1Build Options 2============= 3 4The TF-A build system supports the following build options. Unless mentioned 5otherwise, these options are expected to be specified at the build command 6line and are not to be modified in any component makefiles. Note that the 7build system doesn't track dependency for build options. Therefore, if any of 8the build options are changed from a previous build, a clean build must be 9performed. 10 11.. _build_options_common: 12 13Common build options 14-------------------- 15 16- ``AARCH32_INSTRUCTION_SET``: Choose the AArch32 instruction set that the 17 compiler should use. Valid values are T32 and A32. It defaults to T32 due to 18 code having a smaller resulting size. 19 20- ``AARCH32_SP`` : Choose the AArch32 Secure Payload component to be built as 21 as the BL32 image when ``ARCH=aarch32``. The value should be the path to the 22 directory containing the SP source, relative to the ``bl32/``; the directory 23 is expected to contain a makefile called ``<aarch32_sp-value>.mk``. 24 25- ``AMU_RESTRICT_COUNTERS``: Register reads to the group 1 counters will return 26 zero at all but the highest implemented exception level. Reads from the 27 memory mapped view are unaffected by this control. 28 29- ``ARCH`` : Choose the target build architecture for TF-A. It can take either 30 ``aarch64`` or ``aarch32`` as values. By default, it is defined to 31 ``aarch64``. 32 33- ``ARM_ARCH_FEATURE``: Optional Arm Architecture build option which specifies 34 one or more feature modifiers. This option has the form ``[no]feature+...`` 35 and defaults to ``none``. It translates into compiler option 36 ``-march=armvX[.Y]-a+[no]feature+...``. See compiler's documentation for the 37 list of supported feature modifiers. 38 39- ``ARM_ARCH_MAJOR``: The major version of Arm Architecture to target when 40 compiling TF-A. Its value must be numeric, and defaults to 8 . See also, 41 *Armv8 Architecture Extensions* and *Armv7 Architecture Extensions* in 42 :ref:`Firmware Design`. 43 44- ``ARM_ARCH_MINOR``: The minor version of Arm Architecture to target when 45 compiling TF-A. Its value must be a numeric, and defaults to 0. See also, 46 *Armv8 Architecture Extensions* in :ref:`Firmware Design`. 47 48- ``BL2``: This is an optional build option which specifies the path to BL2 49 image for the ``fip`` target. In this case, the BL2 in the TF-A will not be 50 built. 51 52- ``BL2U``: This is an optional build option which specifies the path to 53 BL2U image. In this case, the BL2U in TF-A will not be built. 54 55- ``BL2_AT_EL3``: This is an optional build option that enables the use of 56 BL2 at EL3 execution level. 57 58- ``BL2_IN_XIP_MEM``: In some use-cases BL2 will be stored in eXecute In Place 59 (XIP) memory, like BL1. In these use-cases, it is necessary to initialize 60 the RW sections in RAM, while leaving the RO sections in place. This option 61 enable this use-case. For now, this option is only supported when BL2_AT_EL3 62 is set to '1'. 63 64- ``BL31``: This is an optional build option which specifies the path to 65 BL31 image for the ``fip`` target. In this case, the BL31 in TF-A will not 66 be built. 67 68- ``BL31_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the 69 file that contains the BL31 private key in PEM format. If ``SAVE_KEYS=1``, 70 this file name will be used to save the key. 71 72- ``BL32``: This is an optional build option which specifies the path to 73 BL32 image for the ``fip`` target. In this case, the BL32 in TF-A will not 74 be built. 75 76- ``BL32_EXTRA1``: This is an optional build option which specifies the path to 77 Trusted OS Extra1 image for the ``fip`` target. 78 79- ``BL32_EXTRA2``: This is an optional build option which specifies the path to 80 Trusted OS Extra2 image for the ``fip`` target. 81 82- ``BL32_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the 83 file that contains the BL32 private key in PEM format. If ``SAVE_KEYS=1``, 84 this file name will be used to save the key. 85 86- ``BL33``: Path to BL33 image in the host file system. This is mandatory for 87 ``fip`` target in case TF-A BL2 is used. 88 89- ``BL33_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the 90 file that contains the BL33 private key in PEM format. If ``SAVE_KEYS=1``, 91 this file name will be used to save the key. 92 93- ``BRANCH_PROTECTION``: Numeric value to enable ARMv8.3 Pointer Authentication 94 and ARMv8.5 Branch Target Identification support for TF-A BL images themselves. 95 If enabled, it is needed to use a compiler that supports the option 96 ``-mbranch-protection``. Selects the branch protection features to use: 97- 0: Default value turns off all types of branch protection 98- 1: Enables all types of branch protection features 99- 2: Return address signing to its standard level 100- 3: Extend the signing to include leaf functions 101- 4: Turn on branch target identification mechanism 102 103 The table below summarizes ``BRANCH_PROTECTION`` values, GCC compilation options 104 and resulting PAuth/BTI features. 105 106 +-------+--------------+-------+-----+ 107 | Value | GCC option | PAuth | BTI | 108 +=======+==============+=======+=====+ 109 | 0 | none | N | N | 110 +-------+--------------+-------+-----+ 111 | 1 | standard | Y | Y | 112 +-------+--------------+-------+-----+ 113 | 2 | pac-ret | Y | N | 114 +-------+--------------+-------+-----+ 115 | 3 | pac-ret+leaf | Y | N | 116 +-------+--------------+-------+-----+ 117 | 4 | bti | N | Y | 118 +-------+--------------+-------+-----+ 119 120 This option defaults to 0 and this is an experimental feature. 121 Note that Pointer Authentication is enabled for Non-secure world 122 irrespective of the value of this option if the CPU supports it. 123 124- ``BUILD_MESSAGE_TIMESTAMP``: String used to identify the time and date of the 125 compilation of each build. It must be set to a C string (including quotes 126 where applicable). Defaults to a string that contains the time and date of 127 the compilation. 128 129- ``BUILD_STRING``: Input string for VERSION_STRING, which allows the TF-A 130 build to be uniquely identified. Defaults to the current git commit id. 131 132- ``BUILD_BASE``: Output directory for the build. Defaults to ``./build`` 133 134- ``CFLAGS``: Extra user options appended on the compiler's command line in 135 addition to the options set by the build system. 136 137- ``COLD_BOOT_SINGLE_CPU``: This option indicates whether the platform may 138 release several CPUs out of reset. It can take either 0 (several CPUs may be 139 brought up) or 1 (only one CPU will ever be brought up during cold reset). 140 Default is 0. If the platform always brings up a single CPU, there is no 141 need to distinguish between primary and secondary CPUs and the boot path can 142 be optimised. The ``plat_is_my_cpu_primary()`` and 143 ``plat_secondary_cold_boot_setup()`` platform porting interfaces do not need 144 to be implemented in this case. 145 146- ``COT``: When Trusted Boot is enabled, selects the desired chain of trust. 147 Defaults to ``tbbr``. 148 149- ``CRASH_REPORTING``: A non-zero value enables a console dump of processor 150 register state when an unexpected exception occurs during execution of 151 BL31. This option defaults to the value of ``DEBUG`` - i.e. by default 152 this is only enabled for a debug build of the firmware. 153 154- ``CREATE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the 155 certificate generation tool to create new keys in case no valid keys are 156 present or specified. Allowed options are '0' or '1'. Default is '1'. 157 158- ``CTX_INCLUDE_AARCH32_REGS`` : Boolean option that, when set to 1, will cause 159 the AArch32 system registers to be included when saving and restoring the 160 CPU context. The option must be set to 0 for AArch64-only platforms (that 161 is on hardware that does not implement AArch32, or at least not at EL1 and 162 higher ELs). Default value is 1. 163 164- ``CTX_INCLUDE_EL2_REGS`` : This boolean option provides context save/restore 165 operations when entering/exiting an EL2 execution context. This is of primary 166 interest when Armv8.4-SecEL2 extension is implemented. Default is 0 (disabled). 167 This option must be equal to 1 (enabled) when ``SPD=spmd`` and 168 ``SPMD_SPM_AT_SEL2`` is set. 169 170- ``CTX_INCLUDE_FPREGS``: Boolean option that, when set to 1, will cause the FP 171 registers to be included when saving and restoring the CPU context. Default 172 is 0. 173 174- ``CTX_INCLUDE_NEVE_REGS``: Boolean option that, when set to 1, will cause the 175 Armv8.4-NV registers to be saved/restored when entering/exiting an EL2 176 execution context. Default value is 0. 177 178- ``CTX_INCLUDE_PAUTH_REGS``: Boolean option that, when set to 1, enables 179 Pointer Authentication for Secure world. This will cause the ARMv8.3-PAuth 180 registers to be included when saving and restoring the CPU context as 181 part of world switch. Default value is 0 and this is an experimental feature. 182 Note that Pointer Authentication is enabled for Non-secure world irrespective 183 of the value of this flag if the CPU supports it. 184 185- ``DEBUG``: Chooses between a debug and release build. It can take either 0 186 (release) or 1 (debug) as values. 0 is the default. 187 188- ``DECRYPTION_SUPPORT``: This build flag enables the user to select the 189 authenticated decryption algorithm to be used to decrypt firmware/s during 190 boot. It accepts 2 values: ``aes_gcm`` and ``none``. The default value of 191 this flag is ``none`` to disable firmware decryption which is an optional 192 feature as per TBBR. Also, it is an experimental feature. 193 194- ``DISABLE_BIN_GENERATION``: Boolean option to disable the generation 195 of the binary image. If set to 1, then only the ELF image is built. 196 0 is the default. 197 198- ``DISABLE_MTPMU``: Boolean option to disable FEAT_MTPMU if implemented 199 (Armv8.6 onwards). Its default value is 0 to keep consistency with platforms 200 that do not implement FEAT_MTPMU. For more information on FEAT_MTPMU, 201 check the latest Arm ARM. 202 203- ``DYN_DISABLE_AUTH``: Provides the capability to dynamically disable Trusted 204 Board Boot authentication at runtime. This option is meant to be enabled only 205 for development platforms. ``TRUSTED_BOARD_BOOT`` flag must be set if this 206 flag has to be enabled. 0 is the default. 207 208- ``E``: Boolean option to make warnings into errors. Default is 1. 209 210- ``EL3_PAYLOAD_BASE``: This option enables booting an EL3 payload instead of 211 the normal boot flow. It must specify the entry point address of the EL3 212 payload. Please refer to the "Booting an EL3 payload" section for more 213 details. 214 215- ``ENABLE_AMU``: Boolean option to enable Activity Monitor Unit extensions. 216 This is an optional architectural feature available on v8.4 onwards. Some 217 v8.2 implementations also implement an AMU and this option can be used to 218 enable this feature on those systems as well. Default is 0. 219 220- ``ENABLE_ASSERTIONS``: This option controls whether or not calls to ``assert()`` 221 are compiled out. For debug builds, this option defaults to 1, and calls to 222 ``assert()`` are left in place. For release builds, this option defaults to 0 223 and calls to ``assert()`` function are compiled out. This option can be set 224 independently of ``DEBUG``. It can also be used to hide any auxiliary code 225 that is only required for the assertion and does not fit in the assertion 226 itself. 227 228- ``ENABLE_BACKTRACE``: This option controls whether to enable backtrace 229 dumps or not. It is supported in both AArch64 and AArch32. However, in 230 AArch32 the format of the frame records are not defined in the AAPCS and they 231 are defined by the implementation. This implementation of backtrace only 232 supports the format used by GCC when T32 interworking is disabled. For this 233 reason enabling this option in AArch32 will force the compiler to only 234 generate A32 code. This option is enabled by default only in AArch64 debug 235 builds, but this behaviour can be overridden in each platform's Makefile or 236 in the build command line. 237 238- ``ENABLE_LTO``: Boolean option to enable Link Time Optimization (LTO) 239 support in GCC for TF-A. This option is currently only supported for 240 AArch64. Default is 0. 241 242- ``ENABLE_MPAM_FOR_LOWER_ELS``: Boolean option to enable lower ELs to use MPAM 243 feature. MPAM is an optional Armv8.4 extension that enables various memory 244 system components and resources to define partitions; software running at 245 various ELs can assign themselves to desired partition to control their 246 performance aspects. 247 248 When this option is set to ``1``, EL3 allows lower ELs to access their own 249 MPAM registers without trapping into EL3. This option doesn't make use of 250 partitioning in EL3, however. Platform initialisation code should configure 251 and use partitions in EL3 as required. This option defaults to ``0``. 252 253- ``ENABLE_PIE``: Boolean option to enable Position Independent Executable(PIE) 254 support within generic code in TF-A. This option is currently only supported 255 in BL2_AT_EL3, BL31, and BL32 (TSP) for AARCH64 binaries, and in BL32 256 (SP_min) for AARCH32. Default is 0. 257 258- ``ENABLE_PMF``: Boolean option to enable support for optional Performance 259 Measurement Framework(PMF). Default is 0. 260 261- ``ENABLE_PSCI_STAT``: Boolean option to enable support for optional PSCI 262 functions ``PSCI_STAT_RESIDENCY`` and ``PSCI_STAT_COUNT``. Default is 0. 263 In the absence of an alternate stat collection backend, ``ENABLE_PMF`` must 264 be enabled. If ``ENABLE_PMF`` is set, the residency statistics are tracked in 265 software. 266 267- ``ENABLE_RUNTIME_INSTRUMENTATION``: Boolean option to enable runtime 268 instrumentation which injects timestamp collection points into TF-A to 269 allow runtime performance to be measured. Currently, only PSCI is 270 instrumented. Enabling this option enables the ``ENABLE_PMF`` build option 271 as well. Default is 0. 272 273- ``ENABLE_SPE_FOR_LOWER_ELS`` : Boolean option to enable Statistical Profiling 274 extensions. This is an optional architectural feature for AArch64. 275 The default is 1 but is automatically disabled when the target architecture 276 is AArch32. 277 278- ``ENABLE_SVE_FOR_NS``: Boolean option to enable Scalable Vector Extension 279 (SVE) for the Non-secure world only. SVE is an optional architectural feature 280 for AArch64. Note that when SVE is enabled for the Non-secure world, access 281 to SIMD and floating-point functionality from the Secure world is disabled. 282 This is to avoid corruption of the Non-secure world data in the Z-registers 283 which are aliased by the SIMD and FP registers. The build option is not 284 compatible with the ``CTX_INCLUDE_FPREGS`` build option, and will raise an 285 assert on platforms where SVE is implemented and ``ENABLE_SVE_FOR_NS`` set to 286 1. The default is 1 but is automatically disabled when the target 287 architecture is AArch32. 288 289- ``ENABLE_STACK_PROTECTOR``: String option to enable the stack protection 290 checks in GCC. Allowed values are "all", "strong", "default" and "none". The 291 default value is set to "none". "strong" is the recommended stack protection 292 level if this feature is desired. "none" disables the stack protection. For 293 all values other than "none", the ``plat_get_stack_protector_canary()`` 294 platform hook needs to be implemented. The value is passed as the last 295 component of the option ``-fstack-protector-$ENABLE_STACK_PROTECTOR``. 296 297- ``ENCRYPT_BL31``: Binary flag to enable encryption of BL31 firmware. This 298 flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as 299 experimental. 300 301- ``ENCRYPT_BL32``: Binary flag to enable encryption of Secure BL32 payload. 302 This flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as 303 experimental. 304 305- ``ENC_KEY``: A 32-byte (256-bit) symmetric key in hex string format. It could 306 either be SSK or BSSK depending on ``FW_ENC_STATUS`` flag. This value depends 307 on ``DECRYPTION_SUPPORT`` build flag which is marked as experimental. 308 309- ``ENC_NONCE``: A 12-byte (96-bit) encryption nonce or Initialization Vector 310 (IV) in hex string format. This value depends on ``DECRYPTION_SUPPORT`` 311 build flag which is marked as experimental. 312 313- ``ERROR_DEPRECATED``: This option decides whether to treat the usage of 314 deprecated platform APIs, helper functions or drivers within Trusted 315 Firmware as error. It can take the value 1 (flag the use of deprecated 316 APIs as error) or 0. The default is 0. 317 318- ``EL3_EXCEPTION_HANDLING``: When set to ``1``, enable handling of exceptions 319 targeted at EL3. When set ``0`` (default), no exceptions are expected or 320 handled at EL3, and a panic will result. This is supported only for AArch64 321 builds. 322 323- ``EVENT_LOG_LEVEL``: Chooses the log level to use for Measured Boot when 324 ``MEASURED_BOOT`` is enabled. For a list of valid values, see ``LOG_LEVEL``. 325 Default value is 40 (LOG_LEVEL_INFO). 326 327- ``FAULT_INJECTION_SUPPORT``: ARMv8.4 extensions introduced support for fault 328 injection from lower ELs, and this build option enables lower ELs to use 329 Error Records accessed via System Registers to inject faults. This is 330 applicable only to AArch64 builds. 331 332 This feature is intended for testing purposes only, and is advisable to keep 333 disabled for production images. 334 335- ``FIP_NAME``: This is an optional build option which specifies the FIP 336 filename for the ``fip`` target. Default is ``fip.bin``. 337 338- ``FWU_FIP_NAME``: This is an optional build option which specifies the FWU 339 FIP filename for the ``fwu_fip`` target. Default is ``fwu_fip.bin``. 340 341- ``FW_ENC_STATUS``: Top level firmware's encryption numeric flag, values: 342 343 :: 344 345 0: Encryption is done with Secret Symmetric Key (SSK) which is common 346 for a class of devices. 347 1: Encryption is done with Binding Secret Symmetric Key (BSSK) which is 348 unique per device. 349 350 This flag depends on ``DECRYPTION_SUPPORT`` build flag which is marked as 351 experimental. 352 353- ``GENERATE_COT``: Boolean flag used to build and execute the ``cert_create`` 354 tool to create certificates as per the Chain of Trust described in 355 :ref:`Trusted Board Boot`. The build system then calls ``fiptool`` to 356 include the certificates in the FIP and FWU_FIP. Default value is '0'. 357 358 Specify both ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=1`` to include support 359 for the Trusted Board Boot feature in the BL1 and BL2 images, to generate 360 the corresponding certificates, and to include those certificates in the 361 FIP and FWU_FIP. 362 363 Note that if ``TRUSTED_BOARD_BOOT=0`` and ``GENERATE_COT=1``, the BL1 and BL2 364 images will not include support for Trusted Board Boot. The FIP will still 365 include the corresponding certificates. This FIP can be used to verify the 366 Chain of Trust on the host machine through other mechanisms. 367 368 Note that if ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=0``, the BL1 and BL2 369 images will include support for Trusted Board Boot, but the FIP and FWU_FIP 370 will not include the corresponding certificates, causing a boot failure. 371 372- ``GICV2_G0_FOR_EL3``: Unlike GICv3, the GICv2 architecture doesn't have 373 inherent support for specific EL3 type interrupts. Setting this build option 374 to ``1`` assumes GICv2 *Group 0* interrupts are expected to target EL3, both 375 by :ref:`platform abstraction layer<platform Interrupt Controller API>` and 376 :ref:`Interrupt Management Framework<Interrupt Management Framework>`. 377 This allows GICv2 platforms to enable features requiring EL3 interrupt type. 378 This also means that all GICv2 Group 0 interrupts are delivered to EL3, and 379 the Secure Payload interrupts needs to be synchronously handed over to Secure 380 EL1 for handling. The default value of this option is ``0``, which means the 381 Group 0 interrupts are assumed to be handled by Secure EL1. 382 383- ``HANDLE_EA_EL3_FIRST``: When set to ``1``, External Aborts and SError 384 Interrupts will be always trapped in EL3 i.e. in BL31 at runtime. When set to 385 ``0`` (default), these exceptions will be trapped in the current exception 386 level (or in EL1 if the current exception level is EL0). 387 388- ``HW_ASSISTED_COHERENCY``: On most Arm systems to-date, platform-specific 389 software operations are required for CPUs to enter and exit coherency. 390 However, newer systems exist where CPUs' entry to and exit from coherency 391 is managed in hardware. Such systems require software to only initiate these 392 operations, and the rest is managed in hardware, minimizing active software 393 management. In such systems, this boolean option enables TF-A to carry out 394 build and run-time optimizations during boot and power management operations. 395 This option defaults to 0 and if it is enabled, then it implies 396 ``WARMBOOT_ENABLE_DCACHE_EARLY`` is also enabled. 397 398 If this flag is disabled while the platform which TF-A is compiled for 399 includes cores that manage coherency in hardware, then a compilation error is 400 generated. This is based on the fact that a system cannot have, at the same 401 time, cores that manage coherency in hardware and cores that don't. In other 402 words, a platform cannot have, at the same time, cores that require 403 ``HW_ASSISTED_COHERENCY=1`` and cores that require 404 ``HW_ASSISTED_COHERENCY=0``. 405 406 Note that, when ``HW_ASSISTED_COHERENCY`` is enabled, version 2 of 407 translation library (xlat tables v2) must be used; version 1 of translation 408 library is not supported. 409 410- ``INVERTED_MEMMAP``: memmap tool print by default lower addresses at the 411 bottom, higher addresses at the top. This build flag can be set to '1' to 412 invert this behavior. Lower addresses will be printed at the top and higher 413 addresses at the bottom. 414 415- ``JUNO_AARCH32_EL3_RUNTIME``: This build flag enables you to execute EL3 416 runtime software in AArch32 mode, which is required to run AArch32 on Juno. 417 By default this flag is set to '0'. Enabling this flag builds BL1 and BL2 in 418 AArch64 and facilitates the loading of ``SP_MIN`` and BL33 as AArch32 executable 419 images. 420 421- ``KEY_ALG``: This build flag enables the user to select the algorithm to be 422 used for generating the PKCS keys and subsequent signing of the certificate. 423 It accepts 3 values: ``rsa``, ``rsa_1_5`` and ``ecdsa``. The option 424 ``rsa_1_5`` is the legacy PKCS#1 RSA 1.5 algorithm which is not TBBR 425 compliant and is retained only for compatibility. The default value of this 426 flag is ``rsa`` which is the TBBR compliant PKCS#1 RSA 2.1 scheme. 427 428- ``KEY_SIZE``: This build flag enables the user to select the key size for 429 the algorithm specified by ``KEY_ALG``. The valid values for ``KEY_SIZE`` 430 depend on the chosen algorithm and the cryptographic module. 431 432 +-----------+------------------------------------+ 433 | KEY_ALG | Possible key sizes | 434 +===========+====================================+ 435 | rsa | 1024 , 2048 (default), 3072, 4096* | 436 +-----------+------------------------------------+ 437 | ecdsa | unavailable | 438 +-----------+------------------------------------+ 439 440 * Only 2048 bits size is available with CryptoCell 712 SBROM release 1. 441 Only 3072 bits size is available with CryptoCell 712 SBROM release 2. 442 443- ``HASH_ALG``: This build flag enables the user to select the secure hash 444 algorithm. It accepts 3 values: ``sha256``, ``sha384`` and ``sha512``. 445 The default value of this flag is ``sha256``. 446 447- ``LDFLAGS``: Extra user options appended to the linkers' command line in 448 addition to the one set by the build system. 449 450- ``LOG_LEVEL``: Chooses the log level, which controls the amount of console log 451 output compiled into the build. This should be one of the following: 452 453 :: 454 455 0 (LOG_LEVEL_NONE) 456 10 (LOG_LEVEL_ERROR) 457 20 (LOG_LEVEL_NOTICE) 458 30 (LOG_LEVEL_WARNING) 459 40 (LOG_LEVEL_INFO) 460 50 (LOG_LEVEL_VERBOSE) 461 462 All log output up to and including the selected log level is compiled into 463 the build. The default value is 40 in debug builds and 20 in release builds. 464 465- ``MEASURED_BOOT``: Boolean flag to include support for the Measured Boot 466 feature. If this flag is enabled ``TRUSTED_BOARD_BOOT`` must be set. 467 This option defaults to 0 and is an experimental feature in the stage of 468 development. 469 470- ``NON_TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It 471 specifies the file that contains the Non-Trusted World private key in PEM 472 format. If ``SAVE_KEYS=1``, this file name will be used to save the key. 473 474- ``NS_BL2U``: Path to NS_BL2U image in the host file system. This image is 475 optional. It is only needed if the platform makefile specifies that it 476 is required in order to build the ``fwu_fip`` target. 477 478- ``NS_TIMER_SWITCH``: Enable save and restore for non-secure timer register 479 contents upon world switch. It can take either 0 (don't save and restore) or 480 1 (do save and restore). 0 is the default. An SPD may set this to 1 if it 481 wants the timer registers to be saved and restored. 482 483- ``OVERRIDE_LIBC``: This option allows platforms to override the default libc 484 for the BL image. It can be either 0 (include) or 1 (remove). The default 485 value is 0. 486 487- ``PL011_GENERIC_UART``: Boolean option to indicate the PL011 driver that 488 the underlying hardware is not a full PL011 UART but a minimally compliant 489 generic UART, which is a subset of the PL011. The driver will not access 490 any register that is not part of the SBSA generic UART specification. 491 Default value is 0 (a full PL011 compliant UART is present). 492 493- ``PLAT``: Choose a platform to build TF-A for. The chosen platform name 494 must be subdirectory of any depth under ``plat/``, and must contain a 495 platform makefile named ``platform.mk``. For example, to build TF-A for the 496 Arm Juno board, select PLAT=juno. 497 498- ``PRELOADED_BL33_BASE``: This option enables booting a preloaded BL33 image 499 instead of the normal boot flow. When defined, it must specify the entry 500 point address for the preloaded BL33 image. This option is incompatible with 501 ``EL3_PAYLOAD_BASE``. If both are defined, ``EL3_PAYLOAD_BASE`` has priority 502 over ``PRELOADED_BL33_BASE``. 503 504- ``PROGRAMMABLE_RESET_ADDRESS``: This option indicates whether the reset 505 vector address can be programmed or is fixed on the platform. It can take 506 either 0 (fixed) or 1 (programmable). Default is 0. If the platform has a 507 programmable reset address, it is expected that a CPU will start executing 508 code directly at the right address, both on a cold and warm reset. In this 509 case, there is no need to identify the entrypoint on boot and the boot path 510 can be optimised. The ``plat_get_my_entrypoint()`` platform porting interface 511 does not need to be implemented in this case. 512 513- ``PSCI_EXTENDED_STATE_ID``: As per PSCI1.0 Specification, there are 2 formats 514 possible for the PSCI power-state parameter: original and extended State-ID 515 formats. This flag if set to 1, configures the generic PSCI layer to use the 516 extended format. The default value of this flag is 0, which means by default 517 the original power-state format is used by the PSCI implementation. This flag 518 should be specified by the platform makefile and it governs the return value 519 of PSCI_FEATURES API for CPU_SUSPEND smc function id. When this option is 520 enabled on Arm platforms, the option ``ARM_RECOM_STATE_ID_ENC`` needs to be 521 set to 1 as well. 522 523- ``RAS_EXTENSION``: When set to ``1``, enable Armv8.2 RAS features. RAS features 524 are an optional extension for pre-Armv8.2 CPUs, but are mandatory for Armv8.2 525 or later CPUs. 526 527 When ``RAS_EXTENSION`` is set to ``1``, ``HANDLE_EA_EL3_FIRST`` must also be 528 set to ``1``. 529 530 This option is disabled by default. 531 532- ``RESET_TO_BL31``: Enable BL31 entrypoint as the CPU reset vector instead 533 of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1 534 entrypoint) or 1 (CPU reset to BL31 entrypoint). 535 The default value is 0. 536 537- ``RESET_TO_SP_MIN``: SP_MIN is the minimal AArch32 Secure Payload provided 538 in TF-A. This flag configures SP_MIN entrypoint as the CPU reset vector 539 instead of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1 540 entrypoint) or 1 (CPU reset to SP_MIN entrypoint). The default value is 0. 541 542- ``ROT_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the 543 file that contains the ROT private key in PEM format and enforces public key 544 hash generation. If ``SAVE_KEYS=1``, this 545 file name will be used to save the key. 546 547- ``SAVE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the 548 certificate generation tool to save the keys used to establish the Chain of 549 Trust. Allowed options are '0' or '1'. Default is '0' (do not save). 550 551- ``SCP_BL2``: Path to SCP_BL2 image in the host file system. This image is optional. 552 If a SCP_BL2 image is present then this option must be passed for the ``fip`` 553 target. 554 555- ``SCP_BL2_KEY``: This option is used when ``GENERATE_COT=1``. It specifies the 556 file that contains the SCP_BL2 private key in PEM format. If ``SAVE_KEYS=1``, 557 this file name will be used to save the key. 558 559- ``SCP_BL2U``: Path to SCP_BL2U image in the host file system. This image is 560 optional. It is only needed if the platform makefile specifies that it 561 is required in order to build the ``fwu_fip`` target. 562 563- ``SDEI_SUPPORT``: Setting this to ``1`` enables support for Software 564 Delegated Exception Interface to BL31 image. This defaults to ``0``. 565 566 When set to ``1``, the build option ``EL3_EXCEPTION_HANDLING`` must also be 567 set to ``1``. 568 569- ``SEPARATE_CODE_AND_RODATA``: Whether code and read-only data should be 570 isolated on separate memory pages. This is a trade-off between security and 571 memory usage. See "Isolating code and read-only data on separate memory 572 pages" section in :ref:`Firmware Design`. This flag is disabled by default 573 and affects all BL images. 574 575- ``SEPARATE_NOBITS_REGION``: Setting this option to ``1`` allows the NOBITS 576 sections of BL31 (.bss, stacks, page tables, and coherent memory) to be 577 allocated in RAM discontiguous from the loaded firmware image. When set, the 578 platform is expected to provide definitions for ``BL31_NOBITS_BASE`` and 579 ``BL31_NOBITS_LIMIT``. When the option is ``0`` (the default), NOBITS 580 sections are placed in RAM immediately following the loaded firmware image. 581 582- ``SPD``: Choose a Secure Payload Dispatcher component to be built into TF-A. 583 This build option is only valid if ``ARCH=aarch64``. The value should be 584 the path to the directory containing the SPD source, relative to 585 ``services/spd/``; the directory is expected to contain a makefile called 586 ``<spd-value>.mk``. The SPM Dispatcher standard service is located in 587 services/std_svc/spmd and enabled by ``SPD=spmd``. The SPM Dispatcher 588 cannot be enabled when the ``SPM_MM`` option is enabled. 589 590- ``SPIN_ON_BL1_EXIT``: This option introduces an infinite loop in BL1. It can 591 take either 0 (no loop) or 1 (add a loop). 0 is the default. This loop stops 592 execution in BL1 just before handing over to BL31. At this point, all 593 firmware images have been loaded in memory, and the MMU and caches are 594 turned off. Refer to the "Debugging options" section for more details. 595 596- ``SPMD_SPM_AT_SEL2`` : this boolean option is used jointly with the SPM 597 Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC 598 component runs at the S-EL2 execution state provided by the Armv8.4-SecEL2 599 extension. This is the default when enabling the SPM Dispatcher. When 600 disabled (0) it indicates the SPMC component runs at the S-EL1 execution 601 state. This latter configuration supports pre-Armv8.4 platforms (aka not 602 implementing the Armv8.4-SecEL2 extension). 603 604- ``SPM_MM`` : Boolean option to enable the Management Mode (MM)-based Secure 605 Partition Manager (SPM) implementation. The default value is ``0`` 606 (disabled). This option cannot be enabled (``1``) when SPM Dispatcher is 607 enabled (``SPD=spmd``). 608 609- ``SP_LAYOUT_FILE``: Platform provided path to JSON file containing the 610 description of secure partitions. The build system will parse this file and 611 package all secure partition blobs into the FIP. This file is not 612 necessarily part of TF-A tree. Only available when ``SPD=spmd``. 613 614- ``SP_MIN_WITH_SECURE_FIQ``: Boolean flag to indicate the SP_MIN handles 615 secure interrupts (caught through the FIQ line). Platforms can enable 616 this directive if they need to handle such interruption. When enabled, 617 the FIQ are handled in monitor mode and non secure world is not allowed 618 to mask these events. Platforms that enable FIQ handling in SP_MIN shall 619 implement the api ``sp_min_plat_fiq_handler()``. The default value is 0. 620 621- ``TRUSTED_BOARD_BOOT``: Boolean flag to include support for the Trusted Board 622 Boot feature. When set to '1', BL1 and BL2 images include support to load 623 and verify the certificates and images in a FIP, and BL1 includes support 624 for the Firmware Update. The default value is '0'. Generation and inclusion 625 of certificates in the FIP and FWU_FIP depends upon the value of the 626 ``GENERATE_COT`` option. 627 628 .. warning:: 629 This option depends on ``CREATE_KEYS`` to be enabled. If the keys 630 already exist in disk, they will be overwritten without further notice. 631 632- ``TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It 633 specifies the file that contains the Trusted World private key in PEM 634 format. If ``SAVE_KEYS=1``, this file name will be used to save the key. 635 636- ``TSP_INIT_ASYNC``: Choose BL32 initialization method as asynchronous or 637 synchronous, (see "Initializing a BL32 Image" section in 638 :ref:`Firmware Design`). It can take the value 0 (BL32 is initialized using 639 synchronous method) or 1 (BL32 is initialized using asynchronous method). 640 Default is 0. 641 642- ``TSP_NS_INTR_ASYNC_PREEMPT``: A non zero value enables the interrupt 643 routing model which routes non-secure interrupts asynchronously from TSP 644 to EL3 causing immediate preemption of TSP. The EL3 is responsible 645 for saving and restoring the TSP context in this routing model. The 646 default routing model (when the value is 0) is to route non-secure 647 interrupts to TSP allowing it to save its context and hand over 648 synchronously to EL3 via an SMC. 649 650 .. note:: 651 When ``EL3_EXCEPTION_HANDLING`` is ``1``, ``TSP_NS_INTR_ASYNC_PREEMPT`` 652 must also be set to ``1``. 653 654- ``USE_ARM_LINK``: This flag determines whether to enable support for ARM 655 linker. When the ``LINKER`` build variable points to the armlink linker, 656 this flag is enabled automatically. To enable support for armlink, platforms 657 will have to provide a scatter file for the BL image. Currently, Tegra 658 platforms use the armlink support to compile BL3-1 images. 659 660- ``USE_COHERENT_MEM``: This flag determines whether to include the coherent 661 memory region in the BL memory map or not (see "Use of Coherent memory in 662 TF-A" section in :ref:`Firmware Design`). It can take the value 1 663 (Coherent memory region is included) or 0 (Coherent memory region is 664 excluded). Default is 1. 665 666- ``USE_DEBUGFS``: When set to 1 this option activates an EXPERIMENTAL feature 667 exposing a virtual filesystem interface through BL31 as a SiP SMC function. 668 Default is 0. 669 670- ``ARM_IO_IN_DTB``: This flag determines whether to use IO based on the 671 firmware configuration framework. This will move the io_policies into a 672 configuration device tree, instead of static structure in the code base. 673 This is currently an experimental feature. 674 675- ``COT_DESC_IN_DTB``: This flag determines whether to create COT descriptors 676 at runtime using fconf. If this flag is enabled, COT descriptors are 677 statically captured in tb_fw_config file in the form of device tree nodes 678 and properties. Currently, COT descriptors used by BL2 are moved to the 679 device tree and COT descriptors used by BL1 are retained in the code 680 base statically. This is currently an experimental feature. 681 682- ``SDEI_IN_FCONF``: This flag determines whether to configure SDEI setup in 683 runtime using firmware configuration framework. The platform specific SDEI 684 shared and private events configuration is retrieved from device tree rather 685 than static C structures at compile time. This is currently an experimental 686 feature and is only supported if SDEI_SUPPORT build flag is enabled. 687 688- ``SEC_INT_DESC_IN_FCONF``: This flag determines whether to configure Group 0 689 and Group1 secure interrupts using the firmware configuration framework. The 690 platform specific secure interrupt property descriptor is retrieved from 691 device tree in runtime rather than depending on static C structure at compile 692 time. This is currently an experimental feature. 693 694- ``USE_ROMLIB``: This flag determines whether library at ROM will be used. 695 This feature creates a library of functions to be placed in ROM and thus 696 reduces SRAM usage. Refer to :ref:`Library at ROM` for further details. Default 697 is 0. 698 699- ``V``: Verbose build. If assigned anything other than 0, the build commands 700 are printed. Default is 0. 701 702- ``VERSION_STRING``: String used in the log output for each TF-A image. 703 Defaults to a string formed by concatenating the version number, build type 704 and build string. 705 706- ``W``: Warning level. Some compiler warning options of interest have been 707 regrouped and put in the root Makefile. This flag can take the values 0 to 3, 708 each level enabling more warning options. Default is 0. 709 710- ``WARMBOOT_ENABLE_DCACHE_EARLY`` : Boolean option to enable D-cache early on 711 the CPU after warm boot. This is applicable for platforms which do not 712 require interconnect programming to enable cache coherency (eg: single 713 cluster platforms). If this option is enabled, then warm boot path 714 enables D-caches immediately after enabling MMU. This option defaults to 0. 715 716- ``SUPPORT_STACK_MEMTAG``: This flag determines whether to enable memory 717 tagging for stack or not. It accepts 2 values: ``yes`` and ``no``. The 718 default value of this flag is ``no``. Note this option must be enabled only 719 for ARM architecture greater than Armv8.5-A. 720 721- ``ERRATA_SPECULATIVE_AT``: This flag determines whether to enable ``AT`` 722 speculative errata workaround or not. It accepts 2 values: ``1`` and ``0``. 723 The default value of this flag is ``0``. 724 725 ``AT`` speculative errata workaround disables stage1 page table walk for 726 lower ELs (EL1 and EL0) in EL3 so that ``AT`` speculative fetch at any point 727 produces either the correct result or failure without TLB allocation. 728 729 This boolean option enables errata for all below CPUs. 730 731 +---------+--------------+-------------------------+ 732 | Errata | CPU | Workaround Define | 733 +=========+==============+=========================+ 734 | 1165522 | Cortex-A76 | ``ERRATA_A76_1165522`` | 735 +---------+--------------+-------------------------+ 736 | 1319367 | Cortex-A72 | ``ERRATA_A72_1319367`` | 737 +---------+--------------+-------------------------+ 738 | 1319537 | Cortex-A57 | ``ERRATA_A57_1319537`` | 739 +---------+--------------+-------------------------+ 740 | 1530923 | Cortex-A55 | ``ERRATA_A55_1530923`` | 741 +---------+--------------+-------------------------+ 742 | 1530924 | Cortex-A53 | ``ERRATA_A53_1530924`` | 743 +---------+--------------+-------------------------+ 744 745 .. note:: 746 This option is enabled by build only if platform sets any of above defines 747 mentioned in ’Workaround Define' column in the table. 748 If this option is enabled for the EL3 software then EL2 software also must 749 implement this workaround due to the behaviour of the errata mentioned 750 in new SDEN document which will get published soon. 751 752- ``RAS_TRAP_LOWER_EL_ERR_ACCESS``: This flag enables/disables the SCR_EL3.TERR 753 bit, to trap access to the RAS ERR and RAS ERX registers from lower ELs. 754 This flag is disabled by default. 755 756- ``OPENSSL_DIR``: This flag is used to provide the installed openssl directory 757 path on the host machine which is used to build certificate generation and 758 firmware encryption tool. 759 760- ``USE_SP804_TIMER``: Use the SP804 timer instead of the Generic Timer for 761 functions that wait for an arbitrary time length (udelay and mdelay). The 762 default value is 0. 763 764GICv3 driver options 765-------------------- 766 767GICv3 driver files are included using directive: 768 769``include drivers/arm/gic/v3/gicv3.mk`` 770 771The driver can be configured with the following options set in the platform 772makefile: 773 774- ``GICV3_SUPPORT_GIC600``: Add support for the GIC-600 variants of GICv3. 775 Enabling this option will add runtime detection support for the 776 GIC-600, so is safe to select even for a GIC500 implementation. 777 This option defaults to 0. 778 779- ``GICV3_IMPL_GIC600_MULTICHIP``: Selects GIC-600 variant with multichip 780 functionality. This option defaults to 0 781 782- ``GICV3_OVERRIDE_DISTIF_PWR_OPS``: Allows override of default implementation 783 of ``arm_gicv3_distif_pre_save`` and ``arm_gicv3_distif_post_restore`` 784 functions. This is required for FVP platform which need to simulate GIC save 785 and restore during SYSTEM_SUSPEND without powering down GIC. Default is 0. 786 787- ``GIC_ENABLE_V4_EXTN`` : Enables GICv4 related changes in GICv3 driver. 788 This option defaults to 0. 789 790- ``GIC_EXT_INTID``: When set to ``1``, GICv3 driver will support extended 791 PPI (1056-1119) and SPI (4096-5119) range. This option defaults to 0. 792 793Debugging options 794----------------- 795 796To compile a debug version and make the build more verbose use 797 798.. code:: shell 799 800 make PLAT=<platform> DEBUG=1 V=1 all 801 802AArch64 GCC uses DWARF version 4 debugging symbols by default. Some tools (for 803example DS-5) might not support this and may need an older version of DWARF 804symbols to be emitted by GCC. This can be achieved by using the 805``-gdwarf-<version>`` flag, with the version being set to 2 or 3. Setting the 806version to 2 is recommended for DS-5 versions older than 5.16. 807 808When debugging logic problems it might also be useful to disable all compiler 809optimizations by using ``-O0``. 810 811.. warning:: 812 Using ``-O0`` could cause output images to be larger and base addresses 813 might need to be recalculated (see the **Memory layout on Arm development 814 platforms** section in the :ref:`Firmware Design`). 815 816Extra debug options can be passed to the build system by setting ``CFLAGS`` or 817``LDFLAGS``: 818 819.. code:: shell 820 821 CFLAGS='-O0 -gdwarf-2' \ 822 make PLAT=<platform> DEBUG=1 V=1 all 823 824Note that using ``-Wl,`` style compilation driver options in ``CFLAGS`` will be 825ignored as the linker is called directly. 826 827It is also possible to introduce an infinite loop to help in debugging the 828post-BL2 phase of TF-A. This can be done by rebuilding BL1 with the 829``SPIN_ON_BL1_EXIT=1`` build flag. Refer to the :ref:`build_options_common` 830section. In this case, the developer may take control of the target using a 831debugger when indicated by the console output. When using DS-5, the following 832commands can be used: 833 834:: 835 836 # Stop target execution 837 interrupt 838 839 # 840 # Prepare your debugging environment, e.g. set breakpoints 841 # 842 843 # Jump over the debug loop 844 set var $AARCH64::$Core::$PC = $AARCH64::$Core::$PC + 4 845 846 # Resume execution 847 continue 848 849-------------- 850 851*Copyright (c) 2019-2021, Arm Limited. All rights reserved.* 852