Add channel-aware release tooling and updater recovery

scripts/verify-release.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+if [[ $# -ne 3 ]]
+then
+	printf 'Usage: %s VERSION CHANNEL OUTPUT_DIR\n' "$0" >&2
+	exit 2
+fi
+
+SCRIPT_ROOT="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(cd -- "${SCRIPT_ROOT}/.." && pwd)"
+PYTHON_BIN="${PTLINUX_PYTHON:-python3}"
+ARGUMENTS=(
+	"${SCRIPT_ROOT}/verify_release.py"
+	"$1"
+	"$2"
+	"$3"
+)
+
+if [[ -n "${PTLINUX_UPDATE_PUBLIC_KEY:-}" ]]
+then
+	ARGUMENTS+=(--public-key "$PTLINUX_UPDATE_PUBLIC_KEY")
+fi
+if [[ "${REQUIRE_RELEASE_SIGNATURE:-0}" == "1" ]]
+then
+	ARGUMENTS+=(--require-signature)
+fi
+
+cd -- "$PROJECT_ROOT"
+exec "$PYTHON_BIN" "${ARGUMENTS[@]}"