Files
ninlight-w600/tools/mkimage/nl_mkimage.py
T
Michael SauerandClaude Haiku 4.5 0ba269a39a feat: nl_mkimage prüft Images mit --verify
deploy.sh soll kein Image auf die Station schieben, das jede Lampe
ablehnen würde. Die Prüfung sitzt in nl_mkimage, weil dort das
Trailer-Layout ohnehin steht - eine zweite Kopie derselben Offsets
wäre genau die Doppelung, die beim Abweichen jedes Update killt.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
2026-09-12 12:25:02 +02:00

86 lines
3.3 KiB
Python
Executable File

#!/usr/bin/env python3
"""Appends the ninlight OTA trailer to a `_gz.img` produced by wm_tool.
Layout (512 bytes): "NINL" | version(1) | device[16] | fw_version[16] | sha256[32] | 0xFF padding.
The hash covers the complete `_gz.img` (T_BOOTER header + payload), which is exactly what the
firmware hashes while writing the image to flash.
"""
import argparse
import hashlib
import sys
from pathlib import Path
TRAILER_SIZE = 512
TRAILER_VERSION = 1
FIELD = 16
def field(value: str, name: str) -> bytes:
raw = value.encode()
if len(raw) >= FIELD:
sys.exit(f"error: {name} '{value}' is too long (max {FIELD - 1} bytes)")
return raw.ljust(FIELD, b"\x00")
def verify(path: Path, expect_device: str | None) -> int:
"""Checks an _ota.img the way the firmware does before accepting it."""
data = path.read_bytes()
if len(data) <= TRAILER_SIZE:
print(f"error: {path} is too short to carry a trailer", file=sys.stderr)
return 1
payload, trailer = data[:-TRAILER_SIZE], data[-TRAILER_SIZE:]
if trailer[0:4] != b"NINL":
print(f"error: {path} has no ninlight trailer", file=sys.stderr)
return 1
if trailer[4] != TRAILER_VERSION:
print(f"error: {path} has trailer version {trailer[4]}, expected {TRAILER_VERSION}",
file=sys.stderr)
return 1
device = trailer[5:21].rstrip(b"\x00").decode("ascii", "replace")
version = trailer[21:37].rstrip(b"\x00").decode("ascii", "replace")
if expect_device is not None and device != expect_device:
print(f"error: {path} carries device '{device}', expected '{expect_device}'",
file=sys.stderr)
return 1
if trailer[37:69] != hashlib.sha256(payload).digest():
print(f"error: {path} fails its sha256 - the payload does not match the trailer",
file=sys.stderr)
return 1
print(f"{device} {version} {len(data)}")
return 0
def main() -> None:
p = argparse.ArgumentParser(description="append the ninlight OTA trailer")
p.add_argument("--image", type=Path, help="input _gz.img")
p.add_argument("--device", help="device id, e.g. e27_rgb")
p.add_argument("--version", help="firmware version")
p.add_argument("--out", type=Path, help="output _ota.img")
p.add_argument("--verify", type=Path, help="check an existing _ota.img instead of building one")
p.add_argument("--expect-device", help="with --verify: require this device id")
a = p.parse_args()
if a.verify is not None:
raise SystemExit(verify(a.verify, a.expect_device))
for name in ("image", "device", "version", "out"):
if getattr(a, name) is None:
p.error(f"--{name} is required unless --verify is given")
data = a.image.read_bytes()
if len(data) > TRAILER_SIZE and data[-TRAILER_SIZE : -TRAILER_SIZE + 4] == b"NINL":
sys.exit("error: image already carries a trailer")
trailer = bytearray(b"\xff" * TRAILER_SIZE)
trailer[0:4] = b"NINL"
trailer[4] = TRAILER_VERSION
trailer[5:21] = field(a.device, "device")
trailer[21:37] = field(a.version, "version")
trailer[37:69] = hashlib.sha256(data).digest()
a.out.write_bytes(data + bytes(trailer))
print(f"{a.out} ({len(data) + TRAILER_SIZE} bytes, device={a.device}, version={a.version})")
if __name__ == "__main__":
main()