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