Patrick Williams | c124f4f | 2015-09-15 14:41:29 -0500 | [diff] [blame] | 1 | #!/bin/sh |
| 2 | |
| 3 | PATH=/sbin:/bin:/usr/sbin:/usr/bin |
| 4 | |
Patrick Williams | d8c66bc | 2016-06-20 12:57:21 -0500 | [diff] [blame] | 5 | ROOT_MOUNT="/rootfs" |
Patrick Williams | c124f4f | 2015-09-15 14:41:29 -0500 | [diff] [blame] | 6 | ROOT_IMAGE="rootfs.img" |
| 7 | MOUNT="/bin/mount" |
| 8 | UMOUNT="/bin/umount" |
| 9 | ISOLINUX="" |
| 10 | |
| 11 | ROOT_DISK="" |
| 12 | |
| 13 | # Copied from initramfs-framework. The core of this script probably should be |
| 14 | # turned into initramfs-framework modules to reduce duplication. |
| 15 | udev_daemon() { |
| 16 | OPTIONS="/sbin/udev/udevd /sbin/udevd /lib/udev/udevd /lib/systemd/systemd-udevd" |
| 17 | |
| 18 | for o in $OPTIONS; do |
| 19 | if [ -x "$o" ]; then |
| 20 | echo $o |
| 21 | return 0 |
| 22 | fi |
| 23 | done |
| 24 | |
| 25 | return 1 |
| 26 | } |
| 27 | |
| 28 | _UDEV_DAEMON=`udev_daemon` |
| 29 | |
| 30 | early_setup() { |
| 31 | mkdir -p /proc |
| 32 | mkdir -p /sys |
| 33 | mount -t proc proc /proc |
| 34 | mount -t sysfs sysfs /sys |
| 35 | mount -t devtmpfs none /dev |
| 36 | |
| 37 | # support modular kernel |
| 38 | modprobe isofs 2> /dev/null |
| 39 | |
| 40 | mkdir -p /run |
| 41 | mkdir -p /var/run |
| 42 | |
| 43 | $_UDEV_DAEMON --daemon |
| 44 | udevadm trigger --action=add |
| 45 | } |
| 46 | |
| 47 | read_args() { |
| 48 | [ -z "$CMDLINE" ] && CMDLINE=`cat /proc/cmdline` |
| 49 | for arg in $CMDLINE; do |
| 50 | optarg=`expr "x$arg" : 'x[^=]*=\(.*\)'` |
| 51 | case $arg in |
| 52 | root=*) |
| 53 | ROOT_DEVICE=$optarg ;; |
| 54 | rootimage=*) |
| 55 | ROOT_IMAGE=$optarg ;; |
| 56 | rootfstype=*) |
| 57 | modprobe $optarg 2> /dev/null ;; |
| 58 | LABEL=*) |
| 59 | label=$optarg ;; |
| 60 | video=*) |
| 61 | video_mode=$arg ;; |
| 62 | vga=*) |
| 63 | vga_mode=$arg ;; |
| 64 | console=*) |
| 65 | if [ -z "${console_params}" ]; then |
| 66 | console_params=$arg |
| 67 | else |
| 68 | console_params="$console_params $arg" |
| 69 | fi ;; |
| 70 | debugshell*) |
| 71 | if [ -z "$optarg" ]; then |
| 72 | shelltimeout=30 |
| 73 | else |
| 74 | shelltimeout=$optarg |
| 75 | fi |
| 76 | esac |
| 77 | done |
| 78 | } |
| 79 | |
| 80 | boot_live_root() { |
| 81 | # Watches the udev event queue, and exits if all current events are handled |
| 82 | udevadm settle --timeout=3 --quiet |
Patrick Williams | c0f7c04 | 2017-02-23 20:41:17 -0600 | [diff] [blame^] | 83 | # Kills the current udev running processes, which survived after |
| 84 | # device node creation events were handled, to avoid unexpected behavior |
| 85 | killall -9 "${_UDEV_DAEMON##*/}" 2>/dev/null |
Patrick Williams | c124f4f | 2015-09-15 14:41:29 -0500 | [diff] [blame] | 86 | |
| 87 | # Allow for identification of the real root even after boot |
| 88 | mkdir -p ${ROOT_MOUNT}/media/realroot |
| 89 | mount -n --move "/run/media/${ROOT_DISK}" ${ROOT_MOUNT}/media/realroot |
| 90 | |
| 91 | # Move the mount points of some filesystems over to |
| 92 | # the corresponding directories under the real root filesystem. |
| 93 | for dir in `awk '/\/dev.* \/run\/media/{print $2}' /proc/mounts`; do |
| 94 | mkdir -p ${ROOT_MOUNT}/media/${dir##*/} |
| 95 | mount -n --move $dir ${ROOT_MOUNT}/media/${dir##*/} |
| 96 | done |
| 97 | mount -n --move /proc ${ROOT_MOUNT}/proc |
| 98 | mount -n --move /sys ${ROOT_MOUNT}/sys |
| 99 | mount -n --move /dev ${ROOT_MOUNT}/dev |
| 100 | |
| 101 | cd $ROOT_MOUNT |
| 102 | |
| 103 | # busybox switch_root supports -c option |
| 104 | exec switch_root -c /dev/console $ROOT_MOUNT /sbin/init $CMDLINE || |
| 105 | fatal "Couldn't switch_root, dropping to shell" |
| 106 | } |
| 107 | |
| 108 | fatal() { |
| 109 | echo $1 >$CONSOLE |
| 110 | echo >$CONSOLE |
| 111 | exec sh |
| 112 | } |
| 113 | |
| 114 | early_setup |
| 115 | |
| 116 | [ -z "$CONSOLE" ] && CONSOLE="/dev/console" |
| 117 | |
| 118 | read_args |
| 119 | |
| 120 | echo "Waiting for removable media..." |
| 121 | C=0 |
| 122 | while true |
| 123 | do |
| 124 | for i in `ls /run/media 2>/dev/null`; do |
| 125 | if [ -f /run/media/$i/$ROOT_IMAGE ] ; then |
| 126 | found="yes" |
| 127 | ROOT_DISK="$i" |
| 128 | break |
| 129 | elif [ -f /run/media/$i/isolinux/$ROOT_IMAGE ]; then |
| 130 | found="yes" |
| 131 | ISOLINUX="isolinux" |
| 132 | ROOT_DISK="$i" |
| 133 | break |
| 134 | fi |
| 135 | done |
| 136 | if [ "$found" = "yes" ]; then |
| 137 | break; |
| 138 | fi |
| 139 | # don't wait for more than $shelltimeout seconds, if it's set |
| 140 | if [ -n "$shelltimeout" ]; then |
| 141 | echo -n " " $(( $shelltimeout - $C )) |
| 142 | if [ $C -ge $shelltimeout ]; then |
| 143 | echo "..." |
| 144 | echo "Mounted filesystems" |
| 145 | mount | grep media |
| 146 | echo "Available block devices" |
| 147 | cat /proc/partitions |
| 148 | fatal "Cannot find $ROOT_IMAGE file in /run/media/* , dropping to a shell " |
| 149 | fi |
| 150 | C=$(( C + 1 )) |
| 151 | fi |
| 152 | sleep 1 |
| 153 | done |
| 154 | |
| 155 | # Try to mount the root image read-write and then boot it up. |
| 156 | # This function distinguishes between a read-only image and a read-write image. |
| 157 | # In the former case (typically an iso), it tries to make a union mount if possible. |
| 158 | # In the latter case, the root image could be mounted and then directly booted up. |
| 159 | mount_and_boot() { |
| 160 | mkdir $ROOT_MOUNT |
| 161 | mknod /dev/loop0 b 7 0 2>/dev/null |
| 162 | |
| 163 | if ! mount -o rw,loop,noatime,nodiratime /run/media/$ROOT_DISK/$ISOLINUX/$ROOT_IMAGE $ROOT_MOUNT ; then |
| 164 | fatal "Could not mount rootfs image" |
| 165 | fi |
| 166 | |
| 167 | if touch $ROOT_MOUNT/bin 2>/dev/null; then |
| 168 | # The root image is read-write, directly boot it up. |
| 169 | boot_live_root |
| 170 | fi |
| 171 | |
| 172 | # determine which unification filesystem to use |
| 173 | union_fs_type="" |
Patrick Williams | d8c66bc | 2016-06-20 12:57:21 -0500 | [diff] [blame] | 174 | if grep -q -w "overlay" /proc/filesystems; then |
| 175 | union_fs_type="overlay" |
Patrick Williams | c124f4f | 2015-09-15 14:41:29 -0500 | [diff] [blame] | 176 | elif grep -q -w "aufs" /proc/filesystems; then |
| 177 | union_fs_type="aufs" |
| 178 | else |
| 179 | union_fs_type="" |
| 180 | fi |
| 181 | |
| 182 | # make a union mount if possible |
| 183 | case $union_fs_type in |
Patrick Williams | d8c66bc | 2016-06-20 12:57:21 -0500 | [diff] [blame] | 184 | "overlay") |
Patrick Williams | c124f4f | 2015-09-15 14:41:29 -0500 | [diff] [blame] | 185 | mkdir -p /rootfs.ro /rootfs.rw |
| 186 | if ! mount -n --move $ROOT_MOUNT /rootfs.ro; then |
| 187 | rm -rf /rootfs.ro /rootfs.rw |
| 188 | fatal "Could not move rootfs mount point" |
| 189 | else |
| 190 | mount -t tmpfs -o rw,noatime,mode=755 tmpfs /rootfs.rw |
Patrick Williams | d8c66bc | 2016-06-20 12:57:21 -0500 | [diff] [blame] | 191 | mkdir -p /rootfs.rw/upperdir /rootfs.rw/work |
| 192 | mount -t overlay overlay -o "lowerdir=/rootfs.ro,upperdir=/rootfs.rw/upperdir,workdir=/rootfs.rw/work" $ROOT_MOUNT |
Patrick Williams | c124f4f | 2015-09-15 14:41:29 -0500 | [diff] [blame] | 193 | mkdir -p $ROOT_MOUNT/rootfs.ro $ROOT_MOUNT/rootfs.rw |
| 194 | mount --move /rootfs.ro $ROOT_MOUNT/rootfs.ro |
| 195 | mount --move /rootfs.rw $ROOT_MOUNT/rootfs.rw |
| 196 | fi |
| 197 | ;; |
| 198 | "aufs") |
| 199 | mkdir -p /rootfs.ro /rootfs.rw |
| 200 | if ! mount -n --move $ROOT_MOUNT /rootfs.ro; then |
| 201 | rm -rf /rootfs.ro /rootfs.rw |
| 202 | fatal "Could not move rootfs mount point" |
| 203 | else |
| 204 | mount -t tmpfs -o rw,noatime,mode=755 tmpfs /rootfs.rw |
| 205 | mount -t aufs -o "dirs=/rootfs.rw=rw:/rootfs.ro=ro" aufs $ROOT_MOUNT |
| 206 | mkdir -p $ROOT_MOUNT/rootfs.ro $ROOT_MOUNT/rootfs.rw |
| 207 | mount --move /rootfs.ro $ROOT_MOUNT/rootfs.ro |
| 208 | mount --move /rootfs.rw $ROOT_MOUNT/rootfs.rw |
| 209 | fi |
| 210 | ;; |
| 211 | "") |
| 212 | mount -t tmpfs -o rw,noatime,mode=755 tmpfs $ROOT_MOUNT/media |
| 213 | ;; |
| 214 | esac |
| 215 | |
| 216 | # boot the image |
| 217 | boot_live_root |
| 218 | } |
| 219 | |
Patrick Williams | d8c66bc | 2016-06-20 12:57:21 -0500 | [diff] [blame] | 220 | if [ "$label" != "boot" -a -f $label.sh ] ; then |
Patrick Williams | c124f4f | 2015-09-15 14:41:29 -0500 | [diff] [blame] | 221 | if [ -f /run/media/$i/$ISOLINUX/$ROOT_IMAGE ] ; then |
| 222 | ./$label.sh $i/$ISOLINUX $ROOT_IMAGE $video_mode $vga_mode $console_params |
| 223 | else |
| 224 | fatal "Could not find $label script" |
| 225 | fi |
| 226 | |
| 227 | # If we're getting here, we failed... |
Patrick Williams | d8c66bc | 2016-06-20 12:57:21 -0500 | [diff] [blame] | 228 | fatal "Target $label failed" |
| 229 | fi |
| 230 | |
| 231 | mount_and_boot |
| 232 | |