rebuild_image.py

#!/usr/bin/python

import os, io, sys, zlib
from configparser import ConfigParser
from ipmifw.FirmwareImage import FirmwareImage
from ipmifw.FirmwareFooter import FirmwareFooter

config = ConfigParser()
try:
    config.read("data/image.ini")
except:
    print("Unable to read image configuration")
    os.exit(1)

if config.get("global", "type") == "aspeed":
    from ipmifw.ASpeed import ASpeed

    firmware = ASpeed()
else:
    from ipmifw.Winbond import Winbond

    firmware = Winbond()

new_image = open("data/rebuilt_image.bin", "wb")
new_image.truncate()

# initialize new image
total_size = config.getint("flash", "total_size")
firmware.init_image(new_image, total_size)
new_image.seek(0)

# write bootloader
firmware.write_bootloader(new_image)

# prepare list of images to write
images = []
for (imagenum, dummy) in config.items("images"):
    images.append(int(imagenum))

images.sort()

imagecrc = []
# write all images into the firmware file
for imagenum in images:
    configkey = "image_%i" % imagenum

    # can't use getint, it doesn't support hex
    base_addr = int(config.get(configkey, "base_addr"), 0)
    name = config.get(configkey, "name")

    imagestart = base_addr
    if imagestart > 0x40000000:
        # I'm unsure where this 0x40000000 byte offset is coming from.  Perhaps I'm not parsing the footer correctly?
        imagestart -= 0x40000000

    print("Processing image %i: %s at 0x%X" % (imagenum, name, base_addr))

    if imagestart < new_image.tell():
        print(
            "ERROR: Previous image was too big, and has overriten data where the current image should begin."
        )
        print("Aborting.")
        sys.exit(1)

    # Seek to where this image will start
    new_image.seek(imagestart)

    if name[-4:] != ".bin":
        fname = name + ".bin"
    else:
        fname = name
    with open("data/%s" % fname, "rb") as img:
        cur_image = firmware.process_image(config, imagenum, images, img.read())

    # Write the actual image contents
    new_image.write(cur_image)

    # Compute the CRC32 of this image.  This is used for the global footer, not for each individual footer
    curcrc = zlib.crc32(cur_image) & 0xFFFFFFFF
    imagecrc.append(curcrc)

    config.set(configkey, "curcrc", "0x%x" % curcrc)
    config.set(configkey, "curlen", "0x%x" % len(cur_image))

    (footerpos, curblockend) = firmware.write_image_footer(
        new_image, cur_image, config, configkey, imagenum, base_addr, name
    )

footer = FirmwareFooter()
footer.rev1 = int(config.get("global", "major_version"), 0)
footer.rev2 = int(config.get("global", "minor_version"), 0)
footer.footerver = int(config.get("global", "footer_version"), 0)
footer.checksum = footer.computeFooterChecksum(imagecrc)

# Write the global footer
global_start = firmware.prepare_global_footer(config, footer, footerpos, curblockend)
new_image.seek(global_start)
new_image.write(footer.getRawString())

firmware.write_global_index(config, new_image, images)

print("Done, new firmware written to data/rebuild_image.bin")