69 lines
1.5 KiB
Bash
69 lines
1.5 KiB
Bash
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#!/bin/busybox sh
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#mount the squashfs + unionfs and boot into it
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move_mounts() {
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local base_mounts="/sys /proc /dev"
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local newroot_mnt="$1"
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for mnt in $base_mounts; do
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mkdir -p "$newroot_mnt$mnt"
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mount -n -o move "$mnt" "$newroot_mnt$mnt"
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done
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}
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boot_dir() {
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local target="$1"
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echo "moving mounts to newroot"
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move_mounts $target
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echo "switching root"
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mkdir -p $target/oldroot
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pivot_root $target $target/oldroot
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/bin/bash -c "mount -o bind /oldroot/lib/modules /lib/modules"
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exec /sbin/init < "$TTY1" >> "$TTY1" 2>&1
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}
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mount_squashfs() {
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mkdir -p /lib/modules /mnt/root_squashfs
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mount /root.squashfs /mnt/root_squashfs
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mount -o bind /mnt/root_squashfs/lib/modules /lib/modules
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}
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#based on https://github.com/rpodgorny/unionfs-fuse/blob/master/examples/S01a-unionfs-live-cd.sh
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mount_unionfs() {
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local chroot_path="/tmp/unionfs"
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local data_path="/data"
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local mountpoint="/newroot"
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local squashfs_path="/mnt/root_squashfs"
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local fuse_options="-o allow_other,suid,dev"
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local unionfs_options="-o cow,chroot=$chroot_path,max_files=32768"
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mkdir -p $data_path
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mkdir -p $mountpoint
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mkdir -p $chroot_path/root
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mkdir -p $chroot_path/rw
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mount -o bind $squashfs_path $chroot_path/root
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mount -o bind $data_path $chroot_path/rw
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modprobe fuse
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unionfs $fuse_options $unionfs_options /root=RO:/rw=RW /newroot
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}
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main() {
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echo "mounting squashfs"
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mount_squashfs
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echo "mounting unionfs"
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mount_unionfs
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echo "booting unionfs"
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boot_dir /newroot
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}
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main "$@"
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sleep 1d
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