This is my first public wiki, so please have some indulgence.
I have just updated my nslu2 (slug) to a fat-slug (128M "piggybacked")
I'm running Debian on a nslu2, and the boot order is:
Redboot --> APEX --> Debian.
Before I started this little project, I did have version 1.4.15 of APEX installed. Version 1.4.15 of APEX didn't support the two commands 'sdram-init' and 'memscan' so I hade to upgrade my APEX bootloader.
After the upgrade (as I'll describe soon) I'm running version 1.5.6 that supports the two commands that I needed.
Now, how and what did I do to upgrade my slug to a fat-slug?
First of all, I'm not a HW engineer, so I ask my collage to do the memory replacement for me (you know, the soldering and all that).
Once I got the new bigger memory (128M) in place, I added a connectBlue OEMSPA331i Bluetooth module (just because I like the idea of having a Bluetooth enabled slug, and I can leave it on for future use) to my slug so I could communicate with it via the RS232 interface. If you don't got access to a Bluetooth module, just add a serial cable to the slug (J2) instead. There is a howto guide for this http://www.nslu2-linux.org/wiki/HowTo/AddASerialPort.
Ok, how did I actually replaced my APEX boot loader.
After many hours of reading on the web, I ran in to this web site: http://www.nslu2-linux.org/wiki/Debian/CompileApex
All I did was, downloading the file "apex.flash" (at the end of the page). Copy "apex.flash" to your slug ($ scp apex.flash slug:/tmp, or upload it via ftp or whatever)
[Since the download is not working all the time it would be nice to get this file from www.nslu2-linux.org The link now points to my dynamic ip rather than the old static ip]
Then follow the instructions from "On the NSLU2 below here".
After I have completed all the steps below "On the NSLU2 below here" I did a reboot (but I'm not sure if that's necessary?)
I was recording the boot sequence with my terminal progam, so I could verify that the new APEX version was installed correctly.
Once Debian was booted and I had logged on, I run this command: apex-env setenv startup 'sdram-init; memscan -u 0+256m; copy -s $kernelsrc $bootaddr; copy -s $ramdisksrc $ramdiskaddr; wait 10 Type ^C to cancel autoboot.; boot'
You can then list and verify your APEX env, by executing 'apex-env'.
I believe that the apex-env command comes with the package apex-nslu2 or is it nslu2-utils?
If all seems fine, reboot and check your memory with the command 'free'.
To confirm that the additional RAM is working properly please run:
fatslug:~# memtest all
This will not work with a 128MB Slug since there is still Bug 7760 "Page Allocation Failure on ixp4xx (nslu2) with 128MB RAM"] Look: [http://bugzilla.kernel.org/show_bug.cgi?id=7760] Please check and report otherwise! (btw with 64MB enabled Slug it should!)