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- ``ARCH`` : Choose the target build architecture for TF-A. It can take either 26 ``aarch64`` or ``aarch32`` as values. By default, it is defined to 27 ``aarch64``. 28 29- ``ARM_ARCH_MAJOR``: The major version of Arm Architecture to target when 30 compiling TF-A. Its value must be numeric, and defaults to 8 . See also, 31 *Armv8 Architecture Extensions* and *Armv7 Architecture Extensions* in 32 :ref:`Firmware Design`. 33 34- ``ARM_ARCH_MINOR``: The minor version of Arm Architecture to target when 35 compiling TF-A. Its value must be a numeric, and defaults to 0. See also, 36 *Armv8 Architecture Extensions* in :ref:`Firmware Design`. 37 38- ``BL2``: This is an optional build option which specifies the path to BL2 39 image for the ``fip`` target. In this case, the BL2 in the TF-A will not be 40 built. 41 42- ``BL2U``: This is an optional build option which specifies the path to 43 BL2U image. In this case, the BL2U in TF-A will not be built. 44 45- ``BL2_AT_EL3``: This is an optional build option that enables the use of 46 BL2 at EL3 execution level. 47 48- ``BL2_IN_XIP_MEM``: In some use-cases BL2 will be stored in eXecute In Place 49 (XIP) memory, like BL1. In these use-cases, it is necessary to initialize 50 the RW sections in RAM, while leaving the RO sections in place. This option 51 enable this use-case. For now, this option is only supported when BL2_AT_EL3 52 is set to '1'. 53 54- ``BL31``: This is an optional build option which specifies the path to 55 BL31 image for the ``fip`` target. In this case, the BL31 in TF-A will not 56 be built. 57 58- ``BL31_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the 59 file that contains the BL31 private key in PEM format. If ``SAVE_KEYS=1``, 60 this file name will be used to save the key. 61 62- ``BL32``: This is an optional build option which specifies the path to 63 BL32 image for the ``fip`` target. In this case, the BL32 in TF-A will not 64 be built. 65 66- ``BL32_EXTRA1``: This is an optional build option which specifies the path to 67 Trusted OS Extra1 image for the ``fip`` target. 68 69- ``BL32_EXTRA2``: This is an optional build option which specifies the path to 70 Trusted OS Extra2 image for the ``fip`` target. 71 72- ``BL32_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the 73 file that contains the BL32 private key in PEM format. If ``SAVE_KEYS=1``, 74 this file name will be used to save the key. 75 76- ``BL33``: Path to BL33 image in the host file system. This is mandatory for 77 ``fip`` target in case TF-A BL2 is used. 78 79- ``BL33_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the 80 file that contains the BL33 private key in PEM format. If ``SAVE_KEYS=1``, 81 this file name will be used to save the key. 82 83- ``BRANCH_PROTECTION``: Numeric value to enable ARMv8.3 Pointer Authentication 84 and ARMv8.5 Branch Target Identification support for TF-A BL images themselves. 85 If enabled, it is needed to use a compiler that supports the option 86 ``-mbranch-protection``. Selects the branch protection features to use: 87- 0: Default value turns off all types of branch protection 88- 1: Enables all types of branch protection features 89- 2: Return address signing to its standard level 90- 3: Extend the signing to include leaf functions 91- 4: Turn on branch target identification mechanism 92 93 The table below summarizes ``BRANCH_PROTECTION`` values, GCC compilation options 94 and resulting PAuth/BTI features. 95 96 +-------+--------------+-------+-----+ 97 | Value | GCC option | PAuth | BTI | 98 +=======+==============+=======+=====+ 99 | 0 | none | N | N | 100 +-------+--------------+-------+-----+ 101 | 1 | standard | Y | Y | 102 +-------+--------------+-------+-----+ 103 | 2 | pac-ret | Y | N | 104 +-------+--------------+-------+-----+ 105 | 3 | pac-ret+leaf | Y | N | 106 +-------+--------------+-------+-----+ 107 | 4 | bti | N | Y | 108 +-------+--------------+-------+-----+ 109 110 This option defaults to 0 and this is an experimental feature. 111 Note that Pointer Authentication is enabled for Non-secure world 112 irrespective of the value of this option if the CPU supports it. 113 114- ``BUILD_MESSAGE_TIMESTAMP``: String used to identify the time and date of the 115 compilation of each build. It must be set to a C string (including quotes 116 where applicable). Defaults to a string that contains the time and date of 117 the compilation. 118 119- ``BUILD_STRING``: Input string for VERSION_STRING, which allows the TF-A 120 build to be uniquely identified. Defaults to the current git commit id. 121 122- ``CFLAGS``: Extra user options appended on the compiler's command line in 123 addition to the options set by the build system. 124 125- ``COLD_BOOT_SINGLE_CPU``: This option indicates whether the platform may 126 release several CPUs out of reset. It can take either 0 (several CPUs may be 127 brought up) or 1 (only one CPU will ever be brought up during cold reset). 128 Default is 0. If the platform always brings up a single CPU, there is no 129 need to distinguish between primary and secondary CPUs and the boot path can 130 be optimised. The ``plat_is_my_cpu_primary()`` and 131 ``plat_secondary_cold_boot_setup()`` platform porting interfaces do not need 132 to be implemented in this case. 133 134- ``COT``: When Trusted Boot is enabled, selects the desired chain of trust. 135 Defaults to ``tbbr``. 136 137- ``CRASH_REPORTING``: A non-zero value enables a console dump of processor 138 register state when an unexpected exception occurs during execution of 139 BL31. This option defaults to the value of ``DEBUG`` - i.e. by default 140 this is only enabled for a debug build of the firmware. 141 142- ``CREATE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the 143 certificate generation tool to create new keys in case no valid keys are 144 present or specified. Allowed options are '0' or '1'. Default is '1'. 145 146- ``CTX_INCLUDE_AARCH32_REGS`` : Boolean option that, when set to 1, will cause 147 the AArch32 system registers to be included when saving and restoring the 148 CPU context. The option must be set to 0 for AArch64-only platforms (that 149 is on hardware that does not implement AArch32, or at least not at EL1 and 150 higher ELs). Default value is 1. 151 152- ``CTX_INCLUDE_EL2_REGS`` : This boolean option provides context save/restore 153 operations when entering/exiting an EL2 execution context. This is of primary 154 interest when Armv8.4-SecEL2 extension is implemented. Default is 0 (disabled). 155 This option must be equal to 1 (enabled) when ``SPD=spmd`` and 156 ``SPMD_SPM_AT_SEL2`` is set. 157 158- ``CTX_INCLUDE_FPREGS``: Boolean option that, when set to 1, will cause the FP 159 registers to be included when saving and restoring the CPU context. Default 160 is 0. 161 162- ``CTX_INCLUDE_PAUTH_REGS``: Boolean option that, when set to 1, enables 163 Pointer Authentication for Secure world. This will cause the ARMv8.3-PAuth 164 registers to be included when saving and restoring the CPU context as 165 part of world switch. Default value is 0 and this is an experimental feature. 166 Note that Pointer Authentication is enabled for Non-secure world irrespective 167 of the value of this flag if the CPU supports it. 168 169- ``DEBUG``: Chooses between a debug and release build. It can take either 0 170 (release) or 1 (debug) as values. 0 is the default. 171 172- ``DECRYPTION_SUPPORT``: This build flag enables the user to select the 173 authenticated decryption algorithm to be used to decrypt firmware/s during 174 boot. It accepts 2 values: ``aes_gcm`` and ``none``. The default value of 175 this flag is ``none`` to disable firmware decryption which is an optional 176 feature as per TBBR. Also, it is an experimental feature. 177 178- ``DISABLE_BIN_GENERATION``: Boolean option to disable the generation 179 of the binary image. If set to 1, then only the ELF image is built. 180 0 is the default. 181 182- ``DYN_DISABLE_AUTH``: Provides the capability to dynamically disable Trusted 183 Board Boot authentication at runtime. This option is meant to be enabled only 184 for development platforms. ``TRUSTED_BOARD_BOOT`` flag must be set if this 185 flag has to be enabled. 0 is the default. 186 187- ``E``: Boolean option to make warnings into errors. Default is 1. 188 189- ``EL3_PAYLOAD_BASE``: This option enables booting an EL3 payload instead of 190 the normal boot flow. It must specify the entry point address of the EL3 191 payload. Please refer to the "Booting an EL3 payload" section for more 192 details. 193 194- ``ENABLE_AMU``: Boolean option to enable Activity Monitor Unit extensions. 195 This is an optional architectural feature available on v8.4 onwards. Some 196 v8.2 implementations also implement an AMU and this option can be used to 197 enable this feature on those systems as well. Default is 0. 198 199- ``ENABLE_ASSERTIONS``: This option controls whether or not calls to ``assert()`` 200 are compiled out. For debug builds, this option defaults to 1, and calls to 201 ``assert()`` are left in place. For release builds, this option defaults to 0 202 and calls to ``assert()`` function are compiled out. This option can be set 203 independently of ``DEBUG``. It can also be used to hide any auxiliary code 204 that is only required for the assertion and does not fit in the assertion 205 itself. 206 207- ``ENABLE_BACKTRACE``: This option controls whether to enable backtrace 208 dumps or not. It is supported in both AArch64 and AArch32. However, in 209 AArch32 the format of the frame records are not defined in the AAPCS and they 210 are defined by the implementation. This implementation of backtrace only 211 supports the format used by GCC when T32 interworking is disabled. For this 212 reason enabling this option in AArch32 will force the compiler to only 213 generate A32 code. This option is enabled by default only in AArch64 debug 214 builds, but this behaviour can be overridden in each platform's Makefile or 215 in the build command line. 216 217- ``ENABLE_LTO``: Boolean option to enable Link Time Optimization (LTO) 218 support in GCC for TF-A. This option is currently only supported for 219 AArch64. Default is 0. 220 221- ``ENABLE_MPAM_FOR_LOWER_ELS``: Boolean option to enable lower ELs to use MPAM 222 feature. MPAM is an optional Armv8.4 extension that enables various memory 223 system components and resources to define partitions; software running at 224 various ELs can assign themselves to desired partition to control their 225 performance aspects. 226 227 When this option is set to ``1``, EL3 allows lower ELs to access their own 228 MPAM registers without trapping into EL3. This option doesn't make use of 229 partitioning in EL3, however. Platform initialisation code should configure 230 and use partitions in EL3 as required. This option defaults to ``0``. 231 232- ``ENABLE_PIE``: Boolean option to enable Position Independent Executable(PIE) 233 support within generic code in TF-A. This option is currently only supported 234 in BL2_AT_EL3, BL31, and BL32 (TSP). Default is 0. 235 236- ``ENABLE_PMF``: Boolean option to enable support for optional Performance 237 Measurement Framework(PMF). Default is 0. 238 239- ``ENABLE_PSCI_STAT``: Boolean option to enable support for optional PSCI 240 functions ``PSCI_STAT_RESIDENCY`` and ``PSCI_STAT_COUNT``. Default is 0. 241 In the absence of an alternate stat collection backend, ``ENABLE_PMF`` must 242 be enabled. If ``ENABLE_PMF`` is set, the residency statistics are tracked in 243 software. 244 245- ``ENABLE_RUNTIME_INSTRUMENTATION``: Boolean option to enable runtime 246 instrumentation which injects timestamp collection points into TF-A to 247 allow runtime performance to be measured. Currently, only PSCI is 248 instrumented. Enabling this option enables the ``ENABLE_PMF`` build option 249 as well. Default is 0. 250 251- ``ENABLE_SPE_FOR_LOWER_ELS`` : Boolean option to enable Statistical Profiling 252 extensions. This is an optional architectural feature for AArch64. 253 The default is 1 but is automatically disabled when the target architecture 254 is AArch32. 255 256- ``ENABLE_SVE_FOR_NS``: Boolean option to enable Scalable Vector Extension 257 (SVE) for the Non-secure world only. SVE is an optional architectural feature 258 for AArch64. Note that when SVE is enabled for the Non-secure world, access 259 to SIMD and floating-point functionality from the Secure world is disabled. 260 This is to avoid corruption of the Non-secure world data in the Z-registers 261 which are aliased by the SIMD and FP registers. The build option is not 262 compatible with the ``CTX_INCLUDE_FPREGS`` build option, and will raise an 263 assert on platforms where SVE is implemented and ``ENABLE_SVE_FOR_NS`` set to 264 1. The default is 1 but is automatically disabled when the target 265 architecture is AArch32. 266 267- ``ENABLE_STACK_PROTECTOR``: String option to enable the stack protection 268 checks in GCC. Allowed values are "all", "strong", "default" and "none". The 269 default value is set to "none". "strong" is the recommended stack protection 270 level if this feature is desired. "none" disables the stack protection. For 271 all values other than "none", the ``plat_get_stack_protector_canary()`` 272 platform hook needs to be implemented. The value is passed as the last 273 component of the option ``-fstack-protector-$ENABLE_STACK_PROTECTOR``. 274 275- ``ENCRYPT_BL31``: Binary flag to enable encryption of BL31 firmware. This 276 flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as 277 experimental. 278 279- ``ENCRYPT_BL32``: Binary flag to enable encryption of Secure BL32 payload. 280 This flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as 281 experimental. 282 283- ``ENC_KEY``: A 32-byte (256-bit) symmetric key in hex string format. It could 284 either be SSK or BSSK depending on ``FW_ENC_STATUS`` flag. This value depends 285 on ``DECRYPTION_SUPPORT`` build flag which is marked as experimental. 286 287- ``ENC_NONCE``: A 12-byte (96-bit) encryption nonce or Initialization Vector 288 (IV) in hex string format. This value depends on ``DECRYPTION_SUPPORT`` 289 build flag which is marked as experimental. 290 291- ``ERROR_DEPRECATED``: This option decides whether to treat the usage of 292 deprecated platform APIs, helper functions or drivers within Trusted 293 Firmware as error. It can take the value 1 (flag the use of deprecated 294 APIs as error) or 0. The default is 0. 295 296- ``EL3_EXCEPTION_HANDLING``: When set to ``1``, enable handling of exceptions 297 targeted at EL3. When set ``0`` (default), no exceptions are expected or 298 handled at EL3, and a panic will result. This is supported only for AArch64 299 builds. 300 301- ``FAULT_INJECTION_SUPPORT``: ARMv8.4 extensions introduced support for fault 302 injection from lower ELs, and this build option enables lower ELs to use 303 Error Records accessed via System Registers to inject faults. This is 304 applicable only to AArch64 builds. 305 306 This feature is intended for testing purposes only, and is advisable to keep 307 disabled for production images. 308 309- ``FIP_NAME``: This is an optional build option which specifies the FIP 310 filename for the ``fip`` target. Default is ``fip.bin``. 311 312- ``FWU_FIP_NAME``: This is an optional build option which specifies the FWU 313 FIP filename for the ``fwu_fip`` target. Default is ``fwu_fip.bin``. 314 315- ``FW_ENC_STATUS``: Top level firmware's encryption numeric flag, values: 316 317 :: 318 319 0: Encryption is done with Secret Symmetric Key (SSK) which is common 320 for a class of devices. 321 1: Encryption is done with Binding Secret Symmetric Key (BSSK) which is 322 unique per device. 323 324 This flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as 325 experimental. 326 327- ``GENERATE_COT``: Boolean flag used to build and execute the ``cert_create`` 328 tool to create certificates as per the Chain of Trust described in 329 :ref:`Trusted Board Boot`. The build system then calls ``fiptool`` to 330 include the certificates in the FIP and FWU_FIP. Default value is '0'. 331 332 Specify both ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=1`` to include support 333 for the Trusted Board Boot feature in the BL1 and BL2 images, to generate 334 the corresponding certificates, and to include those certificates in the 335 FIP and FWU_FIP. 336 337 Note that if ``TRUSTED_BOARD_BOOT=0`` and ``GENERATE_COT=1``, the BL1 and BL2 338 images will not include support for Trusted Board Boot. The FIP will still 339 include the corresponding certificates. This FIP can be used to verify the 340 Chain of Trust on the host machine through other mechanisms. 341 342 Note that if ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=0``, the BL1 and BL2 343 images will include support for Trusted Board Boot, but the FIP and FWU_FIP 344 will not include the corresponding certificates, causing a boot failure. 345 346- ``GICV2_G0_FOR_EL3``: Unlike GICv3, the GICv2 architecture doesn't have 347 inherent support for specific EL3 type interrupts. Setting this build option 348 to ``1`` assumes GICv2 *Group 0* interrupts are expected to target EL3, both 349 by `platform abstraction layer`__ and `Interrupt Management Framework`__. 350 This allows GICv2 platforms to enable features requiring EL3 interrupt type. 351 This also means that all GICv2 Group 0 interrupts are delivered to EL3, and 352 the Secure Payload interrupts needs to be synchronously handed over to Secure 353 EL1 for handling. The default value of this option is ``0``, which means the 354 Group 0 interrupts are assumed to be handled by Secure EL1. 355 356 .. __: platform-interrupt-controller-API.rst 357 .. __: interrupt-framework-design.rst 358 359- ``HANDLE_EA_EL3_FIRST``: When set to ``1``, External Aborts and SError 360 Interrupts will be always trapped in EL3 i.e. in BL31 at runtime. When set to 361 ``0`` (default), these exceptions will be trapped in the current exception 362 level (or in EL1 if the current exception level is EL0). 363 364- ``HW_ASSISTED_COHERENCY``: On most Arm systems to-date, platform-specific 365 software operations are required for CPUs to enter and exit coherency. 366 However, newer systems exist where CPUs' entry to and exit from coherency 367 is managed in hardware. Such systems require software to only initiate these 368 operations, and the rest is managed in hardware, minimizing active software 369 management. In such systems, this boolean option enables TF-A to carry out 370 build and run-time optimizations during boot and power management operations. 371 This option defaults to 0 and if it is enabled, then it implies 372 ``WARMBOOT_ENABLE_DCACHE_EARLY`` is also enabled. 373 374 If this flag is disabled while the platform which TF-A is compiled for 375 includes cores that manage coherency in hardware, then a compilation error is 376 generated. This is based on the fact that a system cannot have, at the same 377 time, cores that manage coherency in hardware and cores that don't. In other 378 words, a platform cannot have, at the same time, cores that require 379 ``HW_ASSISTED_COHERENCY=1`` and cores that require 380 ``HW_ASSISTED_COHERENCY=0``. 381 382 Note that, when ``HW_ASSISTED_COHERENCY`` is enabled, version 2 of 383 translation library (xlat tables v2) must be used; version 1 of translation 384 library is not supported. 385 386- ``INVERTED_MEMMAP``: memmap tool print by default lower addresses at the 387 bottom, higher addresses at the top. This buid flag can be set to '1' to 388 invert this behavior. Lower addresses will be printed at the top and higher 389 addresses at the bottom. 390 391- ``JUNO_AARCH32_EL3_RUNTIME``: This build flag enables you to execute EL3 392 runtime software in AArch32 mode, which is required to run AArch32 on Juno. 393 By default this flag is set to '0'. Enabling this flag builds BL1 and BL2 in 394 AArch64 and facilitates the loading of ``SP_MIN`` and BL33 as AArch32 executable 395 images. 396 397- ``KEY_ALG``: This build flag enables the user to select the algorithm to be 398 used for generating the PKCS keys and subsequent signing of the certificate. 399 It accepts 3 values: ``rsa``, ``rsa_1_5`` and ``ecdsa``. The option 400 ``rsa_1_5`` is the legacy PKCS#1 RSA 1.5 algorithm which is not TBBR 401 compliant and is retained only for compatibility. The default value of this 402 flag is ``rsa`` which is the TBBR compliant PKCS#1 RSA 2.1 scheme. 403 404- ``KEY_SIZE``: This build flag enables the user to select the key size for 405 the algorithm specified by ``KEY_ALG``. The valid values for ``KEY_SIZE`` 406 depend on the chosen algorithm and the cryptographic module. 407 408 +-----------+------------------------------------+ 409 | KEY_ALG | Possible key sizes | 410 +===========+====================================+ 411 | rsa | 1024 , 2048 (default), 3072, 4096* | 412 +-----------+------------------------------------+ 413 | ecdsa | unavailable | 414 +-----------+------------------------------------+ 415 416 * Only 2048 bits size is available with CryptoCell 712 SBROM release 1. 417 Only 3072 bits size is available with CryptoCell 712 SBROM release 2. 418 419- ``HASH_ALG``: This build flag enables the user to select the secure hash 420 algorithm. It accepts 3 values: ``sha256``, ``sha384`` and ``sha512``. 421 The default value of this flag is ``sha256``. 422 423- ``LDFLAGS``: Extra user options appended to the linkers' command line in 424 addition to the one set by the build system. 425 426- ``LOG_LEVEL``: Chooses the log level, which controls the amount of console log 427 output compiled into the build. This should be one of the following: 428 429 :: 430 431 0 (LOG_LEVEL_NONE) 432 10 (LOG_LEVEL_ERROR) 433 20 (LOG_LEVEL_NOTICE) 434 30 (LOG_LEVEL_WARNING) 435 40 (LOG_LEVEL_INFO) 436 50 (LOG_LEVEL_VERBOSE) 437 438 All log output up to and including the selected log level is compiled into 439 the build. The default value is 40 in debug builds and 20 in release builds. 440 441- ``MEASURED_BOOT``: Boolean flag to include support for the Measured Boot 442 feature. If this flag is enabled ``TRUSTED_BOARD_BOOT`` must be set. 443 This option defaults to 0 and is an experimental feature in the stage of 444 development. 445 446- ``NON_TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It 447 specifies the file that contains the Non-Trusted World private key in PEM 448 format. If ``SAVE_KEYS=1``, this file name will be used to save the key. 449 450- ``NS_BL2U``: Path to NS_BL2U image in the host file system. This image is 451 optional. It is only needed if the platform makefile specifies that it 452 is required in order to build the ``fwu_fip`` target. 453 454- ``NS_TIMER_SWITCH``: Enable save and restore for non-secure timer register 455 contents upon world switch. It can take either 0 (don't save and restore) or 456 1 (do save and restore). 0 is the default. An SPD may set this to 1 if it 457 wants the timer registers to be saved and restored. 458 459- ``OVERRIDE_LIBC``: This option allows platforms to override the default libc 460 for the BL image. It can be either 0 (include) or 1 (remove). The default 461 value is 0. 462 463- ``PL011_GENERIC_UART``: Boolean option to indicate the PL011 driver that 464 the underlying hardware is not a full PL011 UART but a minimally compliant 465 generic UART, which is a subset of the PL011. The driver will not access 466 any register that is not part of the SBSA generic UART specification. 467 Default value is 0 (a full PL011 compliant UART is present). 468 469- ``PLAT``: Choose a platform to build TF-A for. The chosen platform name 470 must be subdirectory of any depth under ``plat/``, and must contain a 471 platform makefile named ``platform.mk``. For example, to build TF-A for the 472 Arm Juno board, select PLAT=juno. 473 474- ``PRELOADED_BL33_BASE``: This option enables booting a preloaded BL33 image 475 instead of the normal boot flow. When defined, it must specify the entry 476 point address for the preloaded BL33 image. This option is incompatible with 477 ``EL3_PAYLOAD_BASE``. If both are defined, ``EL3_PAYLOAD_BASE`` has priority 478 over ``PRELOADED_BL33_BASE``. 479 480- ``PROGRAMMABLE_RESET_ADDRESS``: This option indicates whether the reset 481 vector address can be programmed or is fixed on the platform. It can take 482 either 0 (fixed) or 1 (programmable). Default is 0. If the platform has a 483 programmable reset address, it is expected that a CPU will start executing 484 code directly at the right address, both on a cold and warm reset. In this 485 case, there is no need to identify the entrypoint on boot and the boot path 486 can be optimised. The ``plat_get_my_entrypoint()`` platform porting interface 487 does not need to be implemented in this case. 488 489- ``PSCI_EXTENDED_STATE_ID``: As per PSCI1.0 Specification, there are 2 formats 490 possible for the PSCI power-state parameter: original and extended State-ID 491 formats. This flag if set to 1, configures the generic PSCI layer to use the 492 extended format. The default value of this flag is 0, which means by default 493 the original power-state format is used by the PSCI implementation. This flag 494 should be specified by the platform makefile and it governs the return value 495 of PSCI_FEATURES API for CPU_SUSPEND smc function id. When this option is 496 enabled on Arm platforms, the option ``ARM_RECOM_STATE_ID_ENC`` needs to be 497 set to 1 as well. 498 499- ``RAS_EXTENSION``: When set to ``1``, enable Armv8.2 RAS features. RAS features 500 are an optional extension for pre-Armv8.2 CPUs, but are mandatory for Armv8.2 501 or later CPUs. 502 503 When ``RAS_EXTENSION`` is set to ``1``, ``HANDLE_EA_EL3_FIRST`` must also be 504 set to ``1``. 505 506 This option is disabled by default. 507 508- ``RESET_TO_BL31``: Enable BL31 entrypoint as the CPU reset vector instead 509 of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1 510 entrypoint) or 1 (CPU reset to BL31 entrypoint). 511 The default value is 0. 512 513- ``RESET_TO_SP_MIN``: SP_MIN is the minimal AArch32 Secure Payload provided 514 in TF-A. This flag configures SP_MIN entrypoint as the CPU reset vector 515 instead of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1 516 entrypoint) or 1 (CPU reset to SP_MIN entrypoint). The default value is 0. 517 518- ``ROT_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the 519 file that contains the ROT private key in PEM format and enforces public key 520 hash generation. If ``SAVE_KEYS=1``, this 521 file name will be used to save the key. 522 523- ``SAVE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the 524 certificate generation tool to save the keys used to establish the Chain of 525 Trust. Allowed options are '0' or '1'. Default is '0' (do not save). 526 527- ``SCP_BL2``: Path to SCP_BL2 image in the host file system. This image is optional. 528 If a SCP_BL2 image is present then this option must be passed for the ``fip`` 529 target. 530 531- ``SCP_BL2_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the 532 file that contains the SCP_BL2 private key in PEM format. If ``SAVE_KEYS=1``, 533 this file name will be used to save the key. 534 535- ``SCP_BL2U``: Path to SCP_BL2U image in the host file system. This image is 536 optional. It is only needed if the platform makefile specifies that it 537 is required in order to build the ``fwu_fip`` target. 538 539- ``SDEI_SUPPORT``: Setting this to ``1`` enables support for Software 540 Delegated Exception Interface to BL31 image. This defaults to ``0``. 541 542 When set to ``1``, the build option ``EL3_EXCEPTION_HANDLING`` must also be 543 set to ``1``. 544 545- ``SEPARATE_CODE_AND_RODATA``: Whether code and read-only data should be 546 isolated on separate memory pages. This is a trade-off between security and 547 memory usage. See "Isolating code and read-only data on separate memory 548 pages" section in :ref:`Firmware Design`. This flag is disabled by default 549 and affects all BL images. 550 551- ``SEPARATE_NOBITS_REGION``: Setting this option to ``1`` allows the NOBITS 552 sections of BL31 (.bss, stacks, page tables, and coherent memory) to be 553 allocated in RAM discontiguous from the loaded firmware image. When set, the 554 platform is expected to provide definitons for ``BL31_NOBITS_BASE`` and 555 ``BL31_NOBITS_LIMIT``. When the option is ``0`` (the default), NOBITS 556 sections are placed in RAM immediately following the loaded firmware image. 557 558- ``SPD``: Choose a Secure Payload Dispatcher component to be built into TF-A. 559 This build option is only valid if ``ARCH=aarch64``. The value should be 560 the path to the directory containing the SPD source, relative to 561 ``services/spd/``; the directory is expected to contain a makefile called 562 ``<spd-value>.mk``. The SPM Dispatcher standard service is located in 563 services/std_svc/spmd and enabled by ``SPD=spmd``. The SPM Dispatcher 564 cannot be enabled when the ``SPM_MM`` option is enabled. 565 566- ``SPIN_ON_BL1_EXIT``: This option introduces an infinite loop in BL1. It can 567 take either 0 (no loop) or 1 (add a loop). 0 is the default. This loop stops 568 execution in BL1 just before handing over to BL31. At this point, all 569 firmware images have been loaded in memory, and the MMU and caches are 570 turned off. Refer to the "Debugging options" section for more details. 571 572- ``SPMD_SPM_AT_SEL2`` : this boolean option is used jointly with the SPM 573 Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC 574 component runs at the S-EL2 execution state provided by the Armv8.4-SecEL2 575 extension. This is the default when enabling the SPM Dispatcher. When 576 disabled (0) it indicates the SPMC component runs at the S-EL1 execution 577 state. This latter configuration supports pre-Armv8.4 platforms (aka not 578 implementing the Armv8.4-SecEL2 extension). 579 580- ``SPM_MM`` : Boolean option to enable the Management Mode (MM)-based Secure 581 Partition Manager (SPM) implementation. The default value is ``0`` 582 (disabled). This option cannot be enabled (``1``) when SPM Dispatcher is 583 enabled (``SPD=spmd``). 584 585- ``SP_LAYOUT_FILE``: Platform provided path to JSON file containing the 586 description of secure partitions. The build system will parse this file and 587 package all secure partition blobs into the FIP. This file is not 588 necessarily part of TF-A tree. Only available when ``SPD=spmd``. 589 590- ``SP_MIN_WITH_SECURE_FIQ``: Boolean flag to indicate the SP_MIN handles 591 secure interrupts (caught through the FIQ line). Platforms can enable 592 this directive if they need to handle such interruption. When enabled, 593 the FIQ are handled in monitor mode and non secure world is not allowed 594 to mask these events. Platforms that enable FIQ handling in SP_MIN shall 595 implement the api ``sp_min_plat_fiq_handler()``. The default value is 0. 596 597- ``TRUSTED_BOARD_BOOT``: Boolean flag to include support for the Trusted Board 598 Boot feature. When set to '1', BL1 and BL2 images include support to load 599 and verify the certificates and images in a FIP, and BL1 includes support 600 for the Firmware Update. The default value is '0'. Generation and inclusion 601 of certificates in the FIP and FWU_FIP depends upon the value of the 602 ``GENERATE_COT`` option. 603 604 .. warning:: 605 This option depends on ``CREATE_KEYS`` to be enabled. If the keys 606 already exist in disk, they will be overwritten without further notice. 607 608- ``TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It 609 specifies the file that contains the Trusted World private key in PEM 610 format. If ``SAVE_KEYS=1``, this file name will be used to save the key. 611 612- ``TSP_INIT_ASYNC``: Choose BL32 initialization method as asynchronous or 613 synchronous, (see "Initializing a BL32 Image" section in 614 :ref:`Firmware Design`). It can take the value 0 (BL32 is initialized using 615 synchronous method) or 1 (BL32 is initialized using asynchronous method). 616 Default is 0. 617 618- ``TSP_NS_INTR_ASYNC_PREEMPT``: A non zero value enables the interrupt 619 routing model which routes non-secure interrupts asynchronously from TSP 620 to EL3 causing immediate preemption of TSP. The EL3 is responsible 621 for saving and restoring the TSP context in this routing model. The 622 default routing model (when the value is 0) is to route non-secure 623 interrupts to TSP allowing it to save its context and hand over 624 synchronously to EL3 via an SMC. 625 626 .. note:: 627 When ``EL3_EXCEPTION_HANDLING`` is ``1``, ``TSP_NS_INTR_ASYNC_PREEMPT`` 628 must also be set to ``1``. 629 630- ``USE_ARM_LINK``: This flag determines whether to enable support for ARM 631 linker. When the ``LINKER`` build variable points to the armlink linker, 632 this flag is enabled automatically. To enable support for armlink, platforms 633 will have to provide a scatter file for the BL image. Currently, Tegra 634 platforms use the armlink support to compile BL3-1 images. 635 636- ``USE_COHERENT_MEM``: This flag determines whether to include the coherent 637 memory region in the BL memory map or not (see "Use of Coherent memory in 638 TF-A" section in :ref:`Firmware Design`). It can take the value 1 639 (Coherent memory region is included) or 0 (Coherent memory region is 640 excluded). Default is 1. 641 642- ``USE_DEBUGFS``: When set to 1 this option activates an EXPERIMENTAL feature 643 exposing a virtual filesystem interface through BL31 as a SiP SMC function. 644 Default is 0. 645 646- ``ARM_IO_IN_DTB``: This flag determines whether to use IO based on the 647 firmware configuration framework. This will move the io_policies into a 648 configuration device tree, instead of static structure in the code base. 649 This is currently an experimental feature. 650 651- ``COT_DESC_IN_DTB``: This flag determines whether to create COT descriptors 652 at runtime using fconf. If this flag is enabled, COT descriptors are 653 statically captured in tb_fw_config file in the form of device tree nodes 654 and properties. Currently, COT descriptors used by BL2 are moved to the 655 device tree and COT descriptors used by BL1 are retained in the code 656 base statically. This is currently an experimental feature. 657 658- ``SDEI_IN_FCONF``: This flag determines whether to configure SDEI setup in 659 runtime using firmware configuration framework. The platform specific SDEI 660 shared and private events configuration is retrieved from device tree rather 661 than static C structures at compile time. This is currently an experimental 662 feature and is only supported if SDEI_SUPPORT build flag is enabled. 663 664- ``SEC_INT_DESC_IN_FCONF``: This flag determines whether to configure Group 0 665 and Group1 secure interrupts using the firmware configuration framework. The 666 platform specific secure interrupt property descriptor is retrieved from 667 device tree in runtime rather than depending on static C structure at compile 668 time. This is currently an experimental feature. 669 670- ``USE_ROMLIB``: This flag determines whether library at ROM will be used. 671 This feature creates a library of functions to be placed in ROM and thus 672 reduces SRAM usage. Refer to :ref:`Library at ROM` for further details. Default 673 is 0. 674 675- ``V``: Verbose build. If assigned anything other than 0, the build commands 676 are printed. Default is 0. 677 678- ``VERSION_STRING``: String used in the log output for each TF-A image. 679 Defaults to a string formed by concatenating the version number, build type 680 and build string. 681 682- ``W``: Warning level. Some compiler warning options of interest have been 683 regrouped and put in the root Makefile. This flag can take the values 0 to 3, 684 each level enabling more warning options. Default is 0. 685 686- ``WARMBOOT_ENABLE_DCACHE_EARLY`` : Boolean option to enable D-cache early on 687 the CPU after warm boot. This is applicable for platforms which do not 688 require interconnect programming to enable cache coherency (eg: single 689 cluster platforms). If this option is enabled, then warm boot path 690 enables D-caches immediately after enabling MMU. This option defaults to 0. 691 692- ``SUPPORT_STACK_MEMTAG``: This flag determines whether to enable memory 693 tagging for stack or not. It accepts 2 values: ``yes`` and ``no``. The 694 default value of this flag is ``no``. Note this option must be enabled only 695 for ARM architecture greater than Armv8.5-A. 696 697- ``ERRATA_SPECULATIVE_AT``: This flag enables/disables page table walk during 698 context restore as speculative AT instructions using an out-of-context 699 translation regime could cause subsequent requests to generate an incorrect 700 translation. 701 System registers are not updated during context save, hence this workaround 702 need not be applied in the context save path. 703 704 This boolean option enables errata for all below CPUs. 705 706 +---------+--------------+ 707 | Errata | CPU | 708 +=========+==============+ 709 | 1165522 | Cortex-A76 | 710 +---------+--------------+ 711 | 1319367 | Cortex-A72 | 712 +---------+--------------+ 713 | 1319537 | Cortex-A57 | 714 +---------+--------------+ 715 | 1530923 | Cortex-A55 | 716 +---------+--------------+ 717 | 1530924 | Cortex-A53 | 718 +---------+--------------+ 719 720- ``RAS_TRAP_LOWER_EL_ERR_ACCESS``: This flag enables/disables the SCR_EL3.TERR 721 bit, to trap access to the RAS ERR and RAS ERX registers from lower ELs. 722 This flag is disabled by default. 723 724GICv3 driver options 725-------------------- 726 727GICv3 driver files are included using directive: 728 729``include drivers/arm/gic/v3/gicv3.mk`` 730 731The driver can be configured with the following options set in the platform 732makefile: 733 734- ``GICV3_SUPPORT_GIC600``: Add support for the GIC-600 variants of GICv3. 735 Enabling this option will add runtime detection support for the 736 GIC-600, so is safe to select even for a GIC500 implementation. 737 This option defaults to 0. 738 739- ``GICV3_IMPL_GIC600_MULTICHIP``: Selects GIC-600 variant with multichip 740 functionality. This option defaults to 0 741 742- ``GICV3_OVERRIDE_DISTIF_PWR_OPS``: Allows override of default implementation 743 of ``arm_gicv3_distif_pre_save`` and ``arm_gicv3_distif_post_restore`` 744 functions. This is required for FVP platform which need to simulate GIC save 745 and restore during SYSTEM_SUSPEND without powering down GIC. Default is 0. 746 747- ``GIC_ENABLE_V4_EXTN`` : Enables GICv4 related changes in GICv3 driver. 748 This option defaults to 0. 749 750- ``GIC_EXT_INTID``: When set to ``1``, GICv3 driver will support extended 751 PPI (1056-1119) and SPI (4096-5119) range. This option defaults to 0. 752 753Debugging options 754----------------- 755 756To compile a debug version and make the build more verbose use 757 758.. code:: shell 759 760 make PLAT=<platform> DEBUG=1 V=1 all 761 762AArch64 GCC uses DWARF version 4 debugging symbols by default. Some tools (for 763example DS-5) might not support this and may need an older version of DWARF 764symbols to be emitted by GCC. This can be achieved by using the 765``-gdwarf-<version>`` flag, with the version being set to 2 or 3. Setting the 766version to 2 is recommended for DS-5 versions older than 5.16. 767 768When debugging logic problems it might also be useful to disable all compiler 769optimizations by using ``-O0``. 770 771.. warning:: 772 Using ``-O0`` could cause output images to be larger and base addresses 773 might need to be recalculated (see the **Memory layout on Arm development 774 platforms** section in the :ref:`Firmware Design`). 775 776Extra debug options can be passed to the build system by setting ``CFLAGS`` or 777``LDFLAGS``: 778 779.. code:: shell 780 781 CFLAGS='-O0 -gdwarf-2' \ 782 make PLAT=<platform> DEBUG=1 V=1 all 783 784Note that using ``-Wl,`` style compilation driver options in ``CFLAGS`` will be 785ignored as the linker is called directly. 786 787It is also possible to introduce an infinite loop to help in debugging the 788post-BL2 phase of TF-A. This can be done by rebuilding BL1 with the 789``SPIN_ON_BL1_EXIT=1`` build flag. Refer to the :ref:`build_options_common` 790section. In this case, the developer may take control of the target using a 791debugger when indicated by the console output. When using DS-5, the following 792commands can be used: 793 794:: 795 796 # Stop target execution 797 interrupt 798 799 # 800 # Prepare your debugging environment, e.g. set breakpoints 801 # 802 803 # Jump over the debug loop 804 set var $AARCH64::$Core::$PC = $AARCH64::$Core::$PC + 4 805 806 # Resume execution 807 continue 808 809-------------- 810 811*Copyright (c) 2019-2020, Arm Limited. All rights reserved.* 812