TI Buildroot external tree

Buildroot is a tool/build framework that simplifies and automates the process of building complete Linux systems for embedded devices. It simplifies the process of building a cross-compiled toolchain, a root filesystem, a Linux kernel, and a bootloader. This repository is a Buildroot BR2_EXTERNAL tree dedicated to supporting TI's SITARA platforms.

The use of an external tree, such as buildroot-external-TI, allows for customization and extension of Buildroot without modifying the original Buildroot source. Upstream Buildroot also contains pre-defined configurations for SITARA platforms, but they use the upstream versions of U-Boot and Linux, while the configurations in this BR2_EXTERNAL tree uses the versions provided and supported by TI.

Available configurations

This BR2_EXTERNAL tree provides two Buildroot configurations:

1. ti_release_am62x_sk_defconfig for Linux
2. ti_release_am62x_sk_rt_defconfig for RT-Linux.

It supports following variants of AM62x EVM:

• SK-AM62
• SK-AM62B
• SK-AM62B-P1

It builds and packages following main components:

• ti-u-boot
• ti-linux-kernel
• optee
• TF-A
• ti-linux-firmware
• busybox

Pre-built SD card images

Pre-built buildroot SD card images are available at:

• PROCESSOR-SDK-AM62X

Building Buildroot from source

Pre-requisites

To use Buildroot, a Linux distribution must be installed on your workstation. Any reasonably recent Linux distribution (Ubuntu, Debian, Fedora, Redhat, OpenSuse, etc.) is suitable.

Additionally, a small set of packages must be installed Buildroot manual System requirements section.

For Debian/Ubuntu distributions, the necessary packages can be installed with the following command:

$ sudo apt install debianutils sed make binutils build-essential gcc g++ bash patch gzip bzip2 perl tar cpio unzip rsync file bc git findutils wget

Optional dependencies are available for enabling Buildroot features such as interface configuration, legal information and documentation. For detailed information refer corresponding manual section.

Steps to build the SD card image

• Clone the Buildroot repository to local machine.

$ git clone -b 2024.05.3 https://github.com/buildroot/buildroot

• Clone the BR2_EXTERNAL tree:

$ git clone -b 10.01.10.04 https://github.com/TexasInstruments/buildroot-external-TI.git

• The directories for buildroot and buildroot-external-ti are now located side-by-side.

Configure and build

• Go to the Buildroot directory:

$ cd buildroot/

• Configure Buildroot to use the external tree by setting the BR2_EXTERNAL environment variable. This tells Buildroot to include the configurations and packages from the external tree during the build process. To configure the system for build, choose any of the defconfigs provided in this BR2_EXTERNAL tree. For example:

# For AM62X Linux
$ make BR2_EXTERNAL=../buildroot-external-TI ti_release_am62x_sk_defconfig

# For AM62X RT-Linux
$ make BR2_EXTERNAL=../buildroot-external-TI ti_release_am62x_sk_rt_defconfig

• To further customize the Buildroot configuration, run make menuconfig. This step is optional but useful if you need to make specific adjustments.

• Build the SD card image for SDK 10.1

buildroot/ $ make TI_K3_BOOT_FIRMWARE_VERSION=10.01.10

• This process compiles the necessary components and creates the root filesystem, kernel, and bootloader. The build process can take some time, depending on your system's resources and the complexity of the configuration.

Flashing and booting the SD card image

• The Buildroot configurations generate a compressed ready-to-use SD card image, available as output/images/sdcard.img.

• Flash the image on a SD card:

buildroot/ $ sudo dd if=output/images/sdcard.img of=/dev/sdX

Replace /dev/sdX with the appropriate device identifier for your SD card.

• Tools like balena-ethcer can also be used to flash the SD card image.

• Insert the SD card in SD card slot and power on the board. The system will start, with the console on UART. You can log-in as root with no password.

Going further

• PROCESSOR-SDK-AM62X

References

• Buildroot
• Buildroot reference manual
• Buildroot system development training course

Technical support

Visit E2E for Technical support.