| #!/bin/sh |
| |
| PATH=/sbin:/bin:/usr/sbin:/usr/bin |
| |
| ROOT_MOUNT="/rootfs" |
| ROOT_IMAGE="rootfs.img" |
| MOUNT="/bin/mount" |
| UMOUNT="/bin/umount" |
| ISOLINUX="" |
| |
| ROOT_DISK="" |
| |
| # Copied from initramfs-framework. The core of this script probably should be |
| # turned into initramfs-framework modules to reduce duplication. |
| udev_daemon() { |
| OPTIONS="/sbin/udev/udevd /sbin/udevd /lib/udev/udevd /lib/systemd/systemd-udevd" |
| |
| for o in $OPTIONS; do |
| if [ -x "$o" ]; then |
| echo $o |
| return 0 |
| fi |
| done |
| |
| return 1 |
| } |
| |
| _UDEV_DAEMON=`udev_daemon` |
| |
| early_setup() { |
| mkdir -p /proc |
| mkdir -p /sys |
| mount -t proc proc /proc |
| mount -t sysfs sysfs /sys |
| mount -t devtmpfs none /dev |
| |
| # support modular kernel |
| modprobe isofs 2> /dev/null |
| |
| mkdir -p /run |
| mkdir -p /var/run |
| |
| $_UDEV_DAEMON --daemon |
| udevadm trigger --action=add |
| } |
| |
| read_args() { |
| [ -z "$CMDLINE" ] && CMDLINE=`cat /proc/cmdline` |
| for arg in $CMDLINE; do |
| optarg=`expr "x$arg" : 'x[^=]*=\(.*\)'` |
| case $arg in |
| root=*) |
| ROOT_DEVICE=$optarg ;; |
| rootimage=*) |
| ROOT_IMAGE=$optarg ;; |
| rootfstype=*) |
| modprobe $optarg 2> /dev/null ;; |
| LABEL=*) |
| label=$optarg ;; |
| video=*) |
| video_mode=$arg ;; |
| vga=*) |
| vga_mode=$arg ;; |
| console=*) |
| if [ -z "${console_params}" ]; then |
| console_params=$arg |
| else |
| console_params="$console_params $arg" |
| fi ;; |
| debugshell*) |
| if [ -z "$optarg" ]; then |
| shelltimeout=30 |
| else |
| shelltimeout=$optarg |
| fi |
| esac |
| done |
| } |
| |
| boot_live_root() { |
| # Watches the udev event queue, and exits if all current events are handled |
| udevadm settle --timeout=3 --quiet |
| killall "${_UDEV_DAEMON##*/}" 2>/dev/null |
| |
| # Allow for identification of the real root even after boot |
| mkdir -p ${ROOT_MOUNT}/media/realroot |
| mount -n --move "/run/media/${ROOT_DISK}" ${ROOT_MOUNT}/media/realroot |
| |
| # Move the mount points of some filesystems over to |
| # the corresponding directories under the real root filesystem. |
| for dir in `awk '/\/dev.* \/run\/media/{print $2}' /proc/mounts`; do |
| mkdir -p ${ROOT_MOUNT}/media/${dir##*/} |
| mount -n --move $dir ${ROOT_MOUNT}/media/${dir##*/} |
| done |
| mount -n --move /proc ${ROOT_MOUNT}/proc |
| mount -n --move /sys ${ROOT_MOUNT}/sys |
| mount -n --move /dev ${ROOT_MOUNT}/dev |
| |
| cd $ROOT_MOUNT |
| |
| # busybox switch_root supports -c option |
| exec switch_root -c /dev/console $ROOT_MOUNT /sbin/init $CMDLINE || |
| fatal "Couldn't switch_root, dropping to shell" |
| } |
| |
| fatal() { |
| echo $1 >$CONSOLE |
| echo >$CONSOLE |
| exec sh |
| } |
| |
| early_setup |
| |
| [ -z "$CONSOLE" ] && CONSOLE="/dev/console" |
| |
| read_args |
| |
| echo "Waiting for removable media..." |
| C=0 |
| while true |
| do |
| for i in `ls /run/media 2>/dev/null`; do |
| if [ -f /run/media/$i/$ROOT_IMAGE ] ; then |
| found="yes" |
| ROOT_DISK="$i" |
| break |
| elif [ -f /run/media/$i/isolinux/$ROOT_IMAGE ]; then |
| found="yes" |
| ISOLINUX="isolinux" |
| ROOT_DISK="$i" |
| break |
| fi |
| done |
| if [ "$found" = "yes" ]; then |
| break; |
| fi |
| # don't wait for more than $shelltimeout seconds, if it's set |
| if [ -n "$shelltimeout" ]; then |
| echo -n " " $(( $shelltimeout - $C )) |
| if [ $C -ge $shelltimeout ]; then |
| echo "..." |
| echo "Mounted filesystems" |
| mount | grep media |
| echo "Available block devices" |
| cat /proc/partitions |
| fatal "Cannot find $ROOT_IMAGE file in /run/media/* , dropping to a shell " |
| fi |
| C=$(( C + 1 )) |
| fi |
| sleep 1 |
| done |
| |
| # Try to mount the root image read-write and then boot it up. |
| # This function distinguishes between a read-only image and a read-write image. |
| # In the former case (typically an iso), it tries to make a union mount if possible. |
| # In the latter case, the root image could be mounted and then directly booted up. |
| mount_and_boot() { |
| mkdir $ROOT_MOUNT |
| mknod /dev/loop0 b 7 0 2>/dev/null |
| |
| if ! mount -o rw,loop,noatime,nodiratime /run/media/$ROOT_DISK/$ISOLINUX/$ROOT_IMAGE $ROOT_MOUNT ; then |
| fatal "Could not mount rootfs image" |
| fi |
| |
| if touch $ROOT_MOUNT/bin 2>/dev/null; then |
| # The root image is read-write, directly boot it up. |
| boot_live_root |
| fi |
| |
| # determine which unification filesystem to use |
| union_fs_type="" |
| if grep -q -w "overlay" /proc/filesystems; then |
| union_fs_type="overlay" |
| elif grep -q -w "aufs" /proc/filesystems; then |
| union_fs_type="aufs" |
| else |
| union_fs_type="" |
| fi |
| |
| # make a union mount if possible |
| case $union_fs_type in |
| "overlay") |
| mkdir -p /rootfs.ro /rootfs.rw |
| if ! mount -n --move $ROOT_MOUNT /rootfs.ro; then |
| rm -rf /rootfs.ro /rootfs.rw |
| fatal "Could not move rootfs mount point" |
| else |
| mount -t tmpfs -o rw,noatime,mode=755 tmpfs /rootfs.rw |
| mkdir -p /rootfs.rw/upperdir /rootfs.rw/work |
| mount -t overlay overlay -o "lowerdir=/rootfs.ro,upperdir=/rootfs.rw/upperdir,workdir=/rootfs.rw/work" $ROOT_MOUNT |
| mkdir -p $ROOT_MOUNT/rootfs.ro $ROOT_MOUNT/rootfs.rw |
| mount --move /rootfs.ro $ROOT_MOUNT/rootfs.ro |
| mount --move /rootfs.rw $ROOT_MOUNT/rootfs.rw |
| fi |
| ;; |
| "aufs") |
| mkdir -p /rootfs.ro /rootfs.rw |
| if ! mount -n --move $ROOT_MOUNT /rootfs.ro; then |
| rm -rf /rootfs.ro /rootfs.rw |
| fatal "Could not move rootfs mount point" |
| else |
| mount -t tmpfs -o rw,noatime,mode=755 tmpfs /rootfs.rw |
| mount -t aufs -o "dirs=/rootfs.rw=rw:/rootfs.ro=ro" aufs $ROOT_MOUNT |
| mkdir -p $ROOT_MOUNT/rootfs.ro $ROOT_MOUNT/rootfs.rw |
| mount --move /rootfs.ro $ROOT_MOUNT/rootfs.ro |
| mount --move /rootfs.rw $ROOT_MOUNT/rootfs.rw |
| fi |
| ;; |
| "") |
| mount -t tmpfs -o rw,noatime,mode=755 tmpfs $ROOT_MOUNT/media |
| ;; |
| esac |
| |
| # boot the image |
| boot_live_root |
| } |
| |
| if [ "$label" != "boot" -a -f $label.sh ] ; then |
| if [ -f /run/media/$i/$ISOLINUX/$ROOT_IMAGE ] ; then |
| ./$label.sh $i/$ISOLINUX $ROOT_IMAGE $video_mode $vga_mode $console_params |
| else |
| fatal "Could not find $label script" |
| fi |
| |
| # If we're getting here, we failed... |
| fatal "Target $label failed" |
| fi |
| |
| mount_and_boot |
| |