I haven't pushed the package out to debian since we're frozen. Still, I thought you may be interested to know that there is a command to reconfigure SDRAM in APEX. The new command, sdram-init, will try different memory configurations until it has the right organization for the attached memory chips. I haven't been able to test with a four-chip configuration as I don't have such. I do have a 128MiB slug that the new command properly detects. Cheers.