@pocketvj https://xnux.eu/howtos/install-arch-linux-arm.html suggests
> Extract the package and follow the README file inside. You'll just need to copy some files to the right place in your mounted filesystems on the SD card, and flash the bootloader to the boot block via dd, and perhaps customize the kernel boot arguments to tell the kernel where to find the root filesystem. You'll need to install uboot-tools to be able to package the bootloader configuration script.
@pocketvj (I have not tried it myself, but have instead used mrtest to install gitlab-ci-built kernels on postmarketOS)