Biscuit research OS

Biscuit research OS

Biscuit is a monolithic, POSIX-subset operating system kernel in Go for x86-64 CPUs. It was written to study the performance trade-offs of using a high-level language with garbage collection to implement a kernel with a common style of architecture. You can find research papers about Biscuit here: https://pdos.csail.mit.edu/projects/biscuit.html

Biscuit has some important features for getting good application performance:

• Multicore
• Kernel-supported threads
• Journaled FS with concurrent, deferred, and group commit
• Virtual memory for copy-on-write and lazily mapped anonymous/file pages
• TCP/IP stack
• AHCI SATA disk driver
• Intel 10Gb NIC driver

Biscuit also includes a bootloader, a partial libc (“litc”), and some user space programs, though we could have used GRUB or existing libc implementations, like musl.

This repo is a fork of the Go repo (https://github.com/golang/go). Nearly all of Biscuit’s code is in biscuit/.

Install

The root of the repository contains the Go 1.10.1 tools/runtime. Some of Biscuit’s code is modifications to the runtime, mostly in src/runtime/os_linux.go.

Biscuit used to build on Linux and OpenBSD, but probably only builds on Linux currently. You must build Biscuit’s modified Go runtime before building Biscuit:

$ git clone https://github.com/mit-pdos/biscuit.git
$ cd biscuit/src
$ ./make.bash

then go to Biscuit’s main part and launch it:

$ cd ../biscuit
$ make qemu CPUS=2

Biscuit should boot, then you can type a command:

# ls

Troubleshooting

• You need qemu-system-x86_64 and python2 in your environment. If your distribution does not name them that way, you have to fix the naming, path, etc.

• If the GOPATH environment variable doesn’t contain biscuit/, the build will fail with something like:

src/ahci/ahci.go:8:8: cannot find package "container/list" in any of:
...

Either unset GOPATH or set it explicitly, for example (assuming that your working directory is where the GNUMakefile is):

$ GOPATH=$(pwd) make qemu CPUS=2

Contributing

Please feel free to hack on Biscuit! We’re happy to accept contributions.