When you run any boot command like “boot net” or “boot -s” from the OK prompt (OBP), you may end up with the error
FATAL: system is not bootable, boot command is disabled
This error indicates that interrupted the boot process prematurely, most likely when the memory checks were run with “STOP + A” or a break from console.
To resolve this problem simply Power OFF and power ON the system. Alternatively, you can perform a “reset-all” from the OK prompt.
This should help!