Hi everyone,
Using the guides here, I successfully crossflashed my Fujitsu CP400i (LSI SAS3008/D3307) to IT mode (SAS9300-8i).
I can fully confirm what was mentioned earlier in this thread regarding the FreeDOS issues on modern server motherboards:
FreeDOS: Warning! IO base address high. Currently not supported.
When trying to run megarec3.exe -writesbr 0 sleyksbr.bin on my original Fujitsu server motherboard, the tool simply errored out or froze on -readsbr due to the UEFI memory mapping.
The Solution: Just like recommended, the only fix was to pull the card from the server and put it into a standard consumer PC. On the consumer motherboard, the FreeDOS tool executed instantly with a Success message.
Once the SBR was wiped in DOS on the desktop PC, I put it back into the server, and the sas3flash.efi -list command in the UEFI Shell recognized the card immediately. From there, the EFI flashing process went flawlessly.
If you are stuck in DOS with this error, don't waste time on BIOS settings—just swap the card into a regular desktop PC for the DOS step!
Hopefully this helps the next person. Have fun flashing!