Add aarch64 support to the base image

Uses already compiled static build of QEMU to avoid reaching the storage
limit of the job

To simplify binfmt registering, update-binfmt (Debian tooling) is
installed and the needed template generated

buildstream/elements/components/binfmt-support.bst

@@ -0,0 +1,16 @@
+kind: autotools
+
+build-depends:
+- freedesktop-sdk.bst:public-stacks/buildsystem-autotools.bst
+
+depends:
+- freedesktop-sdk.bst:components/libpipeline.bst
+
+variables:
+  conf-local: >-
+    --disable-upstart
+
+sources:
+- kind: tar
+  url: https://download.savannah.nongnu.org/releases/binfmt-support/binfmt-support-2.2.2.tar.gz
+  ref: cce14163f9b526283e6f0d00f3be1cfe239fa2c7574e5e0ba8ad3db74166a4a5

buildstream/elements/components/qemu-user.bst

@@ -0,0 +1,30 @@
+kind: manual
+
+build-depends:
+- freedesktop-sdk.bst:components/util-linux.bst
+
+config:
+  configure-commands:
+  - |
+    sed -i 's|${qemu_target_list}|"aarch64"|g' src/scripts/qemu-binfmt-conf.sh
+
+  install-commands:
+  - |
+    install -Dm755 -t "%{install-root}%{bindir}" qemu-aarch64
+  - |
+    mkdir -p %{install-root}%{datadir}/binfmts
+    src/scripts/qemu-binfmt-conf.sh --debian --exportdir "%{install-root}%{datadir}/binfmts" --qemu-path "%{bindir}" --persistent yes --preserve-argv0 yes
+
+  strip-commands:
+  - true
+
+sources:
+- kind: tar
+  base-dir: ''
+  url: 
+    github_files:tonistiigi/binfmt/releases/download/deploy%2Fv8.0.4-33/qemu_v8.0.4_linux-amd64.tar.gz
+  ref: 924cd873807a87d800ea914a7d4b1d81973e935839e9596cf4ff7183290b4572
+- kind: tar
+  directory: src
+  url: qemu:qemu-8.0.4.tar.xz
+  ref: 81c817dda38af958be5bef1a6cf55b658bb2d3fb87c1e6a571de6b7b2c44516c

buildstream/elements/tooling.bst

@@ -10,8 +10,10 @@ depends:
 - freedesktop-sdk.bst:components/appstream-glib.bst
 - gnome-build-meta.bst:vm/git-lfs.bst
 - gnome-build-meta.bst:core-deps/xvfb.bst
+- components/binfmt-support.bst
 - components/flatpak-builder-lint.bst
 - components/gh-cli.bst
+- components/qemu-user.bst
 - flatpakrepo/flathub.bst
 - flatpakrepo/flathub-beta.bst
 - flatpakrepo/gnome-nightly.bst

buildstream/include/aliases.yml

@@ -14,6 +14,7 @@ aliases:
   github_files: https://github.com/
   gnome_nightly: https://nightly.gnome.org/
   pypi: https://files.pythonhosted.org/packages/
+  qemu: https://download.qemu.org/
 
   # git aliases go here
   github: https://github.com/

buildstream/project.conf

@@ -20,6 +20,7 @@ plugins:
 - origin: junction
   junction: plugins/buildstream-plugins.bst
   elements:
+  - autotools
   - meson
   sources:
   - cargo