diff options
Diffstat (limited to 'resources/utilities/ich9deblob')
| -rw-r--r-- | resources/utilities/ich9deblob/ich9deblob.c | 42 |
1 files changed, 23 insertions, 19 deletions
diff --git a/resources/utilities/ich9deblob/ich9deblob.c b/resources/utilities/ich9deblob/ich9deblob.c index b9986ab..35c0188 100644 --- a/resources/utilities/ich9deblob/ich9deblob.c +++ b/resources/utilities/ich9deblob/ich9deblob.c @@ -60,7 +60,9 @@ int main(int argc, char *argv[]) { // descriptor region. Will have actual descriptor mapped to it (from the factory.rom dump) + // and then it will be modified (deblobbed) to remove the ME/AMT struct DESCRIPTORREGIONRECORD factoryDescriptorStruct; + struct DESCRIPTORREGIONRECORD deblobbedDescriptorStruct; unsigned int descriptorRegionStructSize = sizeof(factoryDescriptorStruct); // check compiler bit-packs in a compatible way basically, it is expected that this code will be used on x86 if (DESCRIPTORREGIONSIZE != descriptorRegionStructSize){ @@ -106,6 +108,8 @@ int main(int argc, char *argv[]) // 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); // ----------------------------------------------------------------------------------------------- @@ -156,18 +160,18 @@ int main(int argc, char *argv[]) // 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) - factoryDescriptorStruct.flMaps.flMap0.NR = 2; + 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): - factoryDescriptorStruct.masterAccessSection.flMstr1.fdRegionWriteAccess = 1; + deblobbedDescriptorStruct.masterAccessSection.flMstr1.fdRegionWriteAccess = 1; // relocate BIOS region and increase size to fill image - factoryDescriptorStruct.regionSection.flReg1.BASE = 3; // 3<<12 is 12KiB, which is where BIOS region is to begin (after descriptor and gbe) - factoryDescriptorStruct.regionSection.flReg1.LIMIT = ((romSize >> flRegionBitShift) - 1); + deblobbedDescriptorStruct.regionSection.flReg1.BASE = 3; // 3<<12 is 12KiB, which is where BIOS region is to begin (after descriptor and gbe) + deblobbedDescriptorStruct.regionSection.flReg1.LIMIT = ((romSize >> flRegionBitShift) - 1); // ^ for example, 8MB ROM, that's 8388608 bytes. // ^ 8388608>>12 (or 8388608/4096) = 2048 bytes // 2048 - 1 = 2047 bytes. @@ -176,40 +180,40 @@ int main(int argc, char *argv[]) // (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 - factoryDescriptorStruct.regionSection.flReg2.BASE = 0x1FFF; // setting 1FFF means setting size to 0. 1FFF<<12 is outside of the ROM image (8MB) size? + deblobbedDescriptorStruct.regionSection.flReg2.BASE = 0x1FFF; // setting 1FFF means setting size to 0. 1FFF<<12 is outside of the ROM image (8MB) size? // ^ datasheet says to set this to 1FFF, but FFF was previously used and also worked. - factoryDescriptorStruct.regionSection.flReg2.LIMIT = 0; + deblobbedDescriptorStruct.regionSection.flReg2.LIMIT = 0; // ^ 0<<12=0, so basically, the size is 0, and the base (1FFF>>12) is well outside the higher 8MB range. // relocate Gbe region to begin at 4KiB (immediately after the flash descriptor) - factoryDescriptorStruct.regionSection.flReg3.BASE = 1; // 1<<12 is 4096, which is where the Gbe region is to begin (after the descriptor) - factoryDescriptorStruct.regionSection.flReg3.LIMIT = 2; + deblobbedDescriptorStruct.regionSection.flReg3.BASE = 1; // 1<<12 is 4096, which is where the Gbe region is to begin (after the descriptor) + deblobbedDescriptorStruct.regionSection.flReg3.LIMIT = 2; // ^ 2<<12=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 - factoryDescriptorStruct.regionSection.flReg4.BASE = 0x1FFF; // setting 1FFF means setting size to 0. 1FFF<<12 is outside of the ROM image (8MB) size? + deblobbedDescriptorStruct.regionSection.flReg4.BASE = 0x1FFF; // setting 1FFF means setting size to 0. 1FFF<<12 is outside of the ROM image (8MB) size? // ^ datasheet says to set this to 1FFF, but FFF was previously used and also worked. - factoryDescriptorStruct.regionSection.flReg4.LIMIT = 0; + deblobbedDescriptorStruct.regionSection.flReg4.LIMIT = 0; // ^ 0<<12=0, so basically, the size is 0, and the base (1FFF>>12) is well outside the higher 8MB range. // disable ME in ICHSTRAP0 - the ME is a blob, we don't want it in libreboot - factoryDescriptorStruct.ichStraps.ichStrap0.meDisable = 1; + deblobbedDescriptorStruct.ichStraps.ichStrap0.meDisable = 1; // disable ME and TPM in MCHSTRAP0 - factoryDescriptorStruct.mchStraps.mchStrap0.meDisable = 1; // ME is a blob. not wanted in libreboot. - factoryDescriptorStruct.mchStraps.mchStrap0.tpmDisable = 1; // not wanted in libreboot + 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) - // factoryDescriptorStruct.mchStraps.mchStrap0.meAlternateDisable = 1; + // deblobbedDescriptorStruct.mchStraps.mchStrap0.meAlternateDisable = 1; // debugging - printf("\nRelocated Descriptor start block: %08x ; Descriptor end block: %08x\n", factoryDescriptorStruct.regionSection.flReg0.BASE << flRegionBitShift, factoryDescriptorStruct.regionSection.flReg0.LIMIT << flRegionBitShift); - printf("Relocated BIOS start block: %08x ; BIOS end block: %08x\n", factoryDescriptorStruct.regionSection.flReg1.BASE << flRegionBitShift, factoryDescriptorStruct.regionSection.flReg1.LIMIT << flRegionBitShift); - printf("Relocated ME start block: %08x ; ME end block: %08x\n", factoryDescriptorStruct.regionSection.flReg2.BASE << flRegionBitShift, factoryDescriptorStruct.regionSection.flReg2.LIMIT << flRegionBitShift); - printf("Relocated GBe start block: %08x ; GBe end block: %08x\n", factoryDescriptorStruct.regionSection.flReg3.BASE << flRegionBitShift, factoryDescriptorStruct.regionSection.flReg3.LIMIT << flRegionBitShift); + printf("\nRelocated Descriptor start block: %08x ; Descriptor end block: %08x\n", deblobbedDescriptorStruct.regionSection.flReg0.BASE << flRegionBitShift, deblobbedDescriptorStruct.regionSection.flReg0.LIMIT << flRegionBitShift); + printf("Relocated BIOS start block: %08x ; BIOS end block: %08x\n", deblobbedDescriptorStruct.regionSection.flReg1.BASE << flRegionBitShift, deblobbedDescriptorStruct.regionSection.flReg1.LIMIT << flRegionBitShift); + printf("Relocated ME start block: %08x ; ME end block: %08x\n", deblobbedDescriptorStruct.regionSection.flReg2.BASE << flRegionBitShift, deblobbedDescriptorStruct.regionSection.flReg2.LIMIT << flRegionBitShift); + printf("Relocated GBe start block: %08x ; GBe end block: %08x\n", deblobbedDescriptorStruct.regionSection.flReg3.BASE << flRegionBitShift, deblobbedDescriptorStruct.regionSection.flReg3.LIMIT << flRegionBitShift); // ---------------------------------------------------------------------------------------------------------------- @@ -217,7 +221,7 @@ int main(int argc, char *argv[]) // can more easily be written to files: // deblobbed descriptor region char deblobbedDescriptorBuffer[DESCRIPTORREGIONSIZE]; - memcpy(&deblobbedDescriptorBuffer, &factoryDescriptorStruct, DESCRIPTORREGIONSIZE); + memcpy(&deblobbedDescriptorBuffer, &deblobbedDescriptorStruct, DESCRIPTORREGIONSIZE); // delete old file before continuing remove(deblobbedDescriptorFilename); |