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util: Add me_cleaner me_cleaner is a tool to strip down Intel ME/TXE images by removing all the non-fundamental code, while keeping the ME/TXE image valid and suitable for booting the system. The remaining code (ROMP and BUP modules) is the one responsible for the very basic initialization of the ME/TXE subsystem and can't be removed. This tool exploits the fact that: * Each ME/TXE partition is signed individually and it is possible to remove both the partition and the signature. * The ME/TXE modules are not signed directly, instead they are hashed and the list of their hashes is hashed again and signed: this means that modifying a module doesn't invalidate the signature, but only the hash of that single module. * The modules hashes are checked only when the corresponding module needs to be executed. * The system can boot after the execution of the first module (BUP, inside the FTPR partition), even if the subsequent stages fail. Currently me_cleaner works on every Intel platform with Intel ME or Intel TXE with the following limitations: * Doesn't work when Intel Boot Guard is set in Verified Boot mode. * Doesn't fully work on Nehalem yet. * On Skylake and later generations, since the partitions' internal structure has changed, me_cleaner leaves intact the FTPR partition, removing all the the other partitions. This tool has been tested on multiple platforms and architectures by different users, and seems to be stable. The reports are available here: https://github.com/corna/me_cleaner/issues/3 A more in-depth description of me_cleaner is available here: https://github.com/corna/me_cleaner/wiki/How-does-it-work%3F Change-Id: I9013799e9adea0dea0775b9afe718de5fc4ca748 Signed-off-by: Nicola Corna <nicola@corna.info> Reviewed-on: https://review.coreboot.org/18203 Tested-by: build bot (Jenkins) Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com> Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2017-01-23 15:28:24 +01:00
# ME cleaner
A cleaner for Intel ME/TXE images.
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.
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
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@corna.info> Reviewed-on: https://review.coreboot.org/18473 Tested-by: build bot (Jenkins) Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
2017-02-22 10:16:32 +01:00
* 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)
util: Add me_cleaner me_cleaner is a tool to strip down Intel ME/TXE images by removing all the non-fundamental code, while keeping the ME/TXE image valid and suitable for booting the system. The remaining code (ROMP and BUP modules) is the one responsible for the very basic initialization of the ME/TXE subsystem and can't be removed. This tool exploits the fact that: * Each ME/TXE partition is signed individually and it is possible to remove both the partition and the signature. * The ME/TXE modules are not signed directly, instead they are hashed and the list of their hashes is hashed again and signed: this means that modifying a module doesn't invalidate the signature, but only the hash of that single module. * The modules hashes are checked only when the corresponding module needs to be executed. * The system can boot after the execution of the first module (BUP, inside the FTPR partition), even if the subsequent stages fail. Currently me_cleaner works on every Intel platform with Intel ME or Intel TXE with the following limitations: * Doesn't work when Intel Boot Guard is set in Verified Boot mode. * Doesn't fully work on Nehalem yet. * On Skylake and later generations, since the partitions' internal structure has changed, me_cleaner leaves intact the FTPR partition, removing all the the other partitions. This tool has been tested on multiple platforms and architectures by different users, and seems to be stable. The reports are available here: https://github.com/corna/me_cleaner/issues/3 A more in-depth description of me_cleaner is available here: https://github.com/corna/me_cleaner/wiki/How-does-it-work%3F Change-Id: I9013799e9adea0dea0775b9afe718de5fc4ca748 Signed-off-by: Nicola Corna <nicola@corna.info> Reviewed-on: https://review.coreboot.org/18203 Tested-by: build bot (Jenkins) Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com> Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2017-01-23 15:28:24 +01:00
* 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
(power off and power on, not just reboot).
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.
Special thanks to Federico Amedeo Izzo for his help during the study of Intel ME.