OS-Winter-2006: BOS

Basic Operating System

Project Team

* Bernhard Danninger	(0 4 2 2 5 9 4)
* Clemens Krainer	(9 0 2 0 1 1 2)

Project Overview

Our goal was to implement a basic operating system that can boot on a real 32 Bit Intel Architecture (IA 32) PC hardware and to meet the course requirements. The operating system is required to include at least some form of concurrency support, memory management, device abstraction and file handling.

We have implemented a Basic Operating System (BOS) in C for the IA 32 PC platform based on the GeekOS framework. The BOS software contains the implementation of all six GeekOS projects including a user heap, but no access control lists.

Highlights of BOS

• loads and runs ELF executalbles
• virtual memory management with segmentation and paging
• two runtime switchable paging algorithms
• two runtime switchable scheduling algorithms
• single threaded user processes
• 2GB user process address space
• automatically growing user heap
• automatically growing user stack
• automatic ressource deallocation at process termination
• detection of null pointer references in kernel and user processes
• named semaphores
• message queues capable of handling multiple senders and multiple receivers
• high performance anonymous pipes
• high level device abstraction via a virtual file system layer
• low level device abstraction for block devices
• GosFS: a read and writeable file system up to 4GB disk space
• PFAT: a read only file system
• Access Control Lists in GosFS (not finished and not documented yet)

Downloads

Basic Operating System Technical Report:	Attach:bos-report.pdf	(2007-02-08)
Complete source code with documentation:	Attach:bos-1.0-src.tar.gz	(2007-02-09)
Presentation on 25 January 2007:	Attach:bos.pdf	(2007-02-08)