Stamp git info and build ID into the image

Capture this image build's git state and a BUILD_ID (CI-provided, or
a UTC timestamp fallback) and write both into /etc/os-release of
@minimal before it is snapshotted to @Minimal_stock, so every profile
inherits them via COW. Resolve the os-release symlink so the real
file is edited in place. The MOTD and login banner now report the
build ID instead of a decoded timestamp.

Author: Yury-MonZon

build-rootfs-img.sh

@@ -5,6 +5,17 @@
 
 set -e
 
+# Capture Git information
+[ -n "${GIT_HASH}" ] || GIT_HASH=$(git rev-parse --short HEAD 2>/dev/null || echo "unknown")
+[ -n "${GIT_BRANCH}" ] || GIT_BRANCH=$(git symbolic-ref --short HEAD 2>/dev/null || git describe --tags --exact-match 2>/dev/null || echo "detached")
+[ -n "${GIT_MSG}" ] || GIT_MSG=$(git log -1 --pretty=format:"%s" 2>/dev/null | sed 's/[\"()]/\\&/g; s/'"'"'/\\&/g' || echo "unknown")
+[ -n "${GIT_INFO}" ] || GIT_INFO="${GIT_BRANCH}@${GIT_HASH}: ${GIT_MSG}"
+GIT_INFO=$(echo "$GIT_INFO" | tr -dc '[:alnum:][:space:]')
+
+# Build identifier: CI sets BUILD_ID in the environment (e.g. "build-1419"); otherwise
+# fall back to a UTC timestamp, same default/format as build-images.sh.
+: "${BUILD_ID:=$(date -u '+%Y%m%d-%H%M')}"
+
 if [ -c /dev/kvm -a -w /dev/kvm ]; then
 	# Have virtualization support, can use fakemachine (default, fast, safe)
 	DEBOS="debos -c $(nproc) -m 6Gb"
@@ -29,7 +40,7 @@ mkdir -p "$IMG_OUT"/linux_tmp
 cp -r "$LINUX_OUT"/* "$IMG_OUT"/linux_tmp
 
 echo "Creating the root FS image"
-$DEBOS --artifactdir="$IMG_OUT" -t imagesize:"$IMGSIZE" -t kerneldir:linux_tmp debian-rk3576-img.yaml
+$DEBOS --artifactdir="$IMG_OUT" -t imagesize:"$IMGSIZE" -t kerneldir:linux_tmp -t gitinfo:"$GIT_INFO" -t buildid:"$BUILD_ID" debian-rk3576-img.yaml
 sync "$IMG_OUT"/debian-nobootloader.img
 
 owner=$(stat -c %u "$IMG_OUT"/debian-nobootloader.img)

debian-rk3576-img.yaml

@@ -3,6 +3,8 @@
 {{ $kerneldir  := or .kerneldir  "prebuilt/linux" }}
 {{ $cmdline    := or .cmdline    "audit=0 console=tty1 console=ttyS0,1500000n8" }}
 {{ $fslabel    := or .fslabel    "flipperos" }}
+{{ $gitinfo    := or .gitinfo    "unknown" }}
+{{ $buildid    := or .buildid    "unknown" }}
 {{- /* fs-wide btrfs mount options. ssd is FORCED (loopback/eMMC isn't reliably
        detected as non-rotational). */ -}}
 {{ $btrfsopts  := or .btrfsopts  "compress=zstd,noatime,ssd,discard=async" }}
@@ -130,6 +132,21 @@ actions:
     chroot: true
     command: systemctl set-default multi-user.target
 
+  # The ospack tarball already carries a BUILD_GIT (the ospack build's git state), and the
+  # ospack is cached/reused across image builds. Replace it with THIS image build's git
+  # state so the stamp reflects the actual image. Stamped into @Minimal before it is snapshotted 
+  # to @Minimal_stock, so every profile inherits it via COW. Both are consumed by the MOTD/banner.
+  - action: run
+    description: Save GIT info
+    chroot: true
+    command: |
+      # /etc/os-release is normally a symlink to /usr/lib/os-release; resolve it so
+      # sed edits the real file in place instead of replacing the symlink.
+      osr="$(readlink -f /etc/os-release)"
+      sed -i '/^BUILD_GIT=/d; /^BUILD_ID=/d' "$osr"
+      echo 'BUILD_GIT="{{ $gitinfo }}"' >> "$osr"
+      echo 'BUILD_ID={{ $buildid }}' >> "$osr"
+
   # ===========================================================================
   # Stock (RO) bases + per-profile bootable roots.
   #