Linux - CX5530 - Native mode audio driver
Release 1.0
May 10, 2000

Release Notes:

- Kernel used:  RedHat 2.2.14

Features:

- AC97 interface fully implemented
- Playback of Audio files in all formats
- Recording of Audio files in all formats

How to build:

- In order to use audio drivers under Linux, the OSS (Open sound system) modules have 
  to be installed.  

  How to install the OSS modules:

     1. Type: "cd /usr/src/linux"
     2. Type: "make menuconfig"
     3. Select "Sound" option
     4. Select "OSS Modules" option with an "*" (Press the SpaceBar)
     5. Save configuration and exit
     6. Type "make dep"
     7. Type "make bzImage".  This will make the new kernel image.
     8. Type "make modules"
     9. Type "make modules_install".  This install the modules on the system.
     10. Replace the system image on /boot with the bzImage that you generated
         That can be found at /usr/src/linux/arch/boot/i386/

  Compiling and installing the driver:
    
- Copy all the files to the same directory and type make
- To load the driver: insmod cx5530.o
- To remove the driver: rmmod cx5530

Testing:

- The driver was tested on a Centaurus board (revision 1 with rework up to G) 
  with a GXm 5.4 processor and 128 Mbytes of RAM. The BIOS used for this test 
  was an unreleased version based on XpressROM v2.1.5 with native mode audio 
  support. The operating system used for the validation was RedHat v6.1 with an 
  updated kernel v2.2.14 and the UDMA patch applied.

Results:

- The CX5530 Linux audio driver passed all of the tests. 
  The only anomaly noted was the occasional skipping of audio playback during 
  intensive background file copying.   This happens because of the way Linux 
  handles the interrupts on the system.  The other Audio drivers tested 
  (SoundBlaster, Maestro) showed the same problem. 
  The Linux audio driver v1.0 does not support SoundBlaster compatibility (For Video games).

Applications Tested:

Playback:

- sox (play)
- mpg123
- XMMS
- Kjukebox
- GMedia
- RealPlayer
 
Recording:

- sox (rec)
- Yarec
- Grecord



Mario Raposo
National Semiconductor Corp.
(858) 658-7382