HAL2

HAL2

[Ulf Carlsson]

Hi,

As you know IRIX uses an audio library to provide audio support for user
level applications. The implementation of my HAL2 driver will exist in
kernel space, and a user level library will provide higher level interface
to the applications (the same interface as libaudio.a in IRIX). Do we know
what the interface between libaudio.a and the Irix kernel looks like or am
I free to do what I want?

The code I've written so far is based upon this idea.

Is this the Right Thing to do it?

Is there any further information except audio.h and hal.h which I don't
have? 

- Ulf

Re: HAL2

[Alan Cox]

> level applications. The implementation of my HAL2 driver will exist in
> kernel space, and a user level library will provide higher level interface
> to the applications (the same interface as libaudio.a in IRIX). Do we know
> what the interface between libaudio.a and the Irix kernel looks like or am
> I free to do what I want?
> 
> The code I've written so far is based upon this idea.
> 
> Is this the Right Thing to do it?

Not IMHO, well not unless it also supports the sound ioctls that every
other Linux platform does as well. 

Re: HAL2

[Ulf Carlsson]

On Sun, 4 Oct 1998, Alan Cox wrote:

> > level applications. The implementation of my HAL2 driver will exist in
> > kernel space, and a user level library will provide higher level interface
> > to the applications (the same interface as libaudio.a in IRIX). Do we know
> > what the interface between libaudio.a and the Irix kernel looks like or am
> > I free to do what I want?
> > 
> > The code I've written so far is based upon this idea.
> > 
> > Is this the Right Thing to do it?
> 
> Not IMHO, well not unless it also supports the sound ioctls that every
> other Linux platform does as well. 

If you run Linux on a sparc, it provides access to an interface,
/dev/audio, similar to the one you find in Solaris (I don't have Solaris,
but the include file, asm-sparc/audioio.h tells me that it does). 

You just told me that you thought my way to do it was an incorrect way og
doing it, tell me how it should be done instead. 

- Ulf

Re: HAL2

[Alan Cox]

> If you run Linux on a sparc, it provides access to an interface,
> /dev/audio, similar to the one you find in Solaris (I don't have Solaris,
> but the include file, asm-sparc/audioio.h tells me that it does). 

Yes

> You just told me that you thought my way to do it was an incorrect way og
> doing it, tell me how it should be done instead. 

Supporting the Indy ioctls is fine. However like the sparc, ppc, m68k,
ix86, alpha and arm you need to support the common OSS API. I don't know
if supporting the OSS API is sufficient alone to write libaudio over since
I dont know a ton about the internals of the libaudio stuff on SGI's.

Basically though the OSS API is a common API across all the linux platforms.

Alan

Re: HAL2

[Alan Cox]

> If you run Linux on a sparc, it provides access to an interface,
> /dev/audio, similar to the one you find in Solaris (I don't have Solaris,
> but the include file, asm-sparc/audioio.h tells me that it does). 

Yes

> You just told me that you thought my way to do it was an incorrect way og
> doing it, tell me how it should be done instead. 

Supporting the Indy ioctls is fine. However like the sparc, ppc, m68k,
ix86, alpha and arm you need to support the common OSS API. I don't know
if supporting the OSS API is sufficient alone to write libaudio over since
I dont know a ton about the internals of the libaudio stuff on SGI's.

Basically though the OSS API is a common API across all the linux platforms.

Alan

Re: HAL2

[Alan Cox]

> level applications. The implementation of my HAL2 driver will exist in
> kernel space, and a user level library will provide higher level interface
> to the applications (the same interface as libaudio.a in IRIX). Do we know
> what the interface between libaudio.a and the Irix kernel looks like or am
> I free to do what I want?
> 
> The code I've written so far is based upon this idea.
> 
> Is this the Right Thing to do it?

Not IMHO, well not unless it also supports the sound ioctls that every
other Linux platform does as well. 

Re: HAL2

[Thomas Bogendoerfer]

On Sun, Oct 04, 1998 at 01:23:12PM +0200, Ulf Carlsson wrote:
> level applications. The implementation of my HAL2 driver will exist in
> kernel space, and a user level library will provide higher level interface
> to the applications (the same interface as libaudio.a in IRIX). Do we know
> what the interface between libaudio.a and the Irix kernel looks like or am
> I free to do what I want?

For IRIX compatibilty, we may want to implement the same interface as
IRIX has. But for Linux compatiblity we should have something, which fits
into the current Linux sound devices scheme. And as the Linux interface is 
available in source, I would go that way. And when you do the libaudio.a 
stuff based on the Linux sound devices, it will also be available for other 
Linux architectures.

Maybe it's even possible to get IRIX compatible sound, with a user level
only solution.

Thomas.

-- 
See, you not only have to be a good coder to create a system like Linux,
you have to be a sneaky bastard too ;-)
                   [Linus Torvalds in <4rikft$7g5@linux.cs.Helsinki.FI>]