Boot from a system rescue CD:
Download - SystemRescueCd
then in console mode only - do not use X - you can run fsck.
That answered your question - however, what problem do you have?
Do you know about /dev/MAKEDEV and /dev/MAKEDEV.local? Save those off somewhere first if you can.
Also /dev is a directory maintained by the kernel, so a reboot (assuming the MAKEDEV scripts are still okay) may fix problems. And. If you hose the directory by playing with it you will have to re-install Linux or restore from backup.