Linux

News. in February 2005, less than two years after I bought it, the laptop described on this page died. The symptoms were:

• The fans seemed to start to produce a little bit more noise than they used to do.
• The machine switched itself of from time to time, seemingly from overheating (at least it was quite hot). This effect got worse and worse over the time until the machine was mostly unusable.
• One day it did not recognise it anymore when the power cord was plugged in. After the battery was emptied, the machine was of course no longer very useful.

This might be the problem discussed at the computer hardware forum.

Linux on an Apple Powerbook G4

This text describes the adventures I encountered while installing Linux on an Apple Powerbook G4 (15″ version, 1.67GHz). It seems that with Apple's numbering scheme the machine is a PowerBook5,6. If you have questions or additional hints, feel free to contact me.

The page was originally written in spring 2005, when the machine was new on the market. After a while I got bored by the many difficulties connected to running Linux on the machine and I switched to using MacOS X. Recently I reinstalled the current Debian/unstable distribution on the machine and was happy to notice that Linux support has significantly improved.

Profile of the Boot Process of a Debian System

Introduction

Some time ago, Ziga Mahkovec managed to create a nice graphical representation of the boot process of a Fedora Linux system. The aim of the exercise was find out where the system spends all the time during boot and ultimately to decrease start-up time. Since I liked the idea, I produced a similar (but less beautiful) plot describing the start-up of my Debian/unstable system. The result, a bit dated by now, is presented on this page.

Linux Hardware Support

This page and its sub-pages give information about Linux support for different pieces of computer hardware.

• The M-Audio Revolution 5.1 sound card.
• The Griffin iMic USB sound card.
• The ASUS A8V motherboard.
• Information about how to use Linux on a Apple Powerbook G4
• Information about how to use Linux on a Toshiba laptop

Using the ALSA Sound System

This page summarises things I learned while trying to understand and use the Advanced Linux Sound Architecture (ALSA) on my Debian GNU/Linux system. I would be happy to receive suggestions to improve or extend this web page.

Configuration

This section gives some help with ALSA configuration issues. In order to avoid complications, we avoid use of external programs in figuring things out.

Is ALSA present in your kernel?

Check for the presence of a /proc/asound/ directory. If the directory exists, you have ALSA support in your kernel.

Why does program xyz not recognise my sound card?

On current Linux systems there are several, partially conflicting ways to access the sound card: using ALSA (this is what we aim for here), using OSS (this is an older sound system, but still used by many programs), or by connecting to a sound daemon like esd or artsd (which in turn might use ALSA or OSS to connect to the system). Probably your program is trying to use the wrong method to play sound.

Programs using OSS can be used with ALSA by enabling the OSS compatibility layer of ALSA. You might need to load additional kernel modules to enable this. Check the file /dev/sndstat. If the file exists and can be read, you have the OSS compatibility layer enabled. It should list audio devices which correspond to the ALSA devices on your system.

Linux on Soekris net4521

Summary

The Soekris net4521 is a small computer with an i386 compatible CPU for use in embedded devices. It also makes a very nice toy! Linux support for the device is excellent.

Linux Kernel

• Linux kernel config file: config-2.6.22.5
  This is a near-minimal config file to support the net4521 hardware. This config file has all drivers compiled in instead of using modules. In addition to the drivers necessary for the board I selected support for a few PCMCIA wireless cards. Customise this for your own needs.
• Boot messages: dmesg-2.6.22.5
  These are the kernel boot messages obtained by booting a kernel image generated from the config given above.

References

• the Soekris net4521 product page
• the Soekris Wiki
• AMD's product page for the Elan SC520 processor
• hostapd

ASUS A8V Linux Support

The ASUS A8V is a motherboard for use with 939-pin AMD Athlon 64 processors. This page summarises the Linux support for the board. If you have questions or additional hints, feel free to contact me.

Summary

Linux support for the ASUS A8V mainboard is almost perfect. Only a few minor features are not accessible under Linux.

component	hardware identification	status
CPU	Socket 939	works perfectly
Memory	4x 184-pin DDR DIMM	works perfectly
SATA	VIA VT6420	works perfectly (RAID not tested)
IDE	VIA VT8237 UDMA133	works perfectly
Ethernet	Marvell 88E8001 10/100/1000Base-T	works perfectly
Sound	VIA8237 ALC850 AC97 codec	works sounds a bit cheap

Table 1. This table summarises the Linux support for the ASUS A8V motherboard.

Griffin iMic Linux Support

The Griffin iMic is a simple USB sound card. It is mostly used as an USB audio adapter for Apple computers which lack built-in sound support (for example the PowerBook G4 has no microphone input) but the iMic also works fine with other computers. This page summarises the Linux hardware support for the device. If you have questions or additional hints, feel free to contact me.

Summary

Linux support for the Griffin iMic is very good.

M-Audio Revolution 5.1 Linux Support

This page summarises the Linux hardware support for the M-Audio Revolution 5.1 sound card. If you have questions or additional hints, feel free to contact me.

Summary

The M-Audio Revolution 5.1 sound card is reasonably well supported under Linux with ALSA version 1.0.12 or newer. Support was poor with earlier ALSA versions.

Sound quality is very good and, if you do not need the headphone output (it does not yet work), the M-Audio Revolution 5.1 is a nice sound card for use under Linux.