| Build Options |
| ============= |
| |
| The TF-A build system supports the following build options. Unless mentioned |
| otherwise, these options are expected to be specified at the build command |
| line and are not to be modified in any component makefiles. Note that the |
| build system doesn't track dependency for build options. Therefore, if any of |
| the build options are changed from a previous build, a clean build must be |
| performed. |
| |
| .. _build_options_common: |
| |
| Common build options |
| -------------------- |
| |
| - ``AARCH32_INSTRUCTION_SET``: Choose the AArch32 instruction set that the |
| compiler should use. Valid values are T32 and A32. It defaults to T32 due to |
| code having a smaller resulting size. |
| |
| - ``AARCH32_SP`` : Choose the AArch32 Secure Payload component to be built as |
| as the BL32 image when ``ARCH=aarch32``. The value should be the path to the |
| directory containing the SP source, relative to the ``bl32/``; the directory |
| is expected to contain a makefile called ``<aarch32_sp-value>.mk``. |
| |
| - ``AMU_RESTRICT_COUNTERS``: Register reads to the group 1 counters will return |
| zero at all but the highest implemented exception level. Reads from the |
| memory mapped view are unaffected by this control. |
| |
| - ``ARCH`` : Choose the target build architecture for TF-A. It can take either |
| ``aarch64`` or ``aarch32`` as values. By default, it is defined to |
| ``aarch64``. |
| |
| - ``ARM_ARCH_FEATURE``: Optional Arm Architecture build option which specifies |
| one or more feature modifiers. This option has the form ``[no]feature+...`` |
| and defaults to ``none``. It translates into compiler option |
| ``-march=armvX[.Y]-a+[no]feature+...``. See compiler's documentation for the |
| list of supported feature modifiers. |
| |
| - ``ARM_ARCH_MAJOR``: The major version of Arm Architecture to target when |
| compiling TF-A. Its value must be numeric, and defaults to 8 . See also, |
| *Armv8 Architecture Extensions* and *Armv7 Architecture Extensions* in |
| :ref:`Firmware Design`. |
| |
| - ``ARM_ARCH_MINOR``: The minor version of Arm Architecture to target when |
| compiling TF-A. Its value must be a numeric, and defaults to 0. See also, |
| *Armv8 Architecture Extensions* in :ref:`Firmware Design`. |
| |
| - ``ARM_BL2_SP_LIST_DTS``: Path to DTS file snippet to override the hardcoded |
| SP nodes in tb_fw_config. |
| |
| - ``ARM_SPMC_MANIFEST_DTS`` : path to an alternate manifest file used as the |
| SPMC Core manifest. Valid when ``SPD=spmd`` is selected. |
| |
| - ``BL2``: This is an optional build option which specifies the path to BL2 |
| image for the ``fip`` target. In this case, the BL2 in the TF-A will not be |
| built. |
| |
| - ``BL2U``: This is an optional build option which specifies the path to |
| BL2U image. In this case, the BL2U in TF-A will not be built. |
| |
| - ``RESET_TO_BL2``: Boolean option to enable BL2 entrypoint as the CPU reset |
| vector instead of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1 |
| entrypoint) or 1 (CPU reset to BL2 entrypoint). |
| The default value is 0. |
| |
| - ``BL2_RUNS_AT_EL3``: This is an implicit flag to denote that BL2 runs at EL3. |
| While it is explicitly set to 1 when RESET_TO_BL2 is set to 1 it can also be |
| true in a 4-world system where RESET_TO_BL2 is 0. |
| |
| - ``BL2_ENABLE_SP_LOAD``: Boolean option to enable loading SP packages from the |
| FIP. Automatically enabled if ``SP_LAYOUT_FILE`` is provided. |
| |
| - ``BL2_IN_XIP_MEM``: In some use-cases BL2 will be stored in eXecute In Place |
| (XIP) memory, like BL1. In these use-cases, it is necessary to initialize |
| the RW sections in RAM, while leaving the RO sections in place. This option |
| enable this use-case. For now, this option is only supported |
| when RESET_TO_BL2 is set to '1'. |
| |
| - ``BL31``: This is an optional build option which specifies the path to |
| BL31 image for the ``fip`` target. In this case, the BL31 in TF-A will not |
| be built. |
| |
| - ``BL31_KEY``: This option is used when ``GENERATE_COT=1``. It specifies a |
| file that contains the BL31 private key in PEM format or a PKCS11 URI. If |
| ``SAVE_KEYS=1``, only a file is accepted and it will be used to save the key. |
| |
| - ``BL32``: This is an optional build option which specifies the path to |
| BL32 image for the ``fip`` target. In this case, the BL32 in TF-A will not |
| be built. |
| |
| - ``BL32_EXTRA1``: This is an optional build option which specifies the path to |
| Trusted OS Extra1 image for the ``fip`` target. |
| |
| - ``BL32_EXTRA2``: This is an optional build option which specifies the path to |
| Trusted OS Extra2 image for the ``fip`` target. |
| |
| - ``BL32_KEY``: This option is used when ``GENERATE_COT=1``. It specifies a |
| file that contains the BL32 private key in PEM format or a PKCS11 URI. If |
| ``SAVE_KEYS=1``, only a file is accepted and it will be used to save the key. |
| |
| - ``BL33``: Path to BL33 image in the host file system. This is mandatory for |
| ``fip`` target in case TF-A BL2 is used. |
| |
| - ``BL33_KEY``: This option is used when ``GENERATE_COT=1``. It specifies a |
| file that contains the BL33 private key in PEM format or a PKCS11 URI. If |
| ``SAVE_KEYS=1``, only a file is accepted and it will be used to save the key. |
| |
| - ``BRANCH_PROTECTION``: Numeric value to enable ARMv8.3 Pointer Authentication |
| and ARMv8.5 Branch Target Identification support for TF-A BL images themselves. |
| If enabled, it is needed to use a compiler that supports the option |
| ``-mbranch-protection``. Selects the branch protection features to use: |
| - 0: Default value turns off all types of branch protection |
| - 1: Enables all types of branch protection features |
| - 2: Return address signing to its standard level |
| - 3: Extend the signing to include leaf functions |
| - 4: Turn on branch target identification mechanism |
| |
| The table below summarizes ``BRANCH_PROTECTION`` values, GCC compilation options |
| and resulting PAuth/BTI features. |
| |
| +-------+--------------+-------+-----+ |
| | Value | GCC option | PAuth | BTI | |
| +=======+==============+=======+=====+ |
| | 0 | none | N | N | |
| +-------+--------------+-------+-----+ |
| | 1 | standard | Y | Y | |
| +-------+--------------+-------+-----+ |
| | 2 | pac-ret | Y | N | |
| +-------+--------------+-------+-----+ |
| | 3 | pac-ret+leaf | Y | N | |
| +-------+--------------+-------+-----+ |
| | 4 | bti | N | Y | |
| +-------+--------------+-------+-----+ |
| |
| This option defaults to 0. |
| Note that Pointer Authentication is enabled for Non-secure world |
| irrespective of the value of this option if the CPU supports it. |
| |
| - ``BUILD_MESSAGE_TIMESTAMP``: String used to identify the time and date of the |
| compilation of each build. It must be set to a C string (including quotes |
| where applicable). Defaults to a string that contains the time and date of |
| the compilation. |
| |
| - ``BUILD_STRING``: Input string for VERSION_STRING, which allows the TF-A |
| build to be uniquely identified. Defaults to the current git commit id. |
| |
| - ``BUILD_BASE``: Output directory for the build. Defaults to ``./build`` |
| |
| - ``CFLAGS``: Extra user options appended on the compiler's command line in |
| addition to the options set by the build system. |
| |
| - ``COLD_BOOT_SINGLE_CPU``: This option indicates whether the platform may |
| release several CPUs out of reset. It can take either 0 (several CPUs may be |
| brought up) or 1 (only one CPU will ever be brought up during cold reset). |
| Default is 0. If the platform always brings up a single CPU, there is no |
| need to distinguish between primary and secondary CPUs and the boot path can |
| be optimised. The ``plat_is_my_cpu_primary()`` and |
| ``plat_secondary_cold_boot_setup()`` platform porting interfaces do not need |
| to be implemented in this case. |
| |
| - ``COT``: When Trusted Boot is enabled, selects the desired chain of trust. |
| Defaults to ``tbbr``. |
| |
| - ``CRASH_REPORTING``: A non-zero value enables a console dump of processor |
| register state when an unexpected exception occurs during execution of |
| BL31. This option defaults to the value of ``DEBUG`` - i.e. by default |
| this is only enabled for a debug build of the firmware. |
| |
| - ``CREATE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the |
| certificate generation tool to create new keys in case no valid keys are |
| present or specified. Allowed options are '0' or '1'. Default is '1'. |
| |
| - ``CTX_INCLUDE_AARCH32_REGS`` : Boolean option that, when set to 1, will cause |
| the AArch32 system registers to be included when saving and restoring the |
| CPU context. The option must be set to 0 for AArch64-only platforms (that |
| is on hardware that does not implement AArch32, or at least not at EL1 and |
| higher ELs). Default value is 1. |
| |
| - ``CTX_INCLUDE_FPREGS``: Boolean option that, when set to 1, will cause the FP |
| registers to be included when saving and restoring the CPU context. Default |
| is 0. |
| |
| - ``CTX_INCLUDE_MPAM_REGS``: Boolean option that, when set to 1, will cause the |
| Memory System Resource Partitioning and Monitoring (MPAM) |
| registers to be included when saving and restoring the CPU context. |
| Default is '0'. |
| |
| - ``CTX_INCLUDE_NEVE_REGS``: Numeric value, when set will cause the Armv8.4-NV |
| registers to be saved/restored when entering/exiting an EL2 execution |
| context. This flag can take values 0 to 2, to align with the |
| ``ENABLE_FEAT`` mechanism. Default value is 0. |
| |
| - ``CTX_INCLUDE_PAUTH_REGS``: Numeric value to enable the Pointer |
| Authentication for Secure world. This will cause the ARMv8.3-PAuth registers |
| to be included when saving and restoring the CPU context as part of world |
| switch. This flag can take values 0 to 2, to align with ``ENABLE_FEAT`` |
| mechanism. Default value is 0. |
| |
| Note that Pointer Authentication is enabled for Non-secure world irrespective |
| of the value of this flag if the CPU supports it. |
| |
| - ``DEBUG``: Chooses between a debug and release build. It can take either 0 |
| (release) or 1 (debug) as values. 0 is the default. |
| |
| - ``DECRYPTION_SUPPORT``: This build flag enables the user to select the |
| authenticated decryption algorithm to be used to decrypt firmware/s during |
| boot. It accepts 2 values: ``aes_gcm`` and ``none``. The default value of |
| this flag is ``none`` to disable firmware decryption which is an optional |
| feature as per TBBR. |
| |
| - ``DISABLE_BIN_GENERATION``: Boolean option to disable the generation |
| of the binary image. If set to 1, then only the ELF image is built. |
| 0 is the default. |
| |
| - ``DISABLE_MTPMU``: Numeric option to disable ``FEAT_MTPMU`` (Multi Threaded |
| PMU). ``FEAT_MTPMU`` is an optional feature available on Armv8.6 onwards. |
| This flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default is ``0``. |
| |
| - ``DYN_DISABLE_AUTH``: Provides the capability to dynamically disable Trusted |
| Board Boot authentication at runtime. This option is meant to be enabled only |
| for development platforms. ``TRUSTED_BOARD_BOOT`` flag must be set if this |
| flag has to be enabled. 0 is the default. |
| |
| - ``E``: Boolean option to make warnings into errors. Default is 1. |
| |
| When specifying higher warnings levels (``W=1`` and higher), this option |
| defaults to 0. This is done to encourage contributors to use them, as they |
| are expected to produce warnings that would otherwise fail the build. New |
| contributions are still expected to build with ``W=0`` and ``E=1`` (the |
| default). |
| |
| - ``EL3_PAYLOAD_BASE``: This option enables booting an EL3 payload instead of |
| the normal boot flow. It must specify the entry point address of the EL3 |
| payload. Please refer to the "Booting an EL3 payload" section for more |
| details. |
| |
| - ``ENABLE_AMU_AUXILIARY_COUNTERS``: Enables support for AMU auxiliary counters |
| (also known as group 1 counters). These are implementation-defined counters, |
| and as such require additional platform configuration. Default is 0. |
| |
| - ``ENABLE_AMU_FCONF``: Enables configuration of the AMU through FCONF, which |
| allows platforms with auxiliary counters to describe them via the |
| ``HW_CONFIG`` device tree blob. Default is 0. |
| |
| - ``ENABLE_ASSERTIONS``: This option controls whether or not calls to ``assert()`` |
| are compiled out. For debug builds, this option defaults to 1, and calls to |
| ``assert()`` are left in place. For release builds, this option defaults to 0 |
| and calls to ``assert()`` function are compiled out. This option can be set |
| independently of ``DEBUG``. It can also be used to hide any auxiliary code |
| that is only required for the assertion and does not fit in the assertion |
| itself. |
| |
| - ``ENABLE_BACKTRACE``: This option controls whether to enable backtrace |
| dumps or not. It is supported in both AArch64 and AArch32. However, in |
| AArch32 the format of the frame records are not defined in the AAPCS and they |
| are defined by the implementation. This implementation of backtrace only |
| supports the format used by GCC when T32 interworking is disabled. For this |
| reason enabling this option in AArch32 will force the compiler to only |
| generate A32 code. This option is enabled by default only in AArch64 debug |
| builds, but this behaviour can be overridden in each platform's Makefile or |
| in the build command line. |
| |
| - ``ENABLE_FEAT`` |
| The Arm architecture defines several architecture extension features, |
| named FEAT_xxx in the architecure manual. Some of those features require |
| setup code in higher exception levels, other features might be used by TF-A |
| code itself. |
| Most of the feature flags defined in the TF-A build system permit to take |
| the values 0, 1 or 2, with the following meaning: |
| |
| :: |
| |
| ENABLE_FEAT_* = 0: Feature is disabled statically at compile time. |
| ENABLE_FEAT_* = 1: Feature is enabled unconditionally at compile time. |
| ENABLE_FEAT_* = 2: Feature is enabled, but checked at runtime. |
| |
| When setting the flag to 0, the feature is disabled during compilation, |
| and the compiler's optimisation stage and the linker will try to remove |
| as much of this code as possible. |
| If it is defined to 1, the code will use the feature unconditionally, so the |
| CPU is expected to support that feature. The FEATURE_DETECTION debug |
| feature, if enabled, will verify this. |
| If the feature flag is set to 2, support for the feature will be compiled |
| in, but its existence will be checked at runtime, so it works on CPUs with |
| or without the feature. This is mostly useful for platforms which either |
| support multiple different CPUs, or where the CPU is configured at runtime, |
| like in emulators. |
| |
| - ``ENABLE_FEAT_AMU``: Numeric value to enable Activity Monitor Unit |
| extensions. This flag can take the values 0 to 2, to align with the |
| ``ENABLE_FEAT`` mechanism. This is an optional architectural feature |
| available on v8.4 onwards. Some v8.2 implementations also implement an AMU |
| and this option can be used to enable this feature on those systems as well. |
| This flag can take the values 0 to 2, the default is 0. |
| |
| - ``ENABLE_FEAT_AMUv1p1``: Numeric value to enable the ``FEAT_AMUv1p1`` |
| extension. ``FEAT_AMUv1p1`` is an optional feature available on Arm v8.6 |
| onwards. This flag can take the values 0 to 2, to align with the |
| ``ENABLE_FEAT`` mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_CSV2_2``: Numeric value to enable the ``FEAT_CSV2_2`` |
| extension. It allows access to the SCXTNUM_EL2 (Software Context Number) |
| register during EL2 context save/restore operations. ``FEAT_CSV2_2`` is an |
| optional feature available on Arm v8.0 onwards. This flag can take values |
| 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. |
| Default value is ``0``. |
| |
| - ``ENABLE_FEAT_CSV2_3``: Numeric value to enable support for ``FEAT_CSV2_3`` |
| extension. This feature is supported in AArch64 state only and is an optional |
| feature available in Arm v8.0 implementations. |
| ``FEAT_CSV2_3`` implies the implementation of ``FEAT_CSV2_2``. |
| The flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_DIT``: Numeric value to enable ``FEAT_DIT`` (Data Independent |
| Timing) extension. It allows setting the ``DIT`` bit of PSTATE in EL3. |
| ``FEAT_DIT`` is a mandatory architectural feature and is enabled from v8.4 |
| and upwards. This flag can take the values 0 to 2, to align with the |
| ``ENABLE_FEAT`` mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_ECV``: Numeric value to enable support for the Enhanced Counter |
| Virtualization feature, allowing for access to the CNTPOFF_EL2 (Counter-timer |
| Physical Offset register) during EL2 to EL3 context save/restore operations. |
| Its a mandatory architectural feature and is enabled from v8.6 and upwards. |
| This flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_FGT``: Numeric value to enable support for FGT (Fine Grain Traps) |
| feature allowing for access to the HDFGRTR_EL2 (Hypervisor Debug Fine-Grained |
| Read Trap Register) during EL2 to EL3 context save/restore operations. |
| Its a mandatory architectural feature and is enabled from v8.6 and upwards. |
| This flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_HCX``: Numeric value to set the bit SCR_EL3.HXEn in EL3 to |
| allow access to HCRX_EL2 (extended hypervisor control register) from EL2 as |
| well as adding HCRX_EL2 to the EL2 context save/restore operations. Its a |
| mandatory architectural feature and is enabled from v8.7 and upwards. This |
| flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_MTE``: Numeric value to enable Memory Tagging Extension |
| if the platform wants to use this feature at EL0 ``ENABLE_FEAT_MTE`` is |
| required. This flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` |
| feature detection mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_MTE2``: Numeric value to enable Memory Tagging Extension2 |
| if the platform wants to use this feature and MTE2 is enabled at ELX. |
| This flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_MTE_PERM``: Numeric value to enable support for |
| ``FEAT_MTE_PERM``, which introduces Allocation tag access permission to |
| memory region attributes. ``FEAT_MTE_PERM`` is a optional architectural |
| feature available from v8.9 and upwards. This flag can take the values 0 to |
| 2, to align with the ``ENABLE_FEAT`` mechanism. Default value is |
| ``0``. |
| |
| - ``ENABLE_FEAT_PAN``: Numeric value to enable the ``FEAT_PAN`` (Privileged |
| Access Never) extension. ``FEAT_PAN`` adds a bit to PSTATE, generating a |
| permission fault for any privileged data access from EL1/EL2 to virtual |
| memory address, accessible at EL0, provided (HCR_EL2.E2H=1). It is a |
| mandatory architectural feature and is enabled from v8.1 and upwards. This |
| flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_RNG``: Numeric value to enable the ``FEAT_RNG`` extension. |
| ``FEAT_RNG`` is an optional feature available on Arm v8.5 onwards. This |
| flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_RNG_TRAP``: Numeric value to enable the ``FEAT_RNG_TRAP`` |
| extension. This feature is only supported in AArch64 state. This flag can |
| take values 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. |
| Default value is ``0``. ``FEAT_RNG_TRAP`` is an optional feature from |
| Armv8.5 onwards. |
| |
| - ``ENABLE_FEAT_SB``: Boolean option to let the TF-A code use the ``FEAT_SB`` |
| (Speculation Barrier) instruction ``FEAT_SB`` is an optional feature and |
| defaults to ``0`` for pre-Armv8.5 CPUs, but is mandatory for Armv8.5 or |
| later CPUs. It is enabled from v8.5 and upwards and if needed can be |
| overidden from platforms explicitly. |
| |
| - ``ENABLE_FEAT_SEL2``: Numeric value to enable the ``FEAT_SEL2`` (Secure EL2) |
| extension. ``FEAT_SEL2`` is a mandatory feature available on Arm v8.4. |
| This flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default is ``0``. |
| |
| - ``ENABLE_FEAT_TWED``: Numeric value to enable the ``FEAT_TWED`` (Delayed |
| trapping of WFE Instruction) extension. ``FEAT_TWED`` is a optional feature |
| available on Arm v8.6. This flag can take values 0 to 2, to align with the |
| ``ENABLE_FEAT`` mechanism. Default is ``0``. |
| |
| When ``ENABLE_FEAT_TWED`` is set to ``1``, WFE instruction trapping gets |
| delayed by the amount of value in ``TWED_DELAY``. |
| |
| - ``ENABLE_FEAT_VHE``: Numeric value to enable the ``FEAT_VHE`` (Virtualization |
| Host Extensions) extension. It allows access to CONTEXTIDR_EL2 register |
| during EL2 context save/restore operations.``FEAT_VHE`` is a mandatory |
| architectural feature and is enabled from v8.1 and upwards. It can take |
| values 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. |
| Default value is ``0``. |
| |
| - ``ENABLE_FEAT_TCR2``: Numeric value to set the bit SCR_EL3.ENTCR2 in EL3 to |
| allow access to TCR2_EL2 (extended translation control) from EL2 as |
| well as adding TCR2_EL2 to the EL2 context save/restore operations. Its a |
| mandatory architectural feature and is enabled from v8.9 and upwards. This |
| flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_S2PIE``: Numeric value to enable support for FEAT_S2PIE |
| at EL2 and below, and context switch relevant registers. This flag |
| can take the values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_S1PIE``: Numeric value to enable support for FEAT_S1PIE |
| at EL2 and below, and context switch relevant registers. This flag |
| can take the values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_S2POE``: Numeric value to enable support for FEAT_S2POE |
| at EL2 and below, and context switch relevant registers. This flag |
| can take the values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_S1POE``: Numeric value to enable support for FEAT_S1POE |
| at EL2 and below, and context switch relevant registers. This flag |
| can take the values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default value is ``0``. |
| |
| - ``ENABLE_FEAT_GCS``: Numeric value to set the bit SCR_EL3.GCSEn in EL3 to |
| allow use of Guarded Control Stack from EL2 as well as adding the GCS |
| registers to the EL2 context save/restore operations. This flag can take |
| the values 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. |
| Default value is ``0``. |
| |
| - ``ENABLE_LTO``: Boolean option to enable Link Time Optimization (LTO) |
| support in GCC for TF-A. This option is currently only supported for |
| AArch64. Default is 0. |
| |
| - ``ENABLE_FEAT_MPAM``: Numeric value to enable lower ELs to use MPAM |
| feature. MPAM is an optional Armv8.4 extension that enables various memory |
| system components and resources to define partitions; software running at |
| various ELs can assign themselves to desired partition to control their |
| performance aspects. |
| |
| This flag can take values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. When this option is set to ``1`` or ``2``, EL3 allows lower ELs to |
| access their own MPAM registers without trapping into EL3. This option |
| doesn't make use of partitioning in EL3, however. Platform initialisation |
| code should configure and use partitions in EL3 as required. This option |
| defaults to ``2`` since MPAM is enabled by default for NS world only. |
| The flag is automatically disabled when the target |
| architecture is AArch32. |
| |
| - ``ENABLE_MPMM``: Boolean option to enable support for the Maximum Power |
| Mitigation Mechanism supported by certain Arm cores, which allows the SoC |
| firmware to detect and limit high activity events to assist in SoC processor |
| power domain dynamic power budgeting and limit the triggering of whole-rail |
| (i.e. clock chopping) responses to overcurrent conditions. Defaults to ``0``. |
| |
| - ``ENABLE_MPMM_FCONF``: Enables configuration of MPMM through FCONF, which |
| allows platforms with cores supporting MPMM to describe them via the |
| ``HW_CONFIG`` device tree blob. Default is 0. |
| |
| - ``ENABLE_PIE``: Boolean option to enable Position Independent Executable(PIE) |
| support within generic code in TF-A. This option is currently only supported |
| in BL2, BL31, and BL32 (TSP) for AARCH64 binaries, and |
| in BL32 (SP_min) for AARCH32. Default is 0. |
| |
| - ``ENABLE_PMF``: Boolean option to enable support for optional Performance |
| Measurement Framework(PMF). Default is 0. |
| |
| - ``ENABLE_PSCI_STAT``: Boolean option to enable support for optional PSCI |
| functions ``PSCI_STAT_RESIDENCY`` and ``PSCI_STAT_COUNT``. Default is 0. |
| In the absence of an alternate stat collection backend, ``ENABLE_PMF`` must |
| be enabled. If ``ENABLE_PMF`` is set, the residency statistics are tracked in |
| software. |
| |
| - ``ENABLE_RUNTIME_INSTRUMENTATION``: Boolean option to enable runtime |
| instrumentation which injects timestamp collection points into TF-A to |
| allow runtime performance to be measured. Currently, only PSCI is |
| instrumented. Enabling this option enables the ``ENABLE_PMF`` build option |
| as well. Default is 0. |
| |
| - ``ENABLE_SPE_FOR_NS`` : Numeric value to enable Statistical Profiling |
| extensions. This is an optional architectural feature for AArch64. |
| This flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. The default is 2 but is automatically disabled when the target |
| architecture is AArch32. |
| |
| - ``ENABLE_SVE_FOR_NS``: Numeric value to enable Scalable Vector Extension |
| (SVE) for the Non-secure world only. SVE is an optional architectural feature |
| for AArch64. Note that when SVE is enabled for the Non-secure world, access |
| to SIMD and floating-point functionality from the Secure world is disabled by |
| default and controlled with ENABLE_SVE_FOR_SWD. |
| This is to avoid corruption of the Non-secure world data in the Z-registers |
| which are aliased by the SIMD and FP registers. The build option is not |
| compatible with the ``CTX_INCLUDE_FPREGS`` build option, and will raise an |
| assert on platforms where SVE is implemented and ``ENABLE_SVE_FOR_NS`` |
| enabled. This flag can take the values 0 to 2, to align with the |
| ``ENABLE_FEAT`` mechanism. At this time, this build option cannot be |
| used on systems that have SPM_MM enabled. The default is 1. |
| |
| - ``ENABLE_SVE_FOR_SWD``: Boolean option to enable SVE for the Secure world. |
| SVE is an optional architectural feature for AArch64. Note that this option |
| requires ENABLE_SVE_FOR_NS to be enabled. The default is 0 and it is |
| automatically disabled when the target architecture is AArch32. |
| |
| - ``ENABLE_STACK_PROTECTOR``: String option to enable the stack protection |
| checks in GCC. Allowed values are "all", "strong", "default" and "none". The |
| default value is set to "none". "strong" is the recommended stack protection |
| level if this feature is desired. "none" disables the stack protection. For |
| all values other than "none", the ``plat_get_stack_protector_canary()`` |
| platform hook needs to be implemented. The value is passed as the last |
| component of the option ``-fstack-protector-$ENABLE_STACK_PROTECTOR``. |
| |
| - ``ENCRYPT_BL31``: Binary flag to enable encryption of BL31 firmware. This |
| flag depends on ``DECRYPTION_SUPPORT`` build flag. |
| |
| - ``ENCRYPT_BL32``: Binary flag to enable encryption of Secure BL32 payload. |
| This flag depends on ``DECRYPTION_SUPPORT`` build flag. |
| |
| - ``ENC_KEY``: A 32-byte (256-bit) symmetric key in hex string format. It could |
| either be SSK or BSSK depending on ``FW_ENC_STATUS`` flag. This value depends |
| on ``DECRYPTION_SUPPORT`` build flag. |
| |
| - ``ENC_NONCE``: A 12-byte (96-bit) encryption nonce or Initialization Vector |
| (IV) in hex string format. This value depends on ``DECRYPTION_SUPPORT`` |
| build flag. |
| |
| - ``ERROR_DEPRECATED``: This option decides whether to treat the usage of |
| deprecated platform APIs, helper functions or drivers within Trusted |
| Firmware as error. It can take the value 1 (flag the use of deprecated |
| APIs as error) or 0. The default is 0. |
| |
| - ``ETHOSN_NPU_DRIVER``: boolean option to enable a SiP service that can |
| configure an Arm® Ethos™-N NPU. To use this service the target platform's |
| ``HW_CONFIG`` must include the device tree nodes for the NPU. Currently, only |
| the Arm Juno platform has this included in its ``HW_CONFIG`` and the platform |
| only loads the ``HW_CONFIG`` in AArch64 builds. Default is 0. |
| |
| - ``ETHOSN_NPU_TZMP1``: boolean option to enable TZMP1 support for the |
| Arm® Ethos™-N NPU. Requires ``ETHOSN_NPU_DRIVER`` and |
| ``TRUSTED_BOARD_BOOT`` to be enabled. |
| |
| - ``ETHOSN_NPU_FW``: location of the NPU firmware binary |
| (```ethosn.bin```). This firmware image will be included in the FIP and |
| loaded at runtime. |
| |
| - ``EL3_EXCEPTION_HANDLING``: When set to ``1``, enable handling of exceptions |
| targeted at EL3. When set ``0`` (default), no exceptions are expected or |
| handled at EL3, and a panic will result. The exception to this rule is when |
| ``SPMD_SPM_AT_SEL2`` is set to ``1``, in which case, only exceptions |
| occuring during normal world execution, are trapped to EL3. Any exception |
| trapped during secure world execution are trapped to the SPMC. This is |
| supported only for AArch64 builds. |
| |
| - ``EVENT_LOG_LEVEL``: Chooses the log level to use for Measured Boot when |
| ``MEASURED_BOOT`` is enabled. For a list of valid values, see ``LOG_LEVEL``. |
| Default value is 40 (LOG_LEVEL_INFO). |
| |
| - ``FAULT_INJECTION_SUPPORT``: ARMv8.4 extensions introduced support for fault |
| injection from lower ELs, and this build option enables lower ELs to use |
| Error Records accessed via System Registers to inject faults. This is |
| applicable only to AArch64 builds. |
| |
| This feature is intended for testing purposes only, and is advisable to keep |
| disabled for production images. |
| |
| - ``FIP_NAME``: This is an optional build option which specifies the FIP |
| filename for the ``fip`` target. Default is ``fip.bin``. |
| |
| - ``FWU_FIP_NAME``: This is an optional build option which specifies the FWU |
| FIP filename for the ``fwu_fip`` target. Default is ``fwu_fip.bin``. |
| |
| - ``FW_ENC_STATUS``: Top level firmware's encryption numeric flag, values: |
| |
| :: |
| |
| 0: Encryption is done with Secret Symmetric Key (SSK) which is common |
| for a class of devices. |
| 1: Encryption is done with Binding Secret Symmetric Key (BSSK) which is |
| unique per device. |
| |
| This flag depends on ``DECRYPTION_SUPPORT`` build flag. |
| |
| - ``GENERATE_COT``: Boolean flag used to build and execute the ``cert_create`` |
| tool to create certificates as per the Chain of Trust described in |
| :ref:`Trusted Board Boot`. The build system then calls ``fiptool`` to |
| include the certificates in the FIP and FWU_FIP. Default value is '0'. |
| |
| Specify both ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=1`` to include support |
| for the Trusted Board Boot feature in the BL1 and BL2 images, to generate |
| the corresponding certificates, and to include those certificates in the |
| FIP and FWU_FIP. |
| |
| Note that if ``TRUSTED_BOARD_BOOT=0`` and ``GENERATE_COT=1``, the BL1 and BL2 |
| images will not include support for Trusted Board Boot. The FIP will still |
| include the corresponding certificates. This FIP can be used to verify the |
| Chain of Trust on the host machine through other mechanisms. |
| |
| Note that if ``TRUSTED_BOARD_BOOT=1`` and ``GENERATE_COT=0``, the BL1 and BL2 |
| images will include support for Trusted Board Boot, but the FIP and FWU_FIP |
| will not include the corresponding certificates, causing a boot failure. |
| |
| - ``GICV2_G0_FOR_EL3``: Unlike GICv3, the GICv2 architecture doesn't have |
| inherent support for specific EL3 type interrupts. Setting this build option |
| to ``1`` assumes GICv2 *Group 0* interrupts are expected to target EL3, both |
| by :ref:`platform abstraction layer<platform Interrupt Controller API>` and |
| :ref:`Interrupt Management Framework<Interrupt Management Framework>`. |
| This allows GICv2 platforms to enable features requiring EL3 interrupt type. |
| This also means that all GICv2 Group 0 interrupts are delivered to EL3, and |
| the Secure Payload interrupts needs to be synchronously handed over to Secure |
| EL1 for handling. The default value of this option is ``0``, which means the |
| Group 0 interrupts are assumed to be handled by Secure EL1. |
| |
| - ``HANDLE_EA_EL3_FIRST_NS``: When set to ``1``, External Aborts and SError |
| Interrupts, resulting from errors in NS world, will be always trapped in |
| EL3 i.e. in BL31 at runtime. When set to ``0`` (default), these exceptions |
| will be trapped in the current exception level (or in EL1 if the current |
| exception level is EL0). |
| |
| - ``HW_ASSISTED_COHERENCY``: On most Arm systems to-date, platform-specific |
| software operations are required for CPUs to enter and exit coherency. |
| However, newer systems exist where CPUs' entry to and exit from coherency |
| is managed in hardware. Such systems require software to only initiate these |
| operations, and the rest is managed in hardware, minimizing active software |
| management. In such systems, this boolean option enables TF-A to carry out |
| build and run-time optimizations during boot and power management operations. |
| This option defaults to 0 and if it is enabled, then it implies |
| ``WARMBOOT_ENABLE_DCACHE_EARLY`` is also enabled. |
| |
| If this flag is disabled while the platform which TF-A is compiled for |
| includes cores that manage coherency in hardware, then a compilation error is |
| generated. This is based on the fact that a system cannot have, at the same |
| time, cores that manage coherency in hardware and cores that don't. In other |
| words, a platform cannot have, at the same time, cores that require |
| ``HW_ASSISTED_COHERENCY=1`` and cores that require |
| ``HW_ASSISTED_COHERENCY=0``. |
| |
| Note that, when ``HW_ASSISTED_COHERENCY`` is enabled, version 2 of |
| translation library (xlat tables v2) must be used; version 1 of translation |
| library is not supported. |
| |
| - ``IMPDEF_SYSREG_TRAP``: Numeric value to enable the handling traps for |
| implementation defined system register accesses from lower ELs. Default |
| value is ``0``. |
| |
| - ``INVERTED_MEMMAP``: memmap tool print by default lower addresses at the |
| bottom, higher addresses at the top. This build flag can be set to '1' to |
| invert this behavior. Lower addresses will be printed at the top and higher |
| addresses at the bottom. |
| |
| - ``KEY_ALG``: This build flag enables the user to select the algorithm to be |
| used for generating the PKCS keys and subsequent signing of the certificate. |
| It accepts 5 values: ``rsa``, ``rsa_1_5``, ``ecdsa``, ``ecdsa-brainpool-regular`` |
| and ``ecdsa-brainpool-twisted``. The option ``rsa_1_5`` is the legacy PKCS#1 |
| RSA 1.5 algorithm which is not TBBR compliant and is retained only for |
| compatibility. The default value of this flag is ``rsa`` which is the TBBR |
| compliant PKCS#1 RSA 2.1 scheme. |
| |
| - ``KEY_SIZE``: This build flag enables the user to select the key size for |
| the algorithm specified by ``KEY_ALG``. The valid values for ``KEY_SIZE`` |
| depend on the chosen algorithm and the cryptographic module. |
| |
| +---------------------------+------------------------------------+ |
| | KEY_ALG | Possible key sizes | |
| +===========================+====================================+ |
| | rsa | 1024 , 2048 (default), 3072, 4096 | |
| +---------------------------+------------------------------------+ |
| | ecdsa | 256 (default), 384 | |
| +---------------------------+------------------------------------+ |
| | ecdsa-brainpool-regular | unavailable | |
| +---------------------------+------------------------------------+ |
| | ecdsa-brainpool-twisted | unavailable | |
| +---------------------------+------------------------------------+ |
| |
| - ``HASH_ALG``: This build flag enables the user to select the secure hash |
| algorithm. It accepts 3 values: ``sha256``, ``sha384`` and ``sha512``. |
| The default value of this flag is ``sha256``. |
| |
| - ``LDFLAGS``: Extra user options appended to the linkers' command line in |
| addition to the one set by the build system. |
| |
| - ``LOG_LEVEL``: Chooses the log level, which controls the amount of console log |
| output compiled into the build. This should be one of the following: |
| |
| :: |
| |
| 0 (LOG_LEVEL_NONE) |
| 10 (LOG_LEVEL_ERROR) |
| 20 (LOG_LEVEL_NOTICE) |
| 30 (LOG_LEVEL_WARNING) |
| 40 (LOG_LEVEL_INFO) |
| 50 (LOG_LEVEL_VERBOSE) |
| |
| All log output up to and including the selected log level is compiled into |
| the build. The default value is 40 in debug builds and 20 in release builds. |
| |
| - ``MEASURED_BOOT``: Boolean flag to include support for the Measured Boot |
| feature. This flag can be enabled with ``TRUSTED_BOARD_BOOT`` in order to |
| provide trust that the code taking the measurements and recording them has |
| not been tampered with. |
| |
| This option defaults to 0. |
| |
| - ``DICE_PROTECTION_ENVIRONMENT``: Boolean flag to specify the measured boot |
| backend when ``MEASURED_BOOT`` is enabled. The default value is ``0``. When |
| set to ``1`` then measurements and additional metadata collected during the |
| measured boot process are sent to the DICE Protection Environment for storage |
| and processing. A certificate chain, which represents the boot state of the |
| device, can be queried from the DPE. |
| |
| - ``MARCH_DIRECTIVE``: used to pass a -march option from the platform build |
| options to the compiler. An example usage: |
| |
| .. code:: make |
| |
| MARCH_DIRECTIVE := -march=armv8.5-a |
| |
| - ``HARDEN_SLS``: used to pass -mharden-sls=all from the TF-A build |
| options to the compiler currently supporting only of the options. |
| GCC documentation: |
| https://gcc.gnu.org/onlinedocs/gcc/AArch64-Options.html#index-mharden-sls |
| |
| An example usage: |
| |
| .. code:: make |
| |
| HARDEN_SLS := 1 |
| |
| This option defaults to 0. |
| |
| - ``NON_TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It |
| specifies a file that contains the Non-Trusted World private key in PEM |
| format or a PKCS11 URI. If ``SAVE_KEYS=1``, only a file is accepted and it |
| will be used to save the key. |
| |
| - ``NS_BL2U``: Path to NS_BL2U image in the host file system. This image is |
| optional. It is only needed if the platform makefile specifies that it |
| is required in order to build the ``fwu_fip`` target. |
| |
| - ``NS_TIMER_SWITCH``: Enable save and restore for non-secure timer register |
| contents upon world switch. It can take either 0 (don't save and restore) or |
| 1 (do save and restore). 0 is the default. An SPD may set this to 1 if it |
| wants the timer registers to be saved and restored. |
| |
| - ``OVERRIDE_LIBC``: This option allows platforms to override the default libc |
| for the BL image. It can be either 0 (include) or 1 (remove). The default |
| value is 0. |
| |
| - ``PL011_GENERIC_UART``: Boolean option to indicate the PL011 driver that |
| the underlying hardware is not a full PL011 UART but a minimally compliant |
| generic UART, which is a subset of the PL011. The driver will not access |
| any register that is not part of the SBSA generic UART specification. |
| Default value is 0 (a full PL011 compliant UART is present). |
| |
| - ``PLAT``: Choose a platform to build TF-A for. The chosen platform name |
| must be subdirectory of any depth under ``plat/``, and must contain a |
| platform makefile named ``platform.mk``. For example, to build TF-A for the |
| Arm Juno board, select PLAT=juno. |
| |
| - ``PLATFORM_REPORT_CTX_MEM_USE``: Reports the context memory allocated for |
| each core as well as the global context. The data includes the memory used |
| by each world and each privileged exception level. This build option is |
| applicable only for ``ARCH=aarch64`` builds. The default value is 0. |
| |
| - ``PRELOADED_BL33_BASE``: This option enables booting a preloaded BL33 image |
| instead of the normal boot flow. When defined, it must specify the entry |
| point address for the preloaded BL33 image. This option is incompatible with |
| ``EL3_PAYLOAD_BASE``. If both are defined, ``EL3_PAYLOAD_BASE`` has priority |
| over ``PRELOADED_BL33_BASE``. |
| |
| - ``PROGRAMMABLE_RESET_ADDRESS``: This option indicates whether the reset |
| vector address can be programmed or is fixed on the platform. It can take |
| either 0 (fixed) or 1 (programmable). Default is 0. If the platform has a |
| programmable reset address, it is expected that a CPU will start executing |
| code directly at the right address, both on a cold and warm reset. In this |
| case, there is no need to identify the entrypoint on boot and the boot path |
| can be optimised. The ``plat_get_my_entrypoint()`` platform porting interface |
| does not need to be implemented in this case. |
| |
| - ``PSCI_EXTENDED_STATE_ID``: As per PSCI1.0 Specification, there are 2 formats |
| possible for the PSCI power-state parameter: original and extended State-ID |
| formats. This flag if set to 1, configures the generic PSCI layer to use the |
| extended format. The default value of this flag is 0, which means by default |
| the original power-state format is used by the PSCI implementation. This flag |
| should be specified by the platform makefile and it governs the return value |
| of PSCI_FEATURES API for CPU_SUSPEND smc function id. When this option is |
| enabled on Arm platforms, the option ``ARM_RECOM_STATE_ID_ENC`` needs to be |
| set to 1 as well. |
| |
| - ``PSCI_OS_INIT_MODE``: Boolean flag to enable support for optional PSCI |
| OS-initiated mode. This option defaults to 0. |
| |
| - ``ENABLE_FEAT_RAS``: Boolean flag to enable Armv8.2 RAS features. RAS features |
| are an optional extension for pre-Armv8.2 CPUs, but are mandatory for Armv8.2 |
| or later CPUs. This flag can take the values 0 or 1. The default value is 0. |
| NOTE: This flag enables use of IESB capability to reduce entry latency into |
| EL3 even when RAS error handling is not performed on the platform. Hence this |
| flag is recommended to be turned on Armv8.2 and later CPUs. |
| |
| - ``RESET_TO_BL31``: Enable BL31 entrypoint as the CPU reset vector instead |
| of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1 |
| entrypoint) or 1 (CPU reset to BL31 entrypoint). |
| The default value is 0. |
| |
| - ``RESET_TO_SP_MIN``: SP_MIN is the minimal AArch32 Secure Payload provided |
| in TF-A. This flag configures SP_MIN entrypoint as the CPU reset vector |
| instead of the BL1 entrypoint. It can take the value 0 (CPU reset to BL1 |
| entrypoint) or 1 (CPU reset to SP_MIN entrypoint). The default value is 0. |
| |
| - ``ROT_KEY``: This option is used when ``GENERATE_COT=1``. It specifies a |
| file that contains the ROT private key in PEM format or a PKCS11 URI and |
| enforces public key hash generation. If ``SAVE_KEYS=1``, only a file is |
| accepted and it will be used to save the key. |
| |
| - ``SAVE_KEYS``: This option is used when ``GENERATE_COT=1``. It tells the |
| certificate generation tool to save the keys used to establish the Chain of |
| Trust. Allowed options are '0' or '1'. Default is '0' (do not save). |
| |
| - ``SCP_BL2``: Path to SCP_BL2 image in the host file system. This image is optional. |
| If a SCP_BL2 image is present then this option must be passed for the ``fip`` |
| target. |
| |
| - ``SCP_BL2_KEY``: This option is used when ``GENERATE_COT=1``. It specifies a |
| file that contains the SCP_BL2 private key in PEM format or a PKCS11 URI. |
| If ``SAVE_KEYS=1``, only a file is accepted and it will be used to save the key. |
| |
| - ``SCP_BL2U``: Path to SCP_BL2U image in the host file system. This image is |
| optional. It is only needed if the platform makefile specifies that it |
| is required in order to build the ``fwu_fip`` target. |
| |
| - ``SDEI_SUPPORT``: Setting this to ``1`` enables support for Software |
| Delegated Exception Interface to BL31 image. This defaults to ``0``. |
| |
| When set to ``1``, the build option ``EL3_EXCEPTION_HANDLING`` must also be |
| set to ``1``. |
| |
| - ``SEPARATE_CODE_AND_RODATA``: Whether code and read-only data should be |
| isolated on separate memory pages. This is a trade-off between security and |
| memory usage. See "Isolating code and read-only data on separate memory |
| pages" section in :ref:`Firmware Design`. This flag is disabled by default |
| and affects all BL images. |
| |
| - ``SEPARATE_NOBITS_REGION``: Setting this option to ``1`` allows the NOBITS |
| sections of BL31 (.bss, stacks, page tables, and coherent memory) to be |
| allocated in RAM discontiguous from the loaded firmware image. When set, the |
| platform is expected to provide definitions for ``BL31_NOBITS_BASE`` and |
| ``BL31_NOBITS_LIMIT``. When the option is ``0`` (the default), NOBITS |
| sections are placed in RAM immediately following the loaded firmware image. |
| |
| - ``SEPARATE_BL2_NOLOAD_REGION``: Setting this option to ``1`` allows the |
| NOLOAD sections of BL2 (.bss, stacks, page tables) to be allocated in RAM |
| discontiguous from loaded firmware images. When set, the platform need to |
| provide definitions of ``BL2_NOLOAD_START`` and ``BL2_NOLOAD_LIMIT``. This |
| flag is disabled by default and NOLOAD sections are placed in RAM immediately |
| following the loaded firmware image. |
| |
| - ``SMC_PCI_SUPPORT``: This option allows platforms to handle PCI configuration |
| access requests via a standard SMCCC defined in `DEN0115`_. When combined with |
| UEFI+ACPI this can provide a certain amount of OS forward compatibility |
| with newer platforms that aren't ECAM compliant. |
| |
| - ``SPD``: Choose a Secure Payload Dispatcher component to be built into TF-A. |
| This build option is only valid if ``ARCH=aarch64``. The value should be |
| the path to the directory containing the SPD source, relative to |
| ``services/spd/``; the directory is expected to contain a makefile called |
| ``<spd-value>.mk``. The SPM Dispatcher standard service is located in |
| services/std_svc/spmd and enabled by ``SPD=spmd``. The SPM Dispatcher |
| cannot be enabled when the ``SPM_MM`` option is enabled. |
| |
| - ``SPIN_ON_BL1_EXIT``: This option introduces an infinite loop in BL1. It can |
| take either 0 (no loop) or 1 (add a loop). 0 is the default. This loop stops |
| execution in BL1 just before handing over to BL31. At this point, all |
| firmware images have been loaded in memory, and the MMU and caches are |
| turned off. Refer to the "Debugging options" section for more details. |
| |
| - ``SPMC_AT_EL3`` : This boolean option is used jointly with the SPM |
| Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC |
| component runs at the EL3 exception level. The default value is ``0`` ( |
| disabled). This configuration supports pre-Armv8.4 platforms (aka not |
| implementing the ``FEAT_SEL2`` extension). |
| |
| - ``SPMC_AT_EL3_SEL0_SP`` : Boolean option to enable SEL0 SP load support when |
| ``SPMC_AT_EL3`` is enabled. The default value if ``0`` (disabled). This |
| option cannot be enabled (``1``) when (``SPMC_AT_EL3``) is disabled. |
| |
| - ``SPMC_OPTEE`` : This boolean option is used jointly with the SPM |
| Dispatcher option (``SPD=spmd``) and with ``SPMD_SPM_AT_SEL2=0`` to |
| indicate that the SPMC at S-EL1 is OP-TEE and an OP-TEE specific loading |
| mechanism should be used. |
| |
| - ``SPMD_SPM_AT_SEL2`` : This boolean option is used jointly with the SPM |
| Dispatcher option (``SPD=spmd``). When enabled (1) it indicates the SPMC |
| component runs at the S-EL2 exception level provided by the ``FEAT_SEL2`` |
| extension. This is the default when enabling the SPM Dispatcher. When |
| disabled (0) it indicates the SPMC component runs at the S-EL1 execution |
| state or at EL3 if ``SPMC_AT_EL3`` is enabled. The latter configurations |
| support pre-Armv8.4 platforms (aka not implementing the ``FEAT_SEL2`` |
| extension). |
| |
| - ``SPM_MM`` : Boolean option to enable the Management Mode (MM)-based Secure |
| Partition Manager (SPM) implementation. The default value is ``0`` |
| (disabled). This option cannot be enabled (``1``) when SPM Dispatcher is |
| enabled (``SPD=spmd``). |
| |
| - ``SP_LAYOUT_FILE``: Platform provided path to JSON file containing the |
| description of secure partitions. The build system will parse this file and |
| package all secure partition blobs into the FIP. This file is not |
| necessarily part of TF-A tree. Only available when ``SPD=spmd``. |
| |
| - ``SP_MIN_WITH_SECURE_FIQ``: Boolean flag to indicate the SP_MIN handles |
| secure interrupts (caught through the FIQ line). Platforms can enable |
| this directive if they need to handle such interruption. When enabled, |
| the FIQ are handled in monitor mode and non secure world is not allowed |
| to mask these events. Platforms that enable FIQ handling in SP_MIN shall |
| implement the api ``sp_min_plat_fiq_handler()``. The default value is 0. |
| |
| - ``SVE_VECTOR_LEN``: SVE vector length to configure in ZCR_EL3. |
| Platforms can configure this if they need to lower the hardware |
| limit, for example due to asymmetric configuration or limitations of |
| software run at lower ELs. The default is the architectural maximum |
| of 2048 which should be suitable for most configurations, the |
| hardware will limit the effective VL to the maximum physically supported |
| VL. |
| |
| - ``TRNG_SUPPORT``: Setting this to ``1`` enables support for True |
| Random Number Generator Interface to BL31 image. This defaults to ``0``. |
| |
| - ``TRUSTED_BOARD_BOOT``: Boolean flag to include support for the Trusted Board |
| Boot feature. When set to '1', BL1 and BL2 images include support to load |
| and verify the certificates and images in a FIP, and BL1 includes support |
| for the Firmware Update. The default value is '0'. Generation and inclusion |
| of certificates in the FIP and FWU_FIP depends upon the value of the |
| ``GENERATE_COT`` option. |
| |
| .. warning:: |
| This option depends on ``CREATE_KEYS`` to be enabled. If the keys |
| already exist in disk, they will be overwritten without further notice. |
| |
| - ``TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It |
| specifies a file that contains the Trusted World private key in PEM |
| format or a PKCS11 URI. If ``SAVE_KEYS=1``, only a file is accepted and |
| it will be used to save the key. |
| |
| - ``TSP_INIT_ASYNC``: Choose BL32 initialization method as asynchronous or |
| synchronous, (see "Initializing a BL32 Image" section in |
| :ref:`Firmware Design`). It can take the value 0 (BL32 is initialized using |
| synchronous method) or 1 (BL32 is initialized using asynchronous method). |
| Default is 0. |
| |
| - ``TSP_NS_INTR_ASYNC_PREEMPT``: A non zero value enables the interrupt |
| routing model which routes non-secure interrupts asynchronously from TSP |
| to EL3 causing immediate preemption of TSP. The EL3 is responsible |
| for saving and restoring the TSP context in this routing model. The |
| default routing model (when the value is 0) is to route non-secure |
| interrupts to TSP allowing it to save its context and hand over |
| synchronously to EL3 via an SMC. |
| |
| .. note:: |
| When ``EL3_EXCEPTION_HANDLING`` is ``1``, ``TSP_NS_INTR_ASYNC_PREEMPT`` |
| must also be set to ``1``. |
| |
| - ``TS_SP_FW_CONFIG``: DTC build flag to include Trusted Services (Crypto and |
| internal-trusted-storage) as SP in tb_fw_config device tree. |
| |
| - ``TWED_DELAY``: Numeric value to be set in order to delay the trapping of |
| WFE instruction. ``ENABLE_FEAT_TWED`` build option must be enabled to set |
| this delay. It can take values in the range (0-15). Default value is ``0`` |
| and based on this value, 2^(TWED_DELAY + 8) cycles will be delayed. |
| Platforms need to explicitly update this value based on their requirements. |
| |
| - ``USE_ARM_LINK``: This flag determines whether to enable support for ARM |
| linker. When the ``LINKER`` build variable points to the armlink linker, |
| this flag is enabled automatically. To enable support for armlink, platforms |
| will have to provide a scatter file for the BL image. Currently, Tegra |
| platforms use the armlink support to compile BL3-1 images. |
| |
| - ``USE_COHERENT_MEM``: This flag determines whether to include the coherent |
| memory region in the BL memory map or not (see "Use of Coherent memory in |
| TF-A" section in :ref:`Firmware Design`). It can take the value 1 |
| (Coherent memory region is included) or 0 (Coherent memory region is |
| excluded). Default is 1. |
| |
| - ``ARM_IO_IN_DTB``: This flag determines whether to use IO based on the |
| firmware configuration framework. This will move the io_policies into a |
| configuration device tree, instead of static structure in the code base. |
| |
| - ``COT_DESC_IN_DTB``: This flag determines whether to create COT descriptors |
| at runtime using fconf. If this flag is enabled, COT descriptors are |
| statically captured in tb_fw_config file in the form of device tree nodes |
| and properties. Currently, COT descriptors used by BL2 are moved to the |
| device tree and COT descriptors used by BL1 are retained in the code |
| base statically. |
| |
| - ``SDEI_IN_FCONF``: This flag determines whether to configure SDEI setup in |
| runtime using firmware configuration framework. The platform specific SDEI |
| shared and private events configuration is retrieved from device tree rather |
| than static C structures at compile time. This is only supported if |
| SDEI_SUPPORT build flag is enabled. |
| |
| - ``SEC_INT_DESC_IN_FCONF``: This flag determines whether to configure Group 0 |
| and Group1 secure interrupts using the firmware configuration framework. The |
| platform specific secure interrupt property descriptor is retrieved from |
| device tree in runtime rather than depending on static C structure at compile |
| time. |
| |
| - ``USE_ROMLIB``: This flag determines whether library at ROM will be used. |
| This feature creates a library of functions to be placed in ROM and thus |
| reduces SRAM usage. Refer to :ref:`Library at ROM` for further details. Default |
| is 0. |
| |
| - ``V``: Verbose build. If assigned anything other than 0, the build commands |
| are printed. Default is 0. |
| |
| - ``VERSION_STRING``: String used in the log output for each TF-A image. |
| Defaults to a string formed by concatenating the version number, build type |
| and build string. |
| |
| - ``W``: Warning level. Some compiler warning options of interest have been |
| regrouped and put in the root Makefile. This flag can take the values 0 to 3, |
| each level enabling more warning options. Default is 0. |
| |
| This option is closely related to the ``E`` option, which enables |
| ``-Werror``. |
| |
| - ``W=0`` (default) |
| |
| Enables a wide assortment of warnings, most notably ``-Wall`` and |
| ``-Wextra``, as well as various bad practices and things that are likely to |
| result in errors. Includes some compiler specific flags. No warnings are |
| expected at this level for any build. |
| |
| - ``W=1`` |
| |
| Enables warnings we want the generic build to include but are too time |
| consuming to fix at the moment. It re-enables warnings taken out for |
| ``W=0`` builds (a few of the ``-Wextra`` additions). This level is expected |
| to eventually be merged into ``W=0``. Some warnings are expected on some |
| builds, but new contributions should not introduce new ones. |
| |
| - ``W=2`` (recommended) |
| |
| Enables warnings we want the generic build to include but cannot be enabled |
| due to external libraries. This level is expected to eventually be merged |
| into ``W=0``. Lots of warnings are expected, primarily from external |
| libraries like zlib and compiler-rt, but new controbutions should not |
| introduce new ones. |
| |
| - ``W=3`` |
| |
| Enables warnings that are informative but not necessary and generally too |
| verbose and frequently ignored. A very large number of warnings are |
| expected. |
| |
| The exact set of warning flags depends on the compiler and TF-A warning |
| level, however they are all succinctly set in the top-level Makefile. Please |
| refer to the `GCC`_ or `Clang`_ documentation for more information on the |
| individual flags. |
| |
| - ``WARMBOOT_ENABLE_DCACHE_EARLY`` : Boolean option to enable D-cache early on |
| the CPU after warm boot. This is applicable for platforms which do not |
| require interconnect programming to enable cache coherency (eg: single |
| cluster platforms). If this option is enabled, then warm boot path |
| enables D-caches immediately after enabling MMU. This option defaults to 0. |
| |
| - ``SUPPORT_STACK_MEMTAG``: This flag determines whether to enable memory |
| tagging for stack or not. It accepts 2 values: ``yes`` and ``no``. The |
| default value of this flag is ``no``. Note this option must be enabled only |
| for ARM architecture greater than Armv8.5-A. |
| |
| - ``ERRATA_SPECULATIVE_AT``: This flag determines whether to enable ``AT`` |
| speculative errata workaround or not. It accepts 2 values: ``1`` and ``0``. |
| The default value of this flag is ``0``. |
| |
| ``AT`` speculative errata workaround disables stage1 page table walk for |
| lower ELs (EL1 and EL0) in EL3 so that ``AT`` speculative fetch at any point |
| produces either the correct result or failure without TLB allocation. |
| |
| This boolean option enables errata for all below CPUs. |
| |
| +---------+--------------+-------------------------+ |
| | Errata | CPU | Workaround Define | |
| +=========+==============+=========================+ |
| | 1165522 | Cortex-A76 | ``ERRATA_A76_1165522`` | |
| +---------+--------------+-------------------------+ |
| | 1319367 | Cortex-A72 | ``ERRATA_A72_1319367`` | |
| +---------+--------------+-------------------------+ |
| | 1319537 | Cortex-A57 | ``ERRATA_A57_1319537`` | |
| +---------+--------------+-------------------------+ |
| | 1530923 | Cortex-A55 | ``ERRATA_A55_1530923`` | |
| +---------+--------------+-------------------------+ |
| | 1530924 | Cortex-A53 | ``ERRATA_A53_1530924`` | |
| +---------+--------------+-------------------------+ |
| |
| .. note:: |
| This option is enabled by build only if platform sets any of above defines |
| mentioned in ’Workaround Define' column in the table. |
| If this option is enabled for the EL3 software then EL2 software also must |
| implement this workaround due to the behaviour of the errata mentioned |
| in new SDEN document which will get published soon. |
| |
| - ``RAS_TRAP_NS_ERR_REC_ACCESS``: This flag enables/disables the SCR_EL3.TERR |
| bit, to trap access to the RAS ERR and RAS ERX registers from lower ELs. |
| This flag is disabled by default. |
| |
| - ``OPENSSL_DIR``: This option is used to provide the path to a directory on the |
| host machine where a custom installation of OpenSSL is located, which is used |
| to build the certificate generation, firmware encryption and FIP tools. If |
| this option is not set, the default OS installation will be used. |
| |
| - ``USE_SP804_TIMER``: Use the SP804 timer instead of the Generic Timer for |
| functions that wait for an arbitrary time length (udelay and mdelay). The |
| default value is 0. |
| |
| - ``ENABLE_BRBE_FOR_NS``: Numeric value to enable access to the branch record |
| buffer registers from NS ELs when FEAT_BRBE is implemented. BRBE is an |
| optional architectural feature for AArch64. This flag can take the values |
| 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. The default is 0 |
| and it is automatically disabled when the target architecture is AArch32. |
| |
| - ``ENABLE_TRBE_FOR_NS``: Numeric value to enable access of trace buffer |
| control registers from NS ELs, NS-EL2 or NS-EL1(when NS-EL2 is implemented |
| but unused) when FEAT_TRBE is implemented. TRBE is an optional architectural |
| feature for AArch64. This flag can take the values 0 to 2, to align with the |
| ``ENABLE_FEAT`` mechanism. The default is 0 and it is automatically |
| disabled when the target architecture is AArch32. |
| |
| - ``ENABLE_SYS_REG_TRACE_FOR_NS``: Numeric value to enable trace system |
| registers access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented |
| but unused). This feature is available if trace unit such as ETMv4.x, and |
| ETE(extending ETM feature) is implemented. This flag can take the values |
| 0 to 2, to align with the ``ENABLE_FEAT`` mechanism. The default is 0. |
| |
| - ``ENABLE_TRF_FOR_NS``: Numeric value to enable trace filter control registers |
| access from NS ELs, NS-EL2 or NS-EL1 (when NS-EL2 is implemented but unused), |
| if FEAT_TRF is implemented. This flag can take the values 0 to 2, to align |
| with the ``ENABLE_FEAT`` mechanism. This flag is disabled by default. |
| |
| - ``CONDITIONAL_CMO``: Boolean option to enable call to platform-defined routine |
| ``plat_can_cmo`` which will return zero if cache management operations should |
| be skipped and non-zero otherwise. By default, this option is disabled which |
| means platform hook won't be checked and CMOs will always be performed when |
| related functions are called. |
| |
| - ``ERRATA_ABI_SUPPORT``: Boolean option to enable support for Errata management |
| firmware interface for the BL31 image. By default its disabled (``0``). |
| |
| - ``ERRATA_NON_ARM_INTERCONNECT``: Boolean option to enable support for the |
| errata mitigation for platforms with a non-arm interconnect using the errata |
| ABI. By default its disabled (``0``). |
| |
| - ``ENABLE_CONSOLE_GETC``: Boolean option to enable `getc()` feature in console |
| driver(s). By default it is disabled (``0``) because it constitutes an attack |
| vector into TF-A by potentially allowing an attacker to inject arbitrary data. |
| This option should only be enabled on a need basis if there is a use case for |
| reading characters from the console. |
| |
| GICv3 driver options |
| -------------------- |
| |
| GICv3 driver files are included using directive: |
| |
| ``include drivers/arm/gic/v3/gicv3.mk`` |
| |
| The driver can be configured with the following options set in the platform |
| makefile: |
| |
| - ``GICV3_SUPPORT_GIC600``: Add support for the GIC-600 variants of GICv3. |
| Enabling this option will add runtime detection support for the |
| GIC-600, so is safe to select even for a GIC500 implementation. |
| This option defaults to 0. |
| |
| - ``GICV3_SUPPORT_GIC600AE_FMU``: Add support for the Fault Management Unit |
| for GIC-600 AE. Enabling this option will introduce support to initialize |
| the FMU. Platforms should call the init function during boot to enable the |
| FMU and its safety mechanisms. This option defaults to 0. |
| |
| - ``GICV3_IMPL_GIC600_MULTICHIP``: Selects GIC-600 variant with multichip |
| functionality. This option defaults to 0 |
| |
| - ``GICV3_OVERRIDE_DISTIF_PWR_OPS``: Allows override of default implementation |
| of ``arm_gicv3_distif_pre_save`` and ``arm_gicv3_distif_post_restore`` |
| functions. This is required for FVP platform which need to simulate GIC save |
| and restore during SYSTEM_SUSPEND without powering down GIC. Default is 0. |
| |
| - ``GIC_ENABLE_V4_EXTN`` : Enables GICv4 related changes in GICv3 driver. |
| This option defaults to 0. |
| |
| - ``GIC_EXT_INTID``: When set to ``1``, GICv3 driver will support extended |
| PPI (1056-1119) and SPI (4096-5119) range. This option defaults to 0. |
| |
| Debugging options |
| ----------------- |
| |
| To compile a debug version and make the build more verbose use |
| |
| .. code:: shell |
| |
| make PLAT=<platform> DEBUG=1 V=1 all |
| |
| AArch64 GCC 11 uses DWARF version 5 debugging symbols by default. Some tools |
| (for example Arm-DS) might not support this and may need an older version of |
| DWARF symbols to be emitted by GCC. This can be achieved by using the |
| ``-gdwarf-<version>`` flag, with the version being set to 2, 3, 4 or 5. Setting |
| the version to 4 is recommended for Arm-DS. |
| |
| When debugging logic problems it might also be useful to disable all compiler |
| optimizations by using ``-O0``. |
| |
| .. warning:: |
| Using ``-O0`` could cause output images to be larger and base addresses |
| might need to be recalculated (see the **Memory layout on Arm development |
| platforms** section in the :ref:`Firmware Design`). |
| |
| Extra debug options can be passed to the build system by setting ``CFLAGS`` or |
| ``LDFLAGS``: |
| |
| .. code:: shell |
| |
| CFLAGS='-O0 -gdwarf-2' \ |
| make PLAT=<platform> DEBUG=1 V=1 all |
| |
| Note that using ``-Wl,`` style compilation driver options in ``CFLAGS`` will be |
| ignored as the linker is called directly. |
| |
| It is also possible to introduce an infinite loop to help in debugging the |
| post-BL2 phase of TF-A. This can be done by rebuilding BL1 with the |
| ``SPIN_ON_BL1_EXIT=1`` build flag. Refer to the :ref:`build_options_common` |
| section. In this case, the developer may take control of the target using a |
| debugger when indicated by the console output. When using Arm-DS, the following |
| commands can be used: |
| |
| :: |
| |
| # Stop target execution |
| interrupt |
| |
| # |
| # Prepare your debugging environment, e.g. set breakpoints |
| # |
| |
| # Jump over the debug loop |
| set var $AARCH64::$Core::$PC = $AARCH64::$Core::$PC + 4 |
| |
| # Resume execution |
| continue |
| |
| .. _build_options_experimental: |
| |
| Experimental build options |
| --------------------------- |
| |
| Common build options |
| ~~~~~~~~~~~~~~~~~~~~ |
| |
| - ``DRTM_SUPPORT``: Boolean flag to enable support for Dynamic Root of Trust |
| for Measurement (DRTM). This feature has trust dependency on BL31 for taking |
| the measurements and recording them as per `PSA DRTM specification`_. For |
| platforms which use BL2 to load/authenticate BL31 ``TRUSTED_BOARD_BOOT`` can |
| be used and for the platforms which use ``RESET_TO_BL31`` platform owners |
| should have mechanism to authenticate BL31. This option defaults to 0. |
| |
| - ``ENABLE_RME``: Numeric value to enable support for the ARMv9 Realm |
| Management Extension. This flag can take the values 0 to 2, to align with |
| the ``ENABLE_FEAT`` mechanism. Default value is 0. |
| |
| - ``ENABLE_SME_FOR_NS``: Numeric value to enable Scalable Matrix Extension |
| (SME), SVE, and FPU/SIMD for the non-secure world only. These features share |
| registers so are enabled together. Using this option without |
| ENABLE_SME_FOR_SWD=1 will cause SME, SVE, and FPU/SIMD instructions in secure |
| world to trap to EL3. Requires ``ENABLE_SVE_FOR_NS`` to be set as SME is a |
| superset of SVE. SME is an optional architectural feature for AArch64. |
| At this time, this build option cannot be used on systems that have |
| SPD=spmd/SPM_MM and atempting to build with this option will fail. |
| This flag can take the values 0 to 2, to align with the ``ENABLE_FEAT`` |
| mechanism. Default is 0. |
| |
| - ``ENABLE_SME2_FOR_NS``: Numeric value to enable Scalable Matrix Extension |
| version 2 (SME2) for the non-secure world only. SME2 is an optional |
| architectural feature for AArch64. |
| This should be set along with ENABLE_SME_FOR_NS=1, if not, the default SME |
| accesses will still be trapped. This flag can take the values 0 to 2, to |
| align with the ``ENABLE_FEAT`` mechanism. Default is 0. |
| |
| - ``ENABLE_SME_FOR_SWD``: Boolean option to enable the Scalable Matrix |
| Extension for secure world. Used along with SVE and FPU/SIMD. |
| ENABLE_SME_FOR_NS and ENABLE_SVE_FOR_SWD must also be set to use this. |
| Default is 0. |
| |
| - ``ENABLE_SPMD_LP`` : This boolean option is used jointly with the SPM |
| Dispatcher option (``SPD=spmd``). When enabled (1) it indicates support |
| for logical partitions in EL3, managed by the SPMD as defined in the |
| FF-A v1.2 specification. This flag is disabled by default. This flag |
| must not be used if ``SPMC_AT_EL3`` is enabled. |
| |
| - ``FEATURE_DETECTION``: Boolean option to enable the architectural features |
| verification mechanism. This is a debug feature that compares the |
| architectural features enabled through the feature specific build flags |
| (ENABLE_FEAT_xxx) with the features actually available on the CPU running, |
| and reports any discrepancies. |
| This flag will also enable errata ordering checking for ``DEBUG`` builds. |
| |
| It is expected that this feature is only used for flexible platforms like |
| software emulators, or for hardware platforms at bringup time, to verify |
| that the configured feature set matches the CPU. |
| The ``FEATURE_DETECTION`` macro is disabled by default. |
| |
| - ``PSA_CRYPTO``: Boolean option for enabling MbedTLS PSA crypto APIs support. |
| The platform will use PSA compliant Crypto APIs during authentication and |
| image measurement process by enabling this option. It uses APIs defined as |
| per the `PSA Crypto API specification`_. This feature is only supported if |
| using MbedTLS 3.x version. It is disabled (``0``) by default. |
| |
| - ``TRANSFER_LIST``: Setting this to ``1`` enables support for Firmware |
| Handoff using Transfer List defined in `Firmware Handoff specification`_. |
| This defaults to ``0``. Current implementation follows the Firmware Handoff |
| specification v0.9. |
| |
| - ``USE_DEBUGFS``: When set to 1 this option exposes a virtual filesystem |
| interface through BL31 as a SiP SMC function. |
| Default is disabled (0). |
| |
| Firmware update options |
| ~~~~~~~~~~~~~~~~~~~~~~~ |
| |
| - ``PSA_FWU_SUPPORT``: Enable the firmware update mechanism as per the |
| `PSA FW update specification`_. The default value is 0. |
| PSA firmware update implementation has few limitations, such as: |
| |
| - BL2 is not part of the protocol-updatable images. If BL2 needs to |
| be updated, then it should be done through another platform-defined |
| mechanism. |
| |
| - It assumes the platform's hardware supports CRC32 instructions. |
| |
| - ``NR_OF_FW_BANKS``: Define the number of firmware banks. This flag is used |
| in defining the firmware update metadata structure. This flag is by default |
| set to '2'. |
| |
| - ``NR_OF_IMAGES_IN_FW_BANK``: Define the number of firmware images in each |
| firmware bank. Each firmware bank must have the same number of images as per |
| the `PSA FW update specification`_. |
| This flag is used in defining the firmware update metadata structure. This |
| flag is by default set to '1'. |
| |
| - ``PSA_FWU_METADATA_FW_STORE_DESC``: To be enabled when the FWU |
| metadata contains image description. The default value is 1. |
| |
| The version 2 of the FWU metadata allows for an opaque metadata |
| structure where a platform can choose to not include the firmware |
| store description in the metadata structure. This option indicates |
| if the firmware store description, which provides information on |
| the updatable images is part of the structure. |
| |
| -------------- |
| |
| *Copyright (c) 2019-2024, Arm Limited. All rights reserved.* |
| |
| .. _DEN0115: https://developer.arm.com/docs/den0115/latest |
| .. _PSA FW update specification: https://developer.arm.com/documentation/den0118/latest/ |
| .. _PSA DRTM specification: https://developer.arm.com/documentation/den0113/a |
| .. _GCC: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html |
| .. _Clang: https://clang.llvm.org/docs/DiagnosticsReference.html |
| .. _Firmware Handoff specification: https://github.com/FirmwareHandoff/firmware_handoff/releases/tag/v0.9 |
| .. _PSA Crypto API specification: https://armmbed.github.io/mbed-crypto/html/ |