I edited the 'grub.conf' file of my linux system and changed the 'timeout' value in it and added some other line so as to solve the timeout issue of 'xm console guest' command. I was fool to assume that this 'timeout' parameter in grub.conf is actually related to 'xm console timeout and change it to very large value. So it led me to a big problem. Now when I rebooted my linux machine, it just hangs at boot screen even after manually selecting the Kernel to boot.
So basically I want to undo the changes I did in grub.conf file while booting or through grub. Or somehow force the system to boot once and undo the changes afterwards. I am not able to do it. One way to do it it to boot from the Linux CD in rescue mode and undo it, but I can not do it as it is a virtual machine on XEN and I can't find a way to boot it from external CD.
Is there any way to resolve the mess I created?