Re: alsa on non-linux

[Patrick Welche <prlw1@cam.ac.uk>]

On Tue, Jan 14, 2014 at 03:04:58PM +0100, Clemens Ladisch wrote:
> Patrick Welche wrote:
> > I started out, writing the attached patch in November, but then it looked
> > as though the boundaries of application library interface and linux sound
> > chip driver had become so blurred that I thought that a decision had been
> > taken to bin all OSes bar linux, hence the question. Can you give me a
> > hint on how you think it is supposed to work?
> 
> Only the "hw" plugins access the Linux kernel drivers.  Anything else
> should be portable (with the exception of plugins like "dmix" that
> require a "hw" plugin as their slave).
> 
> For most device types (hwdep/seq/rawmidi/timer), the hw plugin is the
> only implementation, so a portable alsa-lib has only control and pcm
> devices at the moment.

So, rephrasing for the novice that I am, e.g., include/local.h contains

#include <endian.h>
...
#if __BYTE_ORDER == __LITTLE_ENDIAN
...
#include <linux/types.h>
#include <linux/ioctl.h>

which are portability headaches. local.h is included by

src/alisp/alisp.c:#include "local.h"
src/conf.c:#include "local.h"
src/confmisc.c:#include "local.h"
src/control/control_local.h:#include "local.h"
src/control/namehint.c:#include "local.h"
src/control/setup.c:#include "local.h"
src/dlmisc.c:#include "local.h"
src/error.c:#include "local.h"
src/hwdep/hwdep_local.h:#include "local.h"
src/input.c:#include "local.h"
src/mixer/mixer_local.h:#include "local.h"
src/names.c:#include "local.h"
src/output.c:#include "local.h"
src/pcm/pcm_local.h:#include "local.h"
src/rawmidi/rawmidi_local.h:#include "local.h"
src/seq/seq_event.c:#include "local.h"
src/seq/seq_local.h:#include "local.h"
src/seq/seq_midi_event.c:#include "local.h"
src/seq/seq_old.c:#include "local.h"
src/socket.c:#include "local.h"
src/timer/timer_local.h:#include "local.h"
src/ucm/ucm_local.h:#include "local.h"

That is fine except for files under directories src/control and src/pcm
which ought to be portable? Or is it stronger, and everything should be
portable except files under directory src/hwdep?

Cheers,

Patrick