On 29/01/14 22:27, Aaron Durbin wrote:
On Wed, Jan 29, 2014 at 4:25 PM, Aaron Durbin adurbin@google.com wrote:
On Wed, Jan 29, 2014 at 4:16 PM, John Lewis jlewis@johnlewis.ie wrote:
On 29/01/14 22:03, Aaron Durbin wrote:
This is where we reach the crux of the matter - In the stock/shellball firmware, extracting BOOT_STUB doesn't yield a file which cbfstool in upstream coreboot or CrOS coreboot can decipher. Looking at the file in hexedit it appears to be almost identical to a CBFS that is recognised, but that's it. I have managed to extract the SVGA binary from the CBFS in the RW_LEGACY slot, and I've made an educated guess as to where the system-agent begins and ends in the unrecognised CBFS (section beginning "LARCHIVE mrc.bin" or similar with the binary itself following, surrounded by FF's) copying and pasting it to a file. I would like to know if I am correct in my assumptions about extracting that file manually and what size it should be, in bytes?
That's interesting. It is just a regular 'ol cbfs. The images that shipped with your device is an 8MiB SPI. First 2MiB Duncan covered. The next 5 have nothing to do w/ coreboot proper -- all the extra vboot firmware bits. The last 1MiB is the cbfs.
Okay, well I extracted the attached file using:
eval `./fmap_decode bios.bin | grep BOOT_STUB` dd if=c720.rom ibs=$((area_offset)) skip=1 | dd bs=$((area_size)) iflag=fullblock of=c720-coreboot.bin
and:
../coreboot/build/cbfstool c720-coreboot.bin print
produces:
c720-coreboot.bin: 1024 kB, bootblocksize 3144, romsize 8388608, offset 0x700000 alignment: 64 bytes
Name Offset Type Size
zippo.
Try cherry-picking this one: https://chrome-internal-review.googlesource.com/153037
Ugh. If only my copy/past worked. Try this one instead: http://review.coreboot.org/#/c/4771/
Okay. I ran:
git fetch http://review.coreboot.org/coreboot refs/changes/71/4771/1 && git checkout FETCH_HEAD
then ran make, which updated the binary, but still no change in reading the file.
I also compiled and ran the cbfstool in ./util in case that was somehow different, but same result.
-John
On Wed, Jan 29, 2014 at 4:44 PM, John Lewis jlewis@johnlewis.ie wrote:
On 29/01/14 22:27, Aaron Durbin wrote:
On Wed, Jan 29, 2014 at 4:25 PM, Aaron Durbin adurbin@google.com wrote:
On Wed, Jan 29, 2014 at 4:16 PM, John Lewis jlewis@johnlewis.ie wrote:
On 29/01/14 22:03, Aaron Durbin wrote:
This is where we reach the crux of the matter - In the stock/shellball firmware, extracting BOOT_STUB doesn't yield a file which cbfstool in upstream coreboot or CrOS coreboot can decipher. Looking at the file in hexedit it appears to be almost identical to a CBFS that is recognised, but that's it. I have managed to extract the SVGA binary from the CBFS in the RW_LEGACY slot, and I've made an educated guess as to where the system-agent begins and ends in the unrecognised CBFS (section beginning "LARCHIVE mrc.bin" or similar with the binary itself following, surrounded by FF's) copying and pasting it to a file. I would like to know if I am correct in my assumptions about extracting that file manually and what size it should be, in bytes?
That's interesting. It is just a regular 'ol cbfs. The images that shipped with your device is an 8MiB SPI. First 2MiB Duncan covered. The next 5 have nothing to do w/ coreboot proper -- all the extra vboot firmware bits. The last 1MiB is the cbfs.
Okay, well I extracted the attached file using:
eval `./fmap_decode bios.bin | grep BOOT_STUB` dd if=c720.rom ibs=$((area_offset)) skip=1 | dd bs=$((area_size)) iflag=fullblock of=c720-coreboot.bin
and:
../coreboot/build/cbfstool c720-coreboot.bin print
produces:
c720-coreboot.bin: 1024 kB, bootblocksize 3144, romsize 8388608, offset 0x700000 alignment: 64 bytes
Name Offset Type Size
zippo.
Try cherry-picking this one: https://chrome-internal-review.googlesource.com/153037
Ugh. If only my copy/past worked. Try this one instead: http://review.coreboot.org/#/c/4771/
Okay. I ran:
git fetch http://review.coreboot.org/coreboot refs/changes/71/4771/1 && git checkout FETCH_HEAD
then ran make, which updated the binary, but still no change in reading the file.
I also compiled and ran the cbfstool in ./util in case that was somehow different, but same result.
I did this w/ the ChromeOS coreboot:
$ dd if=/dev/zero of=spi.bin bs=1M count=7 $ cat spi.bin c720-coreboot.bin > c720-coreboot-8MiB.bin $ cbfstool c720-coreboot-8MiB.bin print c720-coreboot-8MiB.bin: 8192 kB, bootblocksize 3144, 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 cpu_microcode_blob.bin 0x710500 microcode 41024 config 0x71a5c0 raw 5541 fallback/vboot 0x71bbc0 stage 15081 (empty) 0x71f700 null 2136 fallback/romstage 0x71ff80 stage 42497 fallback/coreboot_ram 0x72a600 stage 91421 fallback/payload 0x740b80 payload 54921 u-boot.dtb 0x74e280 (unknown) 7923 (empty) 0x7501c0 null 327128 mrc.bin 0x79ffc0 (unknown) 190180 (empty) 0x7ce700 null 120984 spd.bin 0x7ebfc0 (unknown) 1792 (empty) 0x7ec700 null 76888
The file you use with cbfstool needs to match the header rom size. In this case it is 8MiB.
Hope that helps.
-Aaron
-
Aaron Durbin -
John Lewis