[Asterisk-Dev] Asterisk Hardware Platform - Intel x86 versus Intel RISC Xscale (ARM)

[Steve Kann]

On Nov 26, 2004, at 4:10 AM, Holger Schurig wrote:

>> [... alignment..]
> There is some iaxclient based Phone software for ARM based PDAs 
> available
> and they this alignment problem in the IAX protocol. Eventually a patch
> made it into iaxclient so that the assembly of the 32 bit long value 
> was
> done in user-space, not in kernel, which is quite faster.
>
> And because this was necessary in iaxclient, I think it will bite you 
> in
> Asterisk as well.

The same alignment issues occur on Solaris/Sparc, and there is an open 
bug in the tracker with patches for asterisk as well.

Many of the present codecs do use floating point, though (I believe the 
iLBC implementation included with asterisk does, for example), and that 
will bite you if you want to run on a non-FP platform.

For example, speex with floating point will not run in real-time for 
even one channel on a non-FP arm.  (There is a fixed-point compile-time 
option which does integer ops for all the time-critical parts).

-SteveK