Booting via nfsroot

The SOM comes with a pre-flashed u-boot so you can connect the USB-to-UART-Debug cable and boot the device. Breaking into u-boot you can boot using a nfsroot filesystem with these commands:

setenv nfsrootboot "setenv bootargs ${args_common} debug root=/dev/nfs ip=:::::eth0:dhcp nfsrootdebug nfsroot=<nfsserverip>:<nfsrootpath>,v3,tcp; dhcp ${loadaddr} Image-librem5-devkit; dhcp ${fdt_addr} librem5-devkit.dtb; booti ${loadaddr} - ${fdt_addr}"
setenv bootcmd run nfsrootboot

You need to fill in nfsrootpath and nfsserverip above. At nfsrootpath there needs to be a armhf or arm64 root filesystem which you can e.g. create via Debian’s deboostrap.

For that to work the BOOT MODE switch needs to be set to eMMC (instead of USB).