I am writing EFI driver for some SCSI card. The basic functionalities of the driver work well. I say so because the exact same card / EFI driver have been tested on Mac Pro, born with a pure EFI environment. Mac Pro can boot up flawlessly from the volume on the SCSI card, right into the OS X.
As to the PC part its not the same story.
1. I test my EFI driver on Intel server board S5000SPL, which has an EFI shell available. If I flash the EFI driver into the option ROM of the adapter and boot the system up, somehow my EFI driver seems won't load. Nevertheless if I load my driver from within the EFI shell with "load", or even "loadpcirom" commands, my driver gets loaded and works fine. Don't know why the driver is not recognized by system BIOS if burned into the flash ROM. The interesting part is: this problem didn't exist with older version of S5000SPL BIOS(not sure which version though :-\)!
2. I try another Intel DT board D975XBX2, which by default has no interactive EFI shell available. This time my EFI drvier gets loaded when the system boots up. That can be seen from the debug messages shown on the screen by the EFI driver. After that Intel splash screen shows up. Then legacy BIOS'es continue to load if there are any(like Marvell BIOS). But after that system just hangs with blinking cursor. However, if I replace my EFI driver with legacy version(INT 13 counterpart, which is mature enough), the system does boot up smoothly. So is there any one out there with any kind of experience of 3rd party EFI driver(would be best if its storage related)?
Sorry if these problems are a bit too technical. But I might be lucky enough that someone(Intel guys?
) happens to be familiar with these issues!