Topsy - A Teachable Operating System

Where is the source?

Here's the current source release: Topsy.tar.gz (compressed). Current source can be retrieved via cvs:

cvs -d :pserver:anonymous@drwho.ethz.ch:/usr/drwho/vault/cvs/topsy login (pw:anonymous)
cvs -d :pserver:anonymous@drwho.ethz.ch:/usr/drwho/vault/cvs/topsy checkout Topsy
cvs -d :pserver:anonymous@drwho.ethz.ch:/usr/drwho/vault/cvs/topsy checkout MipsSim

The source code itself is also available as hyperlinked HTML.

What do I need to run Topsy?

Topsy is a real system running on simulators or real hardware. To compile and run Topsy you'll need the following software and/or hardware:

Software tools: gcc, gas, gld, gsize, objcopy (all cross-mips), gmake, bash. If you compile gcc you need to build it for the MIPS code generating target by specifying the option '--target=mips-idt-ecoff'. The same applies to gdb and the binutils.

Platforms: Topsy runs currently on the following platforms:
- The IDT 7RS385 evaluation board with a 25MHz MIPS R3000 processor and 1MByte RAM (http://www.idt.com/risc/Welcome.html) we use in our students lab.
- An R3000 simulator written in Java that should run on top of any platform that supports Java (due to execution speed we recommend JITs like kaffe). The Simulator is not officially supported for the exercises!

A summary of architectures, ports and tools is given below:

arch	type	platform	simulator	tools
mips	R3000	IDT 7RS385 Eval Board	MipsSim (Java)	gcc, binutils
mips	R4000	-	SimOS	gcc, binutils
ia32	i386 or better	PC clones	Bochs, vmware	gcc, binutils
unix	solaris sparc	Solaris 2.5 or better		gcc, binutils
unix	linux i386	Linux 2.0 or better		gcc, binutils
m68k	CPU32	embedded systems	--	gcc, binutils

What's the license?

Topsy is copyrighted software and may be freely copied and distrbuted under GNU GPL.

Are there any other ports of Topsy?

See 'What do I need to run Topsy?' for available platforms. You should be able to port Topsy in a few weeks to a new platform since the system is strictly divided into a portable operating system part and a hardware abstraction layer (HAL). If you think of porting Topsy please contact Lukas Ruf for coordination.