Hi Andrew.

As you have mentioned:

The EFI Firmware has some default boot options, but when an OS installs

it writes the NVRAM variables that point to OS loader on the EFI System
partition. Note the OS installer is the software that copied OS loader to
the EFI System partition so this is logical for the flow. The NVRAM entry
has a description and that is what gets displayed in a UI. So there could
be a matching NVRAM variable that points to a sound file generated. For
setup my thought was not to execute setup in the OS context, but to just
use it to have the OS generate the audio files and place them some place,
like the EFI System Partition, that the EFI HHI engine for setup could find
them. This is really a use the OS synthesizer strategy.
Answer: Got your point. Seems to be a possibility from my perspective.
Let's wait the feedback from more people here.
About the MP3 I also think we should use other option if available. Just to
avoid turbulence during the flight.

As you have mentioned:

I'm not a lawyer either and GPL 3 usage can be complex for some. It would

be possible to have a stand alone project that built the speech synthesizer
as a stand alone binary driver. Even if the GPL 3 license causes issues for
some a prototype of eSpeak ported to EFI would give us a size estimate and
let us develop an EFI speech synthesizer Protocol that we could publish in
the UEFI Spec.
Answer: This protocol would be really nice, and would make things easy.
There are some synthesizers that are BSD, so we could try them.

As you have mentioned:

I noticed an article @ the Intel Newsroom titled: "Stephen Hawking: Intel

Helped Give Him His Voice". So maybe our Intel friends may know of some
speech synthesizer options other than eSpeak?
Answer. Hope to hear some Intel voices at this discussion. Anxious to see
Intel's perspective. Just as a comment. I have already talked with the
Intel ACAT (Assistive Context-Aware Toolkit) team in the past, and after
this discussion they added the Portuguese language to ACAT (
https://github.com/intel/acat/tree/master/src/LanguagePacks/Portuguese).
They are really easy to access. So they can help us on some accessibility
questions we may have.

Just as a tip for everyone involved at this discussion. Since this thread
is interesting to blind people, it would be easier for them if everyone
follows something like this pattern if possible:

As PersonABC have mentioned at the previous e-mail:

Here does just the part of the e-mail that makes sense to be answered

Answer: Here is my answer or comment

With this blind people gets more located at the text, without the need to
hear the same e-mail contents several times.
Lets keep the discussion.

Thanks and Regards
Rafael R. Machado


Em qua, 25 de set de 2019 às 14:44, Andrew Fish <afish@...> escreveu:

On Sep 25, 2019, at 5:06 AM, Rafael Machado <
rafaelrodrigues.machado@...> wrote:

Hi Ethin.

The patent for MP3 expired a year or so ago, if memory serves. (I

don't know how long ago it expired but it definitely has expired, so
you don't need to worry about IP (I don't think).) An OS setup utility
would be nice if it weren't for the fact that it would prevent you
from modifying things like secure boot. Why can't we just either (1)
embed the audio files in NVRAM

Answer: Good point. But I think Andrew was thinking only on the boot
options, so the sound files would be generated by the OS, and not a OS
based solution that enables the BIOS settings to be changed. By the way, my
opinion is that the market would not like a OS solution that changes the
BIOS settings, due to security reasons.

Andrew
Is my understanding of your proposal correct?


Answer: The EFI Firmware has some default boot options, but when an OS
installs it writes the NVRAM variables that point to OS loader on the EFI
System partition. Note the OS installer is the software that copied OS
loader to the EFI System partition so this is logical for the flow. The
NVRAM entry has a description and that is what gets displayed in a UI. So
there could be a matching NVRAM variable that points to a sound file
generated. For setup my thought was not to execute setup in the OS context,
but to just use it to have the OS generate the audio files and place them
some place, like the EFI System Partition, that the EFI HHI engine for
setup could find them. This is really a use the OS synthesizer strategy.

Answer for MP3: Licensing is complicated, and the license for MP3 has been
bad for a long time so I did not want to assume it was OK. We need to ask
our Free Software friends to find out how OK it is to use, or how well it
would be supported.

or (2) embed a speech synthesizer

directly into the UEFI system (the synthesizer would not need to be
standardized, just easily embeddable) and then send PCM samples
directly to the HDA device using that synthesizer? ESpeak is one such
synthesizer; I don't know how we'd go about modifying it but given
enough time we could probably make it fit in the UEFI environment.

Answer: About porting eSpeak to UEFI, we need to check it's license first.
Considering the fact that it is GPL as presented below (from eSpeak 1.48.0
at https://sourceforge.net/projects/espeak/)






*" GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007 Copyright
(C) 2007 Free Software Foundation, Inc. <http://fsf.org/
<http://fsf.org/>> Everyone is permitted to copy and distribute verbatim
copies*
* of this license document, but changing it is not allowed. "*

I am not a lawyer and also have nothing against GPL and other licenses,
but would this mandate the BIOS vendors to open their BIOS code in case
they decide to use our eSpeak based synthesizer at their products?


Answer: I was thinking that a speech synthesizer would be too complicated
for EFI, but after talking to Santo I realized it might be possible if we
ported an old obsolete version. It might sound out of date but that is
probably the tradeoff we would need to make for not using a modern OS based
speech synthesizer.

I'm not a lawyer either and GPL 3 usage can be complex for some. It would
be possible to have a stand alone project that built the speech synthesizer
as a stand alone binary driver. Even if the GPL 3 license causes issues for
some a prototype of eSpeak ported to EFI would give us a size estimate and
let us develop an EFI speech synthesizer Protocol that we could publish in
the UEFI Spec.

I noticed an article @ the Intel Newsroom titled: "Stephen Hawking: Intel
Helped Give Him His Voice". So maybe our Intel friends may know of some
speech synthesizer options other than eSpeak?

Thanks,

Andrew Fish

My MSc's code was released as BSD to avoid this risk, but I am not sure it
this would be a real problem.

Thanks and Regards
Rafael R. Machado

Em qua, 25 de set de 2019 às 00:04, Ethin Probst <harlydavidsen@...>
escreveu:

The patent for MP3 expired a year or so ago, if memory serves. (I
don't know how long ago it expired but it definitely has expired, so
you don't need to worry about IP (I don't think).) An OS setup utility
would be nice if it weren't for the fact that it would prevent you
from modifying things like secure boot. Why can't we just either (1)
embed the audio files in NVRAM or (2) embed a speech synthesizer
directly into the UEFI system (the synthesizer would not need to be
standardized, just easily embeddable) and then send PCM samples
directly to the HDA device using that synthesizer? ESpeak is one such
synthesizer; I don't know how we'd go about modifying it but given
enough time we could probably make it fit in the UEFI environment.

On 9/24/19, Andrew Fish <afish@...> wrote:

On Sep 24, 2019, at 5:06 AM, Rafael Machado
<rafaelrodrigues.machado@...> wrote:

Hi Everyone

Answering Ethin:

If other platforms are PCI-based (i.e. allow us to scan the PCI bus
and figure out where (in MMIO space) the HDA controller is mapped

to),

then it (theoretically) sould work. I don't know for sure though;

I'm

not very knowledgeable in other CPU architectures

Answer: Neither do I. Lets wait some ARM expert to give some opinion :)

Rafael,

I'm not exactly the ARM expert, but what we have seen is as long as en

EFI

PCI driver follows the EFI rules for DMA it should work just fine on

all CPU

architectures. The historical problem is if you don't follow the rules

on

x86 DMA still works since the memory coherency is maintained by

hardware on

x86. Since the coherency requires software on ARM, you have to do it

right.

Answering Andrew

Did you do much research into CODECs? Like which one(s) should be
supported? I assume the CODEC implies the audio file formats that

can

be decoded? Also how large are the audio files?

Answer: During my research I have studied some codec specs, and the way
the codecs works is really similar. Normally they need to receive some
packets to initialize the nodes (node is the name of each internal
component of the codec), by receiving some commands (named verbs) that

are

defined at the HDASpec. For example the verb "power state" (0xF05) is
used to set the power state of each node on the codec, to really enable
the chip or put the chip to sleep.
The verbs can be found at this document

https://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/high-definition-audio-specification.pdf

<

https://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/high-definition-audio-specification.pdf

,

at page 216.
Not all verbs are standardized, for example the verb "Amplifier Gain

Mute"

(0xB--), each vendor can decide the command. In the case of the ASUS
system I have used, the codec is a Conexant CX20752
(https://www.datasheets360.com/pdf/7550682360275196829
<https://www.datasheets360.com/pdf/7550682360275196829>), and at the
datasheet we can see that the "Amplifier Gain Mute" verb is 0xB00 and
0xB20 (right and left channel in the case of a stereo stream) at page

33.

These verbs that are vendor defined creates the problems to think on a
generic solution.
About the second part of the question, the Codecs are independent, so

they

are only responsible to process signals that are passed to them in a
stream using a DMA buffer, or a command to change their behavior

(increase

/ decrease volume for example). So for the codec to process correctly

the

buffers managed by the audio controller, both need to be configured

with

the same stream format, something like 2 channel 8 bit depth for

example.

At the second video I send previously
(https://www.youtube.com/watch?v=6ED2BSc89-Y&feature=youtu.be
<https://www.youtube.com/watch?v=6ED2BSc89-Y&feature=youtu.be>) the
problem was that the controller was configured to manage a stream with

2

channel and 8 bits depth, but the codec was processing the data as 2
channel 16 bit depth.
About the audio files size, at my work I didn't use any compressed

format,

because I was running out of time to finish my project, so I was
processing raw audio data, that is much bigger than other formats like
MP3. In case we decide to use audio files at this first stage, maybe we
will need to port some audio format lib to UEFI also.

Thanks I tracked down a friend of mine who knows audio so I think I

grok it

better now. It seems HDA is a hardware standard. Seems like most of the

work

in an HDA driver is doing the setup to decode the data.

As far as a file format we might be able to use PCD, or as we know it a

wav

file. It might also be possible to use MP3, but there have been IP

issues in

the past encoding MP3 and I'm not sure how that will work out. The only
issue with WAV file is size, but we may be able to compress the WAV

files

with a decompressor that already lives in the ROM. Saving file space is
probably as simple as wrapping the file with a header that describes the
file type and encryption scheme.

Is the CODEC protocol more of a plug-in for the Intel HDA? By that I
mean it only works on that hardware, or does it work generically on

top

of any EFI_AUDIO_OUTPUT_PROTOCOL?

Answer: My understanding is that the CODEC protocol will need the audio
controller to be already configured, because the communication with the
codec is done using the addresses that are related to the AUDIO
controller. So the access to the AUDIO Codec is managed by the Audio
controller. We need to write the commands at the address that was
previously allocated and set as the CORB/RIRB (Command Output Ring

Buffer

/ Response Input Ring Buffer), and set at the HDA controller registers
(page 36 of the HDA Spec)

I was starting to think about how to store to audio and deal with
dynamic configuration. I guess one crazy idea could be to have the

OS

create the audio files using text to speech, and maybe store them on
the EFI System Partition. For example when an OS installs it is

going

to write the EFI Boot Variable that contains a Description of the

boot

option. Maybe we could convert that to audio and add a nvram

variable

that points to the given audio file?

Answer: This is one option. One question. How would the OS knows the

bios

options and menus so it could create these files?

The EFI Boot options are NVRAM based, so we could use NVRAM for that.

For

the HII (Setup) it may be possible to pass the data up to the OS and

then

have it encoded. We might be able to make it visible to EFI via writing

to

the disk on the EFI System Partition with an NVARM variable for any

extra

information we needed. I see to remember we talked about passing data

up to

the OS at one point so we could have an OS based setup utility. I don't
remember the details. Mike Rothman wrote the HII part of the spec so I

can

hit him up for ideas when we try to figure this out.

Thanks,

Andrew Fish

Thanks and Regards
Rafael


Em seg, 23 de set de 2019 às 12:11, Andrew Fish <afish@...
<mailto:afish@...>> escreveu:
Rafael,

Did you do much research into CODECs? Like which one(s) should be
supported? I assume th CODEC implies the audio file formats that can be
decoded? Also how large are the audio files?

Is the CODEC protocol more of a plug-in for the Intel HDA? By that I

mean

it only works on that hardware, or does it work generically on top of

any

EFI_AUDIO_OUTPUT_PROTOCOL?

I was starting to think about how to store to audio and deal with

dynamic

configuration. I guess one crazy idea could be to have the OS create

the

audio files using text to speech, and maybe store them on the EFI

System

Partition. For example when an OS installs it is going to write the EFI
Boot Variable that contains a Description of the boot option. Maybe we
could convert that to audio and add a nvram variable that points to the
given audio file?

Thanks,

Andrew Fish

On Sep 23, 2019, at 6:20 AM, Rafael Machado
<rafaelrodrigues.machado@...
<mailto:rafaelrodrigues.machado@...>> wrote:

Hi everyone.
So, based on everything was mentioned here.

The idea is to propose the creation of two protocols:

- EFI_AUDIO_OUTPUT_PROTOCOL: This protocol should be the responsible

for

initializing the audio controller, that in the case of my MSc work

does

initialization of the RING buffers, that are used as containers to the
audio streams that need to be processed.

- EFI_AUDIO_CODEC_PROTOCOL: This protocol should be responsible for
initializing the codec (each codec may need different init commands),

and

also is used to control things like mute, volume level and this kind

of

things. (can see the volume control actions at the last video I

mentioned

on the previous e-mail)

Does this approach works at non-x86 platforms? (I don't have

knowledge in

ARM platforms, so feedback from the community will be well received.)

Hope to hear some voices :)

Thanks and Regards
Rafael

Em sáb, 21 de set de 2019 às 09:36, Rafael Machado
<rafaelrodrigues.machado@...
<mailto:rafaelrodrigues.machado@...>> escreveu:
Hi Everyone
Sorry for the delay on the response, to many things happening at the

same

time.
I will try to answer e-mails to this thread every Saturday or Sunday
morning at least.
About Andrew's and Laszlo's comments and questions

Please let us know what you find out. I probably don''t have the

time

to help implement this feature, but I happy to help work on the
architecture and design for UEFI accessibility on the edk2 mailing
lists, and I >>can also represent what ever we come up with at the
UEFI Spec Work Group.

During my MSc I had to study a lot the audio and BIOS architectures.

The

idea was to eliminate the first barrier to the creation of a screen
reader for pre-OS environment, that was the lack of some open
implementation of audio control and actions at UEFI. To do that I

studied

the Intel High Definition Audio Spec and a lot of UEFI specs to
understand better how to do that.
The initial target was to do all this development at OVMF, but as far

as

I could get, the sound card is not available to OVMF. as Laszlo

mentioned

at this e-mail there are some projects that may help on this, but at

the

time I was working on my MSc I didn't find this, so I did everything

on a

real system (a ASUS notebook).
It took me 2 years of work, because I didn't know a lot of things and
working on a MSc degree at the same time having a 40hours/week job,

being

a father and a husband is not an easy task, but it got to what I was
expecting.
The evolution of the project was this:
1 - First tests using some registers named "Immediate Registers", that
later I noticed that are not mandatory. This is a simple C Major

scale:

https://www.youtube.com/watch?v=I-mgzcOnRCg&feature=youtu.be
<https://www.youtube.com/watch?v=I-mgzcOnRCg&feature=youtu.be>
2 - Some months later I started to work with the Ring Buffers and DMA
memory access. For the ones that have good years, it's possible to

listen

some music behing the noise.
https://www.youtube.com/watch?v=6ED2BSc89-Y&feature=youtu.be
<https://www.youtube.com/watch?v=6ED2BSc89-Y&feature=youtu.be>
3 - Later, wen I was almost giving up, I noticed that the problem was
that one of my write operations was causing some misunderstanding

between

the audio controller and the audio codec. The controller was sending
packets with 16bit depth, but the codec was processing them as 8bit
depth
https://www.youtube.com/watch?v=2De9dI9WbwM&feature=youtu.be
<https://www.youtube.com/watch?v=2De9dI9WbwM&feature=youtu.be>

So the conclusion is that doing this at UEFI us much easier that

doing at

the OS level.
The reference code, that is just a proof-of-concept, and that has

several

things to be improved, can be found here:
https://github.com/RafaelRMachado/Msc_UefiHda_PreOs_Accessibility
<https://github.com/RafaelRMachado/Msc_UefiHda_PreOs_Accessibility>

Currently it is just an UEFI Application, but we can convert this to

UEFI

drivers after some discussion. Everything is released as BDS so

companies

can use without IP problems.
Just to give some more information about the need of this kind of
solution. There is a lot of blind people that work with hardware

support,

so formatting disk, configuring RAID and booting dual-boot systems is
always a challenge to them. Even set the BIOS clock. How to do that
without the system's feedback?

It would be hard to have a UEFI mandate for accessibility, given

there

is no guideline on how a User Interface (UI) works. If

accessibility

requires some from of hardware abstraction, like audio, then we

could

likely get that into the UEFI Spec. What might be possible is an

EDK2 reference implementation of accessibility. Maybe we could use

the

reference implementation to write a UEFI white paper on design

for

accessibility? I there is an open source implementation, and an
official design guide this would make it much easier for advocacy
groups to lobby for this feature.

I agree this is the way. Writing a white paper as an official EDK2

papers

is one of my targets since the beginning of my MSc almost 5 years ago.

I've got some experience with accessibility as the macOS EFI OS

Loader

has a UI for the Full Disk Encryption password. If you press the

power

button quickly 3 times at the disk encryption password prompt

accessibility is enabled and Voice Over gets turned on. You then

get

localized voice prompts when you move between UI elements. Since

this

is the OS loader all the resources are stored on the disk. You

quickly run into a range of challenges since, audio is hard,

abstracting audio is hard (what codec does firmware have to

support),

Audio files are not small and firmware is size constrained, the

need

to localize >>the audio responses causes even more size issues, the
boot options are usually written by an OS installer so how would
firmware know what to call them?

The solution to this would be the porting of some voice synthesizer,

so

no audio files would need to be stored. There are some open-source
implementations that are not GPL.
This was described at my MSc as future works that can continue what I
have started.

I listed a lot of reasons it is hard but as Kennedy stated in his

"We

choose to go to the Moon!" speech sometimes we chose to do things
"not because they are easy, but because they are hard; because that

goal will serve to organize and measure the best of our energies

and

skills, because that challenge is one that we are willing to

accept".

If we have a design that means we can break the problem up into

smaller parts, and maybe we can find people that have expertise

in

that part to build a chunk at a time. If we could implement the
prototype in OVMF that would show how it works, but run on

everyone's

machines, so that would be really helpful for demos and design

review.

I totally agree. Amazing words that I didn't have heard yet. Thanks!
As far as I could understand, and with Leif's help, some possible

future

steps could be (not at this specific order):
- 1) Convert proof-of-concept HDA driver to UEFI driver model with
proper PCI discovery.
- 2) Design a prototype EFI_AUDIO_OUTPUT_PROTOCOL, rework driver to
produce this and application to discover and consume it.
- 3) Implement a USB Audio Class driver also producing
EFI_AUDIO_OUTPUT_PROTOCOL and ensure test application remains
functional.
- 4) Separate controller and codec code by creating an
EFI_AUDIO_CODEC_PROTOCOL, implement this in HDA driver, and separate

out

the codec support into individual drivers.
- 5) Prototype audio output additions to HII. (using pre-recorder
audio files)
- 6) Porting of some voice synthesizer to UEFI. (eliminating the

need

of audio files)

Beyond this, there are other things we should look at adding, like
- EFI_AUDIO_INPUT_PROTOCOL.
- Audio input additions to HII.

It's a lot of work, but I accept the challenge.
It may take a long time, but it is possible.

I am still trying to find some time to finish the translation of my
thesis to English.
I wrote everything in Portuguese because there was not material about
UEFI to the Brazilian audience, and another target I have is to show
companies that we have people that can work at this kind of projects

in

Brazil, bringing this kind of development to south america. (Yes, I

have

complicated target, but I like the challenge :) )

Thanks and Regards
Rafael R. Machado

Em qui, 19 de set de 2019 às 14:45, Laszlo Ersek <lersek@...
<mailto:lersek@...>> escreveu:
On 09/18/19 19:57, Andrew Fish wrote:

Rafael,

Please let us know what you find out. I probably don''t have the

time

to help implement this feature, but I happy to help work on the
architecture and design for UEFI accessibility on the edk2 mailing
lists, and I can also represent what ever we come up with at the

UEFI

Spec Work Group.

It would be hard to have a UEFI mandate for accessibility, given
there is no guideline on how a User Interface (UI) works. If
accessibility requires some from of hardware abstraction, like

audio,

then we could likely get that into the UEFI Spec. What might be
possible is an EDK2 reference implementation of accessibility. Maybe
we could use the reference implementation to write a UEFI white

paper

on design for accessibility? I there is an open source
implementation, and an official design guide this would make it much
easier for advocacy groups to lobby for this feature.

I've got some experience with accessibility as the macOS EFI OS
Loader has a UI for the Full Disk Encryption password. If you press
the power button quickly 3 times at the disk encryption password
prompt accessibility is enabled and Voice Over gets turned on. You
then get localized voice prompts when you move between UI elements.
Since this is the OS loader all the resources are stored on the

disk.

You quickly run into a range of challenges since, audio is hard,
abstracting audio is hard (what codec does firmware have to

support),

Audio files are not small and firmware is size constrained, the need
to localize the audio responses causes even more size issues, the
boot options are usually written by an OS installer so how would
firmware know what to call them?

I listed a lot of reasons it is hard but as Kennedy stated in his

"We

choose to go to the Moon!" speech sometimes we chose to do things
"not because they are easy, but because they are hard; because that
goal will serve to organize and measure the best of our energies and
skills, because that challenge is one that we are willing to

accept".

If we have a design that means we can break the problem up into
smaller parts, and maybe we can find people that have expertise in
that part to build a chunk at a time. If we could implement the
prototype in OVMF that would show how it works, but run on everyones
machines, so that would be really helpful for demos and design
review.

Somewhat related, in April there was a thread on virtio-dev that
suggests there is interest in a virtio-audio device model:

https://lists.oasis-open.org/archives/virtio-dev/201904/msg00049.html
<

https://lists.oasis-open.org/archives/virtio-dev/201904/msg00049.html>

It looks like the ACRN project already implements a (non-standard, as

of

now) virtio-audio device already:

https://lists.oasis-open.org/archives/virtio-dev/201907/msg00061.html
<

https://lists.oasis-open.org/archives/virtio-dev/201907/msg00061.html>

(This is all I can mention right now.)

Thanks
Laszlo

--
Signed,
Ethin D. Probst