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authorStephane Desneux <stephane.desneux@iot.bzh>2016-05-23 17:53:36 +0200
committerGerrit Code Review <gerrit@172.30.200.200>2016-05-29 10:21:30 +0000
commit56b1139ef2660535b112d0be4ddb2806f75298a8 (patch)
tree7e71661d2d9f9a407fe58da7e572f7cffa3f51f6 /meta-netboot/recipes-core/initramfs-netboot/files
parent04dad68c951f206bd100e4dd82f9a77475e81f9d (diff)
add layer meta-netboot to enable network boot over NBD (Network Block Device)
To enable the build of network bootable images, the following line must be added to conf/local.conf: INHERIT += "netboot" This layer contains recipes for the following components: * busybox: activate the built-in NBD client * initramfs-netboot: contains the init script started by the kernel, responsible for mounting the remote root filesystem then pivoting and exec'ing systemd * initramfs-netboot-image: image to specify for building the initrd More details are available in meta-netboot/README. Bug-AGL: SPEC-175 Change-Id: Id2328dd9233d238cde77311e64e58344be244988 Signed-off-by: Stephane Desneux <stephane.desneux@iot.bzh>
Diffstat (limited to 'meta-netboot/recipes-core/initramfs-netboot/files')
-rw-r--r--meta-netboot/recipes-core/initramfs-netboot/files/init.sh149
1 files changed, 149 insertions, 0 deletions
diff --git a/meta-netboot/recipes-core/initramfs-netboot/files/init.sh b/meta-netboot/recipes-core/initramfs-netboot/files/init.sh
new file mode 100644
index 000000000..dae9a85cb
--- /dev/null
+++ b/meta-netboot/recipes-core/initramfs-netboot/files/init.sh
@@ -0,0 +1,149 @@
+#!/bin/sh
+
+################################################################################
+#
+# Init script to boot over network through NBD
+#
+# Contact: Stéphane Desneux <stephane.desneux@iot.bzh>
+#
+################################################################################
+
+# banner generator: echo "AGL - Netboot" | figlet -f slant -w 80 -c
+cat <<'EOF' >&2
+________________________________________________________________________________
+ ___ ________ _ __ __ __ __
+ / | / ____/ / / | / /__ / /_/ /_ ____ ____ / /_
+ / /| |/ / __/ / ______ / |/ / _ \/ __/ __ \/ __ \/ __ \/ __/
+ / ___ / /_/ / /___ /_____/ / /| / __/ /_/ /_/ / /_/ / /_/ / /_
+ /_/ |_\____/_____/ /_/ |_/\___/\__/_.___/\____/\____/\__/
+________________________________________________________________________________
+EOF
+
+# global variables
+
+SMACK=n
+NBD_SERVER=
+NBD_PORT=10809
+NBD_DEV=/dev/nbd0
+DEBUG=n
+
+# -------------------------------------------
+
+log_info() { echo "$0[$$]: $@" >&2; }
+log_error() { echo "$0[$$]: ERROR $@" >&2; }
+
+do_mount_fs() {
+ log_info "mounting FS: $@"
+ [[ -e /proc/filesystems ]] && { grep -q "$1" /proc/filesystems || { log_error "Unknown filesystem"; return 1; } }
+ [[ -d "$2" ]] || mkdir -p "$2"
+ [[ -e /proc/mounts ]] && { grep -q -e "^$1 $2 $1" /proc/mounts && { log_info "$2 ($1) already mounted"; return 0; } }
+ mount -t "$1" "$1" "$2"
+}
+
+bail_out() {
+ log_error "$@"
+ check_debug "Reboot will occur after exiting this shell."
+ log_info "Rebooting..."
+ exec reboot -f
+}
+
+check_debug() {
+ case $DEBUG in
+ Y|y|yes|1|true)
+ log_info "$@"
+ /bin/sh -i
+ ;;
+ esac
+}
+
+# -------------------------------------------
+
+export PATH=/sbin:/usr/sbin:/bin:/usr/bin
+
+log_info "starting initrd script"
+
+do_mount_fs proc /proc
+do_mount_fs sysfs /sys
+do_mount_fs devtmpfs /dev
+do_mount_fs devpts /dev/pts
+do_mount_fs tmpfs /dev/shm
+do_mount_fs tmpfs /tmp
+do_mount_fs tmpfs /run
+
+# parse kernel commandline to get NBD server
+for x in $(cat /proc/cmdline); do
+ case $x in
+ nbd.server=*) NBD_SERVER=${x/*=/};;
+ nbd.port=*) NBD_PORT=${x/*=/};;
+ nbd.dev=*) NBD_DEV=/dev/${x/*=/};;
+ nbd.debug=*) DEBUG=${x/*=/};;
+ esac
+done
+
+check_debug "Debug point 1. Exit to continue initrd script (mount NBD device)."
+
+log_info "NBD parameters: device $NBD_DEV, server $NBD_SERVER:$NBD_PORT"
+
+# check if smack is active (and if so, mount smackfs)
+grep -q smackfs /proc/filesystems && {
+ SMACK=y
+
+ do_mount_fs smackfs /sys/fs/smackfs
+
+ # adjust current label and network label
+ echo System >/proc/self/attr/current
+ echo System >/sys/fs/smackfs/ambient
+}
+
+# start nbd client
+try=5
+while :;do
+ log_info "Starting NBD client"
+ nbd-client $NBD_SERVER $NBD_PORT $NBD_DEV && { log_info "NBD client successfully started"; break; }
+ log_info "NBD client failed"
+ [[ $try -gt 0 ]] && { log_info "Retrying ($try trie(s) left)..."; sleep 3; try=$(( try - 1 )); continue; }
+
+ bail_out "Unable to mount NBD device $NBD_DEV using server $NBD_SERVER:$NBD_PORT"
+done
+
+# mount NBD device
+mkdir -p /sysroot
+mount $NBD_DEV /sysroot || bail_out "Unable to mount root NBD device"
+
+# move mounted devices to new root
+cd /sysroot
+for x in dev proc sys tmp run; do
+ log_info "Moving /$x to new rootfs"
+ mount -o move /$x $x
+done
+
+# switch to new rootfs
+log_info "Switching to new rootfs"
+mkdir -p run/initramfs
+pivot_root . run/initramfs || bail_out "pivot_root failed."
+
+# workaround for connman (avoid bringing down the network interface used for booting)
+if [[ -f /lib/systemd/system/connman.service ]]; then
+ log_info "Adjusting Connman configuration"
+ iface=$(ip -o link show up | tr ':' ' ' | awk '{print $2}' | grep -v -e "^lo$" | head -1)
+ sed -i "s|connmand -n\$|connmand -n -I $iface|g" /lib/systemd/system/connman.service
+fi
+
+# finally, run systemd
+check_debug "Debug point 2. Exit to continue initrd script (run systemd)."
+
+log_info "Exec'ing systemd"
+# banner generator: echo "AGL Booting . . ." | figlet -f slant -w 80 -c
+cat <<'EOF' >&2
+________________________________________________________________________________
+ ___ ________ ____ __ _
+ / | / ____/ / / __ )____ ____ / /_(_)___ ____ _
+ / /| |/ / __/ / / __ / __ \/ __ \/ __/ / __ \/ __ `/
+ / ___ / /_/ / /___ / /_/ / /_/ / /_/ / /_/ / / / / /_/ / _ _ _
+ /_/ |_\____/_____/ /_____/\____/\____/\__/_/_/ /_/\__, / (_) (_) (_)
+_____________________________________________________/____/_____________________
+EOF
+
+exec /lib/systemd/systemd </dev/console >/dev/console 2>&1
+bail_out
+