Package: u-boot Version: 2020.07+dfsg-1 Starting from v2020.01 U-Boot have a unified config `rpi_arm64` for RPi3 and RPi4. This defconfig allows to boot Raspberry Pi 4 and Raspberry Pi 3 Model B/B+.
Please accept the MR below to enable this target: https://salsa.debian.org/debian/u-boot/-/merge_requests/12 The unified config has been tested in Apertis (Debian's derivative) with a single bootable image for Raspberry Pi 3 and 4 with U-Boot.