chore(os): shared loop-partition wait, drop the dead --vm flag

os/rauc/loop-wait.sh

@@ -0,0 +1,22 @@
+# shellcheck shell=bash
+#
+# Shared by mkimage.sh (builds a slot image) and tests/os/verify-image.sh (checks one): the wait
+# for a loop device's partition nodes to exist. `losetup -P` returns before the kernel/udev
+# publish them, and the gap widens under loop-device churn (a KVM battery running beside a release
+# build) — without the wait, the first mkfs/mount fails with "No such device or address" and a
+# plain retry succeeds, which is exactly how it stays invisible until release day. This started as
+# two copies of the same nine lines and drifted in wording; the callers keep their own error
+# message (mkimage.sh's build failure reads differently from verify-image.sh's "broken image"
+# verdict), only the polling loop is shared.
+
+# $1 = loop device (e.g. /dev/loop0). Waits for its p1+p2 nodes — the appliance image is
+# exactly ESP + slot A, so both callers want exactly this pair. Returns 0 once both are block
+# devices, 1 if they never showed up.
+wait_loop_partitions() {
+    udevadm settle 2>/dev/null || true
+    for _ in {1..25}; do
+        [ -b "${1}p1" ] && [ -b "${1}p2" ] && return 0
+        sleep 0.2
+    done
+    [ -b "${1}p1" ] && [ -b "${1}p2" ]
+}

os/rauc/mkimage.sh

@@ -37,6 +37,8 @@ SIZE_GIB="${PITHEAD_IMAGE_GIB:-5}"
 TARBALL="os/build/pithead-root.tar"
 # shellcheck source=os/rauc/populate-slot.sh
 . os/rauc/populate-slot.sh
+# shellcheck source=os/rauc/loop-wait.sh
+. os/rauc/loop-wait.sh
 
 [ -s "$TARBALL" ] || {
     echo "missing $TARBALL — run os/build-image.sh first to stage the rootfs" >&2
@@ -67,17 +69,8 @@ cleanup() {
 }
 trap cleanup EXIT
 
-# losetup -P returns before the kernel/udev publish the partition nodes, and the gap widens
-# under loop-device churn (a KVM battery running beside a release build). Without this wait the
-# first mkfs fails with "unable to open ${LOOP}p1: No such device or address" — and a plain
-# retry succeeds, which is exactly how it stays invisible until release day. One guarded wait:
-# settle udev, then poll briefly for both nodes.
-udevadm settle 2>/dev/null || true
-for _ in {1..25}; do
-    [ -b "${LOOP}p1" ] && [ -b "${LOOP}p2" ] && break
-    sleep 0.2
-done
-[ -b "${LOOP}p1" ] && [ -b "${LOOP}p2" ] || {
+# See loop-wait.sh for why this wait exists.
+wait_loop_partitions "$LOOP" || {
     echo "partition nodes for $LOOP never appeared after losetup -P" >&2
     exit 1
 }

tests/os/run.sh

@@ -53,10 +53,6 @@ while [ $# -gt 0 ]; do
         PHASE="$2"
         shift 2
         ;;
-    --vm)
-        VM="$2"
-        shift 2
-        ;;
     -h | --help)
         sed -n '2,20p' "$0" | sed 's/^# \{0,1\}//'
         exit 0

tests/os/verify-image.sh

@@ -12,6 +12,13 @@
 # Exit: 0 all checks pass, 1 otherwise.
 set -uo pipefail
 
+# Directory-independent: this script assumes cwd == repo root for the relative paths later on
+# (./pithead, build/dashboard/...), so resolve the shared helper from the script's own location
+# instead of adding a cd that would change those.
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]:-$0}")" && pwd)"
+# shellcheck source=os/rauc/loop-wait.sh
+. "$SCRIPT_DIR/../../os/rauc/loop-wait.sh"
+
 IMAGE="${1:-}"
 MODE="${2:-}"
 [ -f "$IMAGE" ] || {
@@ -47,15 +54,9 @@ cleanup() {
 }
 trap cleanup EXIT
 
-# Same race as mkimage.sh: losetup -P returns before the partition nodes exist. Wait once here
-# so the checks below read the image, not the timing of udev on a busy box.
-udevadm settle 2>/dev/null || true
-for _ in {1..25}; do
-    [ -b "${LOOP}p1" ] && [ -b "${LOOP}p2" ] && break
-    sleep 0.2
-done
-# Hard-fail like mkimage.sh does: a mount error two screens later names the wrong culprit.
-[ -b "${LOOP}p1" ] && [ -b "${LOOP}p2" ] || {
+# Same race as mkimage.sh (see loop-wait.sh). Hard-fail like it does: a mount error two screens
+# later names the wrong culprit.
+wait_loop_partitions "$LOOP" || {
     echo "partition nodes never appeared on $LOOP — udev timing or a broken image" >&2
     exit 1
 }