I actually figured it out. flash the latest perc6i firmware on the perc6i it came with. Use the megafl.exe commands, not the update.bat.
We have a couple 12 bay C2100s we recently acquired. Unfortunately we cannot get it to work right. When we attempt to enter the raid configuration utility it says "dDm" and then hangs, we have to pull the plug to reset it. We tried it on all of them. We switched out the PERC 6i/r with another one and then it gives us a "direct drive mapping" error. The  firmware on the PERC 6i/r pre-installed doesn't exist anywhere.  We've never seen the message "dDm" before, so we don't know what to make of it.
Dell PowerEdge C2100 FS12-TY Unknown Expander, PERC 6i/r - error(?) dDm