_FOR_NS`` 502 enabled. This flag can take the values 0 to 2, to align with the 503 ``ENABLE_FEAT`` mechanism. At this time, this build option cannot be 504 used on systems that have SPM_MM enabled. The default is 1. 505 506- ``ENABLE_SVE_FOR_SWD``: Boolean option to enable SVE for the Secure world. 507 SVE is an optional architectural feature for AArch64. Note that this option 508 requires ENABLE_SVE_FOR_NS to be enabled. The default is 0 and it is 509 automatically disabled when the target architecture is AArch32. 510 511- ``ENABLE_STACK_PROTECTOR``: String option to enable the stack protection 512 checks in GCC. Allowed values are "all", "strong", "default" and "none". The 513 default value is set to "none". "strong" is the recommended stack protection 514 level if this feature is desired. "none" disables the stack protection. For 515 all values other than "none", the ``plat_get_stack_protector_canary()`` 516 platform hook needs to be implemented. The value is passed as the last 517 component of the option ``-fstack-protector-$ENABLE_STACK_PROTECTOR``. 518 519- ``ENCRYPT_BL31``: Binary flag to enable encryption of BL31 firmware. This 520 flag depends on ``DECRYPTION_SUPPORT`` build flag. 521 522- ``ENCRYPT_BL32``: Binary flag to enable encryption of Secure BL32 payload. 523 This flag depends on ``DECRYPTION_SUPPORT`` build flag. 524 525- ``ENC_KEY``: A 32-byte (256-bit) symmetric key in hex string format. It could 526 either be SSK or BSSK depending on ``FW_ENC_STATUS`` flag. This value depends 527 on ``DECRYPTION_SUPPORT`` build flag. 528 529- ``ENC_NONCE``: A 12-byte (96-bit) encryption nonce or Initialization Vector 530 (IV) in hex string format. This value depends on ``DECRYPTION_SUPPORT`` 531 build flag. 532 533- ``ERROR_DEPRECATED``: This option decides whether to treat the usage of 534 deprecated platform APIs, helper functions or drivers within Trusted 535 Firmware as error. It can take the value 1 (flag the use of deprecated 536 APIs as error) or 0. The default is 0. 537 538- ``ETHOSN_NPU_DRIVER``: boolean option to enable a SiP service that can 539 configure an Arm® Ethos™-N NPU. To use this service the target platform's 540 ``HW_CONFIG`` must include the device tree nodes for the NPU. Currently, only 541 the Arm Juno platform has this included in its ``HW_CONFIG`` and the platform 542 only loads the ``HW_CONFIG`` in AArch64 builds. Default is 0. 543 544- ``ETHOSN_NPU_TZMP1``: boolean option to enable TZMP1 support for the 545 Arm® Ethos™-N NPU. Requires ``ETHOSN_NPU_DRIVER`` and 546 ``TRUSTED_BOARD_BOOT`` to be enabled. 547 548- ``ETHOSN_NPU_FW``: location of the NPU firmware binary 549 (```ethosn.bin```). This firmware image will be included in the FIP and 550 loaded at runtime. 551 552- ``EL3_EXCEPTION_HANDLING``: When set to ``1``, enable handling of exceptions 553 targeted at EL3. When set ``0`` (default), no exceptions are expected or 554 handled at EL3, and a panic will result. The exception to this rule is when 555 ``SPMD_SPM_AT_SEL2`` is set to ``1``, in which case, only exceptions 556 occuring during normal world execution, are trapped to EL3. Any exception 557 trapped during secure world execution are trapped to the SPMC. This is 558 supported only for AArch64 builds. 559 560- ``EVENT_LOG_LEVEL``: Chooses the log level to use for Measured Boot when 561 ``MEASURED_BOOT`` is enabled. For a list of valid values, see ``LOG_LEVEL``. 562 Default value is 40 (LOG_LEVEL_INFO). 563 564- ``FAULT_INJECTION_SUPPORT``: ARMv8.4 extensions introduced support for fault 565 injection from lower ELs, and this build option enables lower ELs to use 566 Error Records accessed via System Registers to inject faults. This is 567 applicable only to AArch64 builds. 568 569 This feature is intended for testing purposes only, and is advisable to keep 570 disabled for production images. 571 572- ``FIP_NAME``: This is an optional build option which specifies the FIP 573 filename for the ``fip`` target. Default is ``fip.bin``. 574 575- ``FWU_FIP_NAME``: This is an optional build option which specifies the FWU 576 FIP filename for the ``fwu_fip`` target. Default is ``fwu_fip.bin``. 577 578- ``FW_ENC_STATUS``: Top level firmware's encryption numeric flag, values: 579 580 :: 581 582 0: Encryption is done with Secret Symmetric Key (SSK) which is common 583 for a class of devices. 584 1: Encryption is done with Binding Secret Symmetric Key (BSSK) which is 585 unique per device. 586 587 This flag depends on ``DECRYPTION_SUPPORT`` build flag. 588 589- ``GENERATE_COT``: Boolean flag used to build and execute the ``cert_create`` 590 tool to create certificates as per the Chain of Trust described in 591 :ref:`Trusted Board Boot`. The build system then calls ``fiptool`` to 592 include the certificates in the FIP and FWU_FIP. Default value is '0'. 593 594 Specify both ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=1`` to include support 595 for the Trusted Board Boot feature in the BL1 and BL2 images, to generate 596 the corresponding certificates, and to include those certificates in the 597 FIP and FWU_FIP. 598 599 Note that if ``TRUSTED_BOARD_BOOT=0`` and ``GENERATE_COT=1``, the BL1 and BL2 600 images will not include support for Trusted Board Boot. The FIP will still 601 include the corresponding certificates. This FIP can be used to verify the 602 Chain of Trust on the host machine through other mechanisms. 603 604 Note that if ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=0``, the BL1 and BL2 605 images will include support for Trusted Board Boot, but the FIP and FWU_FIP 606 will not include the corresponding certificates, causing a boot failure. 607 608- ``GICV2_G0_FOR_EL3``: Unlike GICv3, the GICv2 architecture doesn't have 609 inherent support for specific EL3 type interrupts. Setting this build option 610 to ``1`` assumes GICv2 *Group 0* interrupts are expected to target EL3, both 611 by :ref:`platform abstraction layer<platform Interrupt Controller API>` and 612 :ref:`Interrupt Management Framework<Interrupt Management Framework>`. 613 This allows GICv2 platforms to enable features requiring EL3 interrupt type. 614 This also means that all GICv2 Group 0 interrupts are delivered to EL3, and 615 the Secure Payload interrupts needs to be synchronously handed over to Secure 616 EL1 for handling. The default value of this option is ``0``, which means the 617 Group 0 interrupts are assumed to be handled by Secure EL1. 618 619- ``HANDLE_EA_EL3_FIRST_NS``: When set to ``1``, External Aborts and SError 620 Interrupts, resulting from errors in NS world, will be always trapped in 621 EL3 i.e. in BL31 at runtime. When set to ``0`` (default), these exceptions 622 will be trapped in the current exception level (or in EL1 if the current 623 exception level is EL0). 624 625- ``HW_ASSISTED_COHERENCY``: On most Arm systems to-date, platform-specific 626 software operations are required for CPUs to enter and exit coherency. 627 However, newer systems exist where CPUs' entry to and exit from coherency 628 is managed in hardware. Such systems require software to only initiate these 629 operations, and the rest is managed in hardware, minimizing active software 630 management. In such systems, this boolean option enables TF-A to carry out 631 build and run-time optimizations during boot and power management operations. 632 This option defaults to 0 and if it is enabled, then it implies 633 ``WARMBOOT_ENABLE_DCACHE_EARLY`` is also enabled. 634 635 If this flag is disabled while the platform which TF-A is compiled for 636 includes cores that manage coherency in hardware, then a compilation error is 637 generated. This is based on the fact that a system cannot have, at the same 638 time, cores that manage coherency in hardware and cores that don't. In other 639 words, a platform cannot have, at the same time, cores that require 640 ``HW_ASSISTED_COHERENCY=1`` and cores that require 641 ``HW_ASSISTED_COHERENCY=0``. 642 643 Note that, when ``HW_ASSISTED_COHERENCY`` is enabled, version 2 of 644 translation library (xlat tables v2) must be used; version 1 of translation 645 library is not supported. 646 647- ``IMPDEF_SYSREG_TRAP``: Numeric value to enable the handling traps for 648 implementation defined system register accesses from lower ELs. Default 649 value is ``0``. 650 651- ``INVERTED_MEMMAP``: memmap tool print by default lower addresses at the 652 bottom, higher addresses at the top. This build flag can be set to '1' to 653 invert this behavior. Lower addresses will be printed at the top and higher 654 addresses at the bottom. 655 656- ``KEY_ALG``: This build flag enables the user to select the algorithm to be 657 used for generating the PKCS keys and subsequent signing of the certificate. 658 It accepts 5 values: ``rsa``, ``rsa_1_5``, ``ecdsa``, ``ecdsa-brainpool-regular`` 659 and ``ecdsa-brainpool-twisted``. The option ``rsa_1_5`` is the legacy PKCS#1 660 RSA 1.5 algorithm which is not TBBR compliant and is retained only for 661 compatibility. The default value of this flag is ``rsa`` which is the TBBR 662 compliant PKCS#1 RSA 2.1 scheme. 663 664- ``KEY_SIZE``: This build flag enables the user to select the key size for 665 the algorithm specified by ``KEY_ALG``. The valid values for ``KEY_SIZE`` 666 depend on the chosen algorithm and the cryptographic module. 667 668 +---------------------------+------------------------------------+ 669 | KEY_ALG | Possible key sizes | 670 +===========================+====================================+ 671 | rsa | 1024 , 2048 (default), 3072, 4096 | 672 +---------------------------+------------------------------------+ 673 | ecdsa | 256 (default), 384 | 674 +---------------------------+------------------------------------+ 675 | ecdsa-brainpool-regular | unavailable | 676 +---------------------------+------------------------------------+ 677 | ecdsa-brainpool-twisted | unavailable | 678 +---------------------------+------------------------------------+ 679 680- ``HASH_ALG``: This build flag enables the user to select the secure hash 681 algorithm. It accepts 3 values: ``sha256``, ``sha384`` and ``sha512``. 682 The default value of this flag is ``sha256``. 683 684- ``LDFLAGS``: Extra user options appended to the linkers' command line in 685 addition to the one set by the build system. 686 687- ``LOG_LEVEL``: Chooses the log level, which controls the amount of console log 688 output compiled into the build. This should be one of the following: 689 690 :: 691 692 0 (LOG_LEVEL_NONE) 693 10 (LOG_LEVEL_ERROR) 694 20 (LOG_LEVEL_NOTICE) 695 30 (LOG_LEVEL_WARNING) 696 40 (LOG_LEVEL_INFO) 697 50 (LOG_LEVEL_VERBOSE) 698 699 All log output up to and including the selected log level is compiled into 700 the build. The default value is 40 in debug builds and 20 in release builds. 701 702- ``MEASURED_BOOT``: Boolean flag to include support for the Measured Boot 703 feature. This flag can be enabled with ``TRUSTED_BOARD_BOOT`` in order to 704 provide trust that the code taking the measurements and recording them has 705 not been tampered with. 706 707 This option defaults to 0. 708 709- ``MARCH_DIRECTIVE``: used to pass a -march option from the platform build 710 options to the compiler. An example usage: 711 712 .. code:: make 713 714 MARCH_DIRECTIVE := -march=armv8.5-a 715 716- ``HARDEN_SLS``: used to pass -mharden-sls=all from the TF-A build 717 options to the compiler currently supporting only of the options. 718 GCC documentation: 719 https://gcc.gnu.org/onlinedocs/gcc/AArch64-Options.html#index-mharden-sls 720 721 An example usage: 722 723 .. code:: make 724 725 HARDEN_SLS := 1 726 727 This option defaults to 0. 728 729- ``NON_TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It 730 specifies a file that contains the Non-Trusted World private key in PEM 731 format or a PKCS11 URI. If ``SAVE_KEYS=1``, only a file is accepted and it 732 will be used to save the key. 733 734- ``NS_BL2U``: Path to NS_BL2U image in the host file system. This image is 735 optional. It is only needed if the platform makefile specifies that it 736 is required in order to build the ``fwu_fip`` target. 737 738- ``NS_TIMER_SWITCH``: Enable save and restore for non-secure timer register 739 contents upon world switch. It can take either 0 (don't save and restore) or 740 1 (do save and restore). 0 is the default. An SPD may set this to 1 if it 741 wants the timer registers to be saved and restored. 742 743- ``OPTEE_SP_FW_CONFIG``: DTC build flag to include OP-TEE as SP in 744 tb_fw_config device tree. This flag is defined only when 745 ``ARM_SPMC_MANIFEST_DTS`` manifest file name contains pattern optee_sp. 746 747- ``OVERRIDE_LIBC``: This option allows platforms to override the default libc 748 for the BL image. It can be either 0 (include) or 1 (remove). The default 749 value is 0. 750 751- ``PL011_GENERIC_UART``: Boolean option to indicate the PL011 driver that 752 the underlying hardware is not a full PL011 UART but a minimally compliant 753 generic UART, which is a subset of the PL011. The driver will not access 754 any register that is not part of the SBSA generic UART specification. 755 Default value is 0 (a full PL011 compliant UART is present). 756 757- ``PLAT``: Choose a platform to build TF-A for. The chosen platform name 758 must be subdirectory of any depth under ``plat/``, and must contain a 759 platform makefile named ``platform.mk``. For example, to build TF-A for the 760 Arm Juno board, select PLAT=juno. 761 762- ``PLATFORM_REPORT_CTX_MEM_USE``: Reports the context memory allocated for 763 each core as well as the global context. The data includes the memory used 764 by each world and each privileged exception level. This build option is 765 applicable only for ``ARCH=aarch64`` builds. The default value is 0. 766 767- ``PRELOADED_BL33_BASE``: This option enables booting a preloaded BL33 image 768 instead of the normal boot flow. When defined, it must specify the entry 769 point address for the preloaded BL33 image. This option is incompatible with 770 ``EL3_PAYLOAD_BASE``. If both are defined, ``EL3_PAYLOAD_BASE`` has priority 771 over ``PRELOADED_BL33_BASE``. 772 773- ``PROGRAMMABLE_RESET_ADDRESS``: This option indicates whether the reset 774 vector address can be programmed or is fixed on the platform. It can take 775 either 0 (fixed) or 1 (programmable). Default is 0. If the platform has a 776 programmable reset address, it is expected that a CPU will start executing 777 code directly at the right address, both on a cold and warm reset. In this 778 case, there is no need to identify the entrypoint on boot and the boot path 779 can be optimised. The ``plat_get_my_entrypoint()`` platform porting interface 780 does not need to be implemented in this case. 781 782- ``PSCI_EXTENDED_STATE_ID``: As per PSCI1.0 Specification, there are 2 formats 783 possible for the PSCI power-state parameter: original and extended State-ID 784 formats. This flag if set to 1, configures the generic PSCI layer to use the 785 extended format. The default value of this flag is 0, which means by default 786 the original power-state format is used by the PSCI implementation. This flag 787 should be specified by the platform makefile and it governs the return value 788 of PSCI_FEATURES API for CPU_SUSPEND smc function id. When this option is 789 enabled on Arm platforms, the option ``ARM_RECOM_STATE_ID_ENC`` needs to be 790 set to 1 as well. 791 792- ``PSCI_OS_INIT_MODE``: Boolean flag to enable support for optional PSCI 793 OS-initiated mode. This option defaults to 0. 794 795- ``ENABLE_FEAT_RAS``: Boolean flag to enable Armv8.2 RAS features. RAS features 796 are an optional extension for pre-Armv8.2 CPUs, but are mandatory for Armv8.2 797 or later CPUs. This flag can take the values 0 or 1. The default value is 0. 798 NOTE: This flag enables use of IESB capability to reduce entry latency into 799 EL3 even when RAS error handling is not performed on the platform. Hence this 800 flag is recommended to be turned on Armv8.2 and later CPUs. 801 802- ``RESET_TO_BL31``: Enable BL31 entrypoint as the CPU reset vector instead 803 of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1 804 entrypoint) or 1 (CPU reset to BL31 entrypoint). 805 The default value is 0. 806 807- ``RESET_TO_SP_MIN``: SP_MIN is the minimal AArch32 Secure Payload provided 808 in TF-A. This flag configures SP_MIN entrypoint as the CPU reset vector 809 instead of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1 810 entrypoint) or 1 (CPU reset to SP_MIN entrypoint). The default value is 0. 811 812- ``ROT_KEY``: This option is used when ``GENERATE_COT=1``. It specifies a 813 file that contains the ROT private key in PEM format or a PKCS11 URI and 814 enforces public key hash generation. If ``SAVE_KEYS=1``, only a file is 815 accepted and it will be used to save the key. 816 817- ``SAVE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the 818 certificate generation tool to save the keys used to establish the Chain of 819 Trust. Allowed options are '0' or '1'. Default is '0' (do not save). 820 821- ``SCP_BL2``: Path to SCP_BL2 image in the host file system. This image is optional. 822 If a SCP_BL2 image is present then this option must be passed for the ``fip`` 823 target. 824 825- ``SCP_BL2_KEY``: This option is used when ``GENERATE_COT=1``. It specifies a 826 file that contains the SCP_BL2 private key in PEM format or a PKCS11 URI. 827 If ``SAVE_KEYS=1``, only a file is accepted and it will be used to save the key. 828 829- ``SCP_BL2U``: Path to SCP_BL2U image in the host file system. This image is 830 optional. It is only needed if the platform makefile specifies that it 831 is required in order to build the ``fwu_fip`` target. 832 833- ``SDEI_SUPPORT``: Setting this to ``1`` enables support for Software 834 Delegated Exception Interface to BL31 image. This defaults to ``0``. 835 836 When set to ``1``, the build option ``EL3_EXCEPTION_HANDLING`` must also be 837 set to ``1``. 838 839- ``SEPARATE_CODE_AND_RODATA``: Whether code and read-only data should be 840 isolated on separate memory pages. This is a trade-off between security and 841 memory usage. See "Isolating code and read-only data on separate memory 842 pages" section in :ref:`Firmware Design`. This flag is disabled by default 843 and affects all BL images. 844 845- ``SEPARATE_NOBITS_REGION``: Setting this option to ``1`` allows the NOBITS 846 sections of BL31 (.bss, stacks, page tables, and coherent memory) to be 847 allocated in RAM discontiguous from the loaded firmware image. When set, the 848 platform is expected to provide definitions for ``BL31_NOBITS_BASE`` and 849 ``BL31_NOBITS_LIMIT``. When the option is ``0`` (the default), NOBITS 850 sections are placed in RAM immediately following the loaded firmware image. 851 852- ``SEPARATE_BL2_NOLOAD_REGION``: Setting this option to ``1`` allows the 853 NOLOAD sections of BL2 (.bss, stacks, page tables) to be allocated in RAM 854 discontiguous from loaded firmware images. When set, the platform need to 855 provide definitions of ``BL2_NOLOAD_START`` and ``BL2_NOLOAD_LIMIT``. This 856 flag is disabled by default and NOLOAD sections are placed in RAM immediately 857 following the loaded firmware image. 858 859- ``SMC_PCI_SUPPORT``: This option allows platforms to handle PCI configuration 860 access requests via a standard SMCCC defined in `DEN0115`_. When combined with 861 UEFI+ACPI this can provide a certain amount of OS forward compatibility 862 with newer platforms that aren't ECAM compliant. 863 864- ``SPD``: Choose a Secure Payload Dispatcher component to be built into TF-A. 865 This build option is only valid if ``ARCH=aarch64``. The value should be 866 the path to the directory containing the SPD source, relative to 867 ``services/spd/``; the directory is expected to contain a makefile called 868 ``<spd-value>.mk``. The SPM Dispatcher standard service is located in 869 services/std_svc/spmd and enabled by ``SPD=spmd``. The SPM Dispatcher 870 cannot be enabled when the ``SPM_MM`` option is enabled. 871 872- ``SPIN_ON_BL1_EXIT``: This option introduces an infinite loop in BL1. It can 873 take either 0 (no loop) or 1 (add a loop). 0 is the default. This loop stops 874 execution in BL1 just before handing over to BL31. At this point, all 875 firmware images have been loaded in memory, and the MMU and caches are 876 turned off. Refer to the "Debugging options" section for more details. 877 878- ``SPMC_AT_EL3`` : This boolean option is used jointly with the SPM 879 Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC 880 component runs at the EL3 exception level. The default value is ``0`` ( 881 disabled). This configuration supports pre-Armv8.4 platforms (aka not 882 implementing the ``FEAT_SEL2`` extension). 883 884- ``SPMC_AT_EL3_SEL0_SP`` : Boolean option to enable SEL0 SP load support when 885 ``SPMC_AT_EL3`` is enabled. The default value if ``0`` (disabled). This 886 option cannot be enabled (``1``) when (``SPMC_AT_EL3``) is disabled. 887 888- ``SPMC_OPTEE`` : This boolean option is used jointly with the SPM 889 Dispatcher option (``SPD=spmd``) and with ``SPMD_SPM_AT_SEL2=0`` to 890 indicate that the SPMC at S-EL1 is OP-TEE and an OP-TEE specific loading 891 mechanism should be used. 892 893- ``SPMD_SPM_AT_SEL2`` : This boolean option is used jointly with the SPM 894 Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC 895 component runs at the S-EL2 exception level provided by the ``FEAT_SEL2`` 896 extension. This is the default when enabling the SPM Dispatcher. When 897 disabled (0) it indicates the SPMC component runs at the S-EL1 execution 898 state or at EL3 if ``SPMC_AT_EL3`` is enabled. The latter configurations 899 support pre-Armv8.4 platforms (aka not implementing the ``FEAT_SEL2`` 900 extension). 901 902- ``SPM_MM`` : Boolean option to enable the Management Mode (MM)-based Secure 903 Partition Manager (SPM) implementation. The default value is ``0`` 904 (disabled). This option cannot be enabled (``1``) when SPM Dispatcher is 905 enabled (``SPD=spmd``). 906 907- ``SP_LAYOUT_FILE``: Platform provided path to JSON file containing the 908 description of secure partitions. The build system will parse this file and 909 package all secure partition blobs into the FIP. This file is not 910 necessarily part of TF-A tree. Only available when ``SPD=spmd``. 911 912- ``SP_MIN_WITH_SECURE_FIQ``: Boolean flag to indicate the SP_MIN handles 913 secure interrupts (caught through the FIQ line). Platforms can enable 914 this directive if they need to handle such interruption. When enabled, 915 the FIQ are handled in monitor mode and non secure world is not allowed 916 to mask these events. Platforms that enable FIQ handling in SP_MIN shall 917 implement the api ``sp_min_plat_fiq_handler()``. The default value is 0. 918 919- ``SVE_VECTOR_LEN``: SVE vector length to configure in ZCR_EL3. 920 Platforms can configure this if they need to lower the hardware 921 limit, for example due to asymmetric configuration or limitations of 922 software run at lower ELs. The default is the architectural maximum 923 of 2048 which should be suitable for most configurations, the 924 hardware will limit the effective VL to the maximum physically supported 925 VL. 926 927- ``TRNG_SUPPORT``: Setting this to ``1`` enables support for True 928 Random Number Generator Interface to BL31 image. This defaults to ``0``. 929 930- ``TRUSTED_BOARD_BOOT``: Boolean flag to include support for the Trusted Board 931 Boot feature. When set to '1', BL1 and BL2 images include support to load 932 and verify the certificates and images in a FIP, and BL1 includes support 933 for the Firmware Update. The default value is '0'. Generation and inclusion 934 of certificates in the FIP and FWU_FIP depends upon the value of the 935 ``GENERATE_COT`` option. 936 937 .. warning:: 938 This option depends on ``CREATE_KEYS`` to be enabled. If the keys 939 already exist in disk, they will be overwritten without further notice. 940 941- ``TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It 942 specifies a file that contains the Trusted World private key in PEM 943 format or a PKCS11 URI. If ``SAVE_KEYS=1``, only a file is accepted and 944 it will be used to save the key. 945 946- ``TSP_INIT_ASYNC``: Choose BL32 initialization method as asynchronous or 947 synchronous, (see "Initializing a BL32 Image" section in 948 :ref:`Firmware Design`). It can take the value 0 (BL32 is initialized using 949 synchronous method) or 1 (BL32 is initialized using asynchronous method). 950 Default is 0. 951 952- ``TSP_NS_INTR_ASYNC_PREEMPT``: A non zero value enables the interrupt 953 routing model which routes non-secure interrupts asynchronously from TSP 954 to EL3 causing immediate preemption of TSP. The EL3 is responsible 955 for saving and restoring the TSP context in this routing model. The 956 default routing model (when the value is 0) is to route non-secure 957 interrupts to TSP allowing it to save its context and hand over 958 synchronously to EL3 via an SMC. 959 960 .. note:: 961 When ``EL3_EXCEPTION_HANDLING`` is ``1``, ``TSP_NS_INTR_ASYNC_PREEMPT`` 962 must also be set to ``1``. 963 964- ``TS_SP_FW_CONFIG``: DTC build flag to include Trusted Services (Crypto and 965 internal-trusted-storage) as SP in tb_fw_config device tree. 966 967- ``TWED_DELAY``: Numeric value to be set in order to delay the trapping of 968 WFE instruction. ``ENABLE_FEAT_TWED`` build option must be enabled to set 969 this delay. It can take values in the range (0-15). Default value is ``0`` 970 and based on this value, 2^(TWED_DELAY + 8) cycles will be delayed. 971 Platforms need to explicitly update this value based on their requirements. 972 973- ``USE_ARM_LINK``: This flag determines whether to enable support for ARM 974 linker. When the ``LINKER`` build variable points to the armlink linker, 975 this flag is enabled automatically. To enable support for armlink, platforms 976 will have to provide a scatter file for the BL image. Currently, Tegra 977 platforms use the armlink support to compile BL3-1 images. 978 979- ``USE_COHERENT_MEM``: This flag determines whether to include the coherent 980 memory region in the BL memory map or not (see "Use of Coherent memory in 981 TF-A" section in :ref:`Firmware Design`). It can take the value 1 982 (Coherent memory region is included) or 0 (Coherent memory region is 983 excluded). Default is 1. 984 985- ``ARM_IO_IN_DTB``: This flag determines whether to use IO based on the 986 firmware configuration framework. This will move the io_policies into a 987 configuration device tree, instead of static structure in the code base. 988 989- ``COT_DESC_IN_DTB``: This flag determines whether to create COT descriptors 990 at runtime using fconf. If this flag is enabled, COT descriptors are 991 statically captured in tb_fw_config file in the form of device tree nodes 992 and properties. Currently, COT descriptors used by BL2 are moved to the 993 device tree and COT descriptors used by BL1 are retained in the code 994 base statically. 995 996- ``SDEI_IN_FCONF``: This flag determines whether to configure SDEI setup in 997 runtime using firmware configuration framework. The platform specific SDEI 998 shared and private events configuration is retrieved from device tree rather 999 than static C structures at compile time. This is only supported if 1000 SDEI_SUPPORT build flag is enabled. 1001 1002- ``SEC_INT_DESC_IN_FCONF``: This flag determines whether to configure Group 0 1003 and Group1 secure interrupts using the firmware configuration framework. The 1004 platform specific secure interrupt property descriptor is retrieved from 1005 device tree in runtime rather than depending on static C structure at compile 1006 time. 1007 1008- ``USE_ROMLIB``: This flag determines whether library at ROM will be used. 1009 This feature creates a library of functions to be placed in ROM and thus 1010 reduces SRAM usage. Refer to :ref:`Library at ROM` for further details. Default 1011 is 0. 1012 1013- ``V``: Verbose build. If assigned anything other than 0, the build commands 1014 are printed. Default is 0. 1015 1016- ``VERSION_STRING``: String used in the log output for each TF-A image. 1017 Defaults to a string formed by concatenating the version number, build type 1018 and build string. 1019 1020- ``W``: Warning level. Some compiler warning options of interest have been 1021 regrouped and put in the root Makefile. This flag can take the values 0 to 3, 1022 each level enabling more warning options. Default is 0. 1023 1024 This option is closely related to the ``E`` option, which enables 1025 ``-Werror``. 1026 1027 - ``W=0`` (default) 1028 1029 Enables a wide assortment of warnings, most notably ``-Wall`` and 1030 ``-Wextra``, as well as various bad practices and things that are likely to 1031 result in errors. Includes some compiler specific flags. No warnings are 1032 expected at this level for any build. 1033 1034 - ``W=1`` 1035 1036 Enables warnings we want the generic build to include but are too time 1037 consuming to fix at the moment. It re-enables warnings taken out for 1038 ``W=0`` builds (a few of the ``-Wextra`` additions). This level is expected 1039 to eventually be merged into ``W=0``. Some warnings are expected on some 1040 builds, but new contributions should not introduce new ones. 1041 1042 - ``W=2`` (recommended) 1043 1044 Enables warnings we want the generic build to include but cannot be enabled 1045 due to external libraries. This level is expected to eventually be merged 1046 into ``W=0``. Lots of warnings are expected, primarily from external 1047 libraries like zlib and compiler-rt, but new controbutions should not 1048 introduce new ones. 1049 1050 - ``W=3`` 1051 1052 Enables warnings that are informative but not necessary and generally too 1053 verbose and frequently ignored. A very large number of warnings are 1054 expected. 1055 1056 The exact set of warning flags depends on the compiler and TF-A warning 1057 level, however they are all succinctly set in the top-level Makefile. Please 1058 refer to the `GCC`_ or `Clang`_ documentation for more information on the 1059 individual flags. 1060 1061- ``WARMBOOT_ENABLE_DCACHE_EARLY`` : Boolean option to enable D-cache early on 1062 the CPU after warm boot. This is applicable for platforms which do not 1063 require interconnect programming to enable cache coherency (eg: single 1064 cluster platforms). If this option is enabled, then warm boot path 1065 enables D-caches immediately after enabling MMU. This option defaults to 0. 1066 1067- ``SUPPORT_STACK_MEMTAG``: This flag determines whether to enable memory 1068 tagging for stack or not. It accepts 2 values: ``yes`` and ``no``. The 1069 default value of this flag is ``no``. Note this option must be enabled only 1070 for ARM architecture greater than Armv8.5-A. 1071 1072- ``ERRATA_SPECULATIVE_AT``: This flag determines whether to enable ``AT`` 1073 speculative errata workaround or not. It accepts 2 values: ``1`` and ``0``. 1074 The default value of this flag is ``0``. 1075 1076 ``AT`` speculative errata workaround disables stage1 page table walk for 1077 lower ELs (EL1 and EL0) in EL3 so that ``AT`` speculative fetch at any point 1078 produces either the correct result or failure without TLB allocation. 1079 1080 This boolean option enables errata for all below CPUs. 1081 1082 +---------+--------------+-------------------------+ 1083 | Errata | CPU | Workaround Define | 1084 +=========+==============+=========================+ 1085 | 1165522 | Cortex-A76 | ``ERRATA_A76_1165522`` | 1086 +---------+--------------+-------------------------+ 1087 | 1319367 | Cortex-A72 | ``ERRATA_A72_1319367`` | 1088 +---------+--------------+-------------------------+ 1089 | 1319537 | Cortex-A57 | ``ERRATA_A57_1319537`` | 1090 +---------+--------------+-------------------------+ 1091 | 1530923 | Cortex-A55 | ``ERRATA_A55_1530923`` | 1092 +---------+--------------+-------------------------+ 1093 | 1530924 | Cortex-A53 | ``ERRATA_A53_1530924`` | 1094 +---------+--------------+-------------------------+ 1095 1096 .. note:: 1097 This option is enabled by build only if platform sets any of above defines 1098 mentioned in ’Workaround Define' column in the table. 1099 If this option is enabled for the EL3 software then EL2 software also must 1100 implement this workaround due to the behaviour of the errata mentioned 1101 in new SDEN document which will get published soon. 1102 1103- ``RAS_TRAP_NS_ERR_REC_ACCESS``: This flag enables/disables the SCR_EL3.TERR 1104 bit, to trap access to the RAS ERR and RAS ERX registers from lower ELs. 1105 This flag is disabled by default. 1106 1107- ``OPENSSL_DIR``: This option is used to provide the path to a directory on the 1108 host machine where a custom installation of OpenSSL is located, which is used 1109 to build the certificate generation, firmware encryption and FIP tools. If 1110 this option is not set, the default OS installation will be used. 1111 1112- ``USE_SP804_TIMER``: Use the SP804 timer instead of the Generic Timer for 1113 functions that wait for an arbitrary time length (udelay and mdelay). The 1114 default value is 0. 1115 1116- ``ENABLE_BRBE_FOR_NS``: Numeric value to enable access to the branch record 1117 buffer registers from NS ELs when FEAT_BRBE is implemented. BRBE is an 1118 optional architectural feature for AArch64. This flag can take the values 1119 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. The default is 0 1120 and it is automatically disabled when the target architecture is AArch32. 1121 1122- ``ENABLE_TRBE_FOR_NS``: Numeric value to enable access of trace buffer 1123 control registers from NS ELs, NS-EL2 or NS-EL1(when NS-EL2 is implemented 1124 but unused) when FEAT_TRBE is implemented. TRBE is an optional architectural 1125 feature for AArch64. This flag can take the values 0 to 2, to align with the 1126 ``ENABLE_FEAT`` mechanism. The default is 0 and it is automatically 1127 disabled when the target architecture is AArch32. 1128 1129- ``ENABLE_SYS_REG_TRACE_FOR_NS``: Numeric value to enable trace system 1130 registers access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented 1131 but unused). This feature is available if trace unit such as ETMv4.x, and 1132 ETE(extending ETM feature) is implemented. This flag can take the values 1133 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. The default is 0. 1134 1135- ``ENABLE_TRF_FOR_NS``: Numeric value to enable trace filter control registers 1136 access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented but unused), 1137 if FEAT_TRF is implemented. This flag can take the values 0 to 2, to align 1138 with the ``ENABLE_FEAT`` mechanism. This flag is disabled by default. 1139 1140- ``CONDITIONAL_CMO``: Boolean option to enable call to platform-defined routine 1141 ``plat_can_cmo`` which will return zero if cache management operations should 1142 be skipped and non-zero otherwise. By default, this option is disabled which 1143 means platform hook won't be checked and CMOs will always be performed when 1144 related functions are called. 1145 1146- ``ERRATA_ABI_SUPPORT``: Boolean option to enable support for Errata management 1147 firmware interface for the BL31 image. By default its disabled (``0``). 1148 1149- ``ERRATA_NON_ARM_INTERCONNECT``: Boolean option to enable support for the 1150 errata mitigation for platforms with a non-arm interconnect using the errata 1151 ABI. By default its disabled (``0``). 1152 1153- ``ENABLE_CONSOLE_GETC``: Boolean option to enable `getc()` feature in console 1154 driver(s). By default it is disabled (``0``) because it constitutes an attack 1155 vector into TF-A by potentially allowing an attacker to inject arbitrary data. 1156 This option should only be enabled on a need basis if there is a use case for 1157 reading characters from the console. 1158 1159GICv3 driver options 1160-------------------- 1161 1162GICv3 driver files are included using directive: 1163 1164``include drivers/arm/gic/v3/gicv3.mk`` 1165 1166The driver can be configured with the following options set in the platform 1167makefile: 1168 1169- ``GICV3_SUPPORT_GIC600``: Add support for the GIC-600 variants of GICv3. 1170 Enabling this option will add runtime detection support for the 1171 GIC-600, so is safe to select even for a GIC500 implementation. 1172 This option defaults to 0. 1173 1174- ``GICV3_SUPPORT_GIC600AE_FMU``: Add support for the Fault Management Unit 1175 for GIC-600 AE. Enabling this option will introduce support to initialize 1176 the FMU. Platforms should call the init function during boot to enable the 1177 FMU and its safety mechanisms. This option defaults to 0. 1178 1179- ``GICV3_IMPL_GIC600_MULTICHIP``: Selects GIC-600 variant with multichip 1180 functionality. This option defaults to 0 1181 1182- ``GICV3_OVERRIDE_DISTIF_PWR_OPS``: Allows override of default implementation 1183 of ``arm_gicv3_distif_pre_save`` and ``arm_gicv3_distif_post_restore`` 1184 functions. This is required for FVP platform which need to simulate GIC save 1185 and restore during SYSTEM_SUSPEND without powering down GIC. Default is 0. 1186 1187- ``GIC_ENABLE_V4_EXTN`` : Enables GICv4 related changes in GICv3 driver. 1188 This option defaults to 0. 1189 1190- ``GIC_EXT_INTID``: When set to ``1``, GICv3 driver will support extended 1191 PPI (1056-1119) and SPI (4096-5119) range. This option defaults to 0. 1192 1193Debugging options 1194----------------- 1195 1196To compile a debug version and make the build more verbose use 1197 1198.. code:: shell 1199 1200 make PLAT=<platform> DEBUG=1 V=1 all 1201 1202AArch64 GCC 11 uses DWARF version 5 debugging symbols by default. Some tools 1203(for example Arm-DS) might not support this and may need an older version of 1204DWARF symbols to be emitted by GCC. This can be achieved by using the 1205``-gdwarf-<version>`` flag, with the version being set to 2, 3, 4 or 5. Setting 1206the version to 4 is recommended for Arm-DS. 1207 1208When debugging logic problems it might also be useful to disable all compiler 1209optimizations by using ``-O0``. 1210 1211.. warning:: 1212 Using ``-O0`` could cause output images to be larger and base addresses 1213 might need to be recalculated (see the **Memory layout on Arm development 1214 platforms** section in the :ref:`Firmware Design`). 1215 1216Extra debug options can be passed to the build system by setting ``CFLAGS`` or 1217``LDFLAGS``: 1218 1219.. code:: shell 1220 1221 CFLAGS='-O0 -gdwarf-2' \ 1222 make PLAT=<platform> DEBUG=1 V=1 all 1223 1224Note that using ``-Wl,`` style compilation driver options in ``CFLAGS`` will be 1225ignored as the linker is called directly. 1226 1227It is also possible to introduce an infinite loop to help in debugging the 1228post-BL2 phase of TF-A. This can be done by rebuilding BL1 with the 1229``SPIN_ON_BL1_EXIT=1`` build flag. Refer to the :ref:`build_options_common` 1230section. In this case, the developer may take control of the target using a 1231debugger when indicated by the console output. When using Arm-DS, the following 1232commands can be used: 1233 1234:: 1235 1236 # Stop target execution 1237 interrupt 1238 1239 # 1240 # Prepare your debugging environment, e.g. set breakpoints 1241 # 1242 1243 # Jump over the debug loop 1244 set var $AARCH64::$Core::$PC = $AARCH64::$Core::$PC + 4 1245 1246 # Resume execution 1247 continue 1248 1249.. _build_options_experimental: 1250 1251Experimental build options 1252--------------------------- 1253 1254Common build options 1255~~~~~~~~~~~~~~~~~~~~ 1256 1257- ``DRTM_SUPPORT``: Boolean flag to enable support for Dynamic Root of Trust 1258 for Measurement (DRTM). This feature has trust dependency on BL31 for taking 1259 the measurements and recording them as per `PSA DRTM specification`_. For 1260 platforms which use BL2 to load/authenticate BL31 ``TRUSTED_BOARD_BOOT`` can 1261 be used and for the platforms which use ``RESET_TO_BL31`` platform owners 1262 should have mechanism to authenticate BL31. This option defaults to 0. 1263 1264- ``ENABLE_RME``: Numeric value to enable support for the ARMv9 Realm 1265 Management Extension. This flag can take the values 0 to 2, to align with 1266 the ``ENABLE_FEAT`` mechanism. Default value is 0. 1267 1268- ``ENABLE_SME_FOR_NS``: Numeric value to enable Scalable Matrix Extension 1269 (SME), SVE, and FPU/SIMD for the non-secure world only. These features share 1270 registers so are enabled together. Using this option without 1271 ENABLE_SME_FOR_SWD=1 will cause SME, SVE, and FPU/SIMD instructions in secure 1272 world to trap to EL3. Requires ``ENABLE_SVE_FOR_NS`` to be set as SME is a 1273 superset of SVE. SME is an optional architectural feature for AArch64. 1274 At this time, this build option cannot be used on systems that have 1275 SPD=spmd/SPM_MM and atempting to build with this option will fail. 1276 This flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` 1277 mechanism. Default is 0. 1278 1279- ``ENABLE_SME2_FOR_NS``: Numeric value to enable Scalable Matrix Extension 1280 version 2 (SME2) for the non-secure world only. SME2 is an optional 1281 architectural feature for AArch64. 1282 This should be set along with ENABLE_SME_FOR_NS=1, if not, the default SME 1283 accesses will still be trapped. This flag can take the values 0 to 2, to 1284 align with the ``ENABLE_FEAT`` mechanism. Default is 0. 1285 1286- ``ENABLE_SME_FOR_SWD``: Boolean option to enable the Scalable Matrix 1287 Extension for secure world. Used along with SVE and FPU/SIMD. 1288 ENABLE_SME_FOR_NS and ENABLE_SVE_FOR_SWD must also be set to use this. 1289 Default is 0. 1290 1291- ``ENABLE_SPMD_LP`` : This boolean option is used jointly with the SPM 1292 Dispatcher option (``SPD=spmd``). When enabled (1) it indicates support 1293 for logical partitions in EL3, managed by the SPMD as defined in the 1294 FF-A v1.2 specification. This flag is disabled by default. This flag 1295 must not be used if ``SPMC_AT_EL3`` is enabled. 1296 1297- ``FEATURE_DETECTION``: Boolean option to enable the architectural features 1298 verification mechanism. This is a debug feature that compares the 1299 architectural features enabled through the feature specific build flags 1300 (ENABLE_FEAT_xxx) with the features actually available on the CPU running, 1301 and reports any discrepancies. 1302 This flag will also enable errata ordering checking for ``DEBUG`` builds. 1303 1304 It is expected that this feature is only used for flexible platforms like 1305 software emulators, or for hardware platforms at bringup time, to verify 1306 that the configured feature set matches the CPU. 1307 The ``FEATURE_DETECTION`` macro is disabled by default. 1308 1309- ``PSA_CRYPTO``: Boolean option for enabling MbedTLS PSA crypto APIs support. 1310 The platform will use PSA compliant Crypto APIs during authentication and 1311 image measurement process by enabling this option. It uses APIs defined as 1312 per the `PSA Crypto API specification`_. This feature is only supported if 1313 using MbedTLS 3.x version. It is disabled (``0``) by default. 1314 1315- ``TRANSFER_LIST``: Setting this to ``1`` enables support for Firmware 1316 Handoff using Transfer List defined in `Firmware Handoff specification`_. 1317 This defaults to ``0``. Current implementation follows the Firmware Handoff 1318 specification v0.9. 1319 1320- ``USE_DEBUGFS``: When set to 1 this option exposes a virtual filesystem 1321 interface through BL31 as a SiP SMC function. 1322 Default is disabled (0). 1323 1324Firmware update options 1325~~~~~~~~~~~~~~~~~~~~~~~ 1326 1327- ``PSA_FWU_SUPPORT``: Enable the firmware update mechanism as per the 1328 `PSA FW update specification`_. The default value is 0. 1329 PSA firmware update implementation has few limitations, such as: 1330 1331 - BL2 is not part of the protocol-updatable images. If BL2 needs to 1332 be updated, then it should be done through another platform-defined 1333 mechanism. 1334 1335 - It assumes the platform's hardware supports CRC32 instructions. 1336 1337- ``NR_OF_FW_BANKS``: Define the number of firmware banks. This flag is used 1338 in defining the firmware update metadata structure. This flag is by default 1339 set to '2'. 1340 1341- ``NR_OF_IMAGES_IN_FW_BANK``: Define the number of firmware images in each 1342 firmware bank. Each firmware bank must have the same number of images as per 1343 the `PSA FW update specification`_. 1344 This flag is used in defining the firmware update metadata structure. This 1345 flag is by default set to '1'. 1346 1347-------------- 1348 1349*Copyright (c) 2019-2024, Arm Limited. All rights reserved.* 1350 1351.. _DEN0115: https://developer.arm.com/docs/den0115/latest 1352.. _PSA FW update specification: https://developer.arm.com/documentation/den0118/a/ 1353.. _PSA DRTM specification: https://developer.arm.com/documentation/den0113/a 1354.. _GCC: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html 1355.. _Clang: https://clang.llvm.org/docs/DiagnosticsReference.html 1356.. _Firmware Handoff specification: https://github.com/FirmwareHandoff/firmware_handoff/releases/tag/v0.9 1357.. _PSA Crypto API specification: https://armmbed.github.io/mbed-crypto/html/ 1358