This post serves more as a reminder to myself about Grub rather than providing new and exciting information.
The /boot/grub/grub.conf file is either empty, or corrupted.
Check Point FW boots into grub command prompt – Manual boot
If all you can see is a grub command prompt you need to do the following to manually boot the firewall.
1) Mount the root partition
2) Specify Initial RAM Disk
3) Specify Kernel to load
grub> find /grub/stage1
(Returns something along the lines of (hd0,0)
grub> root (hd0,0)
grub> kernel /vmlinuz (Press tab and choose correct architecture)
grub> initrd /initrd (Press tab and choose correct architecture)
* The operating system should boot and a new ‘/boot/grub/grub.conf’-file should be generated.
* The default=X in /boot/grub/grub.conf refers to title number X (First title is 0, second title is 1 and so on)
* vmlinuz in /boot/ is a symbolic link
Check Point articles on GRUB
Fixing corrupted GRUB on Check Point appliance (sk92591)
Gaia / SecurePlatform OS boots into GRUB instead of normal mode (sk105785)
How to boot manually from the GRUB command prompt (sk100289)
During boot, machine enters the GRUB command prompt (sk100287)