Re: Reconfiguring the PEI blob for the Overdrive1000 (AMD A1100)

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 1 June 2017 at 13:55, Rebecca Cran <rebecca@bluestop.org> wrote:
> On Thu, 1 Jun 2017 07:29:05 +0000
> Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
>
>> Which PEI binary are you referring to? There is the PEI core, and a
>> collection of PEI modules (PEIMs) that do various platform related
>> things, including PCIe link training (and believe me, looking at that
>> code will make your eyes bleed), which is the only closed source PEIM
>> IIRC.
>>
>> Whether you can get access to the FDK is a question I cannot answer,
>> but I don't think there are any people left at AMD working on the
>> Seattle project.
>>
>> Which tree are you building from?
>
> I'm using the OpenPlatformPkg tree from
> https://git.linaro.org/uefi/OpenPlatformPkg.git .
>
> The binary I was interested in is PreUefiFirmware.bin in
> https://git.linaro.org/uefi/OpenPlatformPkg.git/tree/Platforms/AMD/Styx/Overdrive1000Board/Binary .
>
> I should probably explain what problem I'm trying to solve. I'm working
> on NVDIMM support, and have been starting to plan work around
> making changes to the EDK2 to support the modules, starting with
> reading the DDR4 SPD data.
>
> However, the i2c access protocols etc. that I'd need appear to be
> implemented in the PreUefiFirmware.bin binary and are currently not
> exposed to UEFI drivers via the protocols from the PI spec.
>

The SoC has a separate System Control Processor (SCP), which is a
Cortex-A5 ARM core that has its own firmware. The source for this
firmware is not included in the FDK, nor is it (or any of the secure
firmware that /is/ included) based on PI/UEFI or EDK2. So if you need
I2C support in UEFI, you will need to add drivers for the Synopsys
Designware I2C controllers on this board. The FDK does not contain
anything useful, I'm afraid.