Implemented a simple addon mechanism

If asked to do so, mkarchiso simply copies a
directory full of addons to the iso root.

On boot, after union-mounting /real_root, the
archiso hook will look for and source an addon
config file. This file is a plain old bash
script, which makes it quite flexible. The addon
config should be written to take care of any
mounting that needs to be done, an example of
typical tasks is also included.

Signed-off-by: Simo Leone <simo@archlinux.org>

3 files changed, 33 insertions, 1 deletions

diff --git a/addon_config b/addon_config
new file mode 100644
index 0000000..e8bbdea
--- /dev/null
+++ b/addon_config
@@ -0,0 +1,17 @@
+# This script gets run around the end of the archiso hook
+# These are some typical examples of what addons may need
+
+# installer package payload in a plain directory
+mkdir -p /real_root/packages
+mount -o bind $BOOT_MOUNT/addons/core /real_root/packages
+
+# a squashed livecd-specific overlay for a pristine system
+#TODO: we should keep track of used loop devices in case of multiple images
+mkdir -p /tmpfs/mnt/live_overlay
+if ! /bin/losetup /dev/loop1 "${BOOT_MOUNT}/addons/live_overlay.sqfs" >/dev/null 2>&1; then
+    echo "ERROR: Cannot mount loop device /dev/loop1...aborting"
+fi
+/bin/mount -r -t squashfs /dev/loop1 /tmpfs/mnt/live_overlay
+mount -t unionfs -o remount,add=/tmpfs/squashfs_root:/tmpfs/mnt/live_overlay=ro none /real_root
+
+# vim:ft=sh:ts=4:sw=4:et:
diff --git a/hooks/archiso b/hooks/archiso
index f06e56b..e345382 100644
--- a/hooks/archiso
+++ b/hooks/archiso
@@ -33,6 +33,12 @@ run_hook ()
     /bin/modprobe -q unionfs >/dev/null 2>&1
     /bin/mount -t unionfs -o dirs=/tmpfs=rw:/tmpfs/squashfs_root=ro none /real_root
 
+    addon_conf="${BOOT_MOUNT}/addons/config"
+    if [ -e "${addon_conf}" ]; then
+        msg ":: Mounting addons"
+        . $addon_conf
+    fi
+
     if [ -d /proc/sys/dev/cdrom ]; then
         echo 0 > /proc/sys/dev/cdrom/lock
         echo 1 > /proc/sys/dev/cdrom/autoeject
diff --git a/mkarchiso b/mkarchiso
index c158ef9..3703b0b 100755
--- a/mkarchiso
+++ b/mkarchiso
@@ -6,6 +6,7 @@ PKGFILE="$(pwd)/packages.list"
 PKGLIST=""
 QUIET="y"
 FORCE="n"
+ADDON_DIR=""
 
 command_name=""
 work_dir=""
@@ -22,6 +23,7 @@ usage ()
     echo "    -i CPIO_CONFIG   Use CONFIG file for mkinitcpio. default: ${CPIOCONFIG}"
     echo "    -P PKGFILE       File with list of packages to install. default: ${PKGFILE}"
     echo "    -p PACKAGE       Additional package to install, can be used multiple times"
+    echo "    -a ADDON_DIR     Use addons from DIR. default: none"
     echo "    -v               Enable verbose output."
     echo "    -h               This message."
     echo " commands:"
@@ -32,11 +34,12 @@ usage ()
     exit $1
 }
 
-while getopts 'i:P:p:fvh' arg; do
+while getopts 'i:P:p:a:fvh' arg; do
     case "${arg}" in
         i) CPIOCONFIG="${OPTARG}" ;;
         P) PKGFILE="${OPTARG}" ;;
         p) PKGLIST="${PKGLIST} ${OPTARG}" ;;
+        a) ADDON_DIR="${OPTARG}" ;;
         f) FORCE="y" ;;
         v) QUIET="n" ;;
         h|?) usage 0 ;;
@@ -172,6 +175,12 @@ if [ "${command_name}" = "install" -o "${command_name}" = "all" ]; then
         rm -rf "${isoroot}/boot"
         mv "${instroot}/boot" "${isoroot}"
     fi
+
+    # TODO: this might belong somewhere else
+    if [ -d "${ADDON_DIR}" ]; then
+        echo "Copying addons from ${ADDON_DIR}..."
+        cp -r ${ADDON_DIR} ${isoroot}/addons
+    fi
 fi
 
 # Squash is the next step.