Re: [coreboot] What purpose the "mrc.cache"?

[김유석 책임연구원]

Dear Martin.

Thank you, your prompt reply. It is very useful to me.

I'll study the document of FSP. and tools.

Thank you.

2016-06-02 오전 5:23에 Martin Roth 이(가) 쓴 글:
> The MRC cache is a location for saving the state of the memory
>
> registers. These values are typically used to restore the memory
> controller state on resume from S3 suspend, or to help the system boot
> faster.  On systems using the Rangeley FSP it is not optional as it is
> on some other platforms.
> The file you see in cbfs is actually just a placeholder.  If you
>
> look in that area of the rom, you'll see that it's empty.  It's just
> there to reserve the space for coreboot to write the memory register
> information into, and to prevent anything else from being put into
> that location.
> The memory code for Rangeley is part of the FSP.  This is currently
>
> only available for the Rangeley chip as a binary blob.  You can
> download it, along with the FSP documentation and the Binary
> Configuration Tool, from Intel's website:  http://intel.com/fsp
>
> Martin
>
> On Tue, May 31, 2016 at 10:38 PM, 김유석 책임연구원  wrote:
> > Dear Sir.
> >
> > My ENV.
> >
> > Platform : intel atom rangeley mohon peak CRB(C2358)
> >
> > This time, I'm try to study for MRC(Memory Reference Code).
> >
> > But, I'm can not found a some example code on coreboot source tree.(rangely)
> >
> > Anyway, I'm get a some hint on last image.
> >
> > Performing operation on 'COREBOOT' region...
> > Name                           Offset     Type         Size
> > cbfs master header             0x0        cbfs header  32
> > fallback/romstage              0x80       stage        24356
> > config                         0x6040     raw          440
> > revision                       0x6240     raw          567
> > cmos_layout.bin                0x64c0     cmos_layout  1316
> > fallback/dsdt.aml              0x6a40     raw          8074
> > payload_config                 0x8a40     raw          1574
> > payload_revision               0x90c0     raw          244
> > (empty)                        0x9200     null         27800
> > mrc.cache                  0xfec0    mrc_cache  65536
> > cpu_microcode_blob.bin         0x1ff00    microcode    167936
> > fallback/ramstage              0x48f80    stage        48170
> > fallback/payload               0x54c00    payload      61309
> > (empty)                        0x63bc0    null         1163992
> > fsp.bin                        0x17fec0   fsp          389120
> > (empty)                        0x1def00   null         133528
> > bootblock                      0x1ff8c0   bootblock    1528
> >
> > Question.
> >
> > What purpose the "mrc.cache"?
> >
> > Where to location the source code for "mrc.cache" ?
> >
> > How modify the MRC ? for the sdram.
> >
> > Thank you.