House

Haskell User's Operating System and Environment

Note: Kenny Graunke has made available a a newer version of House, ported to GHC 6.8.2 (October 2008)

House is a demo of software written in Haskell, running in a standalone environment. It is a system than can serve as a platform for exploring various ideas relating to low-level and system-level programming in a high-level functional language. More details are available in our ICFP 2005 paper: A Principled Approach to Operating System Construction in Haskell.

House is based on

hOp (older version) by Sébastien Carlier and Jérémy Bobbio - a variant of the Haskell compiler GHC and its run-time system, adapted to produce code that can run in a standalone environment. This includes some device drivers implemented in Haskell, e.g. VGA text screen and PS2 keyboard support.
Gadgets - Rob Noble's window system and demo applications, originally implemented in Gadget Gofer, ported to Concurrent Haskell by us. A PhD thesis and a technical report by Rob Noble and Colin Runciman are available from York University.

To this, we have added

A PS2 mouse driver (Iavor Diatchki).
Simple graphics support, using VBE 2.0 and a variant of Grub to boot into graphics mode and get access to a linear frame buffer. Interestingly enough, we were able to implement the graphics primitives in Haskell, with decent performance, and our Haskell implementation for parsing, decompressing and rending GIF images was fast enough to let us use House to present our slides at ICFP 2005. (Thomas Hallgren).
Support for running binary executables in a separate address space (Andrew Tolmach). Page fault handlers and system call handlers are written in Haskell.
A driver for NE2000 compatible network cards (Iavor Diatchki). (This is the type of card emulated by QEMU.)
A driver for Intel PRO/100 network cards (Thomas Hallgren). (This is the type of card found in e.g. IBM Thinkpad laptops.)
A network protocol stack, with basic support for Ethernet, IPv4, ARP, DHCP, ICMP (ping), UDP, TFTP and TCP. (Iavor Diatchki and Thomas Hallgren).

There is also work in progress on implementing an L4 compatible microkernel based on this platform (Rebekah Leslie and Mark P Jones).

Files to download

The table below lists files available for download.

Bootable floppy images for testing house

These are 1.44MB floppy images that can be used for testing House. They can be booted in a PC emulator like QEMU (qemu -m 256 -fda hOp.flp), or if written to a real floppy disk (cp hOp.flp /dev/fd0), directly on your PC.

Source code

Get a source bundle if you want study the source code, or modify the source code and compile your own version of House. In addition to all the required source code, the bundle contains precompiled Linux binaries of GHC (tested under RH9, FC3, FC4 and Ubuntu 6.06), so that you can get started quickly, without first having to compile the hOp version of ghc-6.2 and its run-time system. To create a floppy image, you also need to install the genext2fs program. If your Linux distribution uses gcc >=4.0, you may need to change the CC=gcc line in the kernel/Makefile to use an older version of gcc (e.g. CC=gcc-3.4).

Source Bundle	Floppy Image	Notes
House-0.8.91.tar.bz2	House.flp	Ported to GHC 6.8.2. See Kenny Graunke's page on House.
House-0.8.tar.bz2 (26MB)	`hOp-0.8.flp`	Updated license info. Interrupt handling fixes.
House-0.7.tar.bz2 (26MB)	`hOp-0.7.flp`	August 2006 version. Bug fixes.
	`hOp-0.6.flp`	February 2006 version. Includes initial support for TCP and DHCP. Some changes to the interrupt handling.
	`hOp-0.5.flp`	Essentially the version that was demoed at ICFP 2005.
	`hOp-0.3.flp`	April 2005 version.
	`hOp-hw2004.flp`	Essentially the version that was demoed at the 2004 Haskell Workshop. It has some Gadget demos, and application binaries that can be run in a separate address space. See screendump-hw2004.png.
	`hOp-0.1.flp`	An early version with some Gadget demo applications. See screendump.png.

House Applications

The following applications are available in the House demo:

The demos that come with the Gadgets system: the Simple Counter, the Calculator, the Explode game, the Escher tile drawing program, the Multiple counter demo, the tree editor, and the Bristol stream merging demo. These are part of House kernel. For more info, see the Glasgow GUI Fest 1995 challenges.
A shell window in which a number of built-in commands can be run.
User-space binaries loaded as separate modules by Grub at boot time. Use the command ls in the shell window to get a list, and the command run module to run one.
User-space binaries loaded dynamically with TFTP over the network. Use the command tftp run host file to load and run one.