Introduction

This is a build package to help ease build and deploy of various K3 Boards. By default, as many upstream components as possible are used. A different repository location for either U-Boot, Arm Trusted Firmware, or OP-TEE can be specified if desired.

Upstream Status

• U-boot: Upstream
• Trusted-Firmware-A: Upstream (used to be called Arm-Trusted-Firmware)
• OPTEE OS: Upstream
• ti-linux-firmware: TI, but hopefully we should upstream the firmware pieces as well.

System pre-requisites:

The following lists the pre-requisites for building the bootloader components

• This assumes a x86_64 Linux system for build. If not, adjust appropriately.

Compiler

Download the following:

• AArch32 GNU/Linux target with hard float (arm-none-linux-gnueabihf)
• AArch64 GNU/Linux target (aarch64-none-linux-gnu)

Ubuntu

Ubuntu provides ARM cross compiler packages. To use, install with:

apt install gcc-aarch64-linux-gnu gcc-arm-none-eabi

and set your cross compiler env variables:

export CROSS_COMPILE_64=aarch64-linux-gnu-

export CROSS_COMPILE_32=arm-none-eabi-

Directly from arm.com

https://developer.arm.com/downloads/-/arm-gnu-toolchain-downloads

Also see: https://www.linaro.org/downloads/#gnu_and_llvm You could optionally use https://snapshots.linaro.org/gnu-toolchain/, but CROSS_COMPILE_64 and CROSS_COMPILE_32 variables need to be adjusted accordingly.

Host package dependencies

• OPTEE: https://optee.readthedocs.io/en/latest/building/prerequisites.html
• U-Boot: https://github.com/u-boot/u-boot/blob/master/tools/docker/Dockerfile#L35 https://github.com/u-boot/u-boot/blob/master/tools/binman/binman.rst
• TFA: https://github.com/ARM-software/arm-trusted-firmware/blob/master/docs/requirements.txt https://github.com/ARM-software/arm-trusted-firmware/blob/master/docs/getting_started/prerequisites.rst

If getting it all correctly seems painful, unfortunately, it is.. (also see TODO)

Build steps

Cloning the environment

If you want the latest:

git clone https://github.com/nmenon/k3-upstream-boot-build.git

OR a specific branch:

git clone -b some-branch https://github.com/nmenon/k3-upstream-boot-build.git

Update the gitsubmodules

To help ease syncing there is a makefile rule to make this happen:

cd k3-upstream-boot-build
make gitsync

Checking what board to build

Look for the various board and bootmodes supported

ls configs

Convention followed is: <soc>_<board>_<security_type>_<bootmode>_defconfig where

• SoC is one of various SoC types - j721e, am64 etc.
• Board is one of the supported boards
• Security type is one of gp (non-secure), hsfs (auth for ti key), hsse (customer/device-specific key fused)
• Bootmode is various supported bootmodes for the board

Building the platform

make mysoc_myboard_gp_mmc_defconfig
make

Building an SD card image

The K3 ROM when booting from an SD card in filesystem boot mode can be very particular about the format it expects. To ease generation of a working SD card this tool can provide an simple SD card image.

To build an SD card image your host system will need xz-utils, mtools, parted, and dosfstools installed:

sudo apt install mtools parted dosfstools xz-utils

After selecting your platform defconfig as above, use the sdcard target:

make sdcard

The resulting SD card will be located at deploy/sdcard.img and can be written directly to an SD card. For instance using dd:

dd if=deploy/sdcard.img of=/dev/sd<card>

Note: This SD card does not contain an OS. U-Boot will attempt to load the OS from media as specified by U-Boot stdboot. One can add a uEnv.txt file to the SD card boot partition to further direct the boot process.

To override a repository location

To use a different repository location for U-Boot, Arm Trusted Firmware, OP-TEE, or ti-linux-firmware define the appropriate variables below

Repo	Location variable
arm trusted firmware	TFA_DIR
optee OS	OPTEE_DIR
U-Boot	UBOOT_DIR
ti-linux-firmware	FW_DIR

For example, to use the TI SDK repo for u-boot, use:

make mysoc_myboard_gp_mmc_defconfig
make UBOOT_DIR=<path to ti-u-boot>

Output files

• Intermediate build artifacts will be located in build/
• Boot files will be located in deploy/ (copy these to your SD card)

Making all platforms

The MAKEALL script is a helper to help build all the platforms in one single shot

./MAKEALL

Or for a specific defconfig:

./MAKEALL am64x_evm_gp_all_defconfig

Internal details of config file

Various variables

Variable name	Description
SOC_NAME	SoC name of the board
BOARD_NAME	Name of the board
SECURITY_TYPE	What kind of security type is the chip? (gp, hs-fs, hs)
TFA_BOARD	What is the board name used in Trusted-firmware cortex-a?
TFA_EXTRA_ARGS	Any extra TFA arguments to pass to build (example: K3_PM_SYSTEM_SUSPEND=1)
OPTEE_PLATFORM	Name of the optee platform
OPTEE_EXTRA_ARGS	Any extra OPTEE arguments to pass to build (example:CFG_CONSOLE_UART=0x8)
UBOOT_ARMV7_DEFCONFIG	Name of the u-boot defconfig for the R5 SPL
UBOOT_ARMV8_DEFCONFIG	Name of the u-boot defconfig for the armv8 processor

FUTURE TODOs

• Create a docker container for building the packages
• Add more platform configurations