C6100 RAID driver for install

Hello - We're trying to reimage these devices on 2012 R2, but the installer will not recognize the mirrored RAID volume as installable. Presumably this is because there is no included driver in the Windows Server 2012 R2 install media, which is not uncommon for old hardware I suppose. So where can we grab the RAID driver in use by these machines to load into the installer? It does not appear available on Dell's site anywhere that we have found.

Thank you.