HAUD(4)

NAME
haud - SGI Hollywood Audio Processor

SYNOPSIS
haud0 at hpc0 offset 0x180

DESCRIPTION
haud is the driver for the audio processor found on Iris Indigo machines (IP12, IP20). The same hardware is available on IP12 Personal Iris machines (4D/3x), with components split across the mainboard and the "Magnum Audio" option card. The processor apparently went by various other names such as "(Iris) Audio Processor" and "Hollywood DSP" in IRIX and the PROM.

The core of Hollywood Audio is a Motorola DSP 56001 processor, which sits in front of audio input and output circuitry and uses sgimips/hpc(4) to read and write 16-bit audio streams via circular buffers in main memory.

The haud driver requires DSP firmware to operate. No open source firmware exists, so this driver currently requires IRIX's proprietary hdsp.lod. haud attempts to load the firmware using firmload(9) when the audio device is first opened.

Because the firmware is proprietary and not licensed for distribution, it is not included with NetBSD. It must be pulled from an IRIX installation CD or from an installed IRIX filesystem, converted into a loadable binary, and placed in a firmload(9) directory as "haud/hdsp.bin".

FIRMWARE INSTALLATION
The following example pulls the IRIX hdsp.lod firmware from an install CD's EFS filesystem, converts it into a loadable binary blob with haudfw(1), and makes the blob available for loading by the kernel:
    cd /tmp
    svhlabel -w /dev/cd0
    mount /dev/cd0a /mnt
    undist -x -P usr/etc/audio/hdsp.lod /mnt/dist/dmedia_eoe.idb
    mkdir /libdata/firmware/haud
    haudfw usr/etc/audio/hdsp.lod /libdata/firmware/haud/hdsp.bin

In IRIX 6.5, the dmedia_eoe dist is found on the "Foundation 1" disc (SGI part number 812-0759-002). In IRIX 6.2 it is found on the first install CD (812-0469-001). In 5.3 it is on the one and only install CD.

In older IRIX releases, hdsp.lod may be in a different dist. For example, in 4.0.5H it is found in eoe1 instead of dmedia_eoe. So the above undist command would change to:
    undist -x -P usr/etc/audio/hdsp.lod /mnt/dist/eoe1.idb

SUPPORTED FIRMWARE
haud was developed with the following firmware:
    cksum -a md5 hdsp.lod
    MD5 (hdsp.lod) = 798b2bff0a0726e12afddd07273d5814

This version of the firmware was distributed with IRIX from at least version 5.3 up through 6.5. Older firmwares may also work but are untested.

SEE ALSO
sgimips/haudfw(1) sgimips/undist(1) sgimips/hpc(4) firmload(9)

HISTORY
The haud driver first appeared in NetBSD 12.0.

CAVEATS
Only basic playback is supported.

The driver relies on the MI audio(9) layer for mixing even though the DSP is capable of mixing multiple output streams automatically.