The Openslug OS on the Linksys NSLU2

Boris the Engineer home page

Warning: this page is now seriously out of date, the openslug revision I was using was replaced and I couldn't get on with the replacement (see Slug 2010) so I'm still running one Vanilla NSLU2 but no more openslug.

A beginner's guide written by a beginner. I intend to show the procedures and configurations that I have actually tried out, along with logfiles of what actually happened. I intend to demonstrate that the openslug firmware image is a viable replacement for the original linksys firmware even for the non-expert user.

• Firmware tools 
  Tools for replacing the original Linksys firmware with the openslug firmware.
• memory stick
  Notes on running from a USB flash drive instead of a hard drive.
• Busybox
  Notes on the standard commands provided by the busybox package.
• easy VI
  A few hints on editing text files.
• Packages
  Installing software on the Slug, e.g. a web server
• Miscellaneous
  More notes on commands you may use.
• Update Upgrade
  Notes on using the ipkg package manager.
• Error- killed
  Notes on an unhelpful error you may see when performing a demanding task.

Definitions:

SlugOS: An implementation of OpenEmbedded (Linux) for the NSLU2

uNSLUng: A modified version of the original Linksys firmware. Unslung adds usefull features like a shell and the "unsling" script to transfer operation to an external disk. uNSLUng is a "Big-Endian" system.

uNSLUng has a slightly irregular directory structure compared to newer Linux versions. It is also stuck with a version 2.4 kernel which cannot be updated.

OpenSLUG or SlugOS/BE: SlugOS compiled in Big-Endian mode. This appears to be the preferred SlugOS model.

DebianSLUG or SlugOS/LE: SlugOS compiled in Little-Endian mode. Since this version stores numbers the same way as a PC it may support some device drivers that don't compile properly on a B.E. system.

NSLU2/Debian: Debian Linux (not OpenEmbedded) on the NSLU2. As of December 2006 this looks a bit tricky but in time this may become the preferred option. As of 2008 it is becoming the preferred option, though licensing issues mean that the "Official" fully open-source version of the firmware cannot support the NSLU2's Ethernet port and a second "Unofficial" version of the firmware is available. 

Big-Endian: A way of expressing 16 bit or larger quantities as multiple 8 bit numbers where the most significant byte comes first.

Big-Endian is the representation used in most network protocols and therefore it is common in network appliances.

Little-Endian: A way of expressing 16 bit or larger quantities as multiple 8 bit numbers where the most significant byte comes last.

Little-Endian is the representation used in Intel processors and therefore it is common on desktop operating systems.

Due to a quirk of it's design the NSLU2 can be run either way so I am choosing to concentrate on Openslug (Big-endian).