/* * ich9deblob.c * This file is part of the ich9deblob utility from the libreboot project * * Purpose: disable and remove the ME from ich9m/gm45 systems in coreboot. * * Copyright (C) 2014 Steve Shenton * Copyright (C) 2014,2015 Leah Rowe * * 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 . */ /* Initially based on proof of concept by Steve Shenton. */ /* Original utility can be found at https://gitorious.org/ich9descriptortool */ /* * Read a factory.rom dump (ich9m/gm45 systems) and * modify the flash descriptor to remove all regions except descriptor, * Gbe and BIOS. Set BIOS region to full size of the ROM image (after * the flash descriptor and gbe). Basically, deblob the descriptor. * * This will will generate a concatenated descriptor+gbe dump suitable * for use in libreboot. Currently tested: ThinkPad X200 (coreboot/libreboot) */ /* * See docs/hardware/x200_remove_me.html for info plus links to datasheet (also linked below) * * Info about flash descriptor (read page 845 onwards): * http://www.intel.co.uk/content/dam/doc/datasheet/io-controller-hub-9-datasheet.pdf * * Info about Gbe region (read whole datasheet): * http://www.intel.co.uk/content/dam/doc/application-note/i-o-controller-hub-9m-82567lf-lm-v-nvm-map-appl-note.pdf * https://web.archive.org/web/20150912070329/https://communities.intel.com/community/wired/blog/2010/10/14/how-to-basic-eeprom-checksums */ #include "ich9deblob.h" int main() { struct DESCRIPTORREGIONRECORD descriptorStruct; uint8_t* descriptorBuffer = (uint8_t*)&descriptorStruct; struct GBEREGIONRECORD_8K gbeStruct8k; uint8_t* gbeBuffer8k = (uint8_t*)&gbeStruct8k; uint32_t gbeRegionStart; char* romFilename = "factory.rom"; char* descriptorGbeFilename = "deblobbed_descriptor.bin"; char* descriptorNoGbeFilename = "deblobbed_4kdescriptor.bin"; unsigned int bufferLength; unsigned int romSize; /* * ------------------------------------------------------------------ * Compatibility checks. This version of ich9deblob is not yet portable. * ------------------------------------------------------------------ */ if (systemOrCompilerIncompatible(descriptorStruct, gbeStruct8k)) return 1; /* If true, fail with error message */ /* * ------------------------------------------------------------------ * Extract the descriptor and gbe regions from the factory.rom dump * ------------------------------------------------------------------ */ FILE* fp = NULL; fp = fopen(romFilename, "rb"); /* open factory.rom */ if (NULL == fp) { printf("\nerror: could not open %s\n", romFilename); fclose(fp); return 1; } printf("\n%s opened successfully\n", romFilename); /* * Get the descriptor region dump from the factory.rom * (goes in factoryDescriptorBuffer variable) */ bufferLength = fread(descriptorBuffer, 1, DESCRIPTORREGIONSIZE, fp); if (DESCRIPTORREGIONSIZE != bufferLength) // { printf("\nerror: could not read descriptor from %s (%i) bytes read\n", romFilename, bufferLength); fclose(fp); return 1; } printf("\ndescriptor region read successfully\n"); if (descriptorDefinesGbeRegion(descriptorStruct)) { gbeRegionStart = descriptorStruct.regionSection.flReg3.BASE << FLREGIONBITSHIFT; /* * Set offset so that we can read the data from * the gbe region */ fseek(fp, gbeRegionStart, SEEK_SET); /* Read the gbe data from the factory.rom and put it in factoryGbeBuffer8k */ bufferLength = fread(gbeBuffer8k, 1, GBEREGIONSIZE_8K, fp); if (GBEREGIONSIZE_8K != bufferLength) { printf("\nerror: could not read GBe region from %s (%i) bytes read\n", romFilename, bufferLength); fclose(fp); return 1; } printf("\ngbe (8KiB) region read successfully\n"); } fseek(fp, 0L, SEEK_END); romSize = ftell(fp); printf("\n%s size: [%i] bytes\n", romFilename, romSize); fclose(fp); /* Debugging (before modification) */ printDescriptorRegionLocations(descriptorStruct, "Original"); if (descriptorDefinesGbeRegion(descriptorStruct)) printGbeChecksumDataFromStruct8k(gbeStruct8k, "Original"); else printf("NO GBE REGION\n"); /* * ------------------------------------------------------------------ * Modify the descriptor and gbe regions, ready to go in libreboot.rom * ------------------------------------------------------------------ */ /* Delete the ME/Platform regions, place Gbe after the descriptor, resize BIOS region to fill the gap */ descriptorStruct = librebootDescriptorStructFromFactory(descriptorStruct, romSize); /* The ME is disallowed read-write access to all regions * (this is probably redundant, since the ME firmware is already removed from libreboot) */ descriptorStruct = descriptorMeRegionsForbidden(descriptorStruct); /* Host/CPU is allowed to read/write all regions. * This makes flashrom -p internal work */ descriptorStruct = descriptorHostRegionsUnlocked(descriptorStruct); /* Set OEM string */ descriptorStruct = descriptorOemString(descriptorStruct); /* Modify the Gbe region (see function for details) */ if (descriptorDefinesGbeRegion(descriptorStruct)) gbeStruct8k = deblobbedGbeStructFromFactory(gbeStruct8k); /* Debugging (after modifying the descriptor and gbe regions) */ printDescriptorRegionLocations(descriptorStruct, "Modified"); if (descriptorDefinesGbeRegion(descriptorStruct)) printGbeChecksumDataFromStruct8k(gbeStruct8k, "Modified"); else printf("NO GBE REGION\n"); /* * ------------------------------------------------------------------ * Create the file with the modified descriptor and gbe inside * ------------------------------------------------------------------ */ printf("\n"); if (descriptorDefinesGbeRegion(descriptorStruct)) { if (notCreatedDescriptorGbeFile(descriptorStruct, gbeStruct8k, descriptorGbeFilename)) { return 1; } } else { if (notCreated4kDescriptorFile(descriptorStruct, descriptorNoGbeFilename)) { return 1; } } /* * ------------------------------------------------------------------ * Generate ich9gen data (C code that will recreate the deblobbed descriptor+gbe from scratch) * ------------------------------------------------------------------ */ /* Code for generating the Descriptor struct */ /* mkdescriptor.h */ if (notCreatedHFileForDescriptorCFile("mkdescriptor.h", "mkdescriptor.c")) { return 1; } /* and now mkdescriptor.c */ if (notCreatedCFileFromDescriptorStruct(descriptorStruct, "mkdescriptor.c", "mkdescriptor.h")) { return 1; } if (descriptorDefinesGbeRegion(descriptorStruct)) { /* Code for generating the Gbe struct */ /* mkgbe.h */ if (notCreatedHFileForGbeCFile("mkgbe.h", "mkgbe.c")) { return 1; } /* and now mkgbe.c */ if (notCreatedCFileFromGbeStruct4k(gbeStruct8k.backup, "mkgbe.c", "mkgbe.h")) { return 1; } } if (descriptorDefinesGbeRegion(descriptorStruct)) { printf("The modified descriptor and gbe regions have also been dumped as src files: mkdescriptor.c, mkdescriptor.h, mkgbe.c, mkgbe.h\n"); printf("To use these in ich9gen, place them in src/ich9gen/ and re-build ich9gen.\n\n"); } else { printf("The modified descriptor region have also been dumped as src files: mkdescriptor.c, mkdescriptor.h\n"); printf("To use these in ich9gen, place them in src/ich9gen/ and re-build ich9gen.\n\n"); } return 0; }