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.

0. 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
   

1. Then, configure the board specific environment variables

   $ export UBOOT_CFG_CORTEXR=am62px_evm_r5_defconfig
   $ export UBOOT_CFG_CORTEXA="am62px_evm_a53_defconfig am62x_android_a53.config"
   $ #OR, for use with experimental U-Boot 2024.04
   $ #export UBOOT_CFG_CORTEXA="am62px_evm_a53_defconfig am62x_a53_android.config"
   

2. 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"
   

3. Build OPTEE-OS:

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

4. Build tiboot3.bin:

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

5. 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}
   

6. 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.

7. Rebuild Android by following Build Instructions.