Re: [PATCH v4 00/25] Add support for OpenCAPI Persistent Memory devices

[Oliver O'Halloran]

On Thu, Apr 2, 2020 at 2:42 PM Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote:
>
> "Alastair D'Silva" <alastair@xxxxxxxxxxx> writes:
> >> -----Original Message-----
> >> From: Dan Williams <dan.j.williams@xxxxxxxxx>
> >>
> >> On Sun, Mar 29, 2020 at 10:23 PM Alastair D'Silva <alastair@xxxxxxxxxxx>
> >> wrote:
> >> >
> >> > *snip*
> >> Are OPAL calls similar to ACPI DSMs? I.e. methods for the OS to invoke
> >> platform firmware services? What's Skiboot?
> >>
> >
> > Yes, OPAL is the interface to firmware for POWER. Skiboot is the open-source (and only) implementation of OPAL.
>
>   https://github.com/open-power/skiboot
>
> In particular the tokens for calls are defined here:
>
>   https://github.com/open-power/skiboot/blob/master/include/opal-api.h#L220
>
> And you can grep for the token to find the implementation:
>
>   https://github.com/open-power/skiboot/blob/master/hw/npu2-opencapi.c#L2328

I'm not sure I'd encourage anyone to read npu2-opencapi.c. I find it
hard enough to follow even with access to the workbooks.

There's an OPAL call API reference here:
http://open-power.github.io/skiboot/doc/opal-api/index.html

Oliver