Codec

[Peter Stuge]

On Thu, Apr 10, 2003 at 05:39:34AM +0000, Devi Priya wrote:
> Hello,
>     I have been assigned the job of writing BIOS. My device is based upon 
> SC1200 chip(National) and it has external devices like ethernet, Audio 
> codec LM4550. My device has linux OS.I need a driver for my LM4550. So I 
> need to know where I shall get this driver either the source or an exe?

Hi.

The SCx2xx series have this feature where binary-only code gets executed in
SMM (System Management Mode) when you (or kernel drivers) access certain
addresses.  It's called VSA, Virtual System Architecture.  There's also VSA2
which adds something.

NSC supplies some binary VSMs (Virtual System Modules) with their royalty
free BIOS kit BLDT (BootLoader Development Toolkit), aka XpressLOADER.
Among others, there are VSMs for enabling audio and video.

LinuxBIOS does not currently implement VSA or VSA2.  I see no reason why it
couldn't, though, I even think it could be made as a separate ELF object
loaded in the same way the bare bones toolkit is, I seem to remember the
idea of being able to plug multiple ELF objects into the bootup sequence but
this still requires some twiddling, right?

NSC offers documentation on VSA/VSA2 but I'm not sure about availability..

NSC also offer a Linux audio driver for the SCx2xx family but this driver
requires the XpressAUDIO VSM to work.


//Peter