px4-firmware/Tools/make_can_boot_descriptor.py

339 lines
12 KiB
Python
Executable File

#!/usr/bin/env python3
import os
import sys
import subprocess
import struct
import optparse
import binascii
from io import BytesIO
class GitWrapper:
@classmethod
def command(cls, txt):
cmd = "git " + txt
pr = subprocess.Popen( cmd , shell = True, stdout = subprocess.PIPE, stderr = subprocess.PIPE )
(out, error) = pr.communicate()
if len(error):
raise Exception(cmd +" failed with [" + error.strip() + "]")
return out
class AppDescriptor(object):
"""
UAVCAN firmware image descriptor format:
uint64_t signature (bytes [7:0] set to 'APDesc00' by linker script)
uint64_t image_crc (set to 0 by linker script)
uint32_t image_size (set to 0 by linker script)
uint32_t vcs_commit (set in source or by this tool)
uint8_t version_major (set in source)
uint8_t version_minor (set in source)
uint8_t reserved[6] (set to 0xFF by linker script)
"""
LENGTH = 8 + 8 + 4 + 4 + 1 + 1 + 6
SIGNATURE = b"APDesc00"
RESERVED = b"\xFF" * 6
def __init__(self, bytes=None):
self.signature = AppDescriptor.SIGNATURE
self.image_crc = 0
self.image_size = 0
self.vcs_commit = 0
self.version_major = 0
self.version_minor = 0
self.reserved = AppDescriptor.RESERVED
if bytes:
try:
self.unpack(bytes)
except Exception:
raise ValueError("Invalid AppDescriptor: {0}".format(
binascii.b2a_hex(bytes)))
def pack(self):
return struct.pack("<8sQLLBB6s", self.signature, self.image_crc,
self.image_size, self.vcs_commit,
self.version_major, self.version_minor,
self.reserved)
def unpack(self, bytes):
(self.signature, self.image_crc, self.image_size, self.vcs_commit,
self.version_major, self.version_minor, self.reserved) = \
struct.unpack("<8sQLLBB6s", bytes)
if not self.empty and not self.valid:
raise ValueError()
@property
def empty(self):
return (self.signature == AppDescriptor.SIGNATURE and
self.image_crc == 0 and self.image_size == 0 and
self.reserved == AppDescriptor.RESERVED)
@property
def valid(self):
return (self.signature == AppDescriptor.SIGNATURE and
self.image_crc != 0 and self.image_size > 0 and
self.reserved == AppDescriptor.RESERVED)
class FirmwareImage(object):
def __init__(self, path_or_file, mode="r"):
if getattr(path_or_file, "read", None):
self._file = path_or_file
self._do_close = False
self._padding = 0
else:
if "b" not in mode:
self._file = open(path_or_file, mode + "b")
else:
self._file = open(path_or_file, mode)
self._do_close = True
self._padding = 4
if "r" in mode:
self._contents = BytesIO(self._file.read())
else:
self._contents = BytesIO()
self._do_write = False
self._length = None
self._descriptor_offset = None
self._descriptor_bytes = None
self._descriptor = None
def __enter__(self):
return self
def __getattr__(self, attr):
if attr == "write":
self._do_write = True
return getattr(self._contents, attr)
def __iter__(self):
return iter(self._contents)
def __exit__(self, *args):
if self._do_write:
if getattr(self._file, "seek", None):
self._file.seek(0)
self._file.write(self._contents.getvalue())
if self._padding:
self._file.write(b'\xff' * self._padding)
if self._do_close:
self._file.close()
def _write_descriptor_raw(self):
# Seek to the appropriate location, write the serialized
# descriptor, and seek back.
prev_offset = self._contents.tell()
self._contents.seek(self._descriptor_offset)
self._contents.write(self._descriptor.pack())
self._contents.seek(prev_offset)
def write_descriptor(self):
# Set the descriptor's length and CRC to the values required for
# CRC computation
self.app_descriptor.image_size = self.length
self.app_descriptor.image_crc = 0
self._write_descriptor_raw()
# Update the descriptor's CRC based on the computed value and write
# it out again
self.app_descriptor.image_crc = self.crc
self._write_descriptor_raw()
@property
def crc(self):
MASK = 0xFFFFFFFFFFFFFFFF
POLY = 0x42F0E1EBA9EA3693
# Calculate the image CRC with the image_crc field in the app
# descriptor zeroed out.
crc_offset = self.app_descriptor_offset + len(AppDescriptor.SIGNATURE)
content = bytearray(self._contents.getvalue())
content[crc_offset:crc_offset + 8] = bytearray.fromhex("00" * 8)
if self._padding:
content += bytearray.fromhex("ff" * self._padding)
val = MASK
for byte in content:
val ^= (byte << 56) & MASK
for bit in range(8):
if val & (1 << 63):
val = ((val << 1) & MASK) ^ POLY
else:
val <<= 1
return (val & MASK) ^ MASK
@property
def padding(self):
return self._padding
@property
def length(self):
if not self._length:
# Find the length of the file by seeking to the end and getting
# the offset
prev_offset = self._contents.tell()
self._contents.seek(0, os.SEEK_END)
self._length = self._contents.tell()
if self._padding:
fill = self._padding - (self._length % self._padding)
if fill:
self._length += fill
self._padding = fill
self._contents.seek(prev_offset)
return self._length
@property
def app_descriptor_offset(self):
if not self._descriptor_offset:
# Save the current position
prev_offset = self._contents.tell()
# Check each byte in the file to see if a valid descriptor starts
# at that location. Slow, but not slow enough to matter.
offset = 0
while offset < self.length - AppDescriptor.LENGTH:
self._contents.seek(offset)
try:
# If this throws an exception, there isn't a valid
# descriptor at this offset
AppDescriptor(self._contents.read(AppDescriptor.LENGTH))
except Exception:
offset += 1
else:
self._descriptor_offset = offset
break
# Go back to the previous position
self._contents.seek(prev_offset)
if not self._descriptor_offset:
raise Exception('AppDescriptor not found')
return self._descriptor_offset
@property
def app_descriptor(self):
if not self._descriptor:
# Save the current position
prev_offset = self._contents.tell()
# Jump to the descriptor adn parse it
self._contents.seek(self.app_descriptor_offset)
self._descriptor_bytes = self._contents.read(AppDescriptor.LENGTH)
self._descriptor = AppDescriptor(self._descriptor_bytes)
# Go back to the previous offset
self._contents.seek(prev_offset)
return self._descriptor
@app_descriptor.setter
def app_descriptor(self, value):
self._descriptor = value
if __name__ == "__main__":
parser = optparse.OptionParser(usage="usage: %prog [options] [IN OUT]")
parser.add_option("--vcs-commit", dest="vcs_commit", default=None,
help="set the descriptor's VCS commit value to COMMIT",
metavar="COMMIT")
parser.add_option("-g", "--use-git-hash", dest="use_git_hash", action="store_true",
help="set the descriptor's VCS commit value to the current git hash",
metavar="GIT")
parser.add_option("--bootloader-size", dest="bootloader_size", default=0,
help="don't write the first SIZE bytes of the image",
metavar="SIZE")
parser.add_option("--bootloader-image", dest="bootloader_image", default=0,
help="prepend a bootloader image to the output file",
metavar="IMAGE")
parser.add_option("-v", "--verbose", dest="verbose", action="store_true",
help="show additional firmware information on stdout")
options, args = parser.parse_args()
if len(args) not in (0, 2):
parser.error("specify both IN or OUT for file operation, or " +
"neither for stdin/stdout operation")
if options.vcs_commit and options.use_git_hash:
parser.error("options --vcs-commit and --use-git-commit are mutually exclusive")
if options.use_git_hash:
try:
options.vcs_commit = int(GitWrapper.command("rev-list HEAD --max-count=1 --abbrev=8 --abbrev-commit"),16)
except Exception as e:
print("Git Command failed "+ str(e) +"- Exiting!")
quit()
if args:
in_file = args[0]
out_file = args[1]
else:
in_file = sys.stdin
out_file = sys.stdout
bootloader_image = b""
if options.bootloader_image:
with open(options.bootloader_image, "rb") as bootloader:
bootloader_image = bootloader.read()
bootloader_size = int(options.bootloader_size)
with FirmwareImage(in_file, "rb") as in_image:
with FirmwareImage(out_file, "wb") as out_image:
image = in_image.read()
out_image.write(bootloader_image)
out_image.write(image[bootloader_size:])
if options.vcs_commit:
out_image.app_descriptor.vcs_commit = options.vcs_commit
out_image.write_descriptor()
if options.verbose:
sys.stderr.write(
"""
Application descriptor located at offset 0x{0.app_descriptor_offset:08X}
""".format(in_image, in_image.app_descriptor, out_image.app_descriptor,
bootloader_size, len(bootloader_image)))
if bootloader_size:
sys.stderr.write(
"""Ignored the first {3:d} bytes of the input image. Prepended {4:d} bytes of
bootloader image to the output image.
""".format(in_image, in_image.app_descriptor, out_image.app_descriptor,
bootloader_size, len(bootloader_image)))
sys.stderr.write(
"""READ VALUES
------------------------------------------------------------------------------
Field Type Value
signature uint64 {1.signature!r}
image_crc uint64 0x{1.image_crc:016X}
image_size uint32 0x{1.image_size:X} ({1.image_size:d} B)
vcs_commit uint32 {1.vcs_commit:08X}
version_major uint8 {1.version_major:d}
version_minor uint8 {1.version_minor:d}
reserved uint8[6] {1.reserved!r}
WRITTEN VALUES
------------------------------------------------------------------------------
Field Type Value
signature uint64 {2.signature!r}
image_crc uint64 0x{2.image_crc:016X}
image_size uint32 0x{2.image_size:X} ({2.image_size:d} B)
vcs_commit uint32 {2.vcs_commit:08X}
version_major uint8 {2.version_major:d}
version_minor uint8 {2.version_minor:d}
reserved uint8[6] {2.reserved!r}
""".format(in_image, in_image.app_descriptor, out_image.app_descriptor,
bootloader_size, len(bootloader_image)))
if out_image.padding:
sys.stderr.write(
"""
padding added {}
""".format(out_image.padding))