Python Operating System

[Diez B. Roggisch]

PythonUsr schrieb:
> Although I know for a fact that an Operating System can be written in
> Python, I need to ask some questions to the more advanced users of
> Python.
> 
> Uuu and Cleese are two operating systems that were / are written in
> Python. Does anyone use them? If so, how do they function / feel? Do
> they have a graphical mode and a command line mode, such as Linux does?
> 
> How hard would it be to write a full blown bootable operating system in
> Python? With a command line and a GUI in all? Would the books you see
> on the shelves at, say, Barnes and Noble, do the trick? Or do you need
> to dig deeper into the language than what is taught in the 1,000 page
> books?

There are limits to what Python can do as a language for OS development. 
For example, Python has no notion of pointers and thus makes
writing interrupt routines impossible, which are the base for nearly all 
lower level OS tasks like IO-drivers, memory virtualization and the like.

What these projects are more like is a bootable interpreter on a minimal 
OS kernel. At least in my book that doesn't count as an operating 
system, but here definitions might vary. Yet it certainly isn't a 
general purpose OS, as no binary interfaces to OS services are defined 
that would make calls from other languages into the OS possible.

In other words: IMHO, it is _not_ possible to write an OS in Python, at 
least not if OS is understood the way current OSses work. And even if 
the definition is stretched, there is a more than fair amount of work 
that needs to be done in other languages, most likely C - either because 
Pyhon isn't capable of doing them at all, or just not fast enough to do 
them proper.

Regarding the books to read: this kind of programming isn't so much 
about the details of python, albeit some of its inner workings like the 
GIL put up quite a few hurdles for the aspiring OS programmer, but of OS 
concepts and designs. Which is a field Andrew Tanenbaum has earned quite 
a few merits, so I guess his book could be a starter:

http://vig.prenhall.com/catalog/academic/product/0,1144,0131429388,00.html

Diez