[coreboot] Out of MTRRs

[Aaron Durbin]

Please post the full logs so we can see the address space. The 'Unable
to insert temporary MTRR range' log message is only for tempoarility
mapping the SPI flash. However, it's impossible to debug w/o the full
logs to see what your address space looks like.

On Sat, Mar 17, 2018 at 12:28 PM, Jay Talbott
<JayTalbott at sysproconsulting.com> wrote:
> I’m working on a coreboot solution for a SkyLake based board that uses
> SO-DIMMs.
>
>
>
> The plan is for two 8GB DIMMs, for a total of 16GB of RAM.
>
>
>
> But with two 8GB DIMMs installed, I get the following during the boot:
>
>
>
> Taking a reserved OS MTRR.
>
> Taking a reserved OS MTRR.
>
> Taking a reserved OS MTRR.
>
> ERROR: Not enough MTRRs available! MTRR indexis 10 with 10 MTTRs in total.
>
> Not enough MTRRs: 11 vs 10
>
> Unable to insert temporary MTRR range: 0x00000000ff800000 -
> 0x0000000100000000 size 0x00800000 type 5
>
>
>
> This is obviously a problem…
>
>
>
> If I remove one DIMM, then I just get:
>
>
>
> Taking a reserved OS MTRR.
>
> Taking a reserved OS MTRR.
>
>
>
> Still an issue, although at least we don’t run out of MTRRs.
>
>
>
> If I use a single 4GB DIMM instead of an 8GB DIMM, there’s no issue with the
> MTRR config at all.
>
>
>
> I’m assuming that I’m not the first person to run into this when using
> coreboot on systems with larger amounts of RAM, so I figured I’d ask the
> community what’s the fix to getting this to work correctly with 16GB of RAM
> before trying to figure it out myself.
>
>
>
> Any help would be most appreciated.
>
>
>
> Thanks,
>
>
>
> - Jay
>
>
>
> Jay Talbott
> Principal Consulting Engineer
> SysPro Consulting, LLC
> 3057 E. Muirfield St.
> Gilbert, AZ 85298
> (480) 704-8045
> (480) 445-9895 (FAX)
> JayTalbott at sysproconsulting.com
>
> http://www.sysproconsulting.com
>
>
>
>
> --
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