zip-img: create, zips all QEMU images

build-all: make gem5 rebuild optional

rootfs_post_image_script: prevent qemu-img from generating trace files

zip-img

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -eu
+# Ideally should be obtained from common.
+# But the paths there are absolute, and get recorded by in zip.
+# and generating relative paths seems hard:
+# https://stackoverflow.com/questions/2564634/convert-absolute-path-into-relative-path-given-a-current-directory-using-bash
+sha="$(git log -1 --format="%H")"
+for arch in x86_64 arm aarch64; do
+  img_dir="out/${arch}/buildroot/images"
+  rm -f "${img_dir}/rootfs.ext2"
+  zip -r "out/images-${sha}.zip" "${img_dir}"
+done