Finally some results!
There's a lot of posts on the Dell forum about how the latest BIOS (3B23) and BMC (1.84) can brick these DCS/Quanta C1100's. It looks like it's possible to recover from bad flashing, however. I was coming from BIOS 3A14 and BMC 0.29, so it was pretty old, and some reports said the server wouldn't update (or be bricked), but it worked.
BIOS: Downloaded the 3B23 from Dell's site and loaded it onto a DOS USB stick. Once booted from the DOS stick, navigate to the directory where the files are.
It's a good idea to backup your current BIOS by running
Code:
AFUDOS <mybiosname>.ROM /O
Then, to update the BIOS run
Code:
AFUDOS <ROM NAME>.ROM /P /B /K /X
This is the same command that the included F.BAT file runs, except with the /X switch added (which apparently overrides the ROM check). I got an additional message saying "CMOS layout difference between system rom and rom has detected. AFU recommend adding /c commands", but it was OK to proceed. The server restarted a few times, and the update was successful. I did not have to try this, but there apparently is a series of jumpers to set in order to recover from a bad BIOS flash (back to the backup hopefully made). The instructions are in this topic:
PowerEdge C1100 dead in the water... - Cloud - Forum - Cloud - Dell Community
I've been running a bunch of VMs (including napp-it AIO with an M1015 passed through), and the system seems stable with the latest BIOS.
BMC: This one's a little trickier, but the BMC seems hard to brick permanently at least. I followed the instructions in this post and the post following:
PowerEdge C1100 dead in the water... - Cloud - Forum - Cloud - Dell Community
In a hex editor, I opened the .bin file downloaded from Dell's site, deleted everything before 0x250 (the firmware apparently actually starts at 0x250 or 0x200 depending on version), and padded the end of the file with FF until the file size was exactly 16,777,216 bytes long. I used HxD, it made it very easy to pad the file to exactly 16,777,216. In the Dell download zip, the .bin file is in a different directory as the socflash utility, so after I edited it, I copied it to the /socflash/dosflash folder to be in the same folder as the socflash utility. I loaded everything onto a DOS USB again, booted, and navigated to /socflash/dosflash.
Once again, you should backup the current BMC by running
Code:
SOCFLASH of=<mybmcname>.bin
Then, to update the BMC, run
Code:
SOCFLASH cs=2 option=fc if=firm.bin
There is no need for the offset=0x200 (or 0x250) flag if you edited the file as above. I tried using the offset flag without editing the .bin, and it did not work. After socflash completes, the blue and orange BMC lights should be lit on the front. Wait 1 or 2 minutes. You will know if flashing was successful if the fans shut down and turn on just like turning on the server. The blue and orange lights will also turn off, and you should be able to access the BMC web interface immediately. If flashing was not successful, the blue and orange lights will remain lit, but you will still be booted to DOS, so you can reflash the old backup firmware immediately. If you turn off the server and the BMC was flashed incorrectly, the power button will not turn the server on. However, these instructions got me up and running again (the orange light was not blinking, but it's the same instructions):
Dell C1100: How to update BIOS and BMC to the latest version. - Cloud - Forum - Cloud - Dell Community
The only possible issue with the new BMCs is that randomly, in the dead of night when nothing is happening on the server, the fans will "pulse" to full speed and back down for ~10 minutes. The ambient temps are cool, and nothing's happening on the server, so I'm trying to work with the seller to see what's going on. This happened with the old original 0.29 BMC as well, so I'm not convinced it's the BMC only.
CAUTION: Again, there are several reports of people bricking these trying to update the BIOS and BMC. There may be differences even between the DCS/Quanta C1100s that prevent these steps from working. Proceed with caution!