[SeaBIOS] 64bit support in SeaBIOS

[Marc Marí]

Hello

I'm working on basic 64 bit support for SeaBIOS. The reason now is
because I want to test booting from an NVDIMM, which is mapped on the
region above 4G:
http://lists.gnu.org/archive/html/qemu-devel/2015-08/msg01774.html

But this feature will also add support for future memory devices that
may be added. Below 4G region is getting too crowded. Another
possibility is to load Linux directly from 64 bits, instead of 16.

I'm now a bit lost on how to continue on this task. I'm not sure if I'm
in the right way, and I'm not sure if I'm overworking things.

You can see my little progress here:
https://github.com/mark-mb/seabios_64/

Does anyone else want to engage in this project?

Thanks
Marc