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| author | Francis Rowe <info@gluglug.org.uk> | 2014-12-22 06:42:35 (EST) |
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| committer | Francis Rowe <info@gluglug.org.uk> | 2014-12-22 06:42:35 (EST) |
| commit | 82e8d082e74de2e17896a9fef9a2949d0c131db8 (patch) | |
| tree | 04aef523a23e41bbdbb474db985bf718beed4e03 /docs/hcl | |
| parent | 479940cf1b7b166dd6884a996f7ade7e2b216de9 (diff) | |
| download | libreboot-82e8d082e74de2e17896a9fef9a2949d0c131db8.zip libreboot-82e8d082e74de2e17896a9fef9a2949d0c131db8.tar.gz libreboot-82e8d082e74de2e17896a9fef9a2949d0c131db8.tar.bz2 | |
docs/hcl/x200_remove_me.html: Add info about faulty Gbe regions
Diffstat (limited to 'docs/hcl')
| -rw-r--r-- | docs/hcl/x200_remove_me.html | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/docs/hcl/x200_remove_me.html b/docs/hcl/x200_remove_me.html index b1a88e2..0cef79b 100644 --- a/docs/hcl/x200_remove_me.html +++ b/docs/hcl/x200_remove_me.html @@ -264,18 +264,24 @@ DD CC 18 00 11 20 17 00 DD DD 18 00 12 20 17 00 <h3 id="gbe_region_changemacaddress">GBE region: change MAC address</h3> <p> - According to the datasheet, it's supposed to add up to 0xBABA but can actually be 0x3ABA. - Either the checksum doesn't matter or the most significant bit of the checksum isn't checked. + According to the datasheet, it's supposed to add up to 0xBABA but can actually be others on the X200. <a href="https://communities.intel.com/community/wired/blog/2010/10/14/how-to-basic-eeprom-checksums">https://communities.intel.com/community/wired/blog/2010/10/14/how-to-basic-eeprom-checksums</a> </p> <p> <i>"One of those engineers loves classic rock music, so he selected 0xBABA"</i> </p> + <p>In honour of the song <i>Baba O'Reilly</i> by <i>The Who</i> apparently. We're not making this stuff up...</p> + <p> - 0xBABA and 0x3ABA only differ by the most significant bit. The checksum of the GBe region from an X200S - was found to be 0x34BA; again, it should be 0xBABA. 34BA is actually BABA in L33T speak (look it up). + 0x3ABA, 0x34BA, 0x40BA and more have been observed in the main Gbe regions on the X200 factory.rom dumps. + The checksums of the backup regions match BABA, however. + </p> + + <p> + By default, the X200 (as shipped by Lenovo) actually has an invalid main gbe checksum. The backup gbe region is correct, + and is what these machines default to. Basically, you should do what you need on the *backup* gbe region, and + then correct the main one by copying from the backup. </p> - <p>In honour of the song <i>Baba O'Reilly</i> by <i>The Who</i> apparently. We're not making this stuff up...</p> <p> Look at resources/utilities/ich9deblob/ich9deblob.c. |