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Diffstat (limited to 'resources/utilities/ich9deblob/gbe/struct.h')
| -rw-r--r-- | resources/utilities/ich9deblob/gbe/struct.h | 128 |
1 files changed, 0 insertions, 128 deletions
diff --git a/resources/utilities/ich9deblob/gbe/struct.h b/resources/utilities/ich9deblob/gbe/struct.h deleted file mode 100644 index cbc2635..0000000 --- a/resources/utilities/ich9deblob/gbe/struct.h +++ /dev/null @@ -1,128 +0,0 @@ -/* - * gbe/struct.h - * This file is part of the ich9deblob utility from the libreboot project - * - * Copyright (C) 2014 Steve Shenton <sgsit@libreboot.org> - * Francis Rowe <info@gluglug.org.uk> - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - */ - -// Purpose: provide struct representing gbe region. -// Map actual buffers of this regions, directly to instances of these -// structs. This makes working with gbe really easy. - -// bit fields used, corresponding to datasheet. See links to datasheets -// and documentation in ich9deblob.c - -#ifndef GBESTRUCT_H -#define GBESTRUCT_H - -#include <stdio.h> -#include <string.h> - -#define GBEREGIONSIZE 0x2000 // 8 KiB -// These will have a modified descriptor+gbe based on what's in the factory.rom -// These will be joined into a single 12KiB buffer (descriptor, then gbe) and saved to a file -// NOTE: The GBE region of 8K is actually 2x 4K regions in a single region; both 4K blocks can be identical (and by default, are) -// The 2nd one is a "backup", but we don't know when it's used. perhaps it's used when the checksum on the first one does not match? - -// --------------------------------------------------------------------- -// Gbe struct representing the data -// --------------------------------------------------------------------- - -struct GBEREGIONRECORD_4K { - unsigned char macAddress[6]; // 0x03 words, or 0x06 bytes - unsigned char otherStuff[120]; // 0x3c words, or 0x7E bytes - unsigned short checkSum; // when added to the sum of all words above, this should be 0xBABA - unsigned char padding1[3968]; -}; - -// main and backup region in gbe -struct GBEREGIONRECORD_8K { - struct GBEREGIONRECORD_4K main; - struct GBEREGIONRECORD_4K backup; - // Backup region: - // This is actually "main" on X200, since the real main has a bad checksum - // and other errors. You should do what you need on this one (if modifying - // lenovobios's gbe region) and then copy to main -}; - -// --------------------------------------------------------------------- -// Gbe functions -// --------------------------------------------------------------------- - -// Read a 16-bit unsigned int from a supplied region buffer -unsigned short gbeGetRegionWordFrom8kBuffer(int index, char* regionData) -{ - return *((unsigned short*)(regionData + (index * 2))); -} - -// checksum calculation for 8k gbe region (algorithm based on datasheet) -// also works for 4k buffers, so long as isBackup remains false -unsigned short gbeGetChecksumFrom8kBuffer(char* regionData, unsigned short desiredValue, char isBackup) -{ - int i; - - unsigned short regionWord; // store words here for adding to checksum - unsigned short checksum = 0; // this gbe's checksum - unsigned short offset = 0; // in bytes, from the start of the gbe region. - - // if isBackup is true, use 2nd gbe region ("backup" region) - if (isBackup) offset = 0x1000>>1; // this function uses *word* not *byte* indexes. - - for (i = 0; i < 0x3F; i++) { - regionWord = gbeGetRegionWordFrom8kBuffer(i+offset, regionData); - checksum += regionWord; - } - checksum = desiredValue - checksum; - return checksum; -} - -// checksum calculation for 4k gbe struct (algorithm based on datasheet) -unsigned short gbeGetChecksumFrom4kStruct(struct GBEREGIONRECORD_4K gbeStruct4k, unsigned short desiredValue) -{ - char gbeBuffer4k[GBEREGIONSIZE>>1]; - memcpy(&gbeBuffer4k, &gbeStruct4k, GBEREGIONSIZE>>1); - return gbeGetChecksumFrom8kBuffer(gbeBuffer4k, desiredValue, 0); -} - -// modify the gbe region extracted from a factory.rom dump -struct GBEREGIONRECORD_8K deblobbedGbeStructFromFactory(struct GBEREGIONRECORD_8K factoryGbeStruct8k) -{ - // Correct the main gbe region. By default, the X200 (as shipped from Lenovo) comes - // with a broken main gbe region, where the backup gbe region is used instead. Modify - // the descriptor so that the main region is usable. - - struct GBEREGIONRECORD_8K deblobbedGbeStruct8k; - memcpy(&deblobbedGbeStruct8k, &factoryGbeStruct8k, GBEREGIONSIZE); - - deblobbedGbeStruct8k.backup.checkSum = gbeGetChecksumFrom4kStruct(deblobbedGbeStruct8k.backup, 0xBABA); - memcpy(&deblobbedGbeStruct8k.main, &deblobbedGbeStruct8k.backup, GBEREGIONSIZE>>1); - - // Debugging: - // calculate the 0x3F'th 16-bit uint to make the desired final checksum for GBe - // observed checksum matches (from X200 factory.rom dumps) on main: 0x3ABA 0x34BA 0x40BA. spec defined as 0xBABA. - // X200 ships with a broken main gbe region by default (invalid checksum, and more) - // The "backup" gbe regions on these machines are correct, though, and is what the machines default to - // For libreboot's purpose, we can do much better than that by fixing the main one... below is only debugging - printf("\nfactory Gbe (main): calculated Gbe checksum: 0x%hx and actual GBe checksum: 0x%hx\n", gbeGetChecksumFrom4kStruct(factoryGbeStruct8k.main, 0xBABA), factoryGbeStruct8k.main.checkSum); - printf("factory Gbe (backup) calculated Gbe checksum: 0x%hx and actual GBe checksum: 0x%hx\n", gbeGetChecksumFrom4kStruct(factoryGbeStruct8k.backup, 0xBABA), factoryGbeStruct8k.backup.checkSum); - printf("\ndeblobbed Gbe (main): calculated Gbe checksum: 0x%hx and actual GBe checksum: 0x%hx\n", gbeGetChecksumFrom4kStruct(deblobbedGbeStruct8k.main, 0xBABA), deblobbedGbeStruct8k.main.checkSum); - printf("deblobbed Gbe (backup) calculated Gbe checksum: 0x%hx and actual GBe checksum: 0x%hx\n", gbeGetChecksumFrom4kStruct(deblobbedGbeStruct8k.backup, 0xBABA), deblobbedGbeStruct8k.backup.checkSum); - - return deblobbedGbeStruct8k; -} - -#endif |