Microcontrollers haven't really become 64-bit yet.
Also this project looks very PC-oriented in other ways (virtual memory management, VGA screen output, keyboard - all of them are PC and no microcontroller devices)
You might be better off starting with a different, more portable, project. As klibertp said, Forth is a possibility. I remember one guy writing a 'Forth bootstrapping framework' called BootForth [1] sometime in 2008, which unfortunately since disappeared off the net, but you may have luck inquiring for the sources.
Also this project looks very PC-oriented in other ways (virtual memory management, VGA screen output, keyboard - all of them are PC and no microcontroller devices)
You might be better off starting with a different, more portable, project. As klibertp said, Forth is a possibility. I remember one guy writing a 'Forth bootstrapping framework' called BootForth [1] sometime in 2008, which unfortunately since disappeared off the net, but you may have luck inquiring for the sources.
[1] http://compgroups.net/comp.lang.forth/forth-bootstrapping-fr...