Load M4 firmware from boot image
I've patched my uboot-imx and imx-mkimage to load the M4 firmware from the boot image.
The main benefit is it allows booting u-boot over USB if the eMMC is wiped.
u-boot patches: https://source.puri.sm/Jookia/uboot-imx/commits/librem_m4
mkimage patches: https://source.puri.sm/Jookia/imx-mkimage/commits/librem-devkit
Instructions on use: https://source.puri.sm/Jookia/imx-mkimage/wikis/home
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information