It makes sense technically, but I don't know if it is practical.

So the 5500 SD control chip is closed and useless, well do we even need it in the first place?

The Linksys WRT54g router has mmc support hacked in, and it has no special chip for that, just gpios http://kiel.kool.dk/

So what if the normal SL-5500 slot was used for this hack, and gpios were stolen from the SD chip? Maybe the power to that POS could even be cut off at the same time.

WRT SD/MMC hack is very speed limited - 200-300KB/s is all you can get.

The 5500 SD/MMC port is very speed limited, All I get is about 450kb, so making it a little bit slower isn't a big deal to me. I put the main programs that tend to not be so big on mmc, and then larger files like mp3 or video on CF.

Another (more zaurus-like) device with sd/mmc hacked in. Aeronix Zip-It wireless instant messenger.

Instructions - http://www.elinux.org/wiki/ZipItMMC
More ZipIt hacks - http://www.elinux.org/wiki/ZipitHardwareMods
Pretty pictures - http://va3uxb.dynip.com/zip_mmc.html
More pretty pictures - http://va3uxb.dynip.com/mmc_2.html

The last two links are served from a Zip-It, presumably from the mmc card (only 2MB flash built in).

Erm. . . Perhaps this is a stupid question. . .

Why do we need to bother rewiring it when the current chip works?

Just to make it GPL?

:/ Just seems kinda. . pointless. . .

Just to make it GPL on pure ideological grounds would seem pretty pointless. but the GPL is also practical.

A GPL driver would allow the use of the 2.6 kernel, which would have a lot of benefits, the biggest probably being battery life. Most people won't want to use 2.6 if it means giving up the SD slot.

It would also allow using MMC cards bigger than 1GB, they are getting pretty cheap these days and I would like to upgrade mine. It is a shame to have to stick with 1GB because of shortsighted programming in a binary only module, especially in linux.

I take it this only affects the 5500 then?

Poodle 2.6 still has SD. . .

Yes. The 5500 has a proprietary (made by sharp) SD controller chip with a binary only module. They refuse to release any info about it to the OE developers,