CI: Use bash arrays to simplify dom0 rootfs construction

For Qubes, this requires switching from sh to bash.

This reduces the number of times the target filename needs to be written to 1.

Expand the comment to explain the concatenation constraints.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

automation/scripts/qubes-x86-64.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 set -ex -o pipefail
 
@@ -22,6 +22,8 @@ domU_type="pvh"
 domU_vif="'bridge=xenbr0',"
 domU_extra_config=
 retrieve_xml=
+dom0_rootfs_extra_comp=()
+dom0_rootfs_extra_uncomp=()
 
 case "${test_variant}" in
     ### test: smoke test & smoke test PVH & smoke test HVM & smoke test PVSHIM
@@ -187,10 +189,16 @@ Kernel \r on an \m (\l)
     rm -rf rootfs
 fi
 
-# Dom0 rootfs
-cp binaries/ucode.cpio binaries/dom0-rootfs.cpio.gz
-cat binaries/rootfs.cpio.gz >> binaries/dom0-rootfs.cpio.gz
-cat binaries/xen-tools.cpio.gz >> binaries/dom0-rootfs.cpio.gz
+# Dom0 rootfs.  The order of concatenation is important; ucode wants to come
+# first, and all uncompressed must be ahead of compressed.
+dom0_rootfs_parts=(
+    binaries/ucode.cpio
+    "${dom0_rootfs_extra_uncomp[@]}"
+    binaries/rootfs.cpio.gz
+    binaries/xen-tools.cpio.gz
+    "${dom0_rootfs_extra_comp[@]}"
+)
+cat "${dom0_rootfs_parts[@]}" > binaries/dom0-rootfs.cpio.gz
 
 # test-local configuration
 mkdir -p rootfs

automation/scripts/xilinx-smoke-dom0-x86_64.sh

@@ -28,6 +28,8 @@ extra = "root=/dev/ram0 console=hvc0"
 memory = 512
 '
 DOMU_CFG_EXTRA=""
+dom0_rootfs_extra_comp=()
+dom0_rootfs_extra_uncomp=()
 
 # Select test variant.
 if [ "${TEST}" = "ping" ]; then
@@ -71,6 +73,7 @@ do
   sleep 1
 done | argo-exec -p 28333 -d 0 -- /bin/echo
 "
+    dom0_rootfs_extra_comp+=(binaries/argo.cpio.gz)
     DOM0_CMD="
 insmod /lib/modules/\$(uname -r)/updates/xen-argo.ko
 xl -vvv create /etc/xen/domU.cfg
@@ -103,13 +106,16 @@ find . | cpio -H newc -o | gzip >> ../binaries/domU-rootfs.cpio.gz
 cd ..
 rm -rf rootfs
 
-# Dom0 rootfs
-cp binaries/ucode.cpio binaries/dom0-rootfs.cpio.gz
-cat binaries/rootfs.cpio.gz >> binaries/dom0-rootfs.cpio.gz
-cat binaries/xen-tools.cpio.gz >> binaries/dom0-rootfs.cpio.gz
-if [[ "${TEST}" == argo ]]; then
-    cat binaries/argo.cpio.gz >> binaries/dom0-rootfs.cpio.gz
-fi
+# Dom0 rootfs.  The order of concatenation is important; ucode wants to come
+# first, and all uncompressed must be ahead of compressed.
+dom0_rootfs_parts=(
+    binaries/ucode.cpio
+    "${dom0_rootfs_extra_uncomp[@]}"
+    binaries/rootfs.cpio.gz
+    binaries/xen-tools.cpio.gz
+    "${dom0_rootfs_extra_comp[@]}"
+)
+cat "${dom0_rootfs_parts[@]}" > binaries/dom0-rootfs.cpio.gz
 
 # test-local configuration
 mkdir -p rootfs