coreboot-kgpe-d16/util/me_cleaner/me_cleaner.py

897 lines
34 KiB
Python
Executable File

#!/usr/bin/python
# me_cleaner - Tool for partial deblobbing of Intel ME/TXE firmware images
# Copyright (C) 2016-2018 Nicola Corna <nicola@corna.info>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
from __future__ import division, print_function
import argparse
import binascii
import hashlib
import itertools
import shutil
import sys
from struct import pack, unpack
min_ftpr_offset = 0x400
spared_blocks = 4
unremovable_modules = ("ROMP", "BUP")
unremovable_modules_me11 = ("rbe", "kernel", "syslib", "bup")
unremovable_partitions = ("FTPR",)
pubkeys_md5 = {
"763e59ebe235e45a197a5b1a378dfa04": ("ME", ("6.x.x.x",)),
"3a98c847d609c253e145bd36512629cb": ("ME", ("6.0.50.x",)),
"0903fc25b0f6bed8c4ed724aca02124c": ("ME", ("7.x.x.x", "8.x.x.x")),
"2011ae6df87c40fba09e3f20459b1ce0": ("ME", ("9.0.x.x", "9.1.x.x")),
"e8427c5691cf8b56bc5cdd82746957ed": ("ME", ("9.5.x.x", "10.x.x.x")),
"986a78e481f185f7d54e4af06eb413f6": ("ME", ("11.x.x.x",)),
"bda0b6bb8ca0bf0cac55ac4c4d55e0f2": ("TXE", ("1.x.x.x",)),
"b726a2ab9cd59d4e62fe2bead7cf6997": ("TXE", ("1.x.x.x",)),
"0633d7f951a3e7968ae7460861be9cfb": ("TXE", ("2.x.x.x",)),
"1d0a36e9f5881540d8e4b382c6612ed8": ("TXE", ("3.x.x.x",)),
"be900fef868f770d266b1fc67e887e69": ("SPS", ("2.x.x.x",)),
"4622e3f2cb212a89c90a4de3336d88d2": ("SPS", ("3.x.x.x",)),
"31ef3d950eac99d18e187375c0764ca4": ("SPS", ("4.x.x.x",))
}
class OutOfRegionException(Exception):
pass
class RegionFile:
def __init__(self, f, region_start, region_end):
self.f = f
self.region_start = region_start
self.region_end = region_end
def read(self, n):
if f.tell() + n <= self.region_end:
return self.f.read(n)
else:
raise OutOfRegionException()
def readinto(self, b):
if f.tell() + len(b) <= self.region_end:
return self.f.readinto(b)
else:
raise OutOfRegionException()
def seek(self, offset):
if self.region_start + offset <= self.region_end:
return self.f.seek(self.region_start + offset)
else:
raise OutOfRegionException()
def write_to(self, offset, data):
if self.region_start + offset + len(data) <= self.region_end:
self.f.seek(self.region_start + offset)
return self.f.write(data)
else:
raise OutOfRegionException()
def fill_range(self, start, end, fill):
if self.region_start + end <= self.region_end:
if start < end:
block = fill * 4096
self.f.seek(self.region_start + start)
self.f.writelines(itertools.repeat(block,
(end - start) // 4096))
self.f.write(block[:(end - start) % 4096])
else:
raise OutOfRegionException()
def fill_all(self, fill):
self.fill_range(0, self.region_end - self.region_start, fill)
def move_range(self, offset_from, size, offset_to, fill):
if self.region_start + offset_from + size <= self.region_end and \
self.region_start + offset_to + size <= self.region_end:
for i in range(0, size, 4096):
self.f.seek(self.region_start + offset_from + i, 0)
block = self.f.read(min(size - i, 4096))
self.f.seek(self.region_start + offset_from + i, 0)
self.f.write(fill * len(block))
self.f.seek(self.region_start + offset_to + i, 0)
self.f.write(block)
else:
raise OutOfRegionException()
def save(self, filename, size):
if self.region_start + size <= self.region_end:
self.f.seek(self.region_start)
copyf = open(filename, "w+b")
for i in range(0, size, 4096):
copyf.write(self.f.read(min(size - i, 4096)))
return copyf
else:
raise OutOfRegionException()
def get_chunks_offsets(llut):
chunk_count = unpack("<I", llut[0x04:0x08])[0]
huffman_stream_end = sum(unpack("<II", llut[0x10:0x18]))
nonzero_offsets = [huffman_stream_end]
offsets = []
for i in range(0, chunk_count):
chunk = llut[0x40 + i * 4:0x44 + i * 4]
offset = 0
if chunk[3] != 0x80:
offset = unpack("<I", chunk[0:3] + b"\x00")[0]
offsets.append([offset, 0])
if offset != 0:
nonzero_offsets.append(offset)
nonzero_offsets.sort()
for i in offsets:
if i[0] != 0:
i[1] = nonzero_offsets[nonzero_offsets.index(i[0]) + 1]
return offsets
def remove_modules(f, mod_headers, ftpr_offset, me_end):
comp_str = ("uncomp.", "Huffman", "LZMA")
unremovable_huff_chunks = []
chunks_offsets = []
base = 0
chunk_size = 0
end_addr = 0
for mod_header in mod_headers:
name = mod_header[0x04:0x14].rstrip(b"\x00").decode("ascii")
offset = unpack("<I", mod_header[0x38:0x3C])[0] + ftpr_offset
size = unpack("<I", mod_header[0x40:0x44])[0]
flags = unpack("<I", mod_header[0x50:0x54])[0]
comp_type = (flags >> 4) & 7
print(" {:<16} ({:<7}, ".format(name, comp_str[comp_type]), end="")
if comp_type == 0x00 or comp_type == 0x02:
print("0x{:06x} - 0x{:06x} ): "
.format(offset, offset + size), end="")
if name in unremovable_modules:
end_addr = max(end_addr, offset + size)
print("NOT removed, essential")
else:
end = min(offset + size, me_end)
f.fill_range(offset, end, b"\xff")
print("removed")
elif comp_type == 0x01:
if not chunks_offsets:
f.seek(offset)
llut = f.read(4)
if llut == b"LLUT":
llut += f.read(0x3c)
chunk_count = unpack("<I", llut[0x4:0x8])[0]
base = unpack("<I", llut[0x8:0xc])[0] + 0x10000000
chunk_size = unpack("<I", llut[0x30:0x34])[0]
llut += f.read(chunk_count * 4)
chunks_offsets = get_chunks_offsets(llut)
else:
sys.exit("Huffman modules found, but LLUT is not present")
module_base = unpack("<I", mod_header[0x34:0x38])[0]
module_size = unpack("<I", mod_header[0x3c:0x40])[0]
first_chunk_num = (module_base - base) // chunk_size
last_chunk_num = first_chunk_num + module_size // chunk_size
huff_size = 0
for chunk in chunks_offsets[first_chunk_num:last_chunk_num + 1]:
huff_size += chunk[1] - chunk[0]
print("fragmented data, {:<9}): "
.format("~" + str(int(round(huff_size / 1024))) + " KiB"),
end="")
if name in unremovable_modules:
print("NOT removed, essential")
unremovable_huff_chunks += \
[x for x in chunks_offsets[first_chunk_num:
last_chunk_num + 1] if x[0] != 0]
else:
print("removed")
else:
print("0x{:06x} - 0x{:06x}): unknown compression, skipping"
.format(offset, offset + size), end="")
if chunks_offsets:
removable_huff_chunks = []
for chunk in chunks_offsets:
if all(not(unremovable_chk[0] <= chunk[0] < unremovable_chk[1] or
unremovable_chk[0] < chunk[1] <= unremovable_chk[1])
for unremovable_chk in unremovable_huff_chunks):
removable_huff_chunks.append(chunk)
for removable_chunk in removable_huff_chunks:
if removable_chunk[1] > removable_chunk[0]:
end = min(removable_chunk[1], me_end)
f.fill_range(removable_chunk[0], end, b"\xff")
end_addr = max(end_addr,
max(unremovable_huff_chunks, key=lambda x: x[1])[1])
return end_addr
def check_partition_signature(f, offset):
f.seek(offset)
header = f.read(0x80)
modulus = int(binascii.hexlify(f.read(0x100)[::-1]), 16)
public_exponent = unpack("<I", f.read(4))[0]
signature = int(binascii.hexlify(f.read(0x100)[::-1]), 16)
header_len = unpack("<I", header[0x4:0x8])[0] * 4
manifest_len = unpack("<I", header[0x18:0x1c])[0] * 4
f.seek(offset + header_len)
sha256 = hashlib.sha256()
sha256.update(header)
sha256.update(f.read(manifest_len - header_len))
decrypted_sig = pow(signature, public_exponent, modulus)
return "{:#x}".format(decrypted_sig).endswith(sha256.hexdigest()) # FIXME
def print_check_partition_signature(f, offset):
if check_partition_signature(f, offset):
print("VALID")
else:
print("INVALID!!")
sys.exit("The FTPR partition signature is not valid. Is the input "
"ME/TXE image valid?")
def relocate_partition(f, me_end, partition_header_offset,
new_offset, mod_headers):
f.seek(partition_header_offset)
name = f.read(4).rstrip(b"\x00").decode("ascii")
f.seek(partition_header_offset + 0x8)
old_offset, partition_size = unpack("<II", f.read(0x8))
llut_start = 0
for mod_header in mod_headers:
if (unpack("<I", mod_header[0x50:0x54])[0] >> 4) & 7 == 0x01:
llut_start = unpack("<I", mod_header[0x38:0x3C])[0] + old_offset
break
if mod_headers and llut_start != 0:
# Bytes 0x9:0xb of the LLUT (bytes 0x1:0x3 of the AddrBase) are added
# to the SpiBase (bytes 0xc:0x10 of the LLUT) to compute the final
# start of the LLUT. Since AddrBase is not modifiable, we can act only
# on SpiBase and here we compute the minimum allowed new_offset.
f.seek(llut_start + 0x9)
lut_start_corr = unpack("<H", f.read(2))[0]
new_offset = max(new_offset,
lut_start_corr - llut_start - 0x40 + old_offset)
new_offset = ((new_offset + 0x1f) // 0x20) * 0x20
offset_diff = new_offset - old_offset
print("Relocating {} from {:#x} - {:#x} to {:#x} - {:#x}..."
.format(name, old_offset, old_offset + partition_size,
new_offset, new_offset + partition_size))
print(" Adjusting FPT entry...")
f.write_to(partition_header_offset + 0x8,
pack("<I", new_offset))
if mod_headers:
if llut_start != 0:
f.seek(llut_start)
if f.read(4) == b"LLUT":
print(" Adjusting LUT start offset...")
lut_offset = llut_start + offset_diff + 0x40 - lut_start_corr
f.write_to(llut_start + 0x0c, pack("<I", lut_offset))
print(" Adjusting Huffman start offset...")
f.seek(llut_start + 0x14)
old_huff_offset = unpack("<I", f.read(4))[0]
f.write_to(llut_start + 0x14,
pack("<I", old_huff_offset + offset_diff))
print(" Adjusting chunks offsets...")
f.seek(llut_start + 0x4)
chunk_count = unpack("<I", f.read(4))[0]
f.seek(llut_start + 0x40)
chunks = bytearray(chunk_count * 4)
f.readinto(chunks)
for i in range(0, chunk_count * 4, 4):
if chunks[i + 3] != 0x80:
chunks[i:i + 3] = \
pack("<I", unpack("<I", chunks[i:i + 3] +
b"\x00")[0] + offset_diff)[0:3]
f.write_to(llut_start + 0x40, chunks)
else:
sys.exit("Huffman modules present but no LLUT found!")
else:
print(" No Huffman modules found")
print(" Moving data...")
partition_size = min(partition_size, me_end - old_offset)
f.move_range(old_offset, partition_size, new_offset, b"\xff")
return new_offset
def check_and_remove_modules(f, me_end, offset, min_offset,
relocate, keep_modules):
f.seek(offset + 0x20)
num_modules = unpack("<I", f.read(4))[0]
f.seek(offset + 0x290)
data = f.read(0x84)
mod_header_size = 0
if data[0x0:0x4] == b"$MME":
if data[0x60:0x64] == b"$MME" or num_modules == 1:
mod_header_size = 0x60
elif data[0x80:0x84] == b"$MME":
mod_header_size = 0x80
if mod_header_size != 0:
f.seek(offset + 0x290)
data = f.read(mod_header_size * num_modules)
mod_headers = [data[i * mod_header_size:(i + 1) * mod_header_size]
for i in range(0, num_modules)]
if all(hdr.startswith(b"$MME") for hdr in mod_headers):
if args.keep_modules:
end_addr = offset + ftpr_length
else:
end_addr = remove_modules(f, mod_headers, offset, me_end)
if args.relocate:
new_offset = relocate_partition(f, me_end, 0x30, min_offset,
mod_headers)
end_addr += new_offset - offset
offset = new_offset
return end_addr, offset
else:
print("Found less modules than expected in the FTPR "
"partition; skipping modules removal")
else:
print("Can't find the module header size; skipping "
"modules removal")
return -1, offset
def check_and_remove_modules_me11(f, me_end, partition_offset,
partition_length, min_offset, relocate,
keep_modules):
comp_str = ("LZMA/uncomp.", "Huffman")
if keep_modules:
end_data = partition_offset + partition_length
else:
end_data = 0
f.seek(partition_offset + 0x4)
module_count = unpack("<I", f.read(4))[0]
modules = []
modules.append(("end", partition_length, 0))
f.seek(partition_offset + 0x10)
for i in range(0, module_count):
data = f.read(0x18)
name = data[0x0:0xc].rstrip(b"\x00").decode("ascii")
offset_block = unpack("<I", data[0xc:0x10])[0]
offset = offset_block & 0x01ffffff
comp_type = (offset_block & 0x02000000) >> 25
modules.append((name, offset, comp_type))
modules.sort(key=lambda x: x[1])
for i in range(0, module_count):
name = modules[i][0]
offset = partition_offset + modules[i][1]
end = partition_offset + modules[i + 1][1]
removed = False
if name.endswith(".man") or name.endswith(".met"):
compression = "uncompressed"
else:
compression = comp_str[modules[i][2]]
print(" {:<12} ({:<12}, 0x{:06x} - 0x{:06x}): "
.format(name, compression, offset, end), end="")
if name.endswith(".man"):
print("NOT removed, partition manif.")
elif name.endswith(".met"):
print("NOT removed, module metadata")
elif any(name.startswith(m) for m in unremovable_modules_me11):
print("NOT removed, essential")
else:
removed = True
f.fill_range(offset, min(end, me_end), b"\xff")
print("removed")
if not removed:
end_data = max(end_data, end)
if relocate:
new_offset = relocate_partition(f, me_end, 0x30, min_offset, [])
end_data += new_offset - partition_offset
partition_offset = new_offset
return end_data, partition_offset
def check_mn2_tag(f, offset):
f.seek(offset + 0x1c)
tag = f.read(4)
if tag != b"$MN2":
sys.exit("Wrong FTPR manifest tag ({}), this image may be corrupted"
.format(tag))
def flreg_to_start_end(flreg):
return (flreg & 0x7fff) << 12, (flreg >> 4 & 0x7fff000 | 0xfff) + 1
def start_end_to_flreg(start, end):
return (start & 0x7fff000) >> 12 | ((end - 1) & 0x7fff000) << 4
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Tool to remove as much code "
"as possible from Intel ME/TXE firmware "
"images")
softdis = parser.add_mutually_exclusive_group()
bw_list = parser.add_mutually_exclusive_group()
parser.add_argument("-v", "--version", action="version",
version="%(prog)s 1.2")
parser.add_argument("file", help="ME/TXE image or full dump")
parser.add_argument("-O", "--output", metavar='output_file', help="save "
"the modified image in a separate file, instead of "
"modifying the original file")
softdis.add_argument("-S", "--soft-disable", help="in addition to the "
"usual operations on the ME/TXE firmware, set the "
"MeAltDisable bit or the HAP bit to ask Intel ME/TXE "
"to disable itself after the hardware initialization "
"(requires a full dump)", action="store_true")
softdis.add_argument("-s", "--soft-disable-only", help="instead of the "
"usual operations on the ME/TXE firmware, just set "
"the MeAltDisable bit or the HAP bit to ask Intel "
"ME/TXE to disable itself after the hardware "
"initialization (requires a full dump)",
action="store_true")
parser.add_argument("-r", "--relocate", help="relocate the FTPR partition "
"to the top of the ME region to save even more space",
action="store_true")
parser.add_argument("-t", "--truncate", help="truncate the empty part of "
"the firmware (requires a separated ME/TXE image or "
"--extract-me)", action="store_true")
parser.add_argument("-k", "--keep-modules", help="don't remove the FTPR "
"modules, even when possible", action="store_true")
bw_list.add_argument("-w", "--whitelist", metavar="whitelist",
help="Comma separated list of additional partitions "
"to keep in the final image. This can be used to "
"specify the MFS partition for example, which stores "
"PCIe and clock settings.")
bw_list.add_argument("-b", "--blacklist", metavar="blacklist",
help="Comma separated list of partitions to remove "
"from the image. This option overrides the default "
"removal list.")
parser.add_argument("-d", "--descriptor", help="remove the ME/TXE "
"Read/Write permissions to the other regions on the "
"flash from the Intel Flash Descriptor (requires a "
"full dump)", action="store_true")
parser.add_argument("-D", "--extract-descriptor",
metavar='output_descriptor', help="extract the flash "
"descriptor from a full dump; when used with "
"--truncate save a descriptor with adjusted regions "
"start and end")
parser.add_argument("-M", "--extract-me", metavar='output_me_image',
help="extract the ME firmware from a full dump; when "
"used with --truncate save a truncated ME/TXE image")
parser.add_argument("-c", "--check", help="verify the integrity of the "
"fundamental parts of the firmware and exit",
action="store_true")
args = parser.parse_args()
if args.check and (args.soft_disable_only or args.soft_disable or
args.relocate or args.descriptor or args.truncate or args.output):
sys.exit("-c can't be used with -S, -s, -r, -d, -t or -O")
if args.soft_disable_only and (args.relocate or args.truncate):
sys.exit("-s can't be used with -r or -t")
if (args.whitelist or args.blacklist) and args.relocate:
sys.exit("Relocation is not yet supported with custom whitelist or "
"blacklist")
f = open(args.file, "rb" if args.check or args.output else "r+b")
f.seek(0x10)
magic = f.read(4)
if magic == b"$FPT":
print("ME/TXE image detected")
if args.descriptor or args.extract_descriptor or args.extract_me or \
args.soft_disable or args.soft_disable_only:
sys.exit("-d, -D, -M, -S and -s require a full dump")
f.seek(0, 2)
me_start = 0
me_end = f.tell()
mef = RegionFile(f, me_start, me_end)
elif magic == b"\x5a\xa5\xf0\x0f":
print("Full image detected")
if args.truncate and not args.extract_me:
sys.exit("-t requires a separated ME/TXE image (or --extract-me)")
f.seek(0x14)
flmap0, flmap1 = unpack("<II", f.read(8))
frba = flmap0 >> 12 & 0xff0
fmba = (flmap1 & 0xff) << 4
fpsba = flmap1 >> 12 & 0xff0
f.seek(frba)
flreg = unpack("<III", f.read(12))
fd_start, fd_end = flreg_to_start_end(flreg[0])
bios_start, bios_end = flreg_to_start_end(flreg[1])
me_start, me_end = flreg_to_start_end(flreg[2])
if me_start >= me_end:
sys.exit("The ME/TXE region in this image has been disabled")
mef = RegionFile(f, me_start, me_end)
mef.seek(0x10)
if mef.read(4) != b"$FPT":
sys.exit("The ME/TXE region is corrupted or missing")
print("The ME/TXE region goes from {:#x} to {:#x}"
.format(me_start, me_end))
else:
sys.exit("Unknown image")
end_addr = me_end
print("Found FPT header at {:#x}".format(mef.region_start + 0x10))
mef.seek(0x14)
entries = unpack("<I", mef.read(4))[0]
print("Found {} partition(s)".format(entries))
mef.seek(0x30)
partitions = mef.read(entries * 0x20)
ftpr_header = b""
for i in range(entries):
if partitions[i * 0x20:(i * 0x20) + 4] == b"FTPR":
ftpr_header = partitions[i * 0x20:(i + 1) * 0x20]
break
if ftpr_header == b"":
sys.exit("FTPR header not found, this image doesn't seem to be valid")
ftpr_offset, ftpr_length = unpack("<II", ftpr_header[0x08:0x10])
print("Found FTPR header: FTPR partition spans from {:#x} to {:#x}"
.format(ftpr_offset, ftpr_offset + ftpr_length))
mef.seek(ftpr_offset)
if mef.read(4) == b"$CPD":
me11 = True
num_entries = unpack("<I", mef.read(4))[0]
mef.seek(ftpr_offset + 0x10)
ftpr_mn2_offset = -1
for i in range(0, num_entries):
data = mef.read(0x18)
name = data[0x0:0xc].rstrip(b"\x00").decode("ascii")
offset = unpack("<I", data[0xc:0xf] + b"\x00")[0]
if name == "FTPR.man":
ftpr_mn2_offset = offset
break
if ftpr_mn2_offset >= 0:
check_mn2_tag(mef, ftpr_offset + ftpr_mn2_offset)
print("Found FTPR manifest at {:#x}"
.format(ftpr_offset + ftpr_mn2_offset))
else:
sys.exit("Can't find the manifest of the FTPR partition")
else:
check_mn2_tag(mef, ftpr_offset)
me11 = False
ftpr_mn2_offset = 0
mef.seek(ftpr_offset + ftpr_mn2_offset + 0x24)
version = unpack("<HHHH", mef.read(0x08))
print("ME/TXE firmware version {}"
.format('.'.join(str(i) for i in version)))
mef.seek(ftpr_offset + ftpr_mn2_offset + 0x80)
pubkey_md5 = hashlib.md5(mef.read(0x104)).hexdigest()
if pubkey_md5 in pubkeys_md5:
variant, pubkey_versions = pubkeys_md5[pubkey_md5]
print("Public key match: Intel {}, firmware versions {}"
.format(variant, ", ".join(pubkey_versions)))
else:
if version[0] >= 6:
variant = "ME"
else:
variant = "TXE"
print("WARNING Unknown public key {}\n"
" Assuming Intel {}\n"
" Please report this warning to the project's maintainer!"
.format(pubkey_md5, variant))
if not args.check and args.output:
f.close()
shutil.copy(args.file, args.output)
f = open(args.output, "r+b")
mef = RegionFile(f, me_start, me_end)
if me_start > 0:
fdf = RegionFile(f, fd_start, fd_end)
if me11:
fdf.seek(fpsba)
pchstrp0 = unpack("<I", fdf.read(4))[0]
print("The HAP bit is " +
("SET" if pchstrp0 & 1 << 16 else "NOT SET"))
else:
fdf.seek(fpsba + 0x28)
pchstrp10 = unpack("<I", fdf.read(4))[0]
print("The AltMeDisable bit is " +
("SET" if pchstrp10 & 1 << 7 else "NOT SET"))
# ME 6 Ignition: wipe everything
me6_ignition = False
if not args.check and not args.soft_disable_only and \
variant == "ME" and version[0] == 6:
mef.seek(ftpr_offset + 0x20)
num_modules = unpack("<I", mef.read(4))[0]
mef.seek(ftpr_offset + 0x290 + (num_modules + 1) * 0x60)
data = mef.read(0xc)
if data[0x0:0x4] == b"$SKU" and data[0x8:0xc] == b"\x00\x00\x00\x00":
print("ME 6 Ignition firmware detected, removing everything...")
mef.fill_all(b"\xff")
me6_ignition = True
if not args.check:
if not args.soft_disable_only and not me6_ignition:
print("Reading partitions list...")
unremovable_part_fpt = b""
extra_part_end = 0
whitelist = []
blacklist = []
whitelist += unremovable_partitions
if args.blacklist:
blacklist = args.blacklist.split(",")
elif args.whitelist:
whitelist += args.whitelist.split(",")
for i in range(entries):
partition = partitions[i * 0x20:(i + 1) * 0x20]
flags = unpack("<I", partition[0x1c:0x20])[0]
try:
part_name = \
partition[0x0:0x4].rstrip(b"\x00").decode("ascii")
except UnicodeDecodeError:
part_name = "????"
part_start, part_length = unpack("<II", partition[0x08:0x10])
# ME 6: the last partition has 0xffffffff as size
if variant == "ME" and version[0] == 6 and \
i == entries - 1 and part_length == 0xffffffff:
part_length = me_end - me_start - part_start
part_end = part_start + part_length
if flags & 0x7f == 2:
print(" {:<4} ({:^24}, 0x{:08x} total bytes): nothing to "
"remove"
.format(part_name, "NVRAM partition, no data",
part_length))
elif part_start == 0 or part_length == 0 or part_end > me_end:
print(" {:<4} ({:^24}, 0x{:08x} total bytes): nothing to "
"remove"
.format(part_name, "no data here", part_length))
else:
print(" {:<4} (0x{:08x} - 0x{:09x}, 0x{:08x} total bytes): "
.format(part_name, part_start, part_end, part_length),
end="")
if part_name in whitelist or (blacklist and
part_name not in blacklist):
unremovable_part_fpt += partition
if part_name != "FTPR":
extra_part_end = max(extra_part_end, part_end)
print("NOT removed")
else:
mef.fill_range(part_start, part_end, b"\xff")
print("removed")
print("Removing partition entries in FPT...")
mef.write_to(0x30, unremovable_part_fpt)
mef.write_to(0x14,
pack("<I", len(unremovable_part_fpt) // 0x20))
mef.fill_range(0x30 + len(unremovable_part_fpt),
0x30 + len(partitions), b"\xff")
if (not blacklist and "EFFS" not in whitelist) or \
"EFFS" in blacklist:
print("Removing EFFS presence flag...")
mef.seek(0x24)
flags = unpack("<I", mef.read(4))[0]
flags &= ~(0x00000001)
mef.write_to(0x24, pack("<I", flags))
if me11:
mef.seek(0x10)
header = bytearray(mef.read(0x20))
header[0x0b] = 0x00
else:
mef.seek(0)
header = bytearray(mef.read(0x30))
header[0x1b] = 0x00
checksum = (0x100 - sum(header) & 0xff) & 0xff
print("Correcting checksum (0x{:02x})...".format(checksum))
# The checksum is just the two's complement of the sum of the first
# 0x30 bytes in ME < 11 or bytes 0x10:0x30 in ME >= 11 (except for
# 0x1b, the checksum itself). In other words, the sum of those
# bytes must be always 0x00.
mef.write_to(0x1b, pack("B", checksum))
print("Reading FTPR modules list...")
if me11:
end_addr, ftpr_offset = \
check_and_remove_modules_me11(mef, me_end,
ftpr_offset, ftpr_length,
min_ftpr_offset,
args.relocate,
args.keep_modules)
else:
end_addr, ftpr_offset = \
check_and_remove_modules(mef, me_end, ftpr_offset,
min_ftpr_offset, args.relocate,
args.keep_modules)
if end_addr > 0:
end_addr = max(end_addr, extra_part_end)
end_addr = (end_addr // 0x1000 + 1) * 0x1000
end_addr += spared_blocks * 0x1000
print("The ME minimum size should be {0} bytes "
"({0:#x} bytes)".format(end_addr))
if me_start > 0:
print("The ME region can be reduced up to:\n"
" {:08x}:{:08x} me"
.format(me_start, me_start + end_addr - 1))
elif args.truncate:
print("Truncating file at {:#x}...".format(end_addr))
f.truncate(end_addr)
if args.soft_disable or args.soft_disable_only:
if me11:
print("Setting the HAP bit in PCHSTRP0 to disable Intel ME...")
pchstrp0 |= (1 << 16)
fdf.write_to(fpsba, pack("<I", pchstrp0))
else:
print("Setting the AltMeDisable bit in PCHSTRP10 to disable "
"Intel ME...")
pchstrp10 |= (1 << 7)
fdf.write_to(fpsba + 0x28, pack("<I", pchstrp10))
if args.descriptor:
print("Removing ME/TXE R/W access to the other flash regions...")
if me11:
flmstr2 = 0x00400500
else:
fdf.seek(fmba + 0x4)
flmstr2 = (unpack("<I", fdf.read(4))[0] | 0x04040000) & 0x0404ffff
fdf.write_to(fmba + 0x4, pack("<I", flmstr2))
if args.extract_descriptor:
if args.truncate:
print("Extracting the descriptor to \"{}\"..."
.format(args.extract_descriptor))
fdf_copy = fdf.save(args.extract_descriptor, fd_end - fd_start)
if bios_start == me_end:
print("Modifying the regions of the extracted descriptor...")
print(" {:08x}:{:08x} me --> {:08x}:{:08x} me"
.format(me_start, me_end - 1,
me_start, me_start + end_addr - 1))
print(" {:08x}:{:08x} bios --> {:08x}:{:08x} bios"
.format(bios_start, bios_end - 1,
me_start + end_addr, bios_end - 1))
flreg1 = start_end_to_flreg(me_start + end_addr, bios_end)
flreg2 = start_end_to_flreg(me_start, me_start + end_addr)
fdf_copy.seek(frba + 0x4)
fdf_copy.write(pack("<II", flreg1, flreg2))
else:
print("\nWARNING:\n The start address of the BIOS region "
"isn't equal to the end address of the ME\n region: if "
"you want to recover the space from the ME region you "
"have to\n manually modify the descriptor.\n")
else:
print("Extracting the descriptor to \"{}\"..."
.format(args.extract_descriptor))
fdf_copy = fdf.save(args.extract_descriptor, fd_end - fd_start)
fdf_copy.close()
if args.extract_me:
if args.truncate:
print("Extracting and truncating the ME image to \"{}\"..."
.format(args.extract_me))
mef_copy = mef.save(args.extract_me, end_addr)
else:
print("Extracting the ME image to \"{}\"..."
.format(args.extract_me))
mef_copy = mef.save(args.extract_me, me_end - me_start)
if not me6_ignition:
print("Checking the FTPR RSA signature of the extracted ME "
"image... ", end="")
print_check_partition_signature(mef_copy,
ftpr_offset + ftpr_mn2_offset)
mef_copy.close()
if not me6_ignition:
print("Checking the FTPR RSA signature... ", end="")
print_check_partition_signature(mef, ftpr_offset + ftpr_mn2_offset)
f.close()
if not args.check:
print("Done! Good luck!")