Yeah it looks like it needs to be assembled and written any time the kernel file's position on disk changes (`current_lba`), or different kernel cmdline is requ

Yeah it looks like it needs to be assembled and written any time the kernel file's position on disk changes (`current_lba`), or different kernel cmdline is required. I seem to remember having to do something similar with lilo… not hand-editing assembly, but running a command to rewrite the boot sector when the kernel moves on disk.