I have an optiplex 790 with an LSI-9212-4i flashed to IR mode that is recconized in windows as "LSI 2008 Controller" as it should, but the BIOS cannot boot to it for whatever reason. When I flashed the IR BIOS file it flashed alright, but I still do not see any option to boot into it for config.
Am I missing some dell specific step to booting into the card?
In BIOS menu is Boot List Option set to Legacy or UEFI?
I think for the LSI controller's Boot Option ROM to be executed you'll need Legacy (aka CSM mode). Of course, if you're in UEFI and already have a boot drive (which must be formatted GPT since that's required to boot UEFI) and you switch to Legacy you won't be able to boot from it, since Legacy required a boot drive formatted MBR.
Ideally, for situations like this some BIOS menus support a UEFI + Legacy mode, but I don't think the OptiPlex 790 does.