Add support for template with partition table on root.img

When TEMPLATE_ROOT_WITH_PARTITIONS is set, include (GPT) partition table
and install actual OS on the first one. This allows installing grub, or
other bootloader.

Fixes QubesOS/qubes-issues#2577

cleanup_image

@@ -1,30 +1,24 @@
 #!/bin/sh
 
-export IMG=$1
+export INSTALLDIR=$1
 
 . ./builder_setup
 
 set -e
 
 if ! [ $# -eq 1 ]; then
-	echo "usage $0 <img_file_name>"
+	echo "usage $0 <mount_point>"
 	exit 1
 fi
 
 
-if ! [ -f $IMG ]; then
+if ! [ -d $INSTALLDIR ]; then
-	echo $IMG does not exist 
+	echo $INSTALLDIR does not exist
 	exit 1
 fi	
-ls -als $IMG
-mount -o loop $IMG mnt || exit 1
-export INSTALLDIR=`pwd`/mnt/
 
 echo "--> Cleaning up image file..."
 $SCRIPTSDIR/09_cleanup.sh
 
 echo "--> Compacting image file..."
-fstrim mnt/
+fstrim -v "$INSTALLDIR"
-umount mnt
-ls -als $IMG
-

prepare_image

@@ -45,15 +45,41 @@ echo "-> Preparing instalation of ${DIST} template..."
 # ------------------------------------------------------------------------------
 if [ -f "${IMG}" ]; then
     echo "-> Image file already exists, assuming *update*..."
+    if [ "0$TEMPLATE_ROOT_WITH_PARTITIONS" -eq 1 ]; then
+        IMG_LOOP=$(losetup -P -f --show "$IMG")
+        IMG_DEV=${IMG_LOOP}p1
+    else
+        IMG_LOOP=$(losetup -f --show "$IMG")
+        IMG_DEV=${IMG_LOOP}
+    fi
 else
     echo "-> Initializing empty image..."
     truncate -s 10G "${IMG}" || exit 1
 
+    if [ "0$TEMPLATE_ROOT_WITH_PARTITIONS" -eq 1 ]; then
+        echo "-> Creating partition table"
+        # have static UUIDs to make partition table reproducible
+        sfdisk "$IMG" <<EOF || exit 1
+label: gpt
+label-id: f4796a2a-e377-45bd-b539-d6d49e569055
+
+size=10000MiB, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, uuid=693244e6-3e07-47bf-ad79-acade4293fe7, name="Root filesystem"
+size=200MiB, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, uuid=fa4d6529-56da-47c7-ae88-e2dfecb72621, name="EFI System"
+size=2MiB, type=21686148-6449-6E6F-744E-656564454649, uuid=1e6c9db4-1e91-46c4-846a-2030dcb13b8c, name="BIOS boot partition"
+EOF
+
+        IMG_LOOP=$(losetup -P -f --show "$IMG")
+        IMG_DEV=${IMG_LOOP}p1
+    else
+        IMG_LOOP=$(losetup -f --show "$IMG")
+        IMG_DEV=${IMG_LOOP}
+    fi
+
     echo "-> Creating filesystem..."
-    mkfs.ext4 -q -F "${IMG}" || exit 1
+    mkfs.ext4 -q -F "${IMG_DEV}" || exit 1
 fi
 
-mount -o loop "${IMG}" "${INSTALLDIR}" || exit 1
+mount "${IMG_DEV}" "${INSTALLDIR}" || exit 1
 trap "umount_kill $(readlink -m ${INSTALLDIR})" EXIT
 "${SCRIPTSDIR}/01_install_core.sh"
 
@@ -70,5 +96,6 @@ trap - EXIT
 
 echo "-> Unmounting prepared_image..."
 umount_kill "$(readlink -m ${INSTALLDIR})" || true
+losetup -d ${IMG_LOOP}
 
 exit ${RETCODE}

qubeize_image

@@ -50,6 +50,7 @@ function cleanup() {
     trap - ERR
     trap
     umount_kill "$PWD/mnt" || true
+    losetup -d ${IMG_LOOP}
     exit $errval
 }
 trap cleanup ERR
@@ -65,7 +66,14 @@ cp "$CLEANIMG" "$IMG" || exit 1
 
 echo "--> Mounting $IMG"
 mkdir -p mnt
-mount -o loop "$IMG" mnt || exit 1
+if [ "0$TEMPLATE_ROOT_WITH_PARTITIONS" -eq 1 ]; then
+    IMG_LOOP=$(losetup -P -f --show "$IMG")
+    IMG_DEV=${IMG_LOOP}p1
+else
+    IMG_LOOP=$(losetup -f --show "$IMG")
+    IMG_DEV=${IMG_LOOP}
+fi
+mount "$IMG_DEV" mnt || exit 1
 export INSTALLDIR=mnt
 
 # ------------------------------------------------------------------------------
@@ -100,14 +108,18 @@ echo "--> Linking /usr/local to /rw/usrlocal..."
 mv mnt/usr/local mnt/usr/local.orig
 ln -sf /rw/usrlocal mnt/usr/local
 
+echo "Reducing image size (calling cleanup_image)..."
+ls -als $IMG
+./cleanup_image "$INSTALLDIR"
+ls -als $IMG
+
 # ------------------------------------------------------------------------------
 # Finsh - unmount image
 # ------------------------------------------------------------------------------
 echo "--> Unmounting $IMG"
 umount_kill "$PWD/mnt" || true
+losetup -d ${IMG_LOOP}
 
 echo "Qubeized image stored at: $IMG"
 
-echo "Reducing image size (calling cleanup_image)..."
-./cleanup_image "$IMG"
 chown -R --reference=. qubeized_images/$NAME