ARM Trusted Firmware User Guide

Contents :

  1. Introduction

  2. Host machine requirements

  3. Tools

  4. Building the Trusted Firmware

  5. Obtaining the normal world software

  6. Preparing the images to run on FVP

  7. Running the software on FVP

  8. Running the software on Juno

  9. Introduction


This document describes how to build ARM Trusted Firmware and run it with a tested set of other software components using defined configurations on the Juno ARM development platform and ARM Fixed Virtual Platform (FVP) models. It is possible to use other software components, configurations and platforms but that is outside the scope of this document.

This document should be used in conjunction with the Firmware Design.

  1. Host machine requirements

The minimum recommended machine specification for building the software and running the FVP models is a dual-core processor running at 2GHz with 12GB of RAM. For best performance, use a machine with a quad-core processor running at 2.6GHz with 16GB of RAM.

The software has been tested on Ubuntu 12.04.04 (64-bit). Packages used for building the software were installed from that distribution unless otherwise specified.

  1. Tools

The following tools are required to use the ARM Trusted Firmware:

  • git package to obtain source code.

  • build-essential, uuid-dev and iasl packages for building UEFI and the Firmware Image Package (FIP) tool.

  • bc and ncurses-dev packages for building Linux.

  • device-tree-compiler package for building the Flattened Device Tree (FDT) source files (.dts files) provided with this software.

  • Baremetal GNU GCC tools. Verified packages can be downloaded from [Linaro] Linaro Toolchain. The rest of this document assumes that the gcc-linaro-aarch64-none-elf-4.9-2014.07_linux.tar.xz tools are used.

    wget http://releases.linaro.org/14.07/components/toolchain/binaries/gcc-linaro-aarch64-none-elf-4.9-2014.07_linux.tar.xz
    tar -xf gcc-linaro-aarch64-none-elf-4.9-2014.07_linux.tar.xz
    
  • libssl-dev package to build the certificate generation tool when support for Trusted Board Boot is needed.

  • (Optional) For debugging, ARM Development Studio 5 (DS-5) v5.21.

  1. Building the Trusted Firmware

To build the Trusted Firmware images, follow these steps:

  1. Clone the ARM Trusted Firmware repository from GitHub:

    git clone https://github.com/ARM-software/arm-trusted-firmware.git
    
  2. Change to the trusted firmware directory:

    cd arm-trusted-firmware
    
  3. Set the compiler path, specify a Non-trusted Firmware image (BL3-3) and a valid platform, and then build:

    CROSS_COMPILE=<path-to-aarch64-gcc>/bin/aarch64-none-elf- \
    BL33=<path-to>/<bl33_image>                               \
    make PLAT=<platform> all fip
    

    If PLAT is not specified, fvp is assumed by default. See the "Summary of build options" for more information on available build options.

    The BL3-3 image corresponds to the software that is executed after switching to the non-secure world. UEFI can be used as the BL3-3 image. Refer to the "Obtaining the normal world software" section below.

    The TSP (Test Secure Payload), corresponding to the BL3-2 image, is not compiled in by default. Refer to the "Building the Test Secure Payload" section below.

    By default this produces a release version of the build. To produce a debug version instead, refer to the "Debugging options" section below.

    The build process creates products in a build directory tree, building the objects and binaries for each boot loader stage in separate sub-directories. The following boot loader binary files are created from the corresponding ELF files:

    • build/<platform>/<build-type>/bl1.bin
    • build/<platform>/<build-type>/bl2.bin
    • build/<platform>/<build-type>/bl31.bin

    where <platform> is the name of the chosen platform and <build-type> is either debug or release. A Firmare Image Package (FIP) will be created as part of the build. It contains all boot loader images except for bl1.bin.

    • build/<platform>/<build-type>/fip.bin

    For more information on FIPs, see the "Firmware Image Package" section in the Firmware Design.

  4. (Optional) Some platforms may require a BL3-0 image to boot. This image can be included in the FIP when building the Trusted Firmware by specifying the BL30 build option:

    BL30=<path-to>/<bl30_image>
    
  5. Output binary files bl1.bin and fip.bin are both required to boot the system. How these files are used is platform specific. Refer to the platform documentation on how to use the firmware images.

  6. (Optional) Build products for a specific build variant can be removed using:

    make DEBUG=<D> PLAT=<platform> clean
    

    ... where <D> is 0 or 1, as specified when building.

    The build tree can be removed completely using:

    make realclean
    
  7. (Optional) Path to binary for certain BL stages (BL2, BL3-1 and BL3-2) can be provided by specifying the BLx=/<blx_image> where BLx is the BL stage. This will bypass the build of the BL component from source, but will include the specified binary in the final FIP image. Please note that BL3-2 will be included in the build, only if the SPD build option is specified.

    For example, specifying BL2=/<bl2_image> in the build option, will skip compilation of BL2 source in trusted firmware, but include the BL2 binary specified in the final FIP image.

Summary of build options

ARM Trusted Firmware 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.

Common build options

  • BL30: Path to BL3-0 image in the host file system. This image is optional. If a BL3-0 image is present then this option must be passed for the fip target.

  • BL33: Path to BL3-3 image in the host file system. This is mandatory for fip target in case the BL2 from ARM Trusted Firmware is used.

  • 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 ARM Trusted Firmware will not be built.

  • BL31: This is an optional build option which specifies the path to BL3-1 image for the fip target. In this case, the BL3-1 in the ARM Trusted Firmware will not be built.

  • BL32: This is an optional build option which specifies the path to BL3-2 image for the fip target. In this case, the BL3-2 in the ARM Trusted Firmware will not be built.

  • FIP_NAME: This is an optional build option which specifies the FIP filename for the fip target. Default is fip.bin.

  • CROSS_COMPILE: Prefix to toolchain binaries. Please refer to examples in this document for usage.

  • DEBUG: Chooses between a debug and release build. It can take either 0 (release) or 1 (debug) as values. 0 is the default.

  • 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_NOTICE)
    20 (LOG_LEVEL_ERROR)
    30 (LOG_LEVEL_WARNING)
    40 (LOG_LEVEL_INFO)
    50 (LOG_LEVEL_VERBOSE)
    

    All log output up to and including the log level is compiled into the build. The default value is 40 in debug builds and 20 in release builds.

  • 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.

  • PLAT: Choose a platform to build ARM Trusted Firmware for. The chosen platform name must be subdirectory of any depth under plat/, and must contain a platform makefile named platform.mk.

  • SPD: Choose a Secure Payload Dispatcher component to be built into the Trusted Firmware. 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.

  • V: Verbose build. If assigned anything other than 0, the build commands are printed. Default is 0.

  • ARM_GIC_ARCH: Choice of ARM GIC architecture version used by the ARM GIC driver for implementing the platform GIC API. This API is used by the interrupt management framework. Default is 2 (that is, version 2.0).

  • ARM_CCI_PRODUCT_ID: Choice of ARM CCI product used by the platform. This is used to determine the number of valid slave interfaces available in the ARM CCI driver. Default is 400 (that is, CCI-400).

  • IMF_READ_INTERRUPT_ID: Boolean flag used by the interrupt management framework to enable passing of the interrupt id to its handler. The id is read using a platform GIC API. INTR_ID_UNAVAILABLE is passed instead if this option set to 0. Default is 0.

  • RESET_TO_BL31: Enable BL3-1 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 BL3-1 entrypoint). The default value is 0.

  • CRASH_REPORTING: A non-zero value enables a console dump of processor register state when an unexpected exception occurs during execution of BL3-1. This option defaults to the value of DEBUG - i.e. by default this is only enabled for a debug build of the firmware.

  • ASM_ASSERTION: This flag determines whether the assertion checks within assembly source files are enabled or not. This option defaults to the value of DEBUG - that is, by default this is only enabled for a debug build of the firmware.

  • TSP_INIT_ASYNC: Choose BL3-2 initialization method as asynchronous or synchronous, (see "Initializing a BL3-2 Image" section in Firmware Design). It can take the value 0 (BL3-2 is initialized using synchronous method) or 1 (BL3-2 is initialized using asynchronous method). Default is 0.

  • 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 Trusted Firmware" section in Firmware Design). It can take the value 1 (Coherent memory region is included) or 0 (Coherent memory region is excluded). Default is 1.

  • TSPD_ROUTE_IRQ_TO_EL3: A non zero value enables the routing model for non-secure interrupts in which they are routed to EL3 (TSPD). The default model (when the value is 0) is to route non-secure interrupts to S-EL1 (TSP).

  • 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. The default value is '0'. Generation and inclusion of certificates in the FIP depends upon the value of the GENERATE_COT option.

  • GENERATE_COT: Boolean flag used to build and execute the cert_create tool to create certificates as per the Chain of Trust described in Trusted Board Boot. The build system then calls the fip_create tool to include the certificates in the FIP. Default value is '0'.

    Specify TRUSTED_BOARD_BOOT=1 and GENERATE_COT=1 to include support for the Trusted Board Boot Sequence in the BL1 and BL2 images and the 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 key and content 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 will not include the key and content certificates, causing a boot failure.

  • 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'.

  • 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).

    Note: This option depends on 'CREATE_KEYS' to be enabled. If the keys already exist in disk, they will be overwritten without further notice.

  • ROT_KEY: This option is used when GENERATE_COT=1. It specifies the file that contains the ROT private key in PEM format. If SAVE_KEYS=1, this file name will be used to save the key.

  • TRUSTED_WORLD_KEY: This option is used when GENERATE_COT=1. It specifies the file that contains the Trusted World private key in PEM format. If SAVE_KEYS=1, this file name will be used to save the key.

  • NON_TRUSTED_WORLD_KEY: This option is used when GENERATE_COT=1. It specifies the file that contains the Non-Trusted World private key in PEM format. If SAVE_KEYS=1, this file name will be used to save the key.

  • BL30_KEY: This option is used when GENERATE_COT=1. It specifies the file that contains the BL3-0 private key in PEM format. If SAVE_KEYS=1, this file name will be used to save the key.

  • BL31_KEY: This option is used when GENERATE_COT=1. It specifies the file that contains the BL3-1 private key in PEM format. If SAVE_KEYS=1, this file name will be used to save the key.

  • BL32_KEY: This option is used when GENERATE_COT=1. It specifies the file that contains the BL3-2 private key in PEM format. If SAVE_KEYS=1, this file name will be used to save the key.

  • BL33_KEY: This option is used when GENERATE_COT=1. It specifies the file that contains the BL3-3 private key in PEM format. If SAVE_KEYS=1, this file name will be used to save the key.

  • 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.

ARM development platform specific build options

  • ARM_TSP_RAM_LOCATION: location of the TSP binary. Options:
    • tsram : Trusted SRAM (default option)
    • tdram : Trusted DRAM (if available)
    • dram : Secure region in DRAM (configured by the TrustZone controller)

For a better understanding of these options, the ARM development platform memory map is explained in the Firmware Design.

  • ARM_ROTPK_LOCATION: used when TRUSTED_BOARD_BOOT=1. It specifies the location of the ROTPK hash returned by the function plat_get_rotpk_info() for ARM platforms. Depending on the selected option, the proper private key must be specified using the ROT_KEY option when building the Trusted Firmware. This private key will be used by the certificate generation tool to sign the BL2 and Trusted Key certificates. Available options for ARM_ROTPK_LOCATION are:

    • regs : return the ROTPK hash stored in the Trusted root-key storage registers. The private key corresponding to this ROTPK hash is not currently available.
    • devel_rsa : return a development public key hash embedded in the BL1 and BL2 binaries. This hash has been obtained from the RSA public key arm_rotpk_rsa.der, located in plat/arm/board/common/rotpk. To use this option, arm_rotprivk_rsa.pem must be specified as ROT_KEY when creating the certificates.

ARM CSS platform specific build options

  • CSS_DETECT_PRE_1_7_0_SCP: Boolean flag to detect SCP version incompatibility. Version 1.7.0 of the SCP firmware made a non-backwards compatible change to the MTL protocol, used for AP/SCP communication. Trusted Firmware no longer supports earlier SCP versions. If this option is set to 1 then Trusted Firmware will detect if an earlier version is in use. Default is 1.

Creating a Firmware Image Package

FIPs are automatically created as part of the build instructions described in the previous section. It is also possible to independently build the FIP creation tool and FIPs if required. To do this, follow these steps:

Build the tool:

make -C tools/fip_create

It is recommended to remove the build artifacts before rebuilding:

make -C tools/fip_create clean

Create a Firmware package that contains existing BL2 and BL3-1 images:

# fip_create --help to print usage information
# fip_create <fip_name> <images to add> [--dump to show result]
./tools/fip_create/fip_create fip.bin --dump \
   --bl2 build/<platform>/debug/bl2.bin --bl31 build/<platform>/debug/bl31.bin

 Firmware Image Package ToC:
---------------------------
- Trusted Boot Firmware BL2: offset=0x88, size=0x81E8
  file: 'build/<platform>/debug/bl2.bin'
- EL3 Runtime Firmware BL3-1: offset=0x8270, size=0xC218
  file: 'build/<platform>/debug/bl31.bin'
---------------------------
Creating "fip.bin"

View the contents of an existing Firmware package:

./tools/fip_create/fip_create fip.bin --dump

 Firmware Image Package ToC:
---------------------------
- Trusted Boot Firmware BL2: offset=0x88, size=0x81E8
- EL3 Runtime Firmware BL3-1: offset=0x8270, size=0xC218
---------------------------

Existing package entries can be individially updated:

# Change the BL2 from Debug to Release version
./tools/fip_create/fip_create fip.bin --dump \
  --bl2 build/<platform>/release/bl2.bin

Firmware Image Package ToC:
---------------------------
- Trusted Boot Firmware BL2: offset=0x88, size=0x7240
  file: 'build/<platform>/release/bl2.bin'
- EL3 Runtime Firmware BL3-1: offset=0x72C8, size=0xC218
---------------------------
Updating "fip.bin"

Debugging options

To compile a debug version and make the build more verbose use

CROSS_COMPILE=<path-to-aarch64-gcc>/bin/aarch64-none-elf- \
BL33=<path-to>/<bl33_image>                               \
make PLAT=<platform> DEBUG=1 V=1 all fip

AArch64 GCC uses DWARF version 4 debugging symbols by default. Some tools (for example DS-5) 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 or 3. Setting the version to 2 is recommended for DS-5 versions older than 5.16.

When debugging logic problems it might also be useful to disable all compiler optimizations by using -O0.

NOTE: 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 Firmware Design).

Extra debug options can be passed to the build system by setting CFLAGS:

CFLAGS='-O0 -gdwarf-2'                                    \
CROSS_COMPILE=<path-to-aarch64-gcc>/bin/aarch64-none-elf- \
BL33=<path-to>/<bl33_image>                               \
make PLAT=<platform> DEBUG=1 V=1 all fip

Building the Test Secure Payload

The TSP is coupled with a companion runtime service in the BL3-1 firmware, called the TSPD. Therefore, if you intend to use the TSP, the BL3-1 image must be recompiled as well. For more information on SPs and SPDs, see the "Secure-EL1 Payloads and Dispatchers" section in the Firmware Design.

First clean the Trusted Firmware build directory to get rid of any previous BL3-1 binary. Then to build the TSP image and include it into the FIP use:

CROSS_COMPILE=<path-to-aarch64-gcc>/bin/aarch64-none-elf- \
BL33=<path-to>/<bl33_image>                               \
make PLAT=<platform> SPD=tspd all fip

An additional boot loader binary file is created in the build directory:

  • build/<platform>/<build-type>/bl32.bin

The FIP will now contain the additional BL3-2 image. Here is an example output from an FVP build in release mode including BL3-2 and using FVP_AARCH64_EFI.fd as BL3-3 image:

Firmware Image Package ToC:
---------------------------
- Trusted Boot Firmware BL2: offset=0xD8, size=0x6000
  file: './build/fvp/release/bl2.bin'
- EL3 Runtime Firmware BL3-1: offset=0x60D8, size=0x9000
  file: './build/fvp/release/bl31.bin'
- Secure Payload BL3-2 (Trusted OS): offset=0xF0D8, size=0x3000
  file: './build/fvp/release/bl32.bin'
- Non-Trusted Firmware BL3-3: offset=0x120D8, size=0x280000
  file: '../FVP_AARCH64_EFI.fd'
---------------------------
Creating "build/fvp/release/fip.bin"

Building the Certificate Generation Tool

The cert_create tool can be built separately through the following commands:

$ cd tools/cert_create
$ make PLAT=<platform> [DEBUG=1] [V=1]

DEBUG=1 builds the tool in debug mode. V=1 makes the build process more verbose. The following command should be used to obtain help about the tool:

$ ./cert_create -h

The cert_create tool is automatically built with the fip target when GENERATE_COT=1.

Building a FIP image with support for Trusted Board Boot

The Trusted Board Boot feature is described in Trusted Board Boot. The following steps should be followed to build a FIP image with support for this feature.

  1. Fulfill the dependencies of the mbedtls cryptographic and image parser modules by checking out the tag mbedtls-1.3.11 from the mbedTLS Repository.

    The drivers/auth/mbedtls/mbedtls_*.mk files contain the list of mbedTLS source files the modules depend upon. include/drivers/auth/mbedtls/mbedtls_config.h contains the configuration options required to build the mbedTLS sources.

    Note that the mbedTLS library is licensed under the GNU GPL version 2 or later license. Using mbedTLS source code will affect the licensing of Trusted Firmware binaries that are built using this library.

  2. Ensure that the following command line variables are set while invoking make to build Trusted Firmware:

    • MBEDTLS_DIR=<path of the directory containing mbedTLS sources>
    • TRUSTED_BOARD_BOOT=1
    • GENERATE_COT=1

    In the case of ARM platforms, the location of the ROTPK hash must also be specified at build time. Two locations are currently supported (see ARM_ROTPK_LOCATION build option):

    • ARM_ROTPK_LOCATION=regs: the ROTPK hash is obtained from the Trusted root-key storage registers present in the platform. On Juno, this registers are read-only. On FVP Base and Cortex models, the registers are read-only, but the value can be specified using the command line option bp.trusted_key_storage.public_key when launching the model. On both Juno and FVP models, the default value corresponds to an ECDSA-SECP256R1 public key hash, whose private part is not currently available.

    • ARM_ROTPK_LOCATION=devel_rsa: use the ROTPK hash that is hardcoded in the ARM platform port. The private/public RSA key pair may be found in plat/arm/board/common/rotpk.

    Example of command line using RSA development keys:

    CROSS_COMPILE=<path-to-aarch64-gcc>/bin/aarch64-none-elf-       \
    BL33=<path-to>/<bl33_image>                                     \
    MBEDTLS_DIR=<path of the directory containing mbedTLS sources>  \
    make PLAT=<platform> TRUSTED_BOARD_BOOT=1 GENERATE_COT=1        \
    ARM_ROTPK_LOCATION=devel_rsa                                    \
    ROT_KEY=plat/arm/board/common/rotpk/arm_rotprivk_rsa.pem        \
    all fip
    

    The result of this build will be the bl1.bin and the fip.bin binaries, with the difference that the FIP will include the certificates corresponding to the Chain of Trust described in the TBBR-client document. These certificates can also be found in the output build directory.

Checking source code style

When making changes to the source for submission to the project, the source must be in compliance with the Linux style guide, and to assist with this check the project Makefile contains two targets, which both utilise the checkpatch.pl script that ships with the Linux source tree.

To check the entire source tree, you must first download a copy of checkpatch.pl (or the full Linux source), set the CHECKPATCH environment variable to point to the script and build the target checkcodebase:

make CHECKPATCH=<path-to-linux>/linux/scripts/checkpatch.pl checkcodebase

To just check the style on the files that differ between your local branch and the remote master, use:

make CHECKPATCH=<path-to-linux>/linux/scripts/checkpatch.pl checkpatch

If you wish to check your patch against something other than the remote master, set the BASE_COMMIT variable to your desired branch. By default, BASE_COMMIT is set to origin/master.

  1. Obtaining the normal world software

Obtaining EDK2

Potentially any kind of non-trusted firmware may be used with the ARM Trusted Firmware but the software has only been tested with the EFI Development Kit 2 (EDK2) open source implementation of the UEFI specification.

To build the software to be compatible with the Foundation and Base FVPs, or the Juno platform, follow these steps:

  1. Clone the EDK2 source code from GitHub:

    git clone -n https://github.com/tianocore/edk2.git
    

    Not all required features are available in the EDK2 mainline yet. These can be obtained from the ARM-software EDK2 repository instead:

    cd edk2
    git remote add -f --tags arm-software https://github.com/ARM-software/edk2.git
    git checkout --detach v3.0
    
  2. Copy build config templates to local workspace

    # in edk2/
    . edksetup.sh
    
  3. Build the EDK2 host tools

    make -C BaseTools clean
    make -C BaseTools
    
  4. Build the EDK2 software

    1. Build for FVP

      GCC49_AARCH64_PREFIX=<absolute-path-to-aarch64-gcc>/bin/aarch64-none-elf- \
      make -f ArmPlatformPkg/Scripts/Makefile EDK2_ARCH=AARCH64 \
      EDK2_DSC=ArmPlatformPkg/ArmVExpressPkg/ArmVExpress-FVP-AArch64.dsc \
      EDK2_TOOLCHAIN=GCC49 EDK2_BUILD=RELEASE \
      EDK2_MACROS="-n 6 -D ARM_FOUNDATION_FVP=1"
      

      The EDK2 binary for use with the ARM Trusted Firmware can then be found here:

       Build/ArmVExpress-FVP-AArch64/RELEASE_GCC49/FV/FVP_AARCH64_EFI.fd
      
    2. Build for Juno

      GCC49_AARCH64_PREFIX=<absolute-path-to-aarch64-gcc>/bin/aarch64-none-elf- \
      make -f ArmPlatformPkg/ArmJunoPkg/Makefile EDK2_ARCH=AARCH64 \
      EDK2_TOOLCHAIN=GCC49 EDK2_BUILD=RELEASE
      

      The EDK2 binary for use with the ARM Trusted Firmware can then be found here:

      Build/ArmJuno/RELEASE_GCC49/FV/BL33_AP_UEFI.fd
      

    The EDK2 binary should be specified as BL33 in in the make command line when building the Trusted Firmware. See the "Building the Trusted Firmware" section above.

  5. (Optional) To build EDK2 in debug mode, remove EDK2_BUILD=RELEASE from the command line.

  6. (Optional) To boot Linux using a VirtioBlock file-system, the command line passed from EDK2 to the Linux kernel must be modified as described in the "Obtaining a root file-system" section below.

  7. (Optional) If legacy GICv2 locations are used, the EDK2 platform description must be updated. This is required as EDK2 does not support probing for the GIC location. To do this, first clean the EDK2 build directory.

    make -f ArmPlatformPkg/Scripts/Makefile EDK2_ARCH=AARCH64          \
    EDK2_DSC=ArmPlatformPkg/ArmVExpressPkg/ArmVExpress-FVP-AArch64.dsc \
    EDK2_TOOLCHAIN=ARMGCC clean
    

    Then rebuild EDK2 as described in step 3, using the following flag:

    -D ARM_FVP_LEGACY_GICV2_LOCATION=1
    

    Finally rebuild the Trusted Firmware to generate a new FIP using the instructions in the "Building the Trusted Firmware" section.

Obtaining a Linux kernel

Preparing a Linux kernel for use on the FVPs can be done as follows (GICv2 support only):

  1. Clone Linux:

    git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
    

    Not all required features are available in the kernel mainline yet. These can be obtained from the ARM-software Linux repository instead:

    cd linux
    git remote add -f --tags arm-software https://github.com/ARM-software/linux.git
    git checkout --detach 1.6-Juno
    
  2. Build with the Linaro GCC tools.

    # in linux/
    make mrproper
    make ARCH=arm64 defconfig
    
    CROSS_COMPILE=<path-to-aarch64-gcc>/bin/aarch64-none-elf- \
    make -j6 ARCH=arm64
    

The compiled Linux image will now be found at arch/arm64/boot/Image.

  1. Preparing the images to run on FVP

Obtaining the Flattened Device Trees

Depending on the FVP configuration and Linux configuration used, different FDT files are required. FDTs for the Foundation and Base FVPs can be found in the Trusted Firmware source directory under fdts/. The Foundation FVP has a subset of the Base FVP components. For example, the Foundation FVP lacks CLCD and MMC support, and has only one CPU cluster.

  • fvp-base-gicv2-psci.dtb

    (Default) For use with both AEMv8 and Cortex-A57-A53 Base FVPs with Base memory map configuration.

  • fvp-base-gicv2legacy-psci.dtb

    For use with AEMv8 Base FVP with legacy VE GIC memory map configuration.

  • fvp-base-gicv3-psci.dtb

    For use with both AEMv8 and Cortex-A57-A53 Base FVPs with Base memory map configuration and Linux GICv3 support.

  • fvp-foundation-gicv2-psci.dtb

    (Default) For use with Foundation FVP with Base memory map configuration.

  • fvp-foundation-gicv2legacy-psci.dtb

    For use with Foundation FVP with legacy VE GIC memory map configuration.

  • fvp-foundation-gicv3-psci.dtb

    For use with Foundation FVP with Base memory map configuration and Linux GICv3 support.

Copy the chosen FDT blob as fdt.dtb to the directory from which the FVP is launched. Alternatively a symbolic link may be used.

Preparing the kernel image

Copy the kernel image file arch/arm64/boot/Image to the directory from which the FVP is launched. Alternatively a symbolic link may be used.

Obtaining a root file-system

To prepare a Linaro LAMP based Open Embedded file-system, the following instructions can be used as a guide. The file-system can be provided to Linux via VirtioBlock or as a RAM-disk. Both methods are described below.

Prepare VirtioBlock

To prepare a VirtioBlock file-system, do the following:

  1. Download and unpack the disk image.

    NOTE: The unpacked disk image grows to 3 GiB in size.

    wget http://releases.linaro.org/15.03/members/arm/openembedded/aarch64/vexpress64-openembedded_lamp-armv8-gcc-4.9_20150324-715.img.gz
    gunzip vexpress64-openembedded_lamp-armv8-gcc-4.9_20150324-715.img.gz
    
  2. Make sure the Linux kernel has Virtio support enabled using make ARCH=arm64 menuconfig.

    Device Drivers  ---> Virtio drivers  ---> <*> Platform bus driver for memory mapped virtio devices
    Device Drivers  ---> [*] Block devices  --->  <*> Virtio block driver
    File systems    ---> <*> The Extended 4 (ext4) filesystem
    

    If some of these configurations are missing, enable them, save the kernel configuration, then rebuild the kernel image using the instructions provided in the section "Obtaining a Linux kernel".

  3. Change the Kernel command line to include root=/dev/vda2. This can either be done in the EDK2 boot menu or in the platform file. Editing the platform file and rebuilding EDK2 will make the change persist. To do this:

    1. In EDK2, edit the following file:

      ArmPlatformPkg/ArmVExpressPkg/ArmVExpress-FVP-AArch64.dsc
      
    2. Add root=/dev/vda2 to:

      gArmPlatformTokenSpaceGuid.PcdDefaultBootArgument|"<Other default options>"
      
    3. Remove the entry:

      gArmPlatformTokenSpaceGuid.PcdDefaultBootInitrdPath|""
      
    4. Rebuild EDK2 (see "Obtaining UEFI" section above).

  4. The file-system image file should be provided to the model environment by passing it the correct command line option. In the FVPs the following option should be provided in addition to the ones described in the "Running the software on FVP" section below.

    NOTE: A symbolic link to this file cannot be used with the FVP; the path to the real file must be provided.

    On the Base FVPs:

    -C bp.virtioblockdevice.image_path="<path-to>/<file-system-image>"
    

    On the Foundation FVP:

    --block-device="<path-to>/<file-system-image>"
    
  5. Ensure that the FVP doesn't output any error messages. If the following error message is displayed:

    ERROR: BlockDevice: Failed to open "<path-to>/<file-system-image>"!
    

    then make sure the path to the file-system image in the model parameter is correct and that read permission is correctly set on the file-system image file.

Prepare RAM-disk

To prepare a RAM-disk root file-system, do the following:

  1. Download the file-system image:

    wget http://releases.linaro.org/15.03/members/arm/openembedded/aarch64/linaro-image-lamp-genericarmv8-20150323-747.rootfs.tar.gz
    
  2. Modify the Linaro image:

    # Prepare for use as RAM-disk. Normally use MMC, NFS or VirtioBlock.
    # Be careful, otherwise you could damage your host file-system.
    mkdir tmp; cd tmp
    sudo sh -c "zcat ../linaro-image-lamp-genericarmv8-20150323-747.rootfs.tar.gz | cpio -id"
    sudo ln -s sbin/init .
    sudo sh -c "echo 'devtmpfs /dev devtmpfs mode=0755,nosuid 0 0' >> etc/fstab"
    sudo sh -c "find . | cpio --quiet -H newc -o | gzip -3 -n > ../filesystem.cpio.gz"
    cd ..
    
  3. Copy the resultant filesystem.cpio.gz to the directory where the FVP is launched from. Alternatively a symbolic link may be used.

  4. Running the software on FVP


This version of the ARM Trusted Firmware has been tested on the following ARM FVPs (64-bit versions only).

  • Foundation_Platform (Version 9.1, Build 9.1.33)
  • FVP_Base_AEMv8A-AEMv8A (Version 6.2, Build 0.8.6202)
  • FVP_Base_Cortex-A57x4-A53x4 (Version 6.2, Build 0.8.6202)
  • FVP_Base_Cortex-A57x1-A53x1 (Version 6.2, Build 0.8.6202)
  • FVP_Base_Cortex-A57x2-A53x4 (Version 6.2, Build 0.8.6202)

NOTE: The build numbers quoted above are those reported by launching the FVP with the --version parameter.

NOTE: The software will not work on Version 1.0 of the Foundation FVP. The commands below would report an unhandled argument error in this case.

NOTE: The Foundation FVP does not provide a debugger interface.

Please refer to the FVP documentation for a detailed description of the model parameter options. A brief description of the important ones that affect the ARM Trusted Firmware and normal world software behavior is provided below.

The Foundation FVP is a cut down version of the AArch64 Base FVP. It can be downloaded for free from ARM's website.

Running on the Foundation FVP with reset to BL1 entrypoint

The following Foundation_Platform parameters should be used to boot Linux with 4 CPUs using the ARM Trusted Firmware.

NOTE: Using the --block-device parameter is not necessary if a Linux RAM-disk file-system is used (see the "Obtaining a File-system" section above).

NOTE: The --data="<path to FIP binary>"@0x8000000 parameter is used to load a Firmware Image Package at the start of NOR FLASH0 (see the "Building the Trusted Firmware" section above).

<path-to>/Foundation_Platform             \
--cores=4                                 \
--secure-memory                           \
--visualization                           \
--gicv3                                   \
--data="<path-to>/<bl1-binary>"@0x0       \
--data="<path-to>/<FIP-binary>"@0x8000000 \
--block-device="<path-to>/<file-system-image>"

The default use-case for the Foundation FVP is to enable the GICv3 device in the model but use the GICv2 FDT, in order for Linux to drive the GIC in GICv2 emulation mode.

The memory mapped addresses 0x0 and 0x8000000 correspond to the start of trusted ROM and NOR FLASH0 respectively.

Notes regarding Base FVP configuration options

Please refer to these notes in the subsequent "Running on the Base FVP" sections.

  1. The -C bp.flashloader0.fname parameter is used to load a Firmware Image Package at the start of NOR FLASH0 (see the "Building the Trusted Firmware" section above).

  2. Using cache_state_modelled=1 makes booting very slow. The software will still work (and run much faster) without this option but this will hide any cache maintenance defects in the software.

  3. Using the -C bp.virtioblockdevice.image_path parameter is not necessary if a Linux RAM-disk file-system is used (see the "Obtaining a root file-system" section above).

  4. Setting the -C bp.secure_memory parameter to 1 is only supported on Base FVP versions 5.4 and newer. Setting this parameter to 0 is also supported. The -C bp.tzc_400.diagnostics=1 parameter is optional. It instructs the FVP to provide some helpful information if a secure memory violation occurs.

  5. This and the following notes only apply when the firmware is built with the RESET_TO_BL31 option.

    The --data="<path-to><bl31|bl32|bl33-binary>"@<base-address-of-binary> parameter is used to load bootloader images into Base FVP memory (see the "Building the Trusted Firmware" section above). The base addresses used should match the image base addresses in platform_def.h used while linking the images. The BL3-2 image is only needed if BL3-1 has been built to expect a Secure-EL1 Payload.

  6. The -C cluster<X>.cpu<Y>.RVBAR=@<base-address-of-bl31> parameter, where X and Y are the cluster and CPU numbers respectively, is used to set the reset vector for each core.

  7. Changing the default value of FVP_SHARED_DATA_LOCATION will also require changing the value of --data="<path-to><bl31-binary>"@<base-address-of-bl31> and -C cluster<X>.cpu<X>.RVBAR=@<base-address-of-bl31>, to the new value of BL31_BASE in platform_def.h.

  8. Changing the default value of FVP_TSP_RAM_LOCATION will also require changing the value of --data="<path-to><bl32-binary>"@<base-address-of-bl32> to the new value of BL32_BASE in platform_def.h.

Running on the AEMv8 Base FVP with reset to BL1 entrypoint

Please read "Notes regarding Base FVP configuration options" section above for information about some of the options to run the software.

The following FVP_Base_AEMv8A-AEMv8A parameters should be used to boot Linux with 8 CPUs using the ARM Trusted Firmware.

<path-to>/FVP_Base_AEMv8A-AEMv8A                       \
-C pctl.startup=0.0.0.0                                \
-C bp.secure_memory=1                                  \
-C bp.tzc_400.diagnostics=1                            \
-C cluster0.NUM_CORES=4                                \
-C cluster1.NUM_CORES=4                                \
-C cache_state_modelled=1                              \
-C bp.secureflashloader.fname="<path-to>/<bl1-binary>" \
-C bp.flashloader0.fname="<path-to>/<FIP-binary>"      \
-C bp.virtioblockdevice.image_path="<path-to>/<file-system-image>"

Running on the Cortex-A57-A53 Base FVP with reset to BL1 entrypoint

Please read "Notes regarding Base FVP configuration options" section above for information about some of the options to run the software.

The following FVP_Base_Cortex-A57x4-A53x4 model parameters should be used to boot Linux with 8 CPUs using the ARM Trusted Firmware.

<path-to>/FVP_Base_Cortex-A57x4-A53x4                  \
-C pctl.startup=0.0.0.0                                \
-C bp.secure_memory=1                                  \
-C bp.tzc_400.diagnostics=1                            \
-C cache_state_modelled=1                              \
-C bp.secureflashloader.fname="<path-to>/<bl1-binary>" \
-C bp.flashloader0.fname="<path-to>/<FIP-binary>"      \
-C bp.virtioblockdevice.image_path="<path-to>/<file-system-image>"

Running on the AEMv8 Base FVP with reset to BL3-1 entrypoint

Please read "Notes regarding Base FVP configuration options" section above for information about some of the options to run the software.

The following FVP_Base_AEMv8A-AEMv8A parameters should be used to boot Linux with 8 CPUs using the ARM Trusted Firmware.

<path-to>/FVP_Base_AEMv8A-AEMv8A                             \
-C pctl.startup=0.0.0.0                                      \
-C bp.secure_memory=1                                        \
-C bp.tzc_400.diagnostics=1                                  \
-C cluster0.NUM_CORES=4                                      \
-C cluster1.NUM_CORES=4                                      \
-C cache_state_modelled=1                                    \
-C cluster0.cpu0.RVBAR=0x04023000                            \
-C cluster0.cpu1.RVBAR=0x04023000                            \
-C cluster0.cpu2.RVBAR=0x04023000                            \
-C cluster0.cpu3.RVBAR=0x04023000                            \
-C cluster1.cpu0.RVBAR=0x04023000                            \
-C cluster1.cpu1.RVBAR=0x04023000                            \
-C cluster1.cpu2.RVBAR=0x04023000                            \
-C cluster1.cpu3.RVBAR=0x04023000                            \
--data cluster0.cpu0="<path-to>/<bl31-binary>"@0x04023000    \
--data cluster0.cpu0="<path-to>/<bl32-binary>"@0x04001000    \
--data cluster0.cpu0="<path-to>/<bl33-binary>"@0x88000000    \
-C bp.virtioblockdevice.image_path="<path-to>/<file-system-image>"

Running on the Cortex-A57-A53 Base FVP with reset to BL3-1 entrypoint

Please read "Notes regarding Base FVP configuration options" section above for information about some of the options to run the software.

The following FVP_Base_Cortex-A57x4-A53x4 model parameters should be used to boot Linux with 8 CPUs using the ARM Trusted Firmware.

<path-to>/FVP_Base_Cortex-A57x4-A53x4                        \
-C pctl.startup=0.0.0.0                                      \
-C bp.secure_memory=1                                        \
-C bp.tzc_400.diagnostics=1                                  \
-C cache_state_modelled=1                                    \
-C cluster0.cpu0.RVBARADDR=0x04023000                        \
-C cluster0.cpu1.RVBARADDR=0x04023000                        \
-C cluster0.cpu2.RVBARADDR=0x04023000                        \
-C cluster0.cpu3.RVBARADDR=0x04023000                        \
-C cluster1.cpu0.RVBARADDR=0x04023000                        \
-C cluster1.cpu1.RVBARADDR=0x04023000                        \
-C cluster1.cpu2.RVBARADDR=0x04023000                        \
-C cluster1.cpu3.RVBARADDR=0x04023000                        \
--data cluster0.cpu0="<path-to>/<bl31-binary>"@0x04023000    \
--data cluster0.cpu0="<path-to>/<bl32-binary>"@0x04001000    \
--data cluster0.cpu0="<path-to>/<bl33-binary>"@0x88000000    \
-C bp.virtioblockdevice.image_path="<path-to>/<file-system-image>"

Configuring the GICv2 memory map

The Base FVP models support GICv2 with the default model parameters at the following addresses. The Foundation FVP also supports these addresses when configured for GICv3 in GICv2 emulation mode.

GICv2 Distributor Interface     0x2f000000
GICv2 CPU Interface             0x2c000000
GICv2 Virtual CPU Interface     0x2c010000
GICv2 Hypervisor Interface      0x2c02f000

The AEMv8 Base FVP can be configured to support GICv2 at addresses corresponding to the legacy (Versatile Express) memory map as follows. These are the default addresses when using the Foundation FVP in GICv2 mode.

GICv2 Distributor Interface     0x2c001000
GICv2 CPU Interface             0x2c002000
GICv2 Virtual CPU Interface     0x2c004000
GICv2 Hypervisor Interface      0x2c006000

The choice of memory map is reflected in the build variant field (bits[15:12]) in the SYS_ID register (Offset 0x0) in the Versatile Express System registers memory map (0x1c010000).

  • SYS_ID.Build[15:12]

    0x1 corresponds to the presence of the Base GIC memory map. This is the default value on the Base FVPs.

  • SYS_ID.Build[15:12]

    0x0 corresponds to the presence of the Legacy VE GIC memory map. This is the default value on the Foundation FVP.

This register can be configured as described in the following sections.

NOTE: If the legacy VE GIC memory map is used, then the corresponding FDT and BL3-3 images should be used.

Configuring AEMv8 Foundation FVP GIC for legacy VE memory map

The following parameters configure the Foundation FVP to use GICv2 with the legacy VE memory map:

<path-to>/Foundation_Platform             \
--cores=4                                 \
--secure-memory                           \
--visualization                           \
--no-gicv3                                \
--data="<path-to>/<bl1-binary>"@0x0       \
--data="<path-to>/<FIP-binary>"@0x8000000 \
--block-device="<path-to>/<file-system-image>"

Explicit configuration of the SYS_ID register is not required.

Configuring AEMv8 Base FVP GIC for legacy VE memory map

The following parameters configure the AEMv8 Base FVP to use GICv2 with the legacy VE memory map. They must added to the parameters described in the "Running on the AEMv8 Base FVP" section above:

-C cluster0.gic.GICD-offset=0x1000                  \
-C cluster0.gic.GICC-offset=0x2000                  \
-C cluster0.gic.GICH-offset=0x4000                  \
-C cluster0.gic.GICH-other-CPU-offset=0x5000        \
-C cluster0.gic.GICV-offset=0x6000                  \
-C cluster0.gic.PERIPH-size=0x8000                  \
-C cluster1.gic.GICD-offset=0x1000                  \
-C cluster1.gic.GICC-offset=0x2000                  \
-C cluster1.gic.GICH-offset=0x4000                  \
-C cluster1.gic.GICH-other-CPU-offset=0x5000        \
-C cluster1.gic.GICV-offset=0x6000                  \
-C cluster1.gic.PERIPH-size=0x8000                  \
-C gic_distributor.GICD-alias=0x2c001000            \
-C gicv3.gicv2-only=1                               \
-C bp.variant=0x0

The bp.variant parameter corresponds to the build variant field of the SYS_ID register. Setting this to 0x0 allows the ARM Trusted Firmware to detect the legacy VE memory map while configuring the GIC.

  1. Running the software on Juno

Preparing Trusted Firmware images

To execute the versions of software components on Juno referred to in this document, the latest Juno Board Recovery Image must be installed. If you have an earlier version installed or are unsure which version is installed, follow the recovery image update instructions in the Juno Software Guide on the ARM Connected Community website.

Note that you must use the board recovery image provided in the Juno R1 Initial Alpha release, even for Juno R0. This is because the Trusted Firmware now supports the new SCPI v1.0 final protocol exclusively, which is not compatible with the SCP firmware provided in the latest Juno R0 release. Although the Juno R1 Initial Alpha release is generally not recommended for use with Juno R0 boards, it is suitable for Trusted Firmware development.

The Juno platform requires a BL0 and a BL3-0 image to boot up. The BL0 image contains the ROM firmware that runs on the SCP (System Control Processor), whereas the BL3-0 image contains the SCP Runtime firmware. Both images are embedded within the Juno Board Recovery Image but they can also be downloaded directly: Juno SCP ROM Firmware and Juno SCP Runtime Firmware.

Rebuild the Trusted Firmware specifying the BL3-0 image. Refer to the section "Building the Trusted Firmware". Alternatively, the FIP image can be updated manually with the BL3-0 image:

fip_create --dump --bl30 <path-to>/<bl30-binary> <path-to>/<FIP-binary>

Obtaining the Flattened Device Tree

Juno's device tree blob is built along with the kernel. It is located in:

<path-to-linux>/arch/arm64/boot/dts/arm/juno.dtb

Other Juno software information

Please refer to the Juno Software Guide to:

  • Deploy a root filesystem
  • Install and run the Juno binaries on the board
  • Obtain any other Juno software information

Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved.