Another option is to put the protocol definition in MdeModulePkg and mark it with the EDKII_ prefix. For my last “code first” UEFI spec contribution I did this with the PPI that added up getting added.

Thanks,

Nate

From: <devel@edk2.groups.io> on behalf of "Andrew Fish via groups.io" <afish=apple.com@groups.io>
Reply-To: "devel@edk2.groups.io" <devel@edk2.groups.io>, "afish@apple.com" <afish@apple.com>
Date: Tuesday, March 30, 2021 at 10:54 PM
To: edk2-devel-groups-io <devel@edk2.groups.io>, "harlydavidsen@gmail.com" <harlydavidsen@gmail.com>
Cc: Rafael Rodrigues Machado <rafaelrodrigues.machado@gmail.com>
Subject: Re: [edk2-devel] VirtIO Sound Driver (GSoC 2021)

On Mar 30, 2021, at 5:01 PM, Ethin Probst <harlydavidsen@gmail.com> wrote:

I'm wondering where exactly I should add the VirtIO sound protocol. I
just familiarized myself with the build system and am about to test it
by building OVMF if possible, but I'm wondering where I should
actually put the protocol and all that stuff. Maybe there's
documentation I've missed as well.

Ethin,

For the driver I’d match the patter of OVMF [1] and use OvmfPkg/VirtioSoundDxe/. Maybe even use one of the other drivers as a template. 

The protocol is more of a public thing. I think eventually we would like to publish the protocol in the UEFI Spec (I can help with that part) and that would mean we put the Protocol definition in MdePkg/Include/Protocol, but we don’t want to do that before it is standardized as that causes compatibility issues. So this is a “code first project” (code prototype and then contribute to the UEFI Forum for inclusion in the specification) so we need to follow some code first rules that I don’t remember of the top of my head? So why not start out the protocol definition OvmfPkg/Include/Protocol. You can also add a test application looks like you can just use the root [2] of OVMF for that. That way the project is not blocked. 

We can have a conversation on the mailing list about better places to put stuff, and it should be easy enough to move stuff around if everything else is working.  

[1] find OvmfPkg  -iname '*Virtio*.inf'

OvmfPkg/VirtioPciDeviceDxe/VirtioPciDeviceDxe.inf

OvmfPkg/VirtioScsiDxe/VirtioScsi.inf

OvmfPkg/Library/VirtioMmioDeviceLib/VirtioMmioDeviceLib.inf

OvmfPkg/Library/VirtioLib/VirtioLib.inf

OvmfPkg/VirtioGpuDxe/VirtioGpu.inf

OvmfPkg/VirtioBlkDxe/VirtioBlk.inf

OvmfPkg/Virtio10Dxe/Virtio10.inf

OvmfPkg/VirtioNetDxe/VirtioNet.inf

OvmfPkg/VirtioRngDxe/VirtioRng.inf

[2] /Volumes/Case/edk2-github/OvmfPkg>git grep APPLICATION -- *.inf | grep MODULE_TYPE

EnrollDefaultKeys/EnrollDefaultKeys.inf:13:  MODULE_TYPE                    = UEFI_APPLICATION

Thanks,

Andrew Fish

On 3/30/21, Ethin Probst via groups.io
<harlydavidsen=gmail.com@groups.io> wrote:

I agree. Plus, it gives me a chance to finally learn the EDK2 build
system and how it works! I've been working on a hobby OS as a side
project and, though learning from other code examples from OSes is
fun, I have to say that learning from the firmware code like from
SeaBIOS has been some of the most enlightening and interesting times
thus far.
Thanks for the link to your code, Rafael; once I get virtIO support
in, I can work on HDA support, though I might tackle USB support
second and HDA third. We'll see, but VirtIO definitely is coming
first.

As I said before, I look forward to working with all of you wonderful
people!

On 3/30/21, Rafael Rodrigues Machado <rafaelrodrigues.machado@gmail.com>
wrote:

This would be amazing so people can continue my work related to
accessibility at BIOS. Something desired by the blind people since the
90's
Just for reference, this is what I have done:

https://github.com/RafaelRMachado/Msc_UefiHda_PreOs_Accessibility

Thanks
Rafael

Em seg, 29 de mar de 2021 20:24, Ethin Probst <harlydavidsen@gmail.com>
escreveu:

Hello everyone,

This is the first time I've ever contributed to EDK2. As part of GSoC
2021, I have submitted a proposal to implement a UEFI audio output
protocol that will utilize the VirtIO sound driver. I've already
submitted a draft proposal, and apologize if I've done things out of
order. This is my first time doing GSoC 2021, and contributing to EDK2
felt like a really fun thing to do!

I look forward to working with you guys on this and any future projects!
:-)

--
Signed,
Ethin D. Probst

--
Signed,
Ethin D. Probst

--
Signed,
Ethin D. Probst