3.2. Android Bootloaders

Getting toolchain for u-boot builds

Links to download toolchains for building u-boot are mentioned in the SDK download page.

Install OPTEE-OS build dependencies

Check OPTEE-OS docs to know list of dependencies needed to be installed : https://optee.readthedocs.io/en/latest/building/prerequisites.html

3.2.1. Downloading sources

$ mkdir ${YOUR_PATH}/ti-bootloader-aosp/ && cd $_
$ git clone -b 10.00.07 git://git.ti.com/atf/arm-trusted-firmware.git
$ git clone -b 10.00.07 git://git.ti.com/optee/ti-optee-os.git
$ git clone -b 09.02.00.010 git://git.ti.com/ti-u-boot/ti-u-boot.git
$ git clone -b 10.00.07 git://git.ti.com/processor-firmware/ti-linux-firmware.git

To test the experimental 2024.04 U-Boot release, clone U-Boot as following instead:

$ git clone -b 10.00.07 git://git.ti.com/ti-u-boot/ti-u-boot.git

3.2.2. Build Instructions

Building the bootloaders is similar to the upstream procedure. For detailed information, see k3 upstream documentation.

Start setting up the generic environment variables:

$ export CC32=arm-none-linux-gnueabihf-
$ export CC64=aarch64-none-linux-gnu-
$ export LNX_FW_PATH=${YOUR_PATH}/ti-bootloaders-aosp/ti-linux-firmware
$ export TFA_PATH=${YOUR_PATH}/ti-bootloader-aosp/arm-trusted-firmware
$ export OPTEE_PATH=${YOUR_PATH}/ti-bootloader-aosp/ti-optee-os
$ export UBOOT_PATH=${YOUR_PATH}/ti-bootloader-aosp/ti-u-boot

Then, configure the board specific environment variables

For AM62x SK EVM, use:

$ export UBOOT_CFG_CORTEXR=am62x_evm_r5_defconfig
$ export UBOOT_CFG_CORTEXA="am62x_evm_a53_defconfig am62x_android_a53.config"
$ #OR, for use with experimental U-Boot 2024.04
$ #export UBOOT_CFG_CORTEXA="am62x_evm_a53_defconfig am62x_a53_android.config"

For AM62x LP SK EVM, use:

$ export UBOOT_CFG_CORTEXR=am62x_lpsk_r5_defconfig
$ export UBOOT_CFG_CORTEXA="am62x_lpsk_a53_defconfig am62x_android_a53.config"
$ #OR, for use with experimental U-Boot 2024.04
$ #export UBOOT_CFG_CORTEXA="am62x_lpsk_a53_defconfig am62x_a53_android.config"

For Beagle Play, use:

$ export UBOOT_CFG_CORTEXR="am62x_evm_r5_defconfig am625_beagleplay_r5.config am625_beagleplay_android_r5.config"
$ export UBOOT_CFG_CORTEXA="am62x_evm_a53_defconfig am625_beagleplay_a53.config am62x_android_a53.config am625_beagleplay_android_a53.config"
$ #OR, for use with experimental U-Boot 2024.04
$ #export UBOOT_CFG_CORTEXR=am62x_beagleplay_r5_defconfig
$ #export UBOOT_CFG_CORTEXA="am62x_beagleplay_a53_defconfig am62x_a53_android.config"

Build ATF:

$ cd ${TFA_PATH}
$ make E=0 CROSS_COMPILE=$CC64 ARCH=aarch64 PLAT=k3 TARGET_BOARD=lite SPD=opteed CFLAGS+="-DK3_PM_SYSTEM_SUSPEND=1"

Build OPTEE-OS:

$ cd ${OPTEE_PATH}
$ make PLATFORM=k3 CFG_ARM64_core=y CROSS_COMPILE=$CC32 CROSS_COMPILE64=$CC64

Build tiboot3.bin:

$ cd ${UBOOT_PATH}
$ make ARCH=arm $UBOOT_CFG_CORTEXR
$ make ARCH=arm CROSS_COMPILE=$CC32 \
        BINMAN_INDIRS=${LNX_FW_PATH}

Build tispl.bin and u-boot.img:

$ cd ${UBOOT_PATH}
$ make ARCH=arm $UBOOT_CFG_CORTEXA
$ make ARCH=arm CROSS_COMPILE=$CC64 \
       BL31=${TFA_PATH}/build/k3/lite/release/bl31.bin \
       TEE=${OPTEE_PATH}/out/arm-plat-k3/core/tee-pager_v2.bin \
       BINMAN_INDIRS=${LNX_FW_PATH}

Copy the tiboot3.bin, tispl.bin and u-boot.img generated in steps 4 and 5 to $YOUR_PATH/ti-aosp-14/vendor/ti/am62x/bootloader. If not copied, the prebuilt bootloader binaries already present in vendor/ti/am62x/bootloader will get used by flashall.sh flashing script.

For picking the correct filenames, refer to the upstream documentation.
Rebuild Android by following Build Instructions.