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diff --git a/doc/README.x86 b/doc/README.x86 index 5b51559..c5c3010 100644 --- a/doc/README.x86 +++ b/doc/README.x86 @@ -105,6 +105,87 @@ $ make all --- +Chromebook Samus (2015 Pixel) instructions for bare mode: + +First, you need the following binary blobs: + +* descriptor.bin - Intel flash descriptor +* me.bin - Intel Management Engine +* mrc.bin - Memory Reference Code, which sets up SDRAM +* refcode.elf - Additional Reference code +* vga.bin - video ROM, which sets up the display + +If you have a samus you can obtain them from your flash, for example, in +developer mode on the Chromebook (use Ctrl-Alt-F2 to obtain a terminal and +log in as 'root'): + + cd /tmp + flashrom -w samus.bin + scp samus.bin username@ip_address:/path/to/somewhere + +If not see the coreboot tree [4] where you can use: + + bash crosfirmware.sh samus + +to get the image. There is also an 'extract_blobs.sh' scripts that you can use +on the 'coreboot-Google_Samus.*' file to short-circuit some of the below. + +Then 'ifdtool -x samus.bin' on your development machine will produce: + + flashregion_0_flashdescriptor.bin + flashregion_1_bios.bin + flashregion_2_intel_me.bin + +Rename flashregion_0_flashdescriptor.bin to descriptor.bin +Rename flashregion_2_intel_me.bin to me.bin +You can ignore flashregion_1_bios.bin - it is not used. + +To get the rest, use 'cbfstool samus.bin print': + +samus.bin: 8192 kB, bootblocksize 2864, romsize 8388608, offset 0x700000 +alignment: 64 bytes, architecture: x86 + +Name Offset Type Size +cmos_layout.bin 0x700000 cmos_layout 1164 +pci8086,0406.rom 0x7004c0 optionrom 65536 +spd.bin 0x710500 (unknown) 4096 +cpu_microcode_blob.bin 0x711540 microcode 70720 +fallback/romstage 0x722a00 stage 54210 +fallback/ramstage 0x72fe00 stage 96382 +config 0x7476c0 raw 6075 +fallback/vboot 0x748ec0 stage 15980 +fallback/refcode 0x74cd80 stage 75578 +fallback/payload 0x75f500 payload 62878 +u-boot.dtb 0x76eb00 (unknown) 5318 +(empty) 0x770000 null 196504 +mrc.bin 0x79ffc0 (unknown) 222876 +(empty) 0x7d66c0 null 167320 + +You can extract what you need: + + cbfstool samus.bin extract -n pci8086,0406.rom -f vga.bin + cbfstool samus.bin extract -n fallback/refcode -f refcode.rmod + cbfstool samus.bin extract -n mrc.bin -f mrc.bin + cbfstool samus.bin extract -n fallback/refcode -f refcode.bin -U + +Note that the -U flag is only supported by the latest cbfstool. It unpacks +and decompresses the stage to produce a coreboot rmodule. This is a simple +representation of an ELF file. You need the patch "Support decoding a stage +with compression". + +Put all 5 files into board/google/chromebook_samus. + +Now you can build U-Boot and obtain u-boot.rom: + +$ make chromebook_link_defconfig +$ make all + +If you are using em100, then this command will flash write -Boot: + + em100 -s -d filename.rom -c W25Q64CV -r + +--- + Intel Crown Bay specific instructions for bare mode: U-Boot support of Intel Crown Bay board [4] relies on a binary blob called |