scripts/ci: add build env rules for aarch32 on aarch64

At least the current crop of Aarch64 HW can support running 32 bit EL0
code. Before we can build and test we need a minimal set of packages
installed. We can't use "apt build-dep" because it currently gets
confused trying to keep two sets of build-deps installed at once.
Instead we install a minimal set of libraries that will allow us to
continue.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220225172021.3493923-8-alex.bennee@linaro.org>

scripts/ci/setup/build-environment.yml

@@ -19,6 +19,13 @@
           - '((ansible_version.major == 2) and (ansible_version.minor >= 8)) or (ansible_version.major >= 3)'
         msg: "Unsuitable ansible version, please use version 2.8.0 or later"
 
+    - name: Add armhf foreign architecture to aarch64 hosts
+      command: dpkg --add-architecture armhf
+      when:
+        - ansible_facts['distribution'] == 'Ubuntu'
+        - ansible_facts['architecture'] == 'aarch64'
+        - ansible_facts['distribution_version'] == '20.04'
+
     - name: Update apt cache / upgrade packages via apt
       apt:
         update_cache: yes
@@ -115,6 +122,24 @@
         - ansible_facts['distribution'] == 'Ubuntu'
         - ansible_facts['distribution_version'] == '20.04'
 
+    - name: Install armhf cross-compile packages to build QEMU on AArch64 Ubuntu 20.04
+      package:
+        name:
+          - binutils-arm-linux-gnueabihf
+          - gcc-arm-linux-gnueabihf
+          - libblkid-dev:armhf
+          - libc6-dev:armhf
+          - libffi-dev:armhf
+          - libglib2.0-dev:armhf
+          - libmount-dev:armhf
+          - libpcre2-dev:armhf
+          - libpixman-1-dev:armhf
+          - zlib1g-dev:armhf
+      when:
+        - ansible_facts['distribution'] == 'Ubuntu'
+        - ansible_facts['distribution_version'] == '20.04'
+        - ansible_facts['architecture'] == 'aarch64'
+
     - name: Install basic packages to build QEMU on EL8
       dnf:
         # This list of packages start with tests/docker/dockerfiles/centos8.docker