A list of the system boot images in the BOOT
environment variable on supervisor modules with
ROMMON. The format of sysBootVariable should be:
<device>:[<fileName>],1;{<device>:[<fileName>],1;...}
If the [fileName] is not specified, the first file
on the <device> will be used.
This MIB object is only supported in systems
having supervisor modules with ROMMON.