[edk2-devel] VirtIO Sound Driver (GSoC 2021)
Andrew Fish via groups.io
afish=apple.com at groups.io
Tue Apr 13 21:38:55 UTC 2021
> On Apr 13, 2021, at 9:53 AM, Ethin Probst <harlydavidsen at gmail.com> wrote:
>
> Would it be possible for us to conduct discussion on the UEFI talkbox?
> I don't mind using email, but things could definitely get moving
> quicker over there (though its not a requirement obviously).
>
Sure, don’t think I’ve really used that but as long as I get pointed int he right direction I can make it work.
For a device driver the general UEFI model is for the Entry point of the driver to publish a EFI_DRIVER_BINDING_PROTOCOL[1]. The Supported() function matches on the PCI devices. The Start() function installs the Protocols to do work, and the Stop() undoes the Start().
Mike Kinney started this back in the day and it describes how to write UEFI drivers: https://github.com/tianocore/tianocore.github.io/wiki/UEFI-Driver-Writer%27s-Guide
[1]https://github.com/tianocore/edk2/blob/master/MdePkg/Include/Protocol/DriverBinding.h#L157
Thanks,
Andrew Fish
> Here's how I generally envision the driver functioning:
>
> 1. Firmware/platform code calls InitaudioOutput() or something like
> it. This function scans the PCIe bus and scans for one of the
> following:
> - Vendor ID 0x1AF4, device ID 0x1059: VirtIO sound device
> - PCI class 0x0C, subclass 0x03, program interface 0x30 or 0x40: for
> USB audio interface (I'm only thinking of targeting XHCI and USB 4,
> and not UHCI, OHCI or EHCI). But maybe EDK2 will take that out of my
> hands. If so, it will make things easier.
> - For USB audio devices I'm not quite sure what to look for; I'm
> definitely unused to USB.
> 2. If any of the above cases are found, appropriate driver
> initialization occurs. Since for the time being I am solely focusing
> on VirtIO sound devices, the VirtIO general initialization sequence
> will occur as outlined in sec. 3 of the VirtIO specification available
> at https://www.kraxel.org/virtio/virtio-v1.1-cs01-sound-v7.html <https://www.kraxel.org/virtio/virtio-v1.1-cs01-sound-v7.html>.
> As for actual protocol exposure that would be spec-worthy, for
> EFI_AUDIO_OUTPUT_PROTOCOL, I'm not quite sure what to expose. VirtIO
> is rather simple: there's a buffer for sending and receiving audio
> data in PCM streams. So for that we could expose a Reset(),
> RemapJack(), GetJackConfig(), GetPcmConfig(), SetPcmParams(),
> Prepare(), Release(), Start(), and Stop() function for the
> corresponding request types VIRTIO_SND_R_JACK_GET_CONFIG,
> VIRTIO_SND_R_JACK_REMAP, VIRTIO_SND_R_PCM_GET_CONFIG,
> VIRTIO_SND_R_PCM_SET_PARAMS, VIRTIO_SND_R_PCM_PREPARE,
> VIRTIO_SND_R_PCM_RELEASE, VIRTIO_SND_R_PCM_START, and
> VIRTIO_SND_R_PCM_STOP control requests. However, for HDA things are a
> lot more complex, so I'm not sure how that should work.
> For VirtIO -- which is what I'll focus on for now -- everything is
> described, in excellent detail, in sec. 5.14 of the above-linked
> document. What are your guys's thoughts thus far and how should
> everything be mapped to UEFI interfaces?
>
> On 4/13/21, Andrew Fish <afish at apple.com <mailto:afish at apple.com>> wrote:
>> Leif,
>>
>> Since I have put some brain cells around this area in the past I can be the
>> backup and help out too.
>>
>> I’d also point out if you are having issues building or have general
>> questions on how things work it is fine to use the mailing list. I’ve got a
>> lot of feedback that folks read or search the mailing list looking for
>> answer to their questions so one person asking can help out a lot of other
>> people.
>>
>> Thanks,
>>
>> Andrew Fish
>>
>>> On Apr 13, 2021, at 5:28 AM, Leif Lindholm <leif at nuviainc.com> wrote:
>>>
>>> Hi all, especially Ethin.
>>>
>>> Apologies for radio silence - last week I was off on holiday, and before
>>> that ... let's just say corporate acquisitions generate some
>>> distractions.
>>> Anyway, I'm back, and since I'm down as the mentor for this task, feel
>>> free to spam me with any remaining/new questions.
>>>
>>> /
>>> Leif
>>>
>>> On Tue, Apr 6, 2021 at 4:17 PM Ethin Probst <harlydavidsen at gmail.com
>>> <mailto:harlydavidsen at gmail.com <mailto:harlydavidsen at gmail.com>>> wrote:
>>> I'll attach the bug for the build tools to the BZ shortly.
>>> Laszlo, thanks for that. I don't know their email addresses though.
>>> And yes, I was going to make it device independent, as the majority
>>> (if not all) of UEFI protocols are.
>>>
>>> On 4/6/21, Laszlo Ersek <lersek at redhat.com <mailto:lersek at redhat.com> <mailto:lersek at redhat.com <mailto:lersek at redhat.com>>>
>>> wrote:
>>>> On 03/31/21 08:41, Nate DeSimone wrote:
>>>>> 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.
>>>>
>>>> The new audio protocol should be generic, only its implementation in
>>>> question should be virtio specific.
>>>>
>>>> Please include Gerd Hoffmann (CC'd) in the protocol design, as well as
>>>> the developers of the virtio-sound device model in QEMU.
>>>>
>>>> Thanks
>>>> Laszlo
>>>>
>>>>
>>>>>
>>>>>
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Nate
>>>>>
>>>>>
>>>>>
>>>>> *From: *<devel at edk2.groups.io <mailto:devel at edk2.groups.io> <mailto:devel at edk2.groups.io <mailto:devel at edk2.groups.io>>> on behalf
>>>>> of "Andrew Fish via groups.io <http://groups.io/> <http://groups.io/ <http://groups.io/>>"
>>>>> <afish=apple.com at groups.io <mailto:afish=apple.com at groups.io> <mailto:apple.com at groups.io <mailto:apple.com at groups.io>>>
>>>>> *Reply-To: *"devel at edk2.groups.io <mailto:devel at edk2.groups.io> <mailto:devel at edk2.groups.io <mailto:devel at edk2.groups.io>>"
>>>>> <devel at edk2.groups.io <mailto:devel at edk2.groups.io> <mailto:devel at edk2.groups.io <mailto:devel at edk2.groups.io>>>,
>>>>> "afish at apple.com <mailto:afish at apple.com> <mailto:afish at apple.com <mailto:afish at apple.com>>" <afish at apple.com <mailto:afish at apple.com>
>>>>> <mailto:afish at apple.com <mailto:afish at apple.com>>>
>>>>> *Date: *Tuesday, March 30, 2021 at 10:54 PM
>>>>> *To: *edk2-devel-groups-io <devel at edk2.groups.io <mailto:devel at edk2.groups.io>
>>>>> <mailto:devel at edk2.groups.io <mailto:devel at edk2.groups.io>>>,
>>>>> "harlydavidsen at gmail.com <mailto:harlydavidsen at gmail.com> <mailto:harlydavidsen at gmail.com <mailto:harlydavidsen at gmail.com>>"
>>>>> <harlydavidsen at gmail.com <mailto:harlydavidsen at gmail.com> <mailto:harlydavidsen at gmail.com <mailto:harlydavidsen at gmail.com>>>
>>>>> *Cc: *Rafael Rodrigues Machado <rafaelrodrigues.machado at gmail.com <mailto:rafaelrodrigues.machado at gmail.com>
>>>>> <mailto:rafaelrodrigues.machado at gmail.com <mailto:rafaelrodrigues.machado at gmail.com>>>
>>>>> *Subject: *Re: [edk2-devel] VirtIO Sound Driver (GSoC 2021)
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On Mar 30, 2021, at 5:01 PM, Ethin Probst <harlydavidsen at gmail.com <mailto:harlydavidsen at gmail.com>
>>>>> <mailto:harlydavidsen at gmail.com <mailto:harlydavidsen at gmail.com>>
>>>>> <mailto:harlydavidsen at gmail.com <mailto:harlydavidsen at gmail.com> <mailto:harlydavidsen at gmail.com <mailto:harlydavidsen at 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 <http://groups.io/> <http://groups.io/ <http://groups.io/>>
>>>>> <http://groups.io/ <http://groups.io/> <http://groups.io/ <http://groups.io/>>>
>>>>> <harlydavidsen=gmail.com at groups.io <mailto:harlydavidsen=gmail.com at groups.io> <mailto:gmail.com at groups.io <mailto:gmail.com at groups.io>>
>>>>> <mailto:harlydavidsen <mailto:harlydavidsen>=gmail.com at groups.io <mailto:gmail.com at groups.io>
>>>>> <mailto:gmail.com at groups.io <mailto:gmail.com at 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 at gmail.com <mailto:rafaelrodrigues.machado at gmail.com>
>>>>> <mailto:rafaelrodrigues.machado at gmail.com <mailto:rafaelrodrigues.machado at gmail.com>>
>>>>> <mailto:rafaelrodrigues.machado at gmail.com <mailto:rafaelrodrigues.machado at gmail.com>
>>>>> <mailto:rafaelrodrigues.machado at gmail.com <mailto:rafaelrodrigues.machado at 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 <https://github.com/RafaelRMachado/Msc_UefiHda_PreOs_Accessibility>
>>>>> <https://github.com/RafaelRMachado/Msc_UefiHda_PreOs_Accessibility <https://github.com/RafaelRMachado/Msc_UefiHda_PreOs_Accessibility>>
>>>>>
>>>>> Thanks
>>>>> Rafael
>>>>>
>>>>> Em seg, 29 de mar de 2021 20:24, Ethin Probst
>>>>> <harlydavidsen at gmail.com <mailto:harlydavidsen at gmail.com> <mailto:harlydavidsen at gmail.com <mailto:harlydavidsen at 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
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Signed,
>>> Ethin D. Probst
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>
>
> --
> Signed,
> Ethin D. Probst
>
>
>
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