Boot options: other images
How cmdline.txt and vram.txt work, how to edit them on the PS5 or from a PC, and every option are on Boot options.
The default line
The official images:
cmdline.txt
root=LABEL=<image> rw rootwait console=ttyTitania0 console=tty0 mitigations=off idle=halt preempt=full video=DP-1:1920x1080@60
video=DP-1:1920x1080@60 starts at 1080p60. Remove it if you get a black screen.
Every option, and which kernel has it, is on Boot options.