Merge lp:~cyphermox/livecd-rootfs/xenial-proposed into lp:~ubuntu-core-dev/livecd-rootfs/xenial-proposed

[Mathieu Trudel-Lapierre]

Clean up grub modules that are listed unnecessarily.

[Mathieu Trudel-Lapierre (cyphermox)]

I'll create a separate MP for removing modules that can't be loaded due to Secure Boot.

[lp:~cyphermox/livecd-rootfs/xenial-proposed]

1409. By Mathieu Trudel-Lapierre on 2017-08-23

Only set a default GRUB_PRELOAD_MODULES if not already defined; otherwise used the existing values.

=== modified file 'live-build/ubuntu-cpc/hooks/033-disk-image-uefi.binary'
--- live-build/ubuntu-cpc/hooks/033-disk-image-uefi.binary	2017-05-12 19:20:22 +0000
+++ live-build/ubuntu-cpc/hooks/033-disk-image-uefi.binary	2017-08-23 23:21:07 +0000
@@ -61,15 +61,20 @@
     efi_boot_dir="/boot/efi/EFI/BOOT"
     chroot mountpoint mkdir -p "${efi_boot_dir}"
 
+    # The modules below only make sense on non-Secure Boot UEFI systems.
+    # Otherwise, with Secure Boot enabled GRUB will refuse to load them.
+    # Any modules already in debian/build-efi-images do not need to be listed.
+    # Furthermore, other modules such as terminal, video_* and efi_* are all
+    # already available.
     case $ARCH in
         arm64)
             chroot mountpoint apt-get -qqy install --no-install-recommends grub-efi-arm64 grub-efi-arm64-bin
-            grub_modules="part_gpt fat gzio ext2 normal chain boot configfile linux search_fs_uuid search_label terminal serial video video_fb efi_gop"
+            grub_modules="serial"
             efi_target=arm64-efi
             ;;
         amd64)
             chroot mountpoint apt-get install -qqy grub-efi-amd64-signed grub-efi-amd64 shim-signed
-            grub_modules="part_gpt fat ext2 normal chain boot configfile linux multiboot search_fs_uuid search_label terminal serial video video_fb video_bochs usb usb_keyboard efi_gop efi_uga"
+            grub_modules="multiboot serial usb usb_keyboard"
             efi_target=x86_64-efi
             ;;
     esac
@@ -77,8 +82,9 @@
     cat << EOF >> mountpoint/etc/default/grub.d/50-cloudimg-settings.cfg
 ${CLOUD_IMG_STR}
 # For Cloud Image compatability
-GRUB_PRELOAD_MODULES="${grub_modules}"
+GRUB_PRELOAD_MODULES="${GRUB_PRELOAD_MODULES:-$grub_modules}"
 EOF
+
     chroot mountpoint grub-install "${loop_device}" \
         --boot-directory=/boot \
         --efi-directory=/boot/efi \