image / create_chroot - update buster image location, and add entry for bullseye.

Default to "buster" if no dist parameter is provided.

Raspberry Pi OS bulleye based image is now out, and is the default image so we needed to update the URL
for buster to the last archived version.

Author: joolswills

scriptmodules/admin/image.sh

@@ -22,7 +22,7 @@ function depends_image() {
 
 function create_chroot_image() {
     local dist="$1"
-    [[ -z "$dist" ]] && dist="stretch"
+    [[ -z "$dist" ]] && dist="buster"
 
     local chroot="$2"
     [[ -z "$chroot" ]] && chroot="$md_build/chroot"
@@ -42,6 +42,9 @@ function create_chroot_image() {
             url="https://downloads.raspberrypi.org/raspbian_lite/images/raspbian_lite-2019-04-09/2019-04-08-raspbian-stretch-lite.zip"
             ;;
         buster)
+            url="https://downloads.raspberrypi.org/raspios_lite_armhf/images/raspios_lite_armhf-2021-05-28/2021-05-07-raspios-buster-armhf-lite.zip"
+            ;;
+        bullseye)
             url="https://downloads.raspberrypi.org/raspios_lite_armhf_latest"
             ;;
         *)