[coreboot-gerrit] New patch to review for coreboot: util/me_cleaner: Pull the latest changes from upstream
Nicola Corna (nicola@corna.info)
gerrit at coreboot.org
Thu Feb 23 14:36:17 CET 2017
Nicola Corna (nicola at corna.info) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/18473
-gerrit
commit 8d09bfb97f9afb7e18cc131b742946a3aae9fe09
Author: Nicola Corna <nicola at corna.info>
Date: Wed Feb 22 10:16:32 2017 +0100
util/me_cleaner: Pull the latest changes from upstream
Relevant changes (commit 250b2ec):
* Fix a bug for ME6 Ignition images.
* Fix signature checking for ME11 and later.
* Add command line arguments.
* Add an option to relocate the FTPR partition to the top of the
ME region, recovering most of the ME region space.
* Print the image minimum size.
* Add write boundary checks, to prevent writes on other regions
in case of bugs.
The new changes have been tested on multiple platforms by the
me_cleaner users. They have been tested also on the author's
X220T with coreboot, where the ME region has been shrinked up to
84 kB without any issue.
Change-Id: I3bd6b4cba9f5eebc3cd4892dd9f188744a06c42b
Signed-off-by: Nicola Corna <nicola at corna.info>
---
util/me_cleaner/README.md | 3 +-
util/me_cleaner/me_cleaner.py | 438 ++++++++++++++++++++++++++++++------------
2 files changed, 317 insertions(+), 124 deletions(-)
diff --git a/util/me_cleaner/README.md b/util/me_cleaner/README.md
index 9a09b55..0ca3d32 100644
--- a/util/me_cleaner/README.md
+++ b/util/me_cleaner/README.md
@@ -12,7 +12,8 @@ Currently this tool:
* Removes any partition except for the fundamental one (FTPR)
* Removes the EFFS presence flag
* Corrects the FPT checksum
- * Removes any non-essential LZMA or Huffman compressed module (pre-Skylake only)
+ * Removes any non-essential LZMA or Huffman compressed module from the FTPR partition (pre-Skylake only)
+ * Relocates the remaining parts of the FTPR partition to the top of the ME region (pre-Skylake only)
* Checks the validity of the RSA signature of the FTPR partition
Don't forget to power cycle your PC after flashing the modified ME/TXE image
diff --git a/util/me_cleaner/me_cleaner.py b/util/me_cleaner/me_cleaner.py
index 2ad5898..8ca5498 100755
--- a/util/me_cleaner/me_cleaner.py
+++ b/util/me_cleaner/me_cleaner.py
@@ -18,12 +18,70 @@ import sys
import itertools
import binascii
import hashlib
+import argparse
+import shutil
from struct import pack, unpack
+min_ftpr_offset = 0x400
+spared_blocks = 4
unremovable_modules = ("BUP", "ROMP")
+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):
+ return self.f.read(n)
+
+ def readinto(self, b):
+ return self.f.readinto(b)
+
+ def seek(self, offset):
+ return self.f.seek(offset)
+
+ def write_to(self, offset, data):
+ if offset >= self.region_start and \
+ offset + len(data) <= self.region_end:
+ self.f.seek(offset)
+ return self.f.write(data)
+ else:
+ raise OutOfRegionException()
+
+ def fill_range(self, start, end, fill):
+ if start >= self.region_start and end <= self.region_end:
+ if start < end:
+ block = fill * 4096
+ self.f.seek(start)
+ self.f.writelines(itertools.repeat(block,
+ (end - start) // 4096))
+ self.f.write(block[:(end - start) % 4096])
+ else:
+ raise OutOfRegionException()
+
+ def move_range(self, offset_from, size, offset_to, fill):
+ if offset_from >= self.region_start and \
+ offset_from + size <= self.region_end and \
+ offset_to >= self.region_start and \
+ offset_to + size <= self.region_end:
+ for i in range(0, size, 4096):
+ self.f.seek(offset_from + i, 0)
+ block = self.f.read(4096 if size - i >= 4096 else size - i)
+ self.f.seek(offset_from + i, 0)
+ self.f.write(fill * len(block))
+ self.f.seek(offset_to + i, 0)
+ self.f.write(block)
+ else:
+ raise OutOfRegionException()
+
+
def get_chunks_offsets(llut, me_start):
chunk_count = unpack("<I", llut[0x04:0x08])[0]
huffman_stream_end = sum(unpack("<II", llut[0x10:0x18])) + me_start
@@ -50,19 +108,13 @@ def get_chunks_offsets(llut, me_start):
return offsets
-def fill_range(f, start, end, fill):
- block = fill * 4096
- f.seek(start)
- f.writelines(itertools.repeat(block, (end - start) // 4096))
- f.write(block[:(end - start) % 4096])
-
-
-def remove_modules(f, mod_headers, ftpr_offset):
+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")
@@ -78,9 +130,11 @@ def remove_modules(f, mod_headers, ftpr_offset):
.format(offset, offset + size))
if name in unremovable_modules:
+ end_addr = max(end_addr, offset + size)
print("NOT removed, essential")
else:
- fill_range(f, offset, offset + size, b"\xff")
+ end = min(offset + size, me_end)
+ f.fill_range(offset, end, b"\xff")
print("removed")
elif comp_type == 0x01:
@@ -93,10 +147,9 @@ def remove_modules(f, mod_headers, ftpr_offset):
chunk_count = unpack("<I", llut[0x4:0x8])[0]
base = unpack("<I", llut[0x8:0xc])[0] + 0x10000000
- huff_data_len = unpack("<I", llut[0x10:0x14])[0]
chunk_size = unpack("<I", llut[0x30:0x34])[0]
- llut += f.read(chunk_count * 4 + huff_data_len)
+ llut += f.read(chunk_count * 4)
chunks_offsets = get_chunks_offsets(llut, me_start)
else:
sys.exit("Huffman modules found, but LLUT is not present")
@@ -129,14 +182,20 @@ def remove_modules(f, mod_headers, ftpr_offset):
for removable_chunk in removable_huff_chunks:
if removable_chunk[1] > removable_chunk[0]:
- fill_range(f, removable_chunk[0], removable_chunk[1], b"\xff")
+ 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 = int(binascii.hexlify(f.read(0x4)[::-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
@@ -152,144 +211,274 @@ def check_partition_signature(f, offset):
return "{:#x}".format(decrypted_sig).endswith(sha256.hexdigest()) # FIXME
-if len(sys.argv) != 2 or sys.argv[1] == "-h" or sys.argv[1] == "--help":
- print("Usage: \n"
- " me_cleaner.py me_or_txe_image.bin\n"
- "or\n"
- " me_cleaner.py full_dump.bin")
-else:
- with open(sys.argv[1], "r+b") as f:
- f.seek(0x10)
- magic = f.read(4)
-
- if magic == b"$FPT":
- print("ME/TXE image detected")
- me_start = 0
- f.seek(0, 2)
- me_end = f.tell()
-
- elif magic == b"\x5a\xa5\xf0\x0f":
- print("Full image detected")
- f.seek(0x14)
- flmap0 = unpack("<I", f.read(4))[0]
- nr = flmap0 >> 24 & 0x7
- frba = flmap0 >> 12 & 0xff0
- if nr >= 2:
- f.seek(frba + 0x8)
- flreg2 = unpack("<I", f.read(4))[0]
- me_start = (flreg2 & 0x1fff) << 12
- me_end = flreg2 >> 4 & 0x1fff000 | 0xfff
-
- if me_start >= me_end:
- sys.exit("The ME/TXE region in this image has been "
- "disabled")
-
- f.seek(me_start + 0x10)
- if f.read(4) != b"$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("This image does not contains a ME/TXE firmware "
- "(NR = {})".format(nr))
+def relocate_partition(f, me_start, 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))
+ old_offset += me_start
+
+ 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 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 + me_start - llut_start - 0x40 +
+ old_offset)
+ new_offset = ((new_offset + 0x1f) // 0x20) * 0x20
+
+ offset_diff = new_offset - old_offset
+ print("Relocating {} to {:#x} - {:#x}..."
+ .format(name, new_offset, new_offset + partition_size))
+
+ print(" Adjusting FPT entry...")
+ f.write_to(partition_header_offset + 0x8,
+ pack("<I", new_offset - me_start))
+
+ 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 - me_start
+ 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
+
+
+if __name__ == "__main__":
+ parser = argparse.ArgumentParser(description="Tool to remove as much code "
+ "as possible from Intel ME/TXE firmwares")
+ parser.add_argument("file", help="ME/TXE image or full dump")
+ parser.add_argument("-O", "--output", help="save the modified image in a "
+ "separate file, instead of modifying the original "
+ "file")
+ parser.add_argument("-r", "--relocate", help="relocate the FTPR partition "
+ "to the top of the ME region", action="store_true")
+ parser.add_argument("-k", "--keep-modules", help="don't remove the FTPR "
+ "modules, even when possible", action="store_true")
+ 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("-c", "--check", help="verify the integrity of the "
+ "fundamental parts of the firmware and exit",
+ action="store_true")
+ args = parser.parse_args()
+
+ f = open(args.file, "rb" if args.check or args.output else "r+b")
+ f.seek(0x10)
+ magic = f.read(4)
+
+ if magic == b"$FPT":
+ print("ME/TXE image detected")
+ me_start = 0
+ f.seek(0, 2)
+ me_end = f.tell()
+
+ if args.descriptor:
+ sys.exit("-d requires a full dump")
+
+ elif magic == b"\x5a\xa5\xf0\x0f":
+ print("Full image detected")
+ f.seek(0x14)
+ flmap0, flmap1 = unpack("<II", f.read(8))
+ nr = flmap0 >> 24 & 0x7
+ frba = flmap0 >> 12 & 0xff0
+ fmba = (flmap1 & 0xff) << 4
+ if nr >= 2:
+ f.seek(frba)
+ flreg0, flreg1, flreg2 = unpack("<III", f.read(12))
+ fd_start = (flreg0 & 0x1fff) << 12
+ fd_end = flreg0 >> 4 & 0x1fff000 | 0xfff + 1
+ me_start = (flreg2 & 0x1fff) << 12
+ me_end = flreg2 >> 4 & 0x1fff000 | 0xfff + 1
+
+ if me_start >= me_end:
+ sys.exit("The ME/TXE region in this image has been disabled")
+
+ f.seek(me_start + 0x10)
+ if f.read(4) != b"$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")
+ sys.exit("This image does not contains a ME/TXE firmware NR = {})"
+ .format(nr))
+ else:
+ sys.exit("Unknown image")
- print("Found FPT header at {:#x}".format(me_start + 0x10))
+ print("Found FPT header at {:#x}".format(me_start + 0x10))
- f.seek(me_start + 0x14)
- entries = unpack("<I", f.read(4))[0]
- print("Found {} partition(s)".format(entries))
+ f.seek(me_start + 0x14)
+ entries = unpack("<I", f.read(4))[0]
+ print("Found {} partition(s)".format(entries))
- f.seek(me_start + 0x14)
- header_len = unpack("B", f.read(1))[0]
+ f.seek(me_start + 0x14)
+ header_len = unpack("B", f.read(1))[0]
- f.seek(me_start + 0x30)
- partitions = f.read(entries * 0x20)
+ f.seek(me_start + 0x30)
+ partitions = f.read(entries * 0x20)
- ftpr_header = b""
+ 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
+ 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")
+ if ftpr_header == b"":
+ sys.exit("FTPR header not found, this image doesn't seem to be valid")
- ftpr_offset, ftpr_lenght = unpack("<II", ftpr_header[0x08:0x10])
- ftpr_offset += me_start
- print("Found FTPR header: FTPR partition spans from {:#x} to {:#x}"
- .format(ftpr_offset, ftpr_offset + ftpr_lenght))
- print("Removing extra partitions...")
+ ftpr_offset, ftpr_lenght = unpack("<II", ftpr_header[0x08:0x10])
+ ftpr_offset += me_start
+ print("Found FTPR header: FTPR partition spans from {:#x} to {:#x}"
+ .format(ftpr_offset, ftpr_offset + ftpr_lenght))
+
+ f.seek(ftpr_offset)
+ if f.read(4) == b"$CPD":
+ me11 = True
+ num_entries = unpack("<I", f.read(4))[0]
+ ftpr_mn2_offset = 0x10 + num_entries * 0x18
+ else:
+ me11 = False
+ ftpr_mn2_offset = 0
+
+ f.seek(ftpr_offset + ftpr_mn2_offset + 0x24)
+ version = unpack("<HHHH", f.read(0x08))
+ print("ME/TXE firmware version {}"
+ .format('.'.join(str(i) for i in version)))
+
+ if not args.check:
+ if args.output:
+ f.close()
+ shutil.copy(args.file, args.output)
+ f = open(args.output, "r+b")
- fill_range(f, me_start + 0x30, ftpr_offset, b"\xff")
- fill_range(f, ftpr_offset + ftpr_lenght, me_end, b"\xff")
+ mef = regionFile(f, me_start, me_end)
+
+ print("Removing extra partitions...")
+ mef.fill_range(me_start + 0x30, ftpr_offset, b"\xff")
+ mef.fill_range(ftpr_offset + ftpr_lenght, me_end, b"\xff")
print("Removing extra partition entries in FPT...")
- f.seek(me_start + 0x30)
- f.write(ftpr_header)
- f.seek(me_start + 0x14)
- f.write(pack("<I", 1))
+ mef.write_to(me_start + 0x30, ftpr_header)
+ mef.write_to(me_start + 0x14, pack("<I", 1))
print("Removing EFFS presence flag...")
- f.seek(me_start + 0x24)
- flags = unpack("<I", f.read(4))[0]
+ mef.seek(me_start + 0x24)
+ flags = unpack("<I", mef.read(4))[0]
flags &= ~(0x00000001)
- f.seek(me_start + 0x24)
- f.write(pack("<I", flags))
+ mef.write_to(me_start + 0x24, pack("<I", flags))
- f.seek(me_start, 0)
- header = bytearray(f.read(0x30))
+ if args.descriptor:
+ print("Removing ME/TXE R/W access to the other flash regions...")
+ fdf = regionFile(f, fd_start, fd_end)
+ fdf.write_to(fmba + 0x4, pack("<I", 0x04040000))
+
+ if me11:
+ mef.seek(me_start + 0x10)
+ header = bytearray(mef.read(0x20))
+ else:
+ mef.seek(me_start)
+ header = bytearray(mef.read(0x30))
checksum = (0x100 - (sum(header) - header[0x1b]) & 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 (except for 0x1b, the checksum itself). In other words,
- # the sum of the first 0x30 bytes must be always 0x00.
- f.seek(me_start + 0x1b)
- f.write(pack("B", checksum))
-
- f.seek(ftpr_offset)
- if f.read(4) == b"$CPD":
- me11 = True
- num_entries = unpack("<I", f.read(4))[0]
- f.seek(ftpr_offset + 0x10 + num_entries * 0x18 + 0x24)
- else:
- me11 = False
- f.seek(ftpr_offset + 0x24)
-
- version = unpack("<HHHH", f.read(0x08))
- print("ME/TXE firmware version {}"
- .format('.'.join(str(i) for i in version)))
+ # 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(me_start + 0x1b, pack("B", checksum))
if not me11:
print("Reading FTPR modules list...")
- f.seek(ftpr_offset + 0x1c)
- tag = f.read(4)
+ mef.seek(ftpr_offset + 0x1c)
+ tag = mef.read(4)
if tag == b"$MN2":
- f.seek(ftpr_offset + 0x20)
- num_modules = unpack("<I", f.read(4))[0]
- f.seek(ftpr_offset + 0x290)
- data = f.read(0x84)
+ mef.seek(ftpr_offset + 0x20)
+ num_modules = unpack("<I", mef.read(4))[0]
+ mef.seek(ftpr_offset + 0x290)
+ data = mef.read(0x84)
module_header_size = 0
if data[0x0:0x4] == b"$MME":
- if data[0x60:0x64] == b"$MME":
+ if data[0x60:0x64] == b"$MME" or num_modules == 1:
module_header_size = 0x60
elif data[0x80:0x84] == b"$MME":
module_header_size = 0x80
if module_header_size != 0:
- f.seek(ftpr_offset + 0x290)
- mod_headers = [f.read(module_header_size)
+ mef.seek(ftpr_offset + 0x290)
+ mod_headers = [mef.read(module_header_size)
for i in range(0, num_modules)]
- if all(mod_h.startswith(b"$MME") for mod_h in mod_headers):
- remove_modules(f, mod_headers, ftpr_offset)
+ if all(hdr.startswith(b"$MME") for hdr in mod_headers):
+ if args.keep_modules:
+ end_addr = ftpr_offset + ftpr_lenght
+ else:
+ end_addr = remove_modules(mef, mod_headers,
+ ftpr_offset, me_end)
+
+ if args.relocate:
+ new_ftpr_offset = relocate_partition(mef,
+ me_start, me_end,
+ me_start + 0x30,
+ min_ftpr_offset + me_start,
+ mod_headers)
+ end_addr += new_ftpr_offset - ftpr_offset
+ ftpr_offset = new_ftpr_offset
+
+ 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 - me_start))
+
+ if me_start > 0:
+ print("The ME region can be reduced up to:\n"
+ " {:08x}:{:08x} me"
+ .format(me_start, end_addr - 1))
else:
print("Found less modules than expected in the FTPR "
"partition; skipping modules removal")
@@ -302,12 +491,15 @@ else:
else:
print("Modules removal in ME v11 or greater is not yet supported")
- sys.stdout.write("Checking FTPR RSA signature... ")
- if check_partition_signature(f, ftpr_offset):
- print("VALID")
- else:
- print("INVALID!!")
- sys.exit("The FTPR partition signature is not valid. Is the input "
- "ME/TXE image valid?")
+ sys.stdout.write("Checking FTPR RSA signature... ")
+ if check_partition_signature(f, ftpr_offset + ftpr_mn2_offset):
+ print("VALID")
+ else:
+ print("INVALID!!")
+ sys.exit("The FTPR partition signature is not valid. Is the input "
+ "ME/TXE image valid?")
+
+ f.close()
+ if not args.check:
print("Done! Good luck!")
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