diff options
Diffstat (limited to 'resources/utilities/ich9deblob/ich9deblob.c')
| -rw-r--r-- | resources/utilities/ich9deblob/ich9deblob.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/resources/utilities/ich9deblob/ich9deblob.c b/resources/utilities/ich9deblob/ich9deblob.c new file mode 100644 index 0000000..7144f32 --- /dev/null +++ b/resources/utilities/ich9deblob/ich9deblob.c @@ -0,0 +1,248 @@ +/* + * ich9deblob.c + * This file is part of the ich9deblob utility from the libreboot project + * + * Purpose: disable and remove the ME from ich9m/gm45 machines in coreboot. + * + * 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/>. + */ + +/* Initially based on proof of concept by Steve Shenton. */ + +/* + * Read a factory.rom dump (ich9m/gm45 machines) 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/hcl/x200_remove_me.html for info plus links to datasheet (also linked below) + * + * Info about flash descriptor (read page 850 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://communities.intel.com/community/wired/blog/2010/10/14/how-to-basic-eeprom-checksums + */ + +#include <stdio.h> +#include <string.h> +#include "descriptor/descriptor.h" /* structs describing what's in the descriptor region */ +#include "gbe/gbe.h" /* structs describing what's in the gbe region */ +#include "x86compatibility.h" /* system/compiler compatibility checks. This code is not portable. */ + +int main(int argc, char *argv[]) +{ + /* + * descriptor region. Will have an actual descriptor struct mapped to it (from the factory.rom dump) + * and then it will be modified (deblobbed) to remove the ME/AMT + */ + char factoryDescriptorBuffer[DESCRIPTORREGIONSIZE]; + struct DESCRIPTORREGIONRECORD factoryDescriptorStruct; + char deblobbedDescriptorBuffer[DESCRIPTORREGIONSIZE]; + struct DESCRIPTORREGIONRECORD deblobbedDescriptorStruct; + + /* + * gbe region. Well have actual gbe buffer mapped to it (from the factory.rom dump) + * and then it will be modified to correct the main region + */ + char factoryGbeBuffer8k[GBEREGIONSIZE_8K]; + struct GBEREGIONRECORD_8K factoryGbeStruct8k; + char deblobbedGbeBuffer8k[GBEREGIONSIZE_8K]; + struct GBEREGIONRECORD_8K deblobbedGbeStruct8k; + + /* + * Used to store the location of the Gbe + * region inside the factory.rom image. + */ + unsigned int factoryGbeRegionStart; + + /* names of the files that this utility will handle */ + char* factoryRomFilename = "factory.rom"; /* user-supplied factory.bin dump (original firmware) */ + char* deblobbedDescriptorFilename = "deblobbed_descriptor.bin"; /* descriptor+gbe: to be dd'd to beginning of a libreboot image */ + + /* Used when reading the factory.rom to extract descriptor/gbe regions */ + unsigned int bufferLength; + + /* For storing the size of the factory.rom dump in bytes */ + unsigned int factoryRomSize; + + /* + * ------------------------------------------------------------------ + * Compatibility checks. This version of ich9deblob is not yet portable. + * ------------------------------------------------------------------ + */ + + if (systemOrCompilerIncompatible(factoryDescriptorStruct, factoryGbeStruct8k)) return 1; + /* If true, fail with error message */ + + /* + * ------------------------------------------------------------------ + * Extract the descriptor and gbe regions from the factory.rom dump + * ------------------------------------------------------------------ + */ + FILE* fileStream = NULL; + fileStream = fopen(factoryRomFilename, "rb"); /* open factory.rom */ + if (NULL == fileStream) + { + printf("\nerror: could not open factory.rom\n"); + return 1; + } + printf("\nfactory.rom opened successfully\n"); + + /* + * Get the descriptor region dump from the factory.rom + * (goes in factoryDescriptorBuffer variable) + */ + bufferLength = fread(factoryDescriptorBuffer, sizeof(char), DESCRIPTORREGIONSIZE, fileStream); + if (DESCRIPTORREGIONSIZE != bufferLength) // + { + printf("\nerror: could not read descriptor from factory.rom (%i) bytes read\n", bufferLength); + return 1; + } + printf("\ndescriptor region read successfully\n"); + /* + * copy descriptor buffer into descriptor struct memory + * factoryDescriptorStruct is an instance of a struct that actually + * defines the locations of all these variables in the descriptor, + * as defined in the datasheets. This allows us to map the extracted + * descriptor over the struct so that it can then be modified + * for libreboot's purpose + */ + memcpy(&factoryDescriptorStruct, &factoryDescriptorBuffer, DESCRIPTORREGIONSIZE); + /* + * ^ the above is just for reference if needed. The modifications will be made here: + */ + memcpy(&deblobbedDescriptorStruct, &factoryDescriptorBuffer, DESCRIPTORREGIONSIZE); + + /* + * Get the gbe region dump from the factory.rom + */ + + /* + * get original GBe region location + * (it will be moved to the beginning of the flash, after the descriptor region) + * note for example, factoryGbeRegionStart is set to <<FLREGIONBITSHIFT of actual address (in C). this is how the addresses + * are stored in the descriptor. + */ + factoryGbeRegionStart = factoryDescriptorStruct.regionSection.flReg3.BASE << FLREGIONBITSHIFT; + + /* + * Set offset so that we can read the data from + * the gbe region + */ + fseek(fileStream, factoryGbeRegionStart, SEEK_SET); + /* Read the gbe data from the factory.rom and put it in factoryGbeBuffer8k */ + bufferLength = fread(factoryGbeBuffer8k, sizeof(char), GBEREGIONSIZE_8K, fileStream); + if (GBEREGIONSIZE_8K != bufferLength) + { + printf("\nerror: could not read GBe region from factory.rom (%i) bytes read\n", bufferLength); + return 1; + } + printf("\ngbe (8KiB) region read successfully\n"); + /* + * copy gbe buffer into gbe struct memory + * factoryGbeStruct8k is an instance of a struct that actually + * defines the locations of all these variables in the gbe, + * as defined in the datasheets. This allows us to map the extracted + * gbe over the struct so that it can then be modified + * for libreboot's purpose + */ + memcpy(&factoryGbeStruct8k, &factoryGbeBuffer8k, GBEREGIONSIZE_8K); + /* + * the original factoryGbeStruct8k is only reference. Changes go here: + */ + memcpy(&deblobbedGbeStruct8k, &factoryGbeBuffer8k, GBEREGIONSIZE_8K); + + /* + * Get size of ROM image + * This is needed for relocating the BIOS region (per descriptor) + */ + fseek(fileStream, 0L, SEEK_END); + factoryRomSize = ftell(fileStream); + + printf("\nfactory.rom size: [%i] bytes\n", factoryRomSize); + + fclose(fileStream); + + /* + * ------------------------------------------------------------------ + * Modify the descriptor and gbe regions, ready to go in libreboot.rom + * ------------------------------------------------------------------ + */ + + /* + * Disable the ME and Platform regions. Put Gbe at the beginning (after descriptor). + * Also, extend the BIOS region to fill the ROM image (after descriptor+gbe). + */ + deblobbedDescriptorStruct = deblobbedDescriptorStructFromFactory(factoryDescriptorStruct, factoryRomSize); + + /* + * Modify the Gbe region (see function for details) + */ + deblobbedGbeStruct8k = deblobbedGbeStructFromFactory(factoryGbeStruct8k); + + /* + * ------------------------------------------------------------------ + * Create the file with the modified descriptor and gbe inside + * ------------------------------------------------------------------ + */ + + /* + * Convert the deblobbed descriptor and gbe back to byte arrays, so that they + * can more easily be written to files: + * deblobbed descriptor region + */ + memcpy(&deblobbedDescriptorBuffer, &deblobbedDescriptorStruct, DESCRIPTORREGIONSIZE); /* descriptor */ + memcpy(&deblobbedGbeBuffer8k, &deblobbedGbeStruct8k, GBEREGIONSIZE_8K); /* gbe */ + + /* delete old file before continuing */ + remove(deblobbedDescriptorFilename); + + /* open new file for writing the deblobbed descriptor+gbe */ + fileStream = fopen(deblobbedDescriptorFilename, "ab"); + + /* write the descriptor region into the first part */ + if (DESCRIPTORREGIONSIZE != fwrite(deblobbedDescriptorBuffer, sizeof(char), DESCRIPTORREGIONSIZE, fileStream)) + { + printf("\nerror: writing descriptor region failed\n"); + return 1; + } + + /* add gbe to the end of the file */ + if (GBEREGIONSIZE_8K != fwrite(deblobbedGbeBuffer8k, sizeof(char), GBEREGIONSIZE_8K, fileStream)) + { + printf("\nerror: writing GBe region failed\n"); + return 1; + } + + fclose(fileStream); + + printf("\ndeblobbed descriptor successfully created: deblobbed_descriptor.bin \n"); + + // ------------------------------------------------------------------------------------- + + printf("\nNow do: dd if=deblobbed_descriptor.bin of=libreboot.rom bs=1 count=12k conv=notrunc"); + printf("\n(in other words, add the modified descriptor+gbe to your ROM image)\n"); + + return 0; +} |