snapcraft.yaml

name: pc
version: '20-0.4'
type: gadget
base: core20
summary: PC gadget for generic devices
description: |
    This gadget enables generic pc devices to work with Ubuntu Core
confinement: strict
grade: stable
icon: icon.png

package-repositories:
 - type: apt
   ppa: ucdev/uc-staging-ppa

# Min version to support shim 15.7
assumes:
  - snapd2.59.3

parts:
  # Temporary workaround until pinning is supported by snapcraft
  pin-ucdev:
    plugin: nil
    override-pull: |
      # This is run before the pull step of grub part, so we make sure
      # we get the packages from the PPA.
      set -x
      cat <<'EOF' > /etc/apt/preferences.d/ucdev
      Package: *
      Pin: release LP-PPA-ucdev-uc-staging-ppa,a=jammy,n=jammy
      Pin: origin ppa.launchpad.net
      Pin-Priority: 1000
      EOF
  grub:
    after: [ pin-ucdev ]
    plugin: nil
    source: .
    build-packages:
      - ubuntu-dev-tools
      - grub-pc-bin
      - grub-common
      - sbsigntool
    stage-packages:
      - grub-efi-amd64-signed
      - shim-signed
    override-build: |
      set -x
      # Make sure we have signatures from the UC certificates
      sbverify --list "$SNAPCRAFT_PART_INSTALL"/usr/lib/shim/shimx64.efi.dualsigned |
          grep -E 'Canonical Ltd. Secure Boot Signing \(Ubuntu Core'
      sbverify --list "$SNAPCRAFT_PART_INSTALL"/usr/lib/grub/x86_64-efi-signed/grubx64.efi.signed |
          grep -E 'Canonical Ltd. Secure Boot Signing \(Ubuntu Core'

      mbr_img="$SNAPCRAFT_PART_INSTALL"/pc-boot.img
      dd if=/usr/lib/grub/i386-pc/boot.img of="$mbr_img" bs=440 count=1
      printf '\x90\x90' | dd of="$mbr_img" seek=102 bs=1 conv=notrunc
      GRUB_MODULES="\
        all_video \
        biosdisk \
        boot \
        cat \
        chain \
        configfile \
        echo \
        ext2 \
        fat \
        font \
        gettext \
        gfxmenu \
        gfxterm \
        gfxterm_background \
        gzio \
        halt \
        jpeg \
        keystatus \
        loadenv \
        loopback \
        linux \
        memdisk \
        minicmd \
        normal \
        part_gpt \
        png \
        reboot \
        regexp \
        search \
        search_fs_uuid \
        search_fs_file \
        search_label \
        sleep \
        squash4 \
        test \
        true \
        video"
      bios_img="$SNAPCRAFT_PART_INSTALL"/pc-core.img
      # shellcheck disable=SC2086
      grub-mkimage -O i386-pc -o "$bios_img" -p '(,gpt2)/EFI/ubuntu' $GRUB_MODULES
      # The first sector of the core image requires an absolute pointer to the
      # second sector of the image.  Since this is always hard-coded, it means our
      # BIOS boot partition must be defined with an absolute offset.  The
      # particular value here is 2049, or 0x01 0x08 0x00 0x00 in little-endian.
      printf '\x01\x08\x00\x00' | dd of="$bios_img" seek=500 bs=1 conv=notrunc
      install -m 644 /dev/null "$SNAPCRAFT_PART_INSTALL"/grub.conf
    organize:
      usr/lib/shim/shimx64.efi.dualsigned: shim.efi.signed
      usr/lib/grub/x86_64-efi-signed/grubx64.efi.signed: grubx64.efi
    prime:
      - shim.efi.signed
      - grubx64.efi
      - grub.conf
      - pc-boot.img
      - pc-core.img