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Diffstat (limited to 'resources/utilities/ich9deblob/src/descriptor/descriptor.c')
| -rw-r--r-- | resources/utilities/ich9deblob/src/descriptor/descriptor.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/resources/utilities/ich9deblob/src/descriptor/descriptor.c b/resources/utilities/ich9deblob/src/descriptor/descriptor.c new file mode 100644 index 0000000..aa3d84e --- /dev/null +++ b/resources/utilities/ich9deblob/src/descriptor/descriptor.c @@ -0,0 +1,170 @@ +/* + * descriptor/descriptor.c + * 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/>. + */ + +/* + * Provide descriptor related functions. + */ + +/* structs describing the data in descriptor region */ +#include "descriptor.h" + +/* + * --------------------------------------------------------------------- + * Descriptor functions + * --------------------------------------------------------------------- + */ + +/* + * Modify the flash descriptor, to remove the ME/AMT, and disable all other regions + * Only Flash Descriptor, Gbe and BIOS regions (BIOS region fills factoryRomSize-12k) are left. + * Tested on ThinkPad X200 and X200S. X200T and other GM45 targets may also work. + * Also described in docs/hcl/x200_remove_me.html + */ +struct DESCRIPTORREGIONRECORD deblobbedDescriptorStructFromFactory(struct DESCRIPTORREGIONRECORD factoryDescriptorStruct, unsigned int factoryRomSize) +{ + struct DESCRIPTORREGIONRECORD deblobbedDescriptorStruct; + memcpy(&deblobbedDescriptorStruct, &factoryDescriptorStruct, DESCRIPTORREGIONSIZE); + + /* + * set number of regions from 4 -> 2 (0 based, so 4 means 5 and 2 + * means 3. We want 3 regions: descriptor, gbe and bios, in that order) + */ + deblobbedDescriptorStruct.flMaps.flMap0.NR = 2; + + /* + * make descriptor writable from OS. This is that the user can run: + * sudo ./flashrom -p internal:laptop=force_I_want_a_brick + * from the OS, without relying an an external SPI flasher, while + * being able to write to the descriptor region (locked by default, + * until making the change below): + */ + deblobbedDescriptorStruct.masterAccessSection.flMstr1.fdRegionWriteAccess = 1; + + /* relocate BIOS region and increase size to fill image */ + deblobbedDescriptorStruct.regionSection.flReg1.BASE = 3; // 3<<FLREGIONBITSHIFT is 12KiB, which is where BIOS region is to begin (after descriptor and gbe) + deblobbedDescriptorStruct.regionSection.flReg1.LIMIT = ((factoryRomSize >> FLREGIONBITSHIFT) - 1); + /* + * ^ for example, 8MB ROM, that's 8388608 bytes. + * ^ 8388608>>FLREGIONBITSHIFT (or 8388608/4096) = 2048 bytes + * 2048 - 1 = 2047 bytes. + * This defines where the final 0x1000 (4KiB) page starts in the flash chip, because the hardware does: + * 2047<<FLREGIONBITSHIFT (or 2047*4096) = 8384512 bytes, or 7FF000 bytes + * (it can't be 0x7FFFFF because of limited number of bits) + */ + + /* set ME region size to 0 - the ME is a blob, we don't want it in libreboot */ + deblobbedDescriptorStruct.regionSection.flReg2.BASE = 0x1FFF; // setting 1FFF means setting size to 0. 1FFF<<FLREGIONBITSHIFT is outside of the ROM image (8MB) size? + /* ^ datasheet says to set this to 1FFF, but FFF was previously used and also worked. */ + deblobbedDescriptorStruct.regionSection.flReg2.LIMIT = 0; + /* + * ^ 0<<FLREGIONBITSHIFT=0, so basically, the size is 0, + * ^ and the base (1FFF>>FLREGIONBITSHIFT) is well outside the higher 8MB range. + */ + + /* relocate Gbe region to begin at 4KiB (immediately after the flash descriptor) */ + deblobbedDescriptorStruct.regionSection.flReg3.BASE = 1; // 1<<FLREGIONBITSHIFT is 4096, which is where the Gbe region is to begin (after the descriptor) + deblobbedDescriptorStruct.regionSection.flReg3.LIMIT = 2; + /* + * ^ 2<<FLREGIONBITSHIFT=8192 bytes. So we are set it to size 8KiB after the first 4KiB in the flash chip. + */ + + /* set Platform region size to 0 - another blob that we don't want */ + deblobbedDescriptorStruct.regionSection.flReg4.BASE = 0x1FFF; // setting 1FFF means setting size to 0. 1FFF<<FLREGIONBITSHIFT is outside of the ROM image (8MB) size? + /* ^ datasheet says to set this to 1FFF, but FFF was previously used and also worked. */ + deblobbedDescriptorStruct.regionSection.flReg4.LIMIT = 0; + /* + * ^ 0<<FLREGIONBITSHIFT=0, so basically, the size is 0, + * and the base (1FFF>>FLREGIONBITSHIFT) is well outside the higher 8MB range. + */ + + /* disable ME in ICHSTRAP0 - the ME is a blob, we don't want it in libreboot */ + deblobbedDescriptorStruct.ichStraps.ichStrap0.meDisable = 1; + + /* disable ME and TPM in MCHSTRAP0 */ + deblobbedDescriptorStruct.mchStraps.mchStrap0.meDisable = 1; // ME is a blob. not wanted in libreboot. + deblobbedDescriptorStruct.mchStraps.mchStrap0.tpmDisable = 1; // not wanted in libreboot + + /* + * disable ME, apart from chipset bugfixes (ME region should first be re-enabled above) + * This is sort of like the CPU microcode updates, but for the chipset + * (commented out below here, since blobs go against libreboot's purpose, + * but may be interesting for others) + * deblobbedDescriptorStruct.mchStraps.mchStrap0.meAlternateDisable = 1; + */ + + return deblobbedDescriptorStruct; +} + +/* + * --------------------------------------------------------------------- + * Debugging functions: + * --------------------------------------------------------------------- + */ + +/* + * show debugging info: descriptor region boundaries, in a 4KB struct. + */ +void printDescriptorRegionLocations(struct DESCRIPTORREGIONRECORD descriptorStruct, char* romName) +{ + printf("\n"); + + /* Descriptor region */ + printf( + "%s: Descriptor start block: %08x ; Descriptor end block: %08x\n", + romName, + descriptorStruct.regionSection.flReg0.BASE << FLREGIONBITSHIFT, + descriptorStruct.regionSection.flReg0.LIMIT << FLREGIONBITSHIFT + ); + + /* BIOS region */ + printf( + "%s: BIOS start block: %08x ; BIOS end block: %08x\n", + romName, + descriptorStruct.regionSection.flReg1.BASE << FLREGIONBITSHIFT, + descriptorStruct.regionSection.flReg1.LIMIT << FLREGIONBITSHIFT + ); + + /* ME region */ + printf( + "%s: ME start block: %08x ; ME end block: %08x\n", + romName, + descriptorStruct.regionSection.flReg2.BASE << FLREGIONBITSHIFT, + descriptorStruct.regionSection.flReg2.LIMIT << FLREGIONBITSHIFT + ); + + /* GBe region */ + printf( + "%s: GBe start block: %08x ; GBe end block: %08x\n", + romName, + descriptorStruct.regionSection.flReg3.BASE << FLREGIONBITSHIFT, + descriptorStruct.regionSection.flReg3.LIMIT << FLREGIONBITSHIFT + ); + + /* Platform region */ + printf( + "%s: Platform start block: %08x ; GBe end block: %08x\n", + romName, + descriptorStruct.regionSection.flReg4.BASE << FLREGIONBITSHIFT, + descriptorStruct.regionSection.flReg4.LIMIT << FLREGIONBITSHIFT + ); + + return; +} |