Indeed, a strange one to pick. I'd even say that if portability isn't a concern, working with x86_64 assembly is quite pleasant. If you avoid the lure of premature optimization, and stick with either function oriented, or at least procedure oriented programming, without too many long jumps -- I think you could get on quite fine in assembly.
The biggest issue, might be one that (sadly too) many low-level languages share: with the move to UTF-8 as the only sane choice for text, there are no string/char datatypes any more. No reason one can't use procedures/functions to deal with strings in assembly, but it would require a bit more planning than in a language that have "native" UTF-8 support.
[ed: I think Kollibri OS proves both points: it's a working OS, but they've yet to port from 32bit to 64bit even though they upstream they forked from (Menuet OS) has a 64 bit version (that's not Free software/open source).
e12e|10 years ago
The biggest issue, might be one that (sadly too) many low-level languages share: with the move to UTF-8 as the only sane choice for text, there are no string/char datatypes any more. No reason one can't use procedures/functions to deal with strings in assembly, but it would require a bit more planning than in a language that have "native" UTF-8 support.
[ed: I think Kollibri OS proves both points: it's a working OS, but they've yet to port from 32bit to 64bit even though they upstream they forked from (Menuet OS) has a 64 bit version (that's not Free software/open source).
http://kolibrios.org/en/
Another "big" asm OS project is: https://github.com/ReturnInfinity/Pure64 ]