Kernel panic with external hdd's connected

[ActionA]

Identifying in cmdline might be cleaner

UUID in cmdline.txt

Hi, I changed boot=/dev/sda1 (a USB device with the FS) to boot=UUID=XXXXXXXXXXXXXX, but it doesn’t work (black screen). ¿Can be UUID used in cmdline.txt boot in OSMC? I readed that some people work with this, other speaks that a initramfs need to be done and used in startup, but kernel needs to be compatible (compiled with some flag).