Change partition layout

Put root filesystem as the last partition, to ease resizing.

Fixes QubesOS/qubes-issues#3173

prepare_image

@@ -47,7 +47,7 @@ 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=${IMG_LOOP}p1
+        IMG_DEV=${IMG_LOOP}p3
     else
         IMG_LOOP=$(losetup -f --show "$IMG")
         IMG_DEV=${IMG_LOOP}
@@ -63,13 +63,13 @@ else
 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"
+type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, uuid=693244e6-3e07-47bf-ad79-acade4293fe7, name="Root filesystem"
 EOF
 
         IMG_LOOP=$(losetup -P -f --show "$IMG")
-        IMG_DEV=${IMG_LOOP}p1
+        IMG_DEV=${IMG_LOOP}p3
     else
         IMG_LOOP=$(losetup -f --show "$IMG")
         IMG_DEV=${IMG_LOOP}

qubeize_image

@@ -73,7 +73,7 @@ echo "--> Mounting $IMG"
 mkdir -p mnt
 if [ "0$TEMPLATE_ROOT_WITH_PARTITIONS" -eq 1 ]; then
     IMG_LOOP=$(losetup -P -f --show "$IMG")
-    IMG_DEV=${IMG_LOOP}p1
+    IMG_DEV=${IMG_LOOP}p3
 else
     IMG_LOOP=$(losetup -f --show "$IMG")
     IMG_DEV=${IMG_LOOP}