After a bit of messing around, I managed to get Squeak
ported to DirectFB so I could run it on my SL-5500 without
X. The code is at:
  http://tunes.org/~eihrul/sqUnixDirectFB.c

It's not entirely polished yet (mainly I can't get alpha blended
blitting for the software cursor to work), but otherwise mostly
works. Just remove sqUnixMozilla.c, sqXWindow.c and friends, and
replace with sqUnixDirectFB.c. I also have a touchscreen driver
for DirectFB for the SL-5500 if anyone is interested. The DirectFB
port also supports rotating the display a quarter turn for LCDs
and the like that display side-ways.

  Lee