58 lines
1.1 KiB
Bash
Executable file
58 lines
1.1 KiB
Bash
Executable file
#!/bin/sh
|
|
|
|
#Mount things needed by this script
|
|
mount -t proc proc /proc
|
|
mount -t sysfs sysfs /sys
|
|
|
|
#Disable kernel messages from popping onto the screen
|
|
echo 0 > /proc/sys/kernel/printk
|
|
|
|
#Clear the screen
|
|
clear
|
|
|
|
#Create all the symlinks to /bin/busybox
|
|
busybox --install -s
|
|
|
|
#Create device nodes
|
|
mknod /dev/null c 1 3
|
|
mknod /dev/tty c 5 0
|
|
mdev -s
|
|
|
|
#Function for parsing command line options with "=" in them
|
|
# get_opt("init=/sbin/init") will return "/sbin/init"
|
|
get_opt() {
|
|
echo "$@" | cut -d "=" -f 2
|
|
}
|
|
|
|
#Defaults
|
|
init="/sbin/init"
|
|
root="/dev/hda1"
|
|
|
|
#Process command line options
|
|
for i in $(cat /proc/cmdline); do
|
|
case $i in
|
|
root\=*)
|
|
root=$(get_opt $i)
|
|
;;
|
|
init\=*)
|
|
init=$(get_opt $i)
|
|
;;
|
|
esac
|
|
done
|
|
|
|
#Mount the root device
|
|
mount "${root}" /newroot
|
|
|
|
#Check if $init exists and is executable
|
|
if [[ -x "/newroot/${init}" ]] ; then
|
|
#Unmount all other mounts so that the ram used by
|
|
#the initramfs can be cleared after switch_root
|
|
umount /sys /proc
|
|
|
|
#Switch to the new root and execute init
|
|
exec switch_root /newroot "${init}"
|
|
fi
|
|
|
|
#This will only be run if the exec above failed
|
|
echo "Failed to switch_root, dropping to a shell"
|
|
exec sh
|