[edk] option ROM debugging

[rangasai C <ran...@gm...>]

Hi all,
I am working on PCIe option ROM development. My driver works fine as long as
I load it from the shell. This mean, I can load from the shell and talk to
my drive. However, when I convert my driver (.efi file) into a .rom file
(using efirom.exe utility) and then flash my card with this image and reboot
my target system, I am seeing all kinds of issues (like no video, or video
comes and system reboots etc. ).. With some elementary debugging techniques
(since I can't use Prints at this stage), I could verify that the option ROM
image is shadowed properly but looks like there are some issues with the
initialization code. What I am missing is a good debugging environment, to
root cause the issue.
I don't have an ITP but from the spec, I read that I could use the DEBUG()
macro.
Could anybody explain how I could use this macro to output my debug prints
onto a COM port and see it in hyperterminal ?

My Target system is an Intel DG43GT motherboard. I tried connecting the 9pin
serial port header to my host system via a Null cable and USB to COM
connector but no luck. Also I don't see any option to do serial redirection.
When I type "sermode" in shell, it can't find any devices.
Is this motherboard a good test bench for option ROM development or should I
think of changing it.

Any pointers would be very helpful.

Thanks in advance.

Regards,
Sai Chaganty