98f30340cf
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>
44 lines
2.7 KiB
Markdown
44 lines
2.7 KiB
Markdown
# me_cleaner
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Intel ME is a coprocessor integrated in all post-2006 Intel boards, for which
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this [Libreboot page](https://libreboot.org/faq.html#intelme) has an excellent
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description. The main component of Intel ME is Intel AMT, and I suggest you to
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read [this Wikipedia page](https://en.wikipedia.org/wiki/Intel_Active_Management_Technology)
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for more information about it. In short, Intel ME is an irremovable environment
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with an obscure signed proprietary firmware, with full network and memory
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access, which poses a serious security threat.
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Even when disabled from the BIOS settings, Intel ME is active: the only way to
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be sure it is disabled is to remove its firmware from the flash chip.
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Before Nehalem (ME version 6, 2008/2009) the ME firmware could be removed
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completely from the flash chip by setting a couple of bits inside the flash
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descriptor, without the need to reverse-engineer the ME firmware.
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Starting from Nehalem the Intel ME firmware can't be removed anymore: without a
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valid firmware the PC shuts off forcefully after 30 minutes. This project is an
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attempt to remove as much code as possible from such firmware without falling
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into the 30 minutes recovery mode.
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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))
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for more info about them. me_cleaner works also on the TXE and SPS firmware.
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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).
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If you want to apply me_cleaner on your platform I suggest you to read the
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["How does it work?" page](https://github.com/corna/me_cleaner/wiki/How-does-it-work%3F)
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and then follow the guide ["How to apply me_cleaner"](https://github.com/corna/me_cleaner/wiki/How-to-apply-me_cleaner).
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For pre-Skylake firmware (ME version < 11) this tool removes almost everything,
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leaving only the two fundamental modules needed for the correct boot, ROMP and
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BUP. The code size is reduced from 1.5 MB (non-AMT firmware) or 5 MB (AMT
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firmware) to ~90 kB of compressed code.
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Starting from Skylake (ME version >= 11) the ME subsystem and the firmware
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structure have changed, requiring substantial changes in me_cleaner.
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The fundamental modules required for the correct boot are now four (rbe, kernel,
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syslib and bup) and the minimum code size is ~300 kB of compressed code (from
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the 2 MB of the non-AMT firmware and the 7 MB of the AMT one).
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This project is based on the work of the community; in particular I thank Igor
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Skochinsky, for the core information about Intel ME and its firmware structure,
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and Federico Amedeo Izzo, for its help during the study of Intel ME.
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