cleaner boot from loopmounted iso file

Currently, when booting loopmounted iso file, it is necessary to
specify not only img_dev and img_loop (which should be sufficient),
but also archisolabel or archisodevice. With this patch, archisodevice
is directly populated with the correct loop device, and it is not
necessary to specify the label when booting from loopmounted iso,
which makes for leaner and cleaner grub.cfg.

2 files changed, 5 insertions, 3 deletions

diff --git a/docs/README.altbootmethods b/docs/README.altbootmethods
index 3c07e03..9df20ef 100644
--- a/docs/README.altbootmethods
+++ b/docs/README.altbootmethods
@@ -31,14 +31,14 @@ Note: Described method is for using with GRUB2.
 menuentry "Arch Linux (x86_64)" {
     set isofile="/<TARGET-PATH>/archlinux-<YYYY>.<MM>.<DD>-dual.iso"
     loopback loop (hd<D>,<P>)$isofile
-    linux (loop)/arch/boot/x86_64/vmlinuz archisolabel=<FS-LABEL> img_label=<TARGET-FS-LABEL> img_loop=$isofile
+    linux (loop)/arch/boot/x86_64/vmlinuz img_label=<TARGET-FS-LABEL> img_loop=$isofile
     initrd (loop)/arch/boot/x86_64/archiso.img
 }
 
 menuentry "Arch Linux (i686)" {
     set isofile="/<TARGET-PATH>/archlinux-<YYYY>.<MM>.<DD>-dual.iso"
     loopback loop (hd<D>,<P>)$isofile
-    linux (loop)/arch/boot/i686/vmlinuz archisolabel=<FS-LABEL> img_label=<TARGET-FS-LABEL> img_loop=$isofile
+    linux (loop)/arch/boot/i686/vmlinuz img_label=<TARGET-FS-LABEL> img_loop=$isofile
     initrd (loop)/arch/boot/i686/archiso.img
 }
 
diff --git a/hooks/archiso_loop_mnt b/hooks/archiso_loop_mnt
index 46338e5..f95a47d 100644
--- a/hooks/archiso_loop_mnt
+++ b/hooks/archiso_loop_mnt
@@ -18,7 +18,9 @@ archiso_loop_mount_handler () {
         echo $(readlink -f ${img_dev}) >> /run/archiso/used_block_devices
     fi
 
-    if ! _dev_loop=$(losetup --find --show --read-only "/run/archiso/img_dev/${img_loop}"); then
+    if _dev_loop=$(losetup --find --show --read-only "/run/archiso/img_dev/${img_loop}"); then
+        archisodevice="${_dev_loop}"
+    else
         echo "ERROR: Setting loopback device for file '/run/archiso/img_dev/${img_loop}'"
         launch_interactive_shell
     fi