Initrd
From Linuxintro
The Linux boot process will first mount an initial ramdisk to mount the harddisks. This is how you modify an initrd:
mkdir tmp cd tmp cp /boot/initrd initrd.gz gunzip initrd.gz mkdir tmp2 cd tmp2 cpio -id < ../initrd
Do the needed changes now in this folder. Then pack the initrd again:
/tmp/tmp2 # find . | cpio --create --format='newc' > ../newinitrd 40242 blocks /tmp/tmp2 # cd .. /tmp # gzip newinitrd
Your new initrd is now called newinitrd.gz.
