reorganize

usr/share/tinyramfs/init

@@ -0,0 +1,163 @@
+#!/sbin/busybox sh
+#
+# tiny init script
+
+panic() {
+    printf "panic >> %s\n" "$1"
+
+    # TODO fix job control
+    sh
+}
+
+parse_cmdline() {
+
+    # store output in variable
+    read -r cmdline < /proc/cmdline
+
+    # turn output into list
+    set -f && set +f -- $cmdline
+
+    for line in "$@"; do
+        value="${line##*=}"
+
+        case "${line%%=*}" in
+            debug)        debug="$value"        ;;
+            init)         init="$value"         ;;
+            root)         root="$value"         ;;
+            root.type)    root_type="$value"    ;;
+            root.opts)    root_opts="$value"    ;;
+            lvm)          lvm="$value"          ;;
+            lvm.name)     lvm_name="$value"     ;;
+            lvm.group)    lvm_group="$value"    ;;
+            lvm.args)     lvm_args="$value"     ;;
+            luks)         luks="$value"         ;;
+            luks.root)    luks_root="$value"    ;;
+            luks.name)    luks_name="$value"    ;;
+            luks.discard) luks_discard="$value" ;;
+            luks.args)    luks_args="$value"    ;;
+            # TODO implement
+            #lvm.discard)  ;;
+            #lvm.config)   ;;
+            #luks.header)  ;;
+            #luks.keyfile) ;;
+        esac
+    done
+}
+
+mount_pseudofs() {
+    mount -t proc     none /proc
+    mount -t sysfs    none /sys
+    mount -t devtmpfs none /dev
+}
+
+setup_devmgr() {
+    case "$devmgr" in
+        udev)
+            udevd -d
+            udevadm trigger -c add -t subsystems
+            udevadm trigger -c add -t devices
+            udevadm settle
+            ;;
+        mdev)
+            mdev -df &
+
+            find /sys -name modalias -type f -exec sort -u {} + |
+                xargs modprobe -ba
+            ;;
+        mdevd)
+            mdevd &
+            mdevd-coldplug
+            ;;
+        *)
+            panic "devmgr option broken"
+            ;;
+    esac
+}
+
+findfs_sh() {
+    value="${1##*=}"
+
+    case "${1%%=*}" in
+        LABEL)    device="/dev/disk/by-label/${value}"    ;;
+        UUID)     device="/dev/disk/by-uuid/${value}"     ;;
+        PARTUUID) device="/dev/disk/by-partuuid/${value}" ;;
+        /dev/*)   device="$1"                             ;;
+        *)        panic "findfs option broken"            ;;
+    esac
+
+    # avoid race condition
+    while [ ! -e "$device" ]; do
+        sleep 0.5
+        [ "$increment" ] || increment=0
+        increment=$(( increment + 1 ))
+        [ "$increment" = 10 ] && panic "failed to lookup partition"
+    done
+
+    printf "%s\n" "$device"
+}
+
+unlock_luks() {
+    [ "$luks_discard" = 1 ] && luks_args="--allow-discards $luks_args"
+
+    cryptsetup $luks_args \
+               luksOpen \
+               $(findfs_sh "$luks_root") \
+               ${luks_name:-luks_root} ||
+               panic "failed to unlock luks container"
+}
+
+trigger_lvm() {
+    if [ "$lvm_group" ] && [ "$lvm_name" ]; then
+        lvm lvchange $lvm_args --sysinit -q -a y "${lvm_group}/${lvm_name}" > /dev/null
+    elif [ "$lvm_group" ]; then
+        lvm vgchange $lvm_args --sysinit -q -a y "$lvm_group" > /dev/null
+    else
+        lvm vgchange $lvm_args --sysinit -q -a y > /dev/null
+    fi
+}
+
+mount_rootfs() {
+    mount ${root_type:+-t $root_type} \
+          ${root_opts:+-o $root_opts} \
+          $(findfs_sh "$root") \
+          /mnt/root ||
+          panic "failed to mount rootfs"
+}
+
+cleanup() {
+    case "$devmgr" in
+        udev)  udevadm control -e ;;
+        mdev)  killall mdev       ;;
+        mdevd) killall mdevd      ;;
+    esac
+
+    # unmount pseudofs's
+    umount /dev /sys /proc
+}
+
+boot_system() {
+    exec switch_root /mnt/root \
+                     ${init:-/sbin/init} ||
+                     panic "failed to boot system"
+}
+
+/sbin/busybox --install -s
+
+. /config || panic "failed to source config"
+
+mount_pseudofs
+parse_cmdline
+[ "$debug" = 1 ] && set -x
+setup_devmgr
+
+# TODO handle situations when LUKS on LVM
+[ "$luks" =  1 ] &&
+    command -v cryptsetup > /dev/null 2>&1 && unlock_luks
+
+[ "$lvm"  =  1 ] &&
+    command -v lvm        > /dev/null 2>&1 && trigger_lvm
+
+mount_rootfs
+[ "$debug" = 1 ] && panic "dropping to shell"
+cleanup
+boot_system