This is a simple builder for Libre Computer boards.
git clone --single-branch https://github.com/libre-computer-project/libretech-builder-simple.git
./build.sh BOARD_TARGET # eg. ./build.sh roc-rk3399-pc
out/BOARD_TARGET is an image that will update the SPI NOR of the board if you write it to a card.
sudo dd if=out/BOARD_TARGET of=/dev/null bs=1M
Replace "BOARD_TARGET" and "null" to the proper file and block device respectively. Be careful!
For a better understanding, please see u-boot v2022.04 for ROC-RK3399-PC.