To recreate bootable image on aix , you have to simply execute
bosboot -ad /dev/hdiskx
This hdiskx could be hdisk0 or hdisk1 ( depending upon output of your lslv -m hd5 command ). In case of mirroring , you have to execute the same command against both disks in rootvg.
In case of RHEL, mkinitrd command can do the same function for you!!!
mkinitrd -v -f /boot/xxx.img xxx
where xxx=you kernel version.
