[coreboot] Re: MRC cache save/readback failure (SKL/KBL)

[Alex Feinman]

Hi Nico,

That's an interesting idea (IFD). Here is a dump of my IFD, but the problem is - I am not sure what the regions are and what they should be.
Perhaps I need a region that includes my MRC cache  (0x9f0000)?

File build/coreboot.rom is 16777216 bytes
Found Flash Descriptor signature at 0x00000010
FLMAP0:    0x00040003
  NR:      0
  FRBA:    0x40
  NC:      1
  FCBA:    0x30
FLMAP1:    0x42100208
  ISL:     0x42
  FPSBA:   0x100
  NM:      2
  FMBA:    0x80
FLMAP2:    0x00310330
  PSL:     0x3103
  FMSBA:   0x300
FLUMAP1:   0x000006df

Found Region Section
FLREG0:    0x00000000
FLREG1:    0x0fff0a00
FLREG2:    0x09ff0003
FLREG3:    0x00020001
FLREG4:    0x00007fff

Found Component Section
FLCOMP     0x365c00f5
  Read ID/Read Status Clock Frequency: unknown<6>MHz
  Write/Erase Clock Frequency:         unknown<6>MHz
  Fast Read Clock Frequency:           unknown<2>MHz
FLILL      0xad604221
FLPB       0xc7c4b9b7

Found PCH Strap Section
PCHSTRP0:  0x00220002
PCHSTRP1:  0x44000100
PCHSTRP2:  0x00010000
PCHSTRP3:  0x00000000
PCHSTRP4:  0x00000000
PCHSTRP5:  0x00010000
PCHSTRP6:  0x00000100
PCHSTRP7:  0x00000000
PCHSTRP8:  0x00000000
PCHSTRP9:  0x00000000
PCHSTRP10: 0x00030000
PCHSTRP11: 0x00000100
PCHSTRP12: 0x00000000
PCHSTRP13: 0x00000000
PCHSTRP14: 0x00000000
PCHSTRP15: 0x00010000

Found Master Section
FLMSTR1:   0xffffff00
FLMSTR2:   0xffffff00
FLMSTR3:   0xffffff00

Found Processor Strap Section
????:      0x00001000
????:      0x00108002
????:      0x00000210
????:      0xffffffff

________________________________________
From: Nico Huber 
Sent: Friday, June 7, 2019 2:41 AM
To: Alex Feinman; [e-mail]
Subject: Re: [coreboot] MRC cache save/readback failure (SKL/KBL)

Hi Alex,

On 07.06.19 08:56, Alex Feinman wrote:
> I've checked the upper 16 MB - simply dumped the block at 0xff9f0000
> (0xff000000 is the last 16 MB + MRC  cache region offset 0x9f0000 from
> the layout file ) where in my image the MRC cache region resides (I can
> confirm it's there by dumping the image from flash). The data I read
> from the supposed memory mapping is all 0xff.

IIRC, you already confirmed with an external programmer that the data
is written at this location, right? If the data is there but not memory
mapped, maybe that offset isn't covered by the BIOS region in IFD?
> fmd and .config files are attached

I didn't spot anything problematic there. But as you don't have
CONFIG_VBOOT selected, you could also try a much simpler FMD file or
just the automatically generated default, by unsetting CONFIG_FMDFILE.

Nico