Files
bootloader/test/pbtest.py
BlackMark a977e507f3 pureboot: every deployment axis is a build parameter
Clock, baud, serial backend (hardware USART 0/1 or the software UART on
any pins) and the activation window all resolve through one CMake
function, pureboot_add_loader() in pureboot/CMakeLists.txt — the unit a
downstream project consumes. The default baud is the fastest standard
rate within 2.5 % (the same best-divisor search libavr's solver runs),
gated on software builds by the polled receiver's 100-cycles-a-bit
floor; every explicit pick is re-checked by the compile's static asserts.

The size matrix builds each axis that can move the image — backend x
clock ladder x USART instance, per chip — against the slot budget, and
two nondefault deployments run the whole protocol suite live: the 328P
on its shipped 1 MHz fuses over software serial on TX=PB1/RX=PB5
(pureboot.custom), and the 644A over USART1 (pureboot.usart1). The sim
runner takes -l to bridge any link, paces a fully quiet bridge toward
real time (a free-running 8 M-cycle window loses the reset-race knock),
and the fixture application speaks the deployment it is built for.

The loader itself shed bytes on the way: the return-address high byte
spelled through byteswap (the double swap folds to the one-byte pick),
the info-block address composed instead of bit_cast, and libavr's new
polled-UART helpers replacing the port's uart::detail reaches. Every
combination fits: 458-506 B across the megas' whole matrix, 470-484 B
on the tinies, 556-562 B in the 1284s' 1 KiB slot.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-21 23:42:57 +02:00

145 lines
6.2 KiB
Python

#!/usr/bin/env python3
"""End-to-end pureboot protocol test: spawn the simavr device, then drive it
with the real host tool (pureboot.py, as a subprocess over the device's pty)
through flash + EEPROM + fuse + hand-over scenarios, and cross-check
the tool's view against the simulator's ground-truth memory dumps.
Usage: pbtest.py <device_bin> <pureboot_elf> <mcu> <hz> <base_hex> <page>
<baud> <eeprom_size> <app_bin> <tool_py> <workdir> [link]
The optional link is the runner's -l spec (usart1, sw:B5,B1, ...) for a
loader built off the chip's natural serial default.
Exits 0 if every scenario passes.
"""
import os
import sys
def fail(message):
print(f"FAIL: {message}")
sys.exit(1)
def rjmp_decode(word, at, flash_words):
"""Where an rjmp word at word-address `at` lands — deliberately written
against the instruction-set definition (12-bit signed offset), not with
the host tool's encoder, so an encoding bug cannot verify itself."""
if word & 0xF000 != 0xC000:
fail(f"word at {at * 2:#06x} is {word:#06x}, not an rjmp")
offset = word & 0x0FFF
if offset >= 0x800:
offset -= 0x1000
return (at + 1 + offset) % flash_words
def main():
args = sys.argv[1:]
link = args.pop() if len(args) == 12 else None
(device_bin, elf, mcu, hz, base_hex, page, baud, eeprom_size, app_bin, tool, workdir) = args
base, page, baud, eeprom_size = int(base_hex, 0), int(page), int(baud), int(eeprom_size)
sys.path.insert(0, os.path.dirname(os.path.abspath(tool)))
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
import pbsim
import pureboot as pb
os.makedirs(workdir, exist_ok=True)
ee_image = bytes(range(0xA0, 0xB0))
ee_path = os.path.join(workdir, "ee.bin")
open(ee_path, "wb").write(ee_image)
dump = os.path.join(workdir, "flash_dump.bin")
read_flash = os.path.join(workdir, "readback_flash.bin")
read_eeprom = os.path.join(workdir, "readback_eeprom.bin")
# The geometry the host will discover, for computing the expected image:
# the boot-sectioned megas need no vector surgery (the tinies and the
# boot-section-less m48s do), the large chips speak word addresses, and
# the page byte is the wire's 0-means-256.
mega = mcu.startswith("atmega")
patch = not mega or mcu.startswith("atmega48")
word_flash = base + 512 > 0x10000
wire_base = base // 2 if word_flash else base
flags = (1 if patch else 0) | (2 if word_flash else 0)
info = pb.Info(
bytes([ord("P"), ord("B"), 1, 0, 0, 0, page & 0xFF])
+ bytes([wire_base & 0xFF, wire_base >> 8, eeprom_size & 0xFF, eeprom_size >> 8])
+ bytes([flags])
)
device = pbsim.Device(device_bin, elf, mcu, hz, base_hex, page, baud, dump, link=link)
try:
# Session 1: knock from reset, identify, program everything, stay.
out = pbsim.run_tool(tool, device.pty, baud, "--info", "--fuses", "--flash", app_bin,
"--eeprom", ee_path, "--stay")
for needed in ("signature", "fuses", "verify:", "stays"):
if needed not in out:
fail(f"session 1 output lacks {needed!r}")
# Session 2: reconnect into the live session, verify, dump, hand over
# is deferred — the pty must be reopened for the APP banner first.
out = pbsim.run_tool(tool, device.pty, baud, "--verify-flash", app_bin, "--verify-eeprom", ee_path,
"--read-flash", read_flash, "--read-eeprom", read_eeprom, "--stay")
if out.count("verify:") != 2:
fail("session 2 did not verify both memories")
eeprom_back = open(read_eeprom, "rb").read()
if eeprom_back[: len(ee_image)] != ee_image:
fail("EEPROM read-back mismatch")
# The expected post-surgery flash, straight from the tool's planner.
pages = pb.plan_flash(open(app_bin, "rb").read(), info)
flash_back = open(read_flash, "rb").read()
for address, data in pages.items():
if flash_back[address : address + page] != data:
fail(f"flash read-back mismatch in page {address:#06x}")
# An external reset re-enters through the patched word 0 (tinies; the
# runner resets them to address 0 like silicon) or BOOTRST (mega).
# The loader must answer a fresh knock, and the 'J' hand-over must
# land in the application, which banners on the same link.
device.reset()
port = pb.Port(device.pty, baud)
try:
loader = pb.Loader(port)
loader.connect(15)
loader.run_application()
banner = port.read_exact(3, 5.0)
if banner != b"APP":
fail(f"application banner was {banner!r}")
finally:
port.close()
finally:
device.stop()
# Ground truth: the simulator's own memories, against the host's view.
flash_true = open(dump, "rb").read()
if flash_true[:base] != flash_back:
fail("host flash read-back differs from the simulator's flash")
if flash_true[base] == 0xFF and flash_true[base + 1] == 0xFF:
fail("loader region looks erased in the ground-truth dump")
# The surgery, decoded independently: the patched vector must land on the
# loader, the trampoline on the application's own entry (patched-vector
# chips only — a boot-sectioned mega's word 0 stays the application's).
if patch:
flash_words = (base + 512) // 2
app = open(app_bin, "rb").read()
word0 = flash_true[0] | (flash_true[1] << 8)
if rjmp_decode(word0, 0, flash_words) != base // 2:
fail("patched reset vector does not land on the loader base")
trampoline = flash_true[base - 2] | (flash_true[base - 1] << 8)
original = app[0] | (app[1] << 8)
if rjmp_decode(trampoline, (base - 2) // 2, flash_words) != rjmp_decode(original, 0, flash_words):
fail("trampoline does not land on the application's own entry")
ee_true_path = dump + ".eeprom"
if os.path.exists(ee_true_path):
ee_true = open(ee_true_path, "rb").read()
if ee_true[: len(ee_image)] != ee_image:
fail("ground-truth EEPROM does not match what was programmed")
print("pbtest: all scenarios pass")
if __name__ == "__main__":
main()