I am using the EFI support to test a UEFI driver I wrote. I use the DEBUG macro to display status messages. When I connect the EFI VM's serial port to a file, I can see some debugging messages, but not the output from my driver. Thinking that the debug mask might not be set right, I tried to locate EFI_DEBUG_MASK_PROTOCOL, and I get EFI_NOTFOUND. I did the same on a DUET bootable USB key, and I can use that protocol to select what messages go out the serial port.
Is there another easy way to control what debug messages are sent through the serial port? I'd think that anyone using VirtualBox's EFI support for driver testing would want to use the DEBUG macro, so that's something that should be in the EFI firmware.