[coreboot] Re: RAM without SPD

[Zvi Vered]

Hi Michal,

Thank you very much for your reply.

You are right. I have soldered down memory. No dimm slot.
In what routine should I  configure RAM ?  Where can I see a sample code ?

From the RAM vendor I got the following table:

Part Number Byte Number Byte Description Byte Value
MT4KTF25664HZ-1G9P1 0 DDR3-CRC RANGE; EEPROM BYTES; BYTES USED 92
MT4KTF25664HZ-1G9P1 1 DDR3-SPD REVISON 13
MT4KTF25664HZ-1G9P1 2 DDR3-DRAM DEVICE TYPE 0B
MT4KTF25664HZ-1G9P1 3 DDR3-MODULE TYPE (FORM FACTOR) 3 ....

Is it possible to use FSP but not for RAM setup ?  How ?
FSP has many features which I want to use. I do not want to write all by
myself.

Best regards,
Zvika

On Tue, Feb 19, 2019 at 12:27 PM Michal Zygowski 
wrote:
> On 18.02.2019 20:28, Zvi Vered wrote:
>
> Hello,
>
> Hi Zvika,
>
> I suspect the RAM on my bay-trail module has no SPD interface.
> Can Intel's FSP work without SPD ?
>
> I tried to run decode-dimms with vendor's bios and got:
> No EEPROM found, try loading the eeprom or at24 module
>
> It looks like You have a platform with soldered down memory.  No DIMM
> slot, am I right?
>
> In this case the is no EEPROM which would hold the SPD data. Typically the
> SPD should be obtained from hardware vendor/platform vendor.
>
> I ran an FSP with debug info and got:
> C0.D0: SPD not present.
> C1.D0: SPD not present.
>
> FSP won't run without SPD, because SPD data is crucial for memory
> training. It contains timing values, memory hierarchy and other memory
> characteristics. The memory training process is so complex that it requires
> the right parameters, which can be retrieved from SPD. The SPD content is
> highly dependent on memory module design, in Your case the memory chips
> layout probably, PCB paths length etc.
>
> Thank you,
> Zvika
>
> Best regards,
> Michał
>
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