ULIX: Literate Unix
A diary documenting the implementation of ULIX-i386
Welcome to the ULIX blog.
Ulix (Literate Unix) is a Unix-like operating system developed at
University of Erlangen-Nürnberg.
I use D. E. Knuth's concept of
for the implementation and documentation. The goal was a fully working system which can be
used in operating system courses to show students how OS concepts (such as paging and scheduling)
can be implemented. Literate programs are very accessible because they can be read like a book;
the order of presentation is not enforced by program logic or compiler restrictions, but instead
is guided by the implementer's creative process.
Ulix is written in C and assembler for the Intel architecture. The literate programming
part is handled by noweb.
On this page I document my progress with the implementation.
|v0.04: Memory Allocation: Get Frame, Get Page, Update Page Tables (17.08.2011) |
OK, the memory system is slowly becoming useful. There's now a bitmap that keeps
track of used/free frames in RAM, and there's a function which requests a new
page (first getting a frame, then updating the page table and eventually creating
a new page table when the old one is full). Next up is some kind of kmalloc()...
Some other things I found out: It's sometimes helpful to use the graphical
debug frontend of Bochs. And: There's a free (LGPL-licensed), simple printf() implementation
(Georges Menie, 2002) which does not depend on the existence of any libraries:
all it needs is a way to put a single character on the console (and I have a
printf, by Georges Menie, http://www.menie.org/georges/embedded/
[ Path: | persistent link ]
Copyright © 2011-2015 Hans-Georg Eßer;
Server: Debian Linux, Apache Web Server,
blog page powered by blosxom :: the zen of blogging,
Theme: Hazard Area 1.6 (modified),
created by Bryan Bell,
Copyright © 2000-2006 Weblogger.com.