Comment to ezhiks procedure:
Basically also worked for me on a D2607.A21 which I obtained with very old firmware from 2010, with the exception that I got the Mfg Page 2 error even with sas2hax and the A21-SBR, SBRempty etc. loaded. I had to use an old SBRIR.bin from an old Supermicro SAS2008 package to get the adapter to flash. Result was that I only got one port working. That was fixed when flashing the sbr-A21.bin on the end as described here. Puuh, was a very long process. BTW: I used the IR firmware.
The adapter is installed in a M5A99X EVO R2, and shall boot an Raid0 in UEFI/GPT mode. Do I need to flash the UEFI BSD too?
Thanks, rolfie