meta-bsp-imx8mm/Documentation/imx_boot_image_build.md

Building Boot Firmware for CompuLab's i.MX8M Mini products

Supported machines:

• IOT-GATE-iMX8

Define a MACHINE environment variable for the target product:

Machine	Command Line
ucm-imx8m-mini	export MACHINE=iot-gate-imx8

Define the following environment variables:

Description	Command Line
NXP firmware name	export NXP_FIRMWARE=firmware-imx-8.14.bin
CompuLab release	export CPL_RELEASE=${MACHINE}_r3.1
CompuLab branch name	export CPL_BRANCH=lf-5.10.72-2.2.0_${MACHINE}
ATF revision	export ATF=lf-5.10.72-2.2.0
OPTEE revision	export OPTEE=lf-5.10.72-2.2.0
U-Boot revision	export UBOOT=lf-5.10.72-2.2.0

Prerequisites

It is up to developer to setup arm64 build environment:

• Download the ARM tool chain
• Set environment variables:

export ARCH=arm64
export CROSS_COMPILE=/opt/gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu/bin/aarch64-none-linux-gnu-

• Create a folder to organize the files:

mkdir -p imx8mm/{sources,results}
export SRC_ROOT=$(readlink -f imx8mm/sources)
export RESULTS=$(readlink -f imx8mm/results)
cd ${SRC_ROOT}

• Download CompuLab BSP

git clone -b ${CPL_RELEASE} https://github.com/compulab-yokneam/meta-bsp-imx8mm.git
export LAYER_DIR=$(pwd)/meta-bsp-imx8mm

Build Procedure

Firmware iMX setup

• Download the firmware-imx file:

wget http://www.freescale.com/lgfiles/NMG/MAD/YOCTO/${NXP_FIRMWARE}
bash -x ${NXP_FIRMWARE} --auto-accept
cp -v $(find firmware* | awk '/train|hdmi_imx8|dp_imx8/' ORS=" ") ${RESULTS}

Arm Trusted Firmware (ATF) setup

• Download the ATF:

git clone https://source.codeaurora.org/external/imx/imx-atf.git
git -C imx-atf checkout ${ATF} -b ${CPL_BRANCH}

• Apply patches if applicable:

[[ -d ${LAYER_DIR}/recipes-bsp/imx-atf/compulab/imx8mm ]] && { \
git -C imx-atf am ${LAYER_DIR}/recipes-bsp/imx-atf/compulab/imx8mm/*.patch
}

• Make bl31.bin

Mode	Command
optee build	make -j 16 -C imx-atf PLAT=imx8mm BUILD_BASE=build PLAT=imx8mm IMX_BOOT_UART_BASE=0x30880000 BL32_BASE=0x56000000 BL32_SIZE=0x2000000 SPD=opteed bl31
non-optee build	make -j 16 -C imx-atf PLAT=imx8mm BUILD_BASE=build PLAT=imx8mm IMX_BOOT_UART_BASE=0x30880000 BL32_BASE=0x56000000 BL32_SIZE=0x2000000 bl31

• Ceate a symlink in the ${RESULTS} folder:

ln -s $(readlink -f imx-atf/build/imx8mm/release/bl31.bin) ${RESULTS}/

OP-TEE Setup

Skip this for a non-optee build

• Download the OP-TEE:

git clone https://source.codeaurora.org/external/imx/imx-optee-os
git -C imx-optee-os checkout ${OPTEE} -b ${CPL_BRANCH}

• Apply patches if applicable:

[[ -d ${LAYER_DIR}/recipes-security/optee-imx/compulab/imx8mm ]] && { \
git -C imx-optee-os am ${LAYER_DIR}/recipes-security/optee-imx/compulab/imx8mm/*.patch
}

• Set environment variables:

export ARCH=arm
export CROSS_COMPILE64=${CROSS_COMPILE}

• Make tee.bin

make -j 16 -C imx-optee-os PLATFORM=imx PLATFORM_FLAVOR=mx8mm_cl_iot_gate
ln -s $(readlink -f imx-optee-os/out/arm-plat-imx/core/tee-raw.bin) ${RESULTS}/tee.bin

U-Boot

• Download the U-Boot source and apply CompuLab BSP patches:

git clone https://source.codeaurora.org/external/imx/uboot-imx.git
git -C uboot-imx checkout ${UBOOT} -b ${CPL_BRANCH}
git -C uboot-imx am ${LAYER_DIR}/recipes-bsp/u-boot/compulab/imx8mm/*.patch

• Restore ARCH environment variables:

export ARCH=arm64

• Compile U-Boot flash.bin:

make -j 16 -C uboot-imx O=${RESULTS} -f defconfig.mk
make -j 16 -C uboot-imx O=${RESULTS}

Flashing

dd if=${RESULTS}/flash.bin of=/dev/ bs=1K seek=33 status=progress