disrvptor / xinu

Xinu ("Xinu Is Not Unix", a recursive acronym) is a Unix-like operating system originally developed by Douglas Comer for instructional purposes at Purdue University in the 1980s. The name is both recursive, and is "Unix" spelled backwards.

xinu

Xinu ("Xinu Is Not Unix", a recursive acronym) is a Unix-like operating system originally developed by Douglas Comer for instructional purposes at Purdue University in the 1980s. The name is both recursive, and is "Unix" spelled backwards.

Overview

This repository is a download of the original x86 archive from The XINU Page at http://www.xinu.cs.purdue.edu. The plan is to

1. Enhance this codebase with a more standard build system
2. Provide instructions on setting up a cross compiler
3. Provide instructions on how to run XINU under a system like Bochs or QEMU

Description

This directory contains a modifiction of the Linksys code that has been ported to the x86 and a 3com Ethernet driver added. In this version, the interrupt mechanism has been replaced by one that uses the Interrupt Flag in the processor FLAGS register (i.e., the bit set with cli/sti). It still maintains a global interrupt mask for the controller that specifies which devices are allowed to interrupt, but it only sets the interrupt mask when a new interrupt handler is added (e.g., at device initialization time).

The Ethernet driver includes multicast, but it is not yet integrated with ethControl (i.e., one has to call eth_mcadd separately.