This is a set of source files to allow you to develop your own custom
x86 PCI Expansion ROM images using only NASM and BSD Make.

This particular implementation contains code for an expansion ROM image
which prints 'Hello World' by making calls directly into the VGA BIOS.

Someone on the pci-sig list asked for this a long while ago, so I thought
I'd finally post one whilst learning.

NOTE: You need to checksum this in order for it to work. This means that
the total contents specified by the init_size have to be checksummed. I'll
produce a tool for checksumming these ROM images in place by setting the
very last byte to be the checksum. The algorithm is very simple, the 8-bit
sum of the ROM region must be zero (it's the same as for the PIR table).

I haven't been able to test this yet, as Bochs is needing a patch to load
arbitrary ROMs into the simulator. You could try fiddling with the
device/vendor IDs and flashing it to a spare network card's ROM, though.

Enjoy!
BMS