zip-img: create, zips all QEMU images

build-all: make gem5 rebuild optional

rootfs_post_image_script: prevent qemu-img from generating trace files

build-all

@@ -4,7 +4,18 @@ set -eux
 # Will take forever from a clean repo, this is most useful
 # after pulling the repository to do an incremental build
 # then quickly test out all the setups.
+gem5=true
+while getopts G OPT; do
+  case "$OPT" in
+    G)
+      gem5=false
+      ;;
+  esac
+done
+shift "$(($OPTIND - 1))"
 for arch in x86_64 arm aarch64; do
   ./build -a "$arch" -klq
-  ./build -a "$arch" -g -Gkl
+  if "$gem5"; then
+    ./build -a "$arch" -g -Gkl
+  fi
 done