Hello Elmar,
On 09.05.2018 22:12, Elmar Stellnberger wrote:
However if I execute this twice I get two different images: wget https://www.elstel.org/uploads/celsius.rom wget https://www.elstel.org/uploads/celsius2.rom
actually, I don't see a BIOS in there at all. And the firmware descrip- tor (first 4KiB of a SPI flash in Intel systems) says there is no BIOS region (output of ich_descriptor_tool):
=== Region Section === FLREG0 0x00000000 FLREG1 0x00000fff FLREG2 0x03ff0005 FLREG3 0x00020001
--- Details --- Region 0 (Descr. ) 0x00000000 - 0x00000fff Region 1 (BIOS ) is unused. Region 2 (ME ) 0x00005000 - 0x003fffff Region 3 (GbE ) 0x00001000 - 0x00002fff
So it seems *this* SPI flash is only used for chipset configuration and ME firmware.
As David pointed out, your BIOS may share the flash chip with an Embed- ded Controller (its unlikely that flashrom wouldn't see the chip other- wise). And I can't advice you to use further try using flashrom. This situation (EC shared flash) is exactly why we have that "I_want_a_brick" option.
If you want to hunt more clues nevertheless, you can send us the output of `flashrom -p internal:laptop=force_I_want_a_brick -V`. IIRC, it also tells from which bus the BIOS was loaded.
Using vbindiff I can see that quite a lot is different between both images. - which would be difficult to achieve if the firmware was changed while I am running my computer. The image may be somehow corrupted as me_cleaner (BIOS offers Intel AMT) can not process the image:
I think the ME has some logging enabled and simply writes to the flash.
Nico