On 15/09/14 22:50, Aaron Durbin wrote:
>
>
>
> On Mon, Sep 15, 2014 at 4:29 PM, John Lewis jlewis@johnlewis.ie
> wrote:
>>
>>
>>
>> On 15/09/14 22:03, Aaron Durbin wrote:
>>>
>>>
>>>
>>>
>>> On Mon, Sep 15, 2014 at 3:35 PM, John Lewis jlewis@johnlewis.ie
>>> wrote:
>>>>
>>>>
>>>>
>>>>
>>>> Hello,
>>>>
>>>> I've purchased the subject Chromebook with a view to getting some
>>>> sort
>>>> of
>>>> custom ROM going for Baytrail based Chromebooks, and I have my
>>>> first
>>>> brick
>>>> of the day.
>>>>
>>>> I'm using ChromeOS coreboot and the firmware-clapper-5218.B branch.
>>>> As
>>>> per
>>>> the advice Aaron gave me regarding the ASUS C200 some time ago, I
>>>> extracted
>>>> the reference code binary and changed line 111 in
>>>> src/arch/x86/Makefile.inc
>>>> as follows:
>>>>
>>>> $(CBFSTOOL) $@.tmp add -f $(CONFIG_REFCODE_BLOB_FILE)
>>>> -n
>>>> $(CONFIG_CBFS_PREFIX)/refcode -t raw
>>>>
>>>
>>> I think I might know. You are using upstream, right? This is my
>>> fault.
>>> The rmodule format changed. We didn't bump the version, and dropped
>>> the old code. Can you run readelf -e on that blob you extracted? I
>>> think I allowed ELF packaging for that file. If that doesn't work
>>> (hexdump -C) would be helpful.
>>>
>> No, I'm using ChromiumOS coreboot. With readelf -e I get:
>>
>> readelf -e refcode.bin
>> readelf: Error: Unable to read in 0x7115 bytes of section headers
>> readelf: Error: Not an ELF file - it has the wrong magic bytes at the
>> start
>>
>> hexdump -C:
>>
>> hexdump -C refcode.bin
>> 00000000 01 00 00 00 00 10 00 00 00 00 00 00 00 00 00 00
>> |................|
>> 00000010 00 00 00 00 ac 10 00 00 b8 4b 00 00 01 00 60 00
>> |.........K....`.|
>> 00000020 00 a0 4b 00 00 00 00 00 00 00 7f 3f ec 22 15 71
>> |..K........?.".q|
>
>
>
>
> snip
>
>> 000010b0 ea 88 85 74 8b 20 1e db 6b 09 b3 c0 40 c3 eb ed |...t.
>> ..k...@...|
>> 000010c0 48 a8 8d c4 08 32 85 80
>> |H....2..|
>> 000010c8
>>
>> You may want to snip that. ;)
>
>
>
>
> OK. A couple of things. Bear with me as I use this thread to think
> things through. This file is compressed. We extracted it, and added it
> back using 'raw'. That means cbfs_file->type != CBFS_TYPE_STAGE. So
> refcode loading would not work. Would it create a brick? I wouldn't
> think so, but I haven't tried.
>
> Offhand, do you have the option rom? Do we see any life out of the
> display? I'm trying to think of ways to see how far we've gotten
> without serial console. Is MRC in the same place as the released
> firmware? Perhaps a cbfstool print might be instructive on your
> resulting image.
Yes, I extracted all the necessary files from the shellball ROM for
Clapper.
No, no life from the display (no backlight even).
coreboot.rom: 8192 kB, bootblocksize 1184, romsize 8388608, offset
0x400000
alignment: 64 bytes, architecture: x86
Name Offset Type Size
cmos_layout.bin 0x400000 cmos_layout 1164
pci8086,0f31.rom 0x4004c0 optionrom 65536
cpu_microcode_blob.bin 0x410500 microcode 103424
config 0x429980 raw 4298
fallback/refcode 0x42aa80 raw 4296
(empty) 0x42bb80 null 17368
fallback/romstage 0x42ff80 stage 35171
fallback/coreboot_ram 0x438980 stage 71515
fallback/payload 0x44a140 payload 34866
img/Jeltka 0x4529c0 payload 2970296
(empty) 0x727cc0 null 492248
mrc.bin 0x79ffc0 (unknown) 70168
(empty) 0x7b1240 null 240984
spd.bin 0x7ebfc0 (unknown) 1536
(empty) 0x7ec600 null 79064
>
> After bricking the device can you re-flash the spi part back to a
> released image?
>
I don't see why not, but it's getting late here and people are sleeping
so
I'll have to do that in the morning. If there's anything else quick
I'll
hang around this end for 10 or so minutes to answer.
Understood. The only thing I can think of trying really quickly is
making the type of the file to be a stage instead of raw. You'll need
to hexedit the rom to change the type.
Aaron Durbin
John Lewis