Re: [edk2-devel] VirtIO Sound Driver (GSoC 2021)

["Ethin Probst" <harlydavidsen@gmail.com>]

So here's the rationale for my extra stuff:

- I hoped to add recording in case we in future want to add
accessibility aids like speech recognition (that was one of the todo
tasks on the EDK2 tasks list)
- Muting and volume control could easily be added by just replacing
the sample buffer with silence and by multiplying all the samples by a
percentage.
- We could have separate protocols for different audio devices, but my
rationale for making it do everything was that it (might) simplify
development. But looking at the UEFI specification there are separate
UEFI protocols for TCP/IP protocols so you have a point there.
- Finally, the reason I used enumerations for specifying parameters
like sample rate and stuff was that I was looking at this protocol
from a general UEFI applications point of view. VirtIO supports all of
the sample configurations listed in my gist, and it seems reasonable
to allow the application to control those parameters instead of
forcing a particular parameter configuration onto the developer.

Perhaps splitting all the separate audio device protocols into their
own individual UEFI protocols would be much easier, though. Volume
control and muting/unmuting shouldn't be too difficult though, I don't
think.

On 4/14/21, Andrew Fish <afish@apple.com> wrote:
>
>
>> On Apr 14, 2021, at 9:01 PM, Ethin Probst <harlydavidsen@gmail.com>
>> wrote:
>>
>> Hi Mike and Andrew,
>>
>> Thanks for your responses. I'm looking at the VirtIO block device now
>> but will certainly have a look at the others as well. We'll also need
>> to define a completely new protocol for audio, as well, as no existing
>> protocol will fit the bill. The generic protocol proposed by Andrew
>> might work, though I was thinking of a couple modifications: primarily
>> that the audio interface will most likely be asynchronous in nature.
>> Every audio library I've looked at out there that's open-source is
>> fully asynchronous, as are operating-system level APIs. For example,
>> the Microsoft Windows WASAPI audio API requires the application that
>> uses the audio engine to poll a particular variable that's updated as
>> the audio stream progresses, as demonstrated here
>> (https://docs.microsoft.com/en-us/windows/win32/coreaudio/rendering-a-stream
>> <https://docs.microsoft.com/en-us/windows/win32/coreaudio/rendering-a-stream>).
>> Obviously, I'm not going to make the code as complicated as the code
>> shown in the aforementioned example, since this is UEFI and not an
>> operating system, and making it too complicated would make it
>> difficult to use and understand, something that I'd like to avoid.
>> Therefore, for protocol design, would this be satisfactory? Not all of
>> it needs to be finished for GSoC; I can implement stubs for those that
>> I don't have time to implement, but I'd like to discuss the protocol
>> before I start working on a driver for it. I have a (incomplete)
>> outline of a (hopefully) good protocol at
>> https://gist.github.com/ethindp/56066e0561b901c1e276e82ff469436d
>> <https://gist.github.com/ethindp/56066e0561b901c1e276e82ff469436d>. I'd
>> appreciate your thoughts on it.
>>
>
> I’d drop the Audio Input part of it. I don’t see a lot of use recording
> audio when you boot the system, and it is going to be a mess dealing with
> built in microphones etc. vs. input jacks etc. If we wanted to do input we
> could define a 2nd protocol that lives on the same handle for that.
>
> The EFI APIs don’t generally have enumeration members so I’d drop that part
> too. The driver is going to get started on a PCI device and that is how the
> device is going to be selection. So we should have a VirtIO Audio driver, a
> USB Audio driver, and an HDA Audio driver, not one driver that does
> everything. If there are common operations then
>
> I really think we need the volume and mute members. I did a prototype for
> the emulator a few years back and it looked like [1] as a simple abstract
> for HDA Audo to the system. I assume we could make this generic.
>
> The firmware really just wants to play the sound for the canned resource.
> The calling code is not some GUI app the user can configure. So I’m not sure
> of the value of having to pass in sampleRate, sampleCout, and sampleFormat.
> I think my proposal basically assumed PCM 16 via a WAVE file or some such.
> So basically the calling code just has to grab a source and pass it to the
> Audio protocol. That is how our GUIs work the artwork is in some encoding we
> can decode and that gets converted to something we can draw to the raw frame
> buffer.
>
>
>  [1] My prototype from a while while back.
>
> /** @file
>   Abstraction for audio modeled on the High Definition Audio Specification.
>
>
>   This API is targeted at "Code First" with the UEFI Forum. Thus the plan is
>
>   to potential make this a standard in the future and definition will then
> move
>   to the MdePkg, and EFI_GUID will likely change.
>
>   Copyright (c) 2018-2019 Rafael Machado
> <rafaelrodrigues.machado@gmail.com>
>   Copyright (c) 2019, Apple Inc. All rights reserved.<BR>
>   SPDX-License-Identifier: BSD-2-Clause-Patent
>
> **/
>
> #ifndef __HDA_AUDIO_H__
> #define __HDA_AUDIO_H__
>
> ///
> /// Global ID for the HDA Audio Protocol
> ///
>
> // 61EE0891-E13E-11E9-A1C7-823F7D860801
> #define CODE_FIRST_HDA_AUDIO_PROTOCOL_GUID \
>   { \
>     0x61EE0891, 0xE13E, 0x11E9, { 0xA1, 0xC7, 0x82, 0x3F, 0x7D, 0x86, 0x08,
> 0x01 } \
>   }
>
> typedef struct _CODE_FIRST_HDA_AUDIO_PROTOCOL
> CODE_FIRST_HDA_AUDIO_PROTOCOL;
>
>
> typedef INT32   HDA_GAIN;
>
>
> /**
>   The struct of Audio Token.
> **/
> typedef struct {
>
>   ///
>   /// Event will be signaled when the read audo has been played.
>   /// If only synchronous playback is supported the Event must still get
> signaled.
>   ///
>   EFI_EVENT               Event;
>
>   ///
>   /// Defines whether or not the signaled event encountered an error.
>   ///
>   EFI_STATUS              TransactionStatus;
> } CODE_FIRST_HDA_AUDIO_TOKEN;
>
>
>
> /**
>   Play synchronous or asynchronous audio. If Token is passed in the audio is
> played
>   asynchronously, if Token is NULL then this call blocks until the Audio is
> complete.
>
>   @param[in]      This         A pointer to the
> CODE_FIRST_HDA_AUDIO_PROTOCOL instance.
>   @param[in, out] Token        A pointer to the token associated with the
> transaction.
>                                If NULL this functions blocks until audio
> play back is complete.
>   @param[in]      Buffer       PCM encoded buffer of the audio to play.
>   @param[in ]     BufferSize   The size of Buffer in bytes.
>
>   @retval EFI_SUCCESS           The audio started playing.
>   @retval EFI_UNSUPPORTED       Buffer is not a supported format.
>   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a
> lack of resources.
>   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
>
> **/
> typedef
> EFI_STATUS
> (EFIAPI *CODE_FIRST_HDA_AUDIO_PROTOCOL_PLAY_STREAM)(
>   IN     CODE_FIRST_HDA_AUDIO_PROTOCOL   *This,
>   IN OUT CODE_FIRST_HDA_AUDIO_TOKEN      *Token,     OPTIONAL
>   IN     UINT8                           *Buffer,
>   IN     UINT64                          BufferSize
>   );
>
>
> /**
>   Stop playing asynchronous audio.
>
>   @param[in]      This         A pointer to the
> CODE_FIRST_HDA_AUDIO_PROTOCOL instance.
>   @param[in, out] Token        A pointer to the token associated with the
> transaction.
>
>   @retval EFI_SUCCESS           Audio stopped playing.
>   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a
> lack of resources.
>   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
>
> **/
> typedef
> EFI_STATUS
> (EFIAPI *CODE_FIRST_HDA_AUDIO_PROTOCOL_STOP_STREAM)(
>   IN     CODE_FIRST_HDA_AUDIO_PROTOCOL   *This,
>   IN     CODE_FIRST_HDA_AUDIO_TOKEN      *Token
>   );
>
>
> /**
>   Return the current volume for audio played by this protocol.
>
>   @param[in]      This         A pointer to the
> CODE_FIRST_HDA_AUDIO_PROTOCOL instance.
>   @param[out]     Gain         A pointer to the value returned between 0 and
> 100.
>
>   @retval EFI_SUCCESS           Gain was returned.
>   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a
> lack of resources.
>   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
>
> **/
> typedef
> EFI_STATUS
> (EFIAPI *CODE_FIRST_HDA_AUDIO_PROTOCOL_GET_VOLUME)(
>   IN     CODE_FIRST_HDA_AUDIO_PROTOCOL  *This,
>   IN OUT HDA_GAIN                       *Gain
>   );
>
>
> /**
>   Set the current volume for audio played by this protocol.
>
>   The result of calling this function while audio is playing asynchronously
> is undefined.
>
>   @param[in]      This         A pointer to the
> CODE_FIRST_HDA_AUDIO_PROTOCOL instance.
>   @param[in]      Gain         A value between 0 and 100 to set the volume.
>
>
>   @retval EFI_SUCCESS           Gain was updated.
>   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a
> lack of resources.
>   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
>
> **/
> typedef
> EFI_STATUS
> (EFIAPI *CODE_FIRST_HDA_AUDIO_PROTOCOL_SET_VOLUME)(
>   IN     CODE_FIRST_HDA_AUDIO_PROTOCOL    *This,
>   IN OUT HDA_GAIN                         Gain
>   );
>
>
> /**
>   Increment the volume in an implementation defined quanta. The value of the
> Gain can never
>   be over 100. The final successful call will round the volume increase to
> 100. If this
>   function is called an the Gain is already set to 100 EFI_NO_MAPPING must
> be returned.
>
>   The result of calling this function while audio is playing asynchronously
> is undefined.
>
>   @param[in]      This         A pointer to the
> CODE_FIRST_HDA_AUDIO_PROTOCOL instance.
>
>   @retval EFI_SUCCESS           Gain was incremented.
>   @retval EFI_NO_MAPPING        Gasin was not updated since it was already
> set to 100.
>   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a
> lack of resources.
>   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
>
> **/
> typedef
> EFI_STATUS
> (EFIAPI *CODE_FIRST_HDA_AUDIO_PROTOCOL_VOLUME_UP)(
>   IN     CODE_FIRST_HDA_AUDIO_PROTOCOL   *This
>   );
>
>
> /**
>   Decrement the volume in an implementation defined quanta. The value of the
> Gain can never
>   be under 0. The final successful call will round the volume decrease to 0.
> If this
>   function is called an the Gain is already set to 0 EFI_NO_MAPPING must be
> returned.
>
>   The result of calling this function while audio is playing asynchronously
> is undefined.
>
>   @param[in]      This         A pointer to the
> CODE_FIRST_HDA_AUDIO_PROTOCOL instance.
>
>   @retval EFI_SUCCESS           Gain was decremented.
>   @retval EFI_NO_MAPPING        Gain was not updated since it was already
> set to 0.
>   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a
> lack of resources.
>   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
>
> **/
> typedef
> EFI_STATUS
> (EFIAPI *CODE_FIRST_HDA_AUDIO_PROTOCOL_VOLUME_DOWN)(
>   IN     CODE_FIRST_HDA_AUDIO_PROTOCOL   *This
>   );
>
>
> /**
>   Mute audio output, but retain the current Gain (volume Level).
>
>   The result of calling this function while audio is playing asynchronously
> is undefined.
>
>   @param[in]      This         A pointer to the
> CODE_FIRST_HDA_AUDIO_PROTOCOL instance.
>
>   @retval EFI_SUCCESS           Audio was muted.
>   @retval EFI_ALREADY_STARTED   Audio is already muted.
>   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a
> lack of resources.
>   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
>
> **/
> typedef
> EFI_STATUS
> (EFIAPI *CODE_FIRST_HDA_AUDIO_PROTOCOL_MUTE)(
>   IN     CODE_FIRST_HDA_AUDIO_PROTOCOL   *This
>   );
>
> /**
>   Unmute audio output, but retain the current Gain (volume Level).
>
>   The result of calling this function while audio is playing asynchronously
> is undefined.
>
>   @param[in]      This         A pointer to the
> CODE_FIRST_HDA_AUDIO_PROTOCOL instance.
>
>   @retval EFI_SUCCESS           Audio was muted.
>   @retval EFI_ALREADY_STARTED   Audio is already unmuted.
>   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a
> lack of resources.
>   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
>
> **/
> typedef
> EFI_STATUS
> (EFIAPI *CODE_FIRST_HDA_AUDIO_PROTOCOL_UNMUTE)(
>   IN     CODE_FIRST_HDA_AUDIO_PROTOCOL   *This
>   );
>
>
> /**
>   Reset the audio hardware.
>
>   The result of calling this function while audio is playing asynchronously
> is undefined.
>
>   @param[in]      This         A pointer to the
> CODE_FIRST_HDA_AUDIO_PROTOCOL instance.
>
>   @retval EFI_SUCCESS           Audio was muted.
>   @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a
> lack of resources.
>   @retval EFI_INVALID_PARAMETER One or more parameters are invalid.
>
> **/
> typedef
> EFI_STATUS
> (EFIAPI *CODE_FIRST_HDA_AUDIO_PROTOCOL_RESET)(
>   IN     CODE_FIRST_HDA_AUDIO_PROTOCOL   *This
>   );
>
>
> #define HDA_AUDIO_VERSION 0x00010000
>
> ///
> /// The CODE_FIRST_HDA_AUDIO_PROTOCOL provides an abstraction for an Audio
> device that
> /// can play PCM files.
> /// There is one CODE_FIRST_HDA_AUDIO_PROTOCOL instance for each Audio
> Hardware device.
> ///
> struct _CODE_FIRST_HDA_AUDIO_PROTOCOL {
>   UINT64                                      Version;
>   CODE_FIRST_HDA_AUDIO_PROTOCOL_PLAY_STREAM   PlayStream;
>   CODE_FIRST_HDA_AUDIO_PROTOCOL_STOP_STREAM   StopStream;
>   CODE_FIRST_HDA_AUDIO_PROTOCOL_GET_VOLUME    GetVolume;
>   CODE_FIRST_HDA_AUDIO_PROTOCOL_SET_VOLUME    SetVolume;
>   CODE_FIRST_HDA_AUDIO_PROTOCOL_VOLUME_UP     VolumeUp;
>   CODE_FIRST_HDA_AUDIO_PROTOCOL_VOLUME_DOWN   VolumeDown;
>   CODE_FIRST_HDA_AUDIO_PROTOCOL_MUTE          Mute;
>   CODE_FIRST_HDA_AUDIO_PROTOCOL_UNMUTE        UnMute;
>   CODE_FIRST_HDA_AUDIO_PROTOCOL_RESET         Reset;
> };
>
> extern EFI_GUID gBz2387HdaAudioProtocolGuid;
>
> #endif
>
>
> Thanks,
>
> Andrew Fish
>
>> On 4/14/21, Andrew Fish <afish@apple.com <mailto:afish@apple.com>> wrote:
>>>
>>>
>>>> On Apr 14, 2021, at 3:30 PM, Kinney, Michael D
>>>> <michael.d.kinney@intel.com> wrote:
>>>>
>>>> Hi Ethin,
>>>>
>>>> Most UEFI Drivers do use polling.
>>>>
>>>> If it is a blocking I/O operation the UEFI Driver waits for completion.
>>>> Typically by polling a status register until the I/O is complete and
>>>> then
>>>> return status.
>>>>
>>>> If it is a non-blocking I/O Operation, then the UEFI Driver can create
>>>> a
>>>> timer event to periodically check the completion status.
>>>>
>>>> Non-blocking APIs may also use an event to know when the I/O operation
>>>> is
>>>> completed and this can be used with the CheckEvent() service to poll
>>>> for
>>>> event completion.
>>>>
>>>> These concepts are discussed in the UEFI Driver Writer's Guide.
>>>>
>>>> https://tianocore-docs.github.io/edk2-UefiDriverWritersGuide/draft/edk2-UefiDriverWritersGuide-draft.pdf
>>>> <https://tianocore-docs.github.io/edk2-UefiDriverWritersGuide/draft/edk2-UefiDriverWritersGuide-draft.pdf
>>>> <https://tianocore-docs.github.io/edk2-UefiDriverWritersGuide/draft/edk2-UefiDriverWritersGuide-draft.pdf>>
>>>>
>>>> Specifically for audio.  If there is an audio playback buffer that will
>>>> take some time to send,
>>>> the Audio Protocol would likely define a non-blocking interface to
>>>> start
>>>> playback.  You may need
>>>> an event that is signaled when more audio data is needed or when the
>>>> playback is complete.  You
>>>> will need to think about the consumer of the Audio Protocol and how it
>>>> will interact with the
>>>> Audio Protocol and if the consumer also needs to do other activities
>>>> while
>>>> audio is playing or
>>>> if it is ok for the consumer to wait until the audio playback is
>>>> completed.
>>>>
>>>
>>> Mike,
>>>
>>> It is likely we want async and synchronous playback. If you are playing
>>> a
>>> boot bong you don’t want to block on its completion. If you are doing a
>>> GUI
>>> UI you don’t want to block on playback and then do a bunch of GUI math
>>> etc.
>>>
>>>
>>> Ethin,
>>>
>>> I’d take a look at some example drivers like VirtioBlkDxe[1]. It also
>>> looks
>>> like there is already a VirtioLib[2] to help with house keeping. I did a
>>> quick skim and I don’t see a VirtIo device with an Event driven API.  It
>>> looks like VirtioNetDxe[3] does have the concept of a callback to poll
>>> [4],
>>> so you might be able to leverage that concept into a timer event to
>>> check
>>> for completion.
>>>
>>> I’d not get hung up on the asynchronous part of the API. It might make
>>> sense
>>> to implement the synchronous version of the API in the driver 1st and
>>> fake
>>> the async for your 1st pass.
>>>
>>> If you look at other UEFI Async APIs they generally pass around a Token
>>> (usually an Event to signal on completion, and an EFI_STATUS)[5]. Thus
>>> faking the Async means making it look like the event fired before your
>>> API
>>> returned. Assuming that *Token is an argument to the protocol you do this
>>> to
>>> fake the Async transaction….
>>>
>>> If (Token != NULL) {
>>>  Token->TransactionStatus = Status;
>>>  gBS->SignalEvent (Token->Event);
>>> }
>>>
>>> This just make it look to the caller like the transaction completed by
>>> the
>>> time you returned to the caller. So from a caller perspective that is a
>>> valid way the API could work. The other upside to this is you can make a
>>> UEFI Shell App to test the protocol and also add a path to test the
>>> async
>>> API, even if for the 1st pass implementation that is faked out.
>>>
>>> [1] https://github.com/tianocore/edk2/tree/master/OvmfPkg/VirtioBlkDxe
>>> [2]
>>> https://github.com/tianocore/edk2/blob/master/OvmfPkg/Library/VirtioLib/VirtioLib.c
>>> [3] https://github.com/tianocore/edk2/tree/master/OvmfPkg/VirtioNetDxe
>>> [4]
>>> https://github.com/tianocore/edk2/blob/master/OvmfPkg/VirtioNetDxe/Events.c#L32
>>> [5]
>>> https://github.com/tianocore/edk2/blob/master/MdePkg/Include/Protocol/BlockIo2.h#L41
>>>
>>> Thanks,
>>>
>>> Andrew Fish
>>>
>>>> Mike
>>>>
>>>>> -----Original Message-----
>>>>> From: devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>
>>>>> <devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>> On Behalf
>>>>> Of Ethin
>>>>> Probst
>>>>> Sent: Wednesday, April 14, 2021 1:48 PM
>>>>> To: Andrew Fish <afish@apple.com <mailto:afish@apple.com>
>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>>>
>>>>> Cc: edk2-devel-groups-io <devel@edk2.groups.io
>>>>> <mailto:devel@edk2.groups.io>
>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>>; Leif
>>>>> Lindholm <leif@nuviainc.com <mailto:leif@nuviainc.com>
>>>>> <mailto:leif@nuviainc.com <mailto:leif@nuviainc.com>>>; Laszlo Ersek
>>>>> <lersek@redhat.com <mailto:lersek@redhat.com>
>>>>> <mailto:lersek@redhat.com <mailto:lersek@redhat.com>>>;
>>>>> Desimone, Nathaniel L <nathaniel.l.desimone@intel.com
>>>>> <mailto:nathaniel.l.desimone@intel.com>
>>>>> <mailto:nathaniel.l.desimone@intel.com
>>>>> <mailto:nathaniel.l.desimone@intel.com>>>; Rafael Rodrigues Machado
>>>>> <rafaelrodrigues.machado@gmail.com
>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>> <mailto:rafaelrodrigues.machado@gmail.com>>>; Gerd
>>>>> Hoffmann <kraxel@redhat.com <mailto:kraxel@redhat.com>
>>>>> <mailto:kraxel@redhat.com <mailto:kraxel@redhat.com>>>
>>>>> Subject: Re: [edk2-devel] VirtIO Sound Driver (GSoC 2021)
>>>>>
>>>>> These are some pretty good suggestions; however, while reading through
>>>>> the VirtIO specification again yesterday, I (re)-discovered that
>>>>> VirtIO devices are usually interrupt based. In particular, a VirtIO
>>>>> PCI/PCIe device defines the common, notifications, ISR status,
>>>>> device-specific configuration, PCI configuration access, shared memory
>>>>> region, and vendor-specific data capability structures in PCI
>>>>> configuration space. It doesn't look like the EFI_CREATE_EVENT or
>>>>> EFI_CREATE_EVENT_EX function works via interrupts, from what I can
>>>>> tell. I'm not sure but it doesn't seem like there's a way I can poll
>>>>> the device, though I might be missing something.
>>>>> The idea for the generic protocol is good. The interrupt issue might
>>>>> be a problem though and I'm not sure how to actually solve that.
>>>>>
>>>>> On 4/13/21, Andrew Fish <afish@apple.com <mailto:afish@apple.com>>
>>>>> wrote:
>>>>>> Ethin,
>>>>>>
>>>>>> In terms of defining the protocol stack it is good to start with the
>>>>>> producers and consumers and think about the problem from both
>>>>>> perspectives.
>>>>>> It is easy enough to think about the producer part of it as you are
>>>>>> thinking
>>>>>> about writing the driver. The driver is going to consume things like
>>>>>> the
>>>>>> PCI
>>>>>> I/O Protocol.
>>>>>>
>>>>>> The consumer of the sound Protocol is going to most likely be generic
>>>>>> EFI
>>>>>> platform code, and possibly an OS loader. In the boot process Audio
>>>>>> has
>>>>>> traditionally be used for error codes, sign of life (for example the
>>>>>> famous
>>>>>> Mac startup sound). We are also would like to have the option of
>>>>>> enabling
>>>>>> better accessibility features, especially for people how are visually
>>>>>> impaired. These days a lot of software engineers think of disk space
>>>>>> as
>>>>>> free
>>>>>> and really don’t consider the size of software, but this is not true
>>>>>> for
>>>>>> firmware. Firmware generally lives in NOR FLASH that is considered
>>>>>> expensive
>>>>>> (it is more expensive than NAND, but at the same time more reliable)
>>>>>> so
>>>>>> firmware implementations are constrained by the size of the code that
>>>>>> can be
>>>>>> carried, and the size of assets/resources that can be used for user
>>>>>> interfaces. The OS loader is some what less constrained, but it still
>>>>>> has to
>>>>>> share the EFI System Partition on the disk with potentially other OS
>>>>>> loaders.
>>>>>>
>>>>>> So the consumer wants a protocol that is unleveled and focused on the
>>>>>> task
>>>>>> at hand. I’m not too caught up on the names but in general I think
>>>>>> things
>>>>>> you want are (How many knobs we need is probably better answered by
>>>>>> an
>>>>>> audiophile, and that is not me):
>>>>>> 1) CompatibleBuffer() - Does driver support this buffer format.
>>>>>> 2) PlayBuffer() - Play the sound
>>>>>> 	a) We probably want a synchronous and asynchronous version of this
>>>>>> API.
>>>>>> For
>>>>>> example you don’t want to slow down the boot to wait for a boot beep
>>>>>> to
>>>>>> complete, and you may chose to implement an API that waits for the
>>>>>> sound
>>>>>> to
>>>>>> complete (and do some GUI work in parallel) vs. blocking on the
>>>>>> sound.
>>>>>> 	b) async in EFI usually means you return a pointer to an EFI_EVENT
>>>>>> that
>>>>>> gets signaled on completion.
>>>>>> 3) StopBuffer() - In case the asynchronous PlayBuffer() needs to be
>>>>>> stopped.
>>>>>> Think error exit.
>>>>>> 3) SetVolume()/GetVolume() - Set/Get Volume in units of 0 - 100
>>>>>> (trying
>>>>>> to
>>>>>> avoid db as that gets into capability and math that is likely best
>>>>>> abstracted by the driver)?
>>>>>> 4) Mute()/UnMute() - Mute and volume are often independent features in
>>>>>> a
>>>>>> UI
>>>>>> keeping them separate in API makes it easier to implement things.
>>>>>> 5) PlayTone() - Maybe for error sounds that don’t require canned
>>>>>> sound
>>>>>> files. Maybe TimeOn, TimeOff, Frequency, and how many times to
>>>>>> repeat.
>>>>>> 6) Do we need tuning values or Tone settings?
>>>>>>
>>>>>> At some point we might consider defining nvram variable for the
>>>>>> default
>>>>>> state of some of the tunable, especially mute and volume. For example
>>>>>> the
>>>>>> user may want to turn off all volume on the system so it would be
>>>>>> nice
>>>>>> if
>>>>>> the OS can set the EFI volume and mute. In the short run we can
>>>>>> probably
>>>>>> use
>>>>>> PCD values to set the default values.
>>>>>>
>>>>>> So I think we have a generic AUDIO API on top and likely a PCI I/O on
>>>>>> the
>>>>>> bottom. If we need more protocols to manage hardware devices then
>>>>>> those
>>>>>> protocols can be defined in the context of that hardware. So for
>>>>>> example
>>>>>> we
>>>>>> would probably end up with an HDA_CODEC protocol. I think the best
>>>>>> way
>>>>>> to
>>>>>> think about this is a disk. A lot of disk adapters just produce a raw
>>>>>> Block
>>>>>> I/O  protocol, but for a more common bus like ATA or SCSI you might
>>>>>> have
>>>>>> an
>>>>>> extra driver in place to make the common bits common code. I think
>>>>>> some
>>>>>> of
>>>>>> the same layers may be in place here. So likely VirtIo is simple and
>>>>>> just
>>>>>> produces the generic AUDIO API, while an HDA audio driver also has to
>>>>>> abstract some of the complexity of its hardware implementation and
>>>>>> standard.
>>>>>>
>>>>>>
>>>>>> In terms of picking the set of APIs and tunables it is probably good
>>>>>> to
>>>>>> start with VirtIo and USB and see what set make sense and what you
>>>>>> could
>>>>>> and
>>>>>> could not implement. HDA Audio is so complex you might want to look
>>>>>> at
>>>>>> it in
>>>>>> terms of the minute you have to implement to make it function. Think
>>>>>> what
>>>>>> assumptions are you forced to make to implement.
>>>>>>
>>>>>> This is a vey 10,000 foot view to start with. I think you will need
>>>>>> to
>>>>>> mix
>>>>>> this in the the reality of how it works in the real world to figure
>>>>>> out
>>>>>> the
>>>>>> right abstraction, but then again that is the beauty of having an
>>>>>> implementation. Likely also get some feedback from audiophiles.
>>>>>>
>>>>>> Oh and make sure you don’t go off an implement a lot of code just
>>>>>> because we
>>>>>> chose the wrong complexity or abstraction point. This is the one time
>>>>>> we
>>>>>> get
>>>>>> to change the public APIs so lets feel free to adjust them to make
>>>>>> the
>>>>>> most
>>>>>> sense for the job at hand.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Andrew Fish
>>>>>>
>>>>>>> On Apr 13, 2021, at 6:20 PM, Ethin Probst <harlydavidsen@gmail.com
>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>> wrote:
>>>>>>>
>>>>>>> Okay, so looking at the EDK2 driver developers guide, here are my
>>>>>>> thoughts:
>>>>>>>
>>>>>>> - Each audio driver will be a bus driver, even if it doesn't control
>>>>>>> buses in the traditional sense.
>>>>>>> - I think the initialization sequence should be different: there
>>>>>>> should be an AudioDxe, but it should contain three separate bus
>>>>>>> drivers for each kind of audio device supported.
>>>>>>> - For the VirtIO audio device driver, it'll most likely consume the
>>>>>>> PCI I/O protocol and produce the EFI_VIRTIO_AUDIO_OUTPUT_PROTOCOL
>>>>>>> and
>>>>>>> EFI_VIRTIO_AUDIO_INPUT_PROTOCOL protocols. This will just be an
>>>>>>> ordinary UEFI device driver.
>>>>>>> - The HDA audio device driver will consume the PCI I/O protocol and
>>>>>>> will produce different device handles per HDA controller found. I'd
>>>>>>> produce a handle per codec, but that seems overkill. Each handle
>>>>>>> will
>>>>>>> be attached to both an audio stream protocol and a controller
>>>>>>> management protocol. The audio stream protocol will manage the
>>>>>>> creation, control, and deletion of audio streams as well as the
>>>>>>> processing of audio data. The controller management protocol is
>>>>>>> responsible for allowing applications or other drivers to manage the
>>>>>>> HDA controller itself.
>>>>>>>
>>>>>>> I haven't planned for the USB audio device driver yet, but these are
>>>>>>> my thoughts so far. What do you guys think? Am I over-complicating
>>>>>>> this setup? How can it be improved upon?
>>>>>>>
>>>>>>> On 4/13/21, Ethin Probst via groups.io <http://groups.io/>
>>>>>>> <http://groups.io/ <http://groups.io/>>
>>>>>>> <harlydavidsen=gmail.com@groups.io
>>>>>>> <mailto:harlydavidsen=gmail.com@groups.io>
>>>>>>> <mailto:harlydavidsen=gmail.com@groups.io
>>>>>>> <mailto:harlydavidsen=gmail.com@groups.io>>> wrote:
>>>>>>>> Hi Andrew,
>>>>>>>>
>>>>>>>> The developer guide for EDK2 drivers is a godsend. Thank you very
>>>>>>>> much, and thank you, Mike, for your excellent work on the guide! I
>>>>>>>> may
>>>>>>>> just ahve to do my building on Linux and not Windows -- unless the
>>>>>>>> Bug
>>>>>>>> -- bug 3302 -- has been fixed. I'll have to do testing on Linux, at
>>>>>>>> any rate, since Windows hosts do not support VirtIO emulation and I
>>>>>>>> can't seem to find any way of emulating them in a guest machine
>>>>>>>> with
>>>>>>>> Windows as a host.
>>>>>>>>
>>>>>>>> On 4/13/21, Andrew Fish <afish@apple.com <mailto:afish@apple.com>
>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>>>
>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> On Apr 13, 2021, at 9:53 AM, Ethin Probst <harlydavidsen@gmail.com
>>>>>>>>>> <mailto:harlydavidsen@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
>>>>>>>>> <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
>>>>>>>>> <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>
>>>>>>>>>> <https://www.kraxel.org/virtio/virtio-v1.1-cs01-sound-v7.html
>>>>>>>>>> <https://www.kraxel.org/virtio/virtio-v1.1-cs01-sound-v7.html>
>>>>>>>>>> <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@apple.com <mailto:afish@apple.com>
>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>>
>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>
>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@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@nuviainc.com
>>>>>>>>>>>> <mailto:leif@nuviainc.com>
>>>>>>>>>>>> <mailto:leif@nuviainc.com <mailto:leif@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@gmail.com <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>> <mailto:harlydavidsen@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@redhat.com
>>>>>>>>>>>> <mailto:lersek@redhat.com>
>>>>>>>>>>>> <mailto:lersek@redhat.com <mailto:lersek@redhat.com>>
>>>>>>>>>>>> <mailto:lersek@redhat.com <mailto:lersek@redhat.com>
>>>>>>>>>>>> <mailto:lersek@redhat.com <mailto:lersek@redhat.com>>>
>>>>>>>>>>>> <mailto:lersek@redhat.com <mailto:lersek@redhat.com>
>>>>>>>>>>>> <mailto:lersek@redhat.com <mailto:lersek@redhat.com>>
>>>>>>>>>>>> <mailto:lersek@redhat.com <mailto:lersek@redhat.com>
>>>>>>>>>>>> <mailto:lersek@redhat.com <mailto:lersek@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@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io>>>>>
>>>>>>>>>>>>>> on
>>>>>>>>>>>>>> behalf
>>>>>>>>>>>>>> of "Andrew Fish via groups.io <http://groups.io/>
>>>>>>>>>>>>>> <http://groups.io/ <http://groups.io/>>
>>>>>>>>>>>>>> <http://groups.io/ <http://groups.io/> <http://groups.io/
>>>>>>>>>>>>>> <http://groups.io/>>> <http://groups.io/ <http://groups.io/>
>>>>>>>>>>>>>> <http://groups.io/ <http://groups.io/>>
>>>>>>>>>>>>>> <http://groups.io/ <http://groups.io/> <http://groups.io/
>>>>>>>>>>>>>> <http://groups.io/>>>>"
>>>>>>>>>>>>>> <afish=apple.com@groups.io <mailto:afish=apple.com@groups.io>
>>>>>>>>>>>>>> <mailto:afish=apple.com@groups.io
>>>>>>>>>>>>>> <mailto:afish=apple.com@groups.io>>
>>>>>>>>>>>>>> <mailto:afish=apple.com@groups.io
>>>>>>>>>>>>>> <mailto:afish=apple.com@groups.io>
>>>>>>>>>>>>>> <mailto:afish=apple.com@groups.io
>>>>>>>>>>>>>> <mailto:afish=apple.com@groups.io>>>
>>>>>>>>>>>>>> <mailto:apple.com@groups.io <mailto:apple.com@groups.io>
>>>>>>>>>>>>>> <mailto:apple.com@groups.io <mailto:apple.com@groups.io>>
>>>>>>>>>>>>>> <mailto:apple.com@groups.io <mailto:apple.com@groups.io>
>>>>>>>>>>>>>> <mailto:apple.com@groups.io <mailto:apple.com@groups.io>>>>>
>>>>>>>>>>>>>> *Reply-To: *"devel@edk2.groups.io
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io> <mailto:devel@edk2.groups.io
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io>>>>"
>>>>>>>>>>>>>> <devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io>>>>>,
>>>>>>>>>>>>>> "afish@apple.com <mailto:afish@apple.com>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>>>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>>>>"
>>>>>>>>>>>>>> <afish@apple.com <mailto:afish@apple.com>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>>>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>
>>>>>>>>>>>>>> <mailto:afish@apple.com <mailto:afish@apple.com>>>>>
>>>>>>>>>>>>>> *Date: *Tuesday, March 30, 2021 at 10:54 PM
>>>>>>>>>>>>>> *To: *edk2-devel-groups-io <devel@edk2.groups.io
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io <mailto:devel@edk2.groups.io>
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io
>>>>>>>>>>>>>> <mailto:devel@edk2.groups.io>>>>>,
>>>>>>>>>>>>>> "harlydavidsen@gmail.com <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>>>"
>>>>>>>>>>>>>> <harlydavidsen@gmail.com <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>>>>
>>>>>>>>>>>>>> *Cc: *Rafael Rodrigues Machado
>>>>>>>>>>>>>> <rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>>>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto: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 <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto: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 <http://groups.io/>
>>>>>>>>>>>>>> <http://groups.io/ <http://groups.io/>>
>>>>>>>>>>>>>> <http://groups.io/ <http://groups.io/> <http://groups.io/
>>>>>>>>>>>>>> <http://groups.io/>>>
>>>>>>>>>>>>>> <http://groups.io/ <http://groups.io/> <http://groups.io/
>>>>>>>>>>>>>> <http://groups.io/>> <http://groups.io/ <http://groups.io/>
>>>>>>>>>>>>>> <http://groups.io/ <http://groups.io/>>>>
>>>>>>>>>>>>>> <http://groups.io/ <http://groups.io/> <http://groups.io/
>>>>>>>>>>>>>> <http://groups.io/>> <http://groups.io/ <http://groups.io/>
>>>>>>>>>>>>>> <http://groups.io/ <http://groups.io/>>> <http://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@groups.io
>>>>>>>>>>>>>> <mailto:harlydavidsen=gmail.com@groups.io>
>>>>>>>>>>>>>> <mailto:harlydavidsen=gmail.com@groups.io
>>>>>>>>>>>>>> <mailto:harlydavidsen=gmail.com@groups.io>>
>>>>>>>>>>>>>> <mailto:harlydavidsen=gmail.com@groups.io
>>>>>>>>>>>>>> <mailto:harlydavidsen=gmail.com@groups.io>
>>>>>>>>>>>>>> <mailto:harlydavidsen=gmail.com@groups.io
>>>>>>>>>>>>>> <mailto:harlydavidsen=gmail.com@groups.io>>>
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io <mailto:gmail.com@groups.io>
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io <mailto:gmail.com@groups.io>>
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io <mailto:gmail.com@groups.io>
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io <mailto:gmail.com@groups.io>>>>
>>>>>>>>>>>>>> <mailto:harlydavidsen
>>>>>>>>>>>>>> <mailto:harlydavidsen>=gmail.com@groups.io
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io>
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io <mailto:gmail.com@groups.io>>
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io <mailto:gmail.com@groups.io>
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io <mailto:gmail.com@groups.io>>>
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io <mailto:gmail.com@groups.io>
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io <mailto:gmail.com@groups.io>>
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io <mailto:gmail.com@groups.io>
>>>>>>>>>>>>>> <mailto:gmail.com@groups.io <mailto: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
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>>>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>>>>
>>>>>>>>>>>>>>     <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>>>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com>
>>>>>>>>>>>>>> <mailto:rafaelrodrigues.machado@gmail.com
>>>>>>>>>>>>>> <mailto: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
>>>>>>>>>>>>>> <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
>>>>>>>>>>>>>> <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
>>>>>>>>>>>>>> <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
>>>>>>>>>>>>>> <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@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com>
>>>>>>>>>>>>>> <mailto:harlydavidsen@gmail.com
>>>>>>>>>>>>>> <mailto: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
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> --
>>>>>>>>>>>> Signed,
>>>>>>>>>>>> Ethin D. Probst
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> Signed,
>>>>>>>>>> Ethin D. Probst
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Signed,
>>>>>>>> Ethin D. Probst
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Signed,
>>>>>>> Ethin D. Probst
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Signed,
>>>>> Ethin D. Probst
>>>>>
>>>>>
>>>>> 
>>>
>>>
>>
>>
>> --
>> Signed,
>> Ethin D. Probst
>
>


-- 
Signed,
Ethin D. Probst