Image description

This image adds cross-compilation support files (a suitable sysroot) on top of the regular linux chip-build image.

The build assumes a file named ubuntu-21.04-aarch64-sysroot.tar.xz exists in the current directory. This can generally be manually built using an existing Raspberry Pi device (or equivalent qemu) and a convenience copy was created in CIPD

Creating a Sysroot

Start with a fresh Raspberry PI image:

• Use the Raspberry pi imager from https://www.raspberrypi.org/software/
• Follow installation instructions from the CHIP BUILDING.md document. Generally this includes:
  • Use Ubuntu 21.04 server 64 bit server image
  • Install required compile dependencies via apt-get. You may skip installing git and python3 dependencies to save some image size

Generate a sysroot. You can do this locally (slow due to SD performance):

rsync -avL /lib ubuntu-21.04-aarch64-sysroot/
rsync -avL /usr/lib ubuntu-21.04-aarch64-sysroot/usr
rsync -avL /usr/include ubuntu-21.04-aarch64-sysroot/usr

or you can copy directly to your host machine via

export PI="ip-of-raspberry-pi"
ssh-copy-id ubuntu@$PI

rsync -avL ubuntu@$PI:/lib ubuntu-21.04-aarch64-sysroot
rsync -avL ubuntu@$PI:/usr/lib ubuntu-21.04-aarch64-sysroot/usr
rsync -avL ubuntu@$PI:/include/lib ubuntu-21.04-aarch64-sysroot/usr

NOTE: in the future, if creating a 32-bit image (not covered by this docker image yet), the following symlinks are required:

• usr/lib/arm-linux-gnueabihf to usr/lib/armv7-linux-gnueabihf
• usr/include/arm-linux-gnueabihf to usr/lib/armv7-linux-gnueabihf

Once the sysroot is on the host machine, create the corresponding tar.xz file:

tar cvfJ ubuntu-21.04-aarch64-sysroot.tar.xz ubuntu-21.04-aarch64-sysroot

CIPD image

CIPD image is provided as a convenience to avoid the need to spend time rebuilding a sysroot. It is located at:

https://chrome-infra-packages.appspot.com/p/experimental/matter/sysroot/ubuntu-21.04-aarch64/+/

and can be downloaded using the cipd script from depot_tools:

echo 'experimental/matter/sysroot/ubuntu-21.04-aarch64 latest' > ensure_file.txt
cipd ensure -ensure-file ensure_file.txt -root ./