sravan/system76-coreboot
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

util/me_cleaner: Pull the latest changes from upstream

Browse Source 
Relevant changes (commit 2e8761e):
 * Add an option to truncate the ME image file
 * Add full support for Skylake (ME 11) and following, including
    modules removal, truncation informations and partition
    relocation
 * Add two options to generate a shrinked ME image file and the
    corresponding descriptor with a modified flash layout
 * Update README.md
 * Bug fixes

Also add a link to the usage guide in the Kconfig help.

Change-Id: I690c5d558139f64f38babf3c0988b53834ba8b37
Signed-off-by: Nicola Corna <nicola@corna.info>
Reviewed-on: https://review.coreboot.org/20915
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
This commit is contained in:
Nicola Corna
2017-08-08 21:24:49 +02:00
committed by Martin Roth
parent 4ff449272d
commit 98f30340cf
3 changed files with 378 additions and 153 deletions
Download Patch File Download Diff File Expand all files Collapse all files

58
util/me_cleaner/README.md
View File

@@ -1,26 +1,44 @@
# ME cleaner
# me_cleaner
A cleaner for Intel ME/TXE images.
Intel ME is a coprocessor integrated in all post-2006 Intel boards, for which
this [Libreboot page](https://libreboot.org/faq.html#intelme) has an excellent
description. The main component of Intel ME is Intel AMT, and I suggest you to
read [this Wikipedia page](https://en.wikipedia.org/wiki/Intel_Active_Management_Technology)
for more information about it. In short, Intel ME is an irremovable environment
with an obscure signed proprietary firmware, with full network and memory
access, which poses a serious security threat.
Even when disabled from the BIOS settings, Intel ME is active: the only way to
be sure it is disabled is to remove its firmware from the flash chip.
This tools removes any unnecessary partition from an Intel ME/TXE firmware, reducing
its size and its ability to interact with the system.
It should work both with coreboot and with the factory firmware.
Before Nehalem (ME version 6, 2008/2009) the ME firmware could be removed
completely from the flash chip by setting a couple of bits inside the flash
descriptor, without the need to reverse-engineer the ME firmware.
Currently this tool:
* Scans the FPT (partition table) and checks that everything is correct
* Removes any partition entry (except for FTPR) from FPT
* 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 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
Starting from Nehalem the Intel ME firmware can't be removed anymore: without a
valid firmware the PC shuts off forcefully after 30 minutes. This project is an
attempt to remove as much code as possible from such firmware without falling
into the 30 minutes recovery mode.
Don't forget to power cycle your PC after flashing the modified ME/TXE image
(power off and power on, not just reboot).
me_cleaner currently works on most architectures, see [me_cleaner status](https://github.com/corna/me_cleaner/wiki/me_cleaner-status) (or [its discussion](https://github.com/corna/me_cleaner/issues/3))
for more info about them. me_cleaner works also on the TXE and SPS firmware.
See the [current status](https://github.com/corna/me_cleaner/wiki/me_cleaner-status)
or [a more detailed description](https://github.com/corna/me_cleaner/wiki/How-does-it-work%3F)
of me_cleaner.
If you want to understand how me_cleaner works, you can read the ["How does it work?" page](https://github.com/corna/me_cleaner/wiki/How-does-it-work%3F).
Special thanks to Federico Amedeo Izzo for his help during the study of Intel ME.
If you want to apply me_cleaner on your platform I suggest you to read the
["How does it work?" page](https://github.com/corna/me_cleaner/wiki/How-does-it-work%3F)
and then follow the guide ["How to apply me_cleaner"](https://github.com/corna/me_cleaner/wiki/How-to-apply-me_cleaner).
For pre-Skylake firmware (ME version < 11) this tool removes almost everything,
leaving only the two fundamental modules needed for the correct boot, ROMP and
BUP. The code size is reduced from 1.5 MB (non-AMT firmware) or 5 MB (AMT
firmware) to ~90 kB of compressed code.
Starting from Skylake (ME version >= 11) the ME subsystem and the firmware
structure have changed, requiring substantial changes in me_cleaner.
The fundamental modules required for the correct boot are now four (rbe, kernel,
syslib and bup) and the minimum code size is ~300 kB of compressed code (from
the 2 MB of the non-AMT firmware and the 7 MB of the AMT one).
This project is based on the work of the community; in particular I thank Igor
Skochinsky, for the core information about Intel ME and its firmware structure,
and Federico Amedeo Izzo, for its help during the study of Intel ME.