There is rudimentary support for booting Barrelfish on the gem5 simulator.
This provides a platform for experimenting with OS/architecture co-design, and for experimenting with architectural support for aspects of Barrelfish (e.g., message passing). It is not intended as a general-purpose platform for experimenting with Barrelfish -- QEMU is typically much faster.
The only configuration that has been exercised is full-system x86 using the simple CPU model. Other x86 configurations may work (e.g., in-order CPU, out-of-order CPU, depending on the underlying implementation of these CPU models in gem5). I have used configurations both with and without Ruby. ARM configurations have not yet been tried.
To get started with Barrelfish on gem5:
1. Build a gem5 tree with x86 simple CPU. I will assume this produces a binary m5.fast, and that this is added to the path.
2. Build an x86_64 Barrelfish tree as usual.
3. In the build directory, run "make m5_kernel". This will construct a single kernel image file that combines the actual kernel along with the modules and a rudimentary boot-loader. The output file is called "m5_kernel". The file "menu.lst.m5" configures which modules are included, and what the physical memory layout of the simulated machine will be. Re-run "make m5_kernel" after changing "menu.lst.m5".
4. In the build directory, run "make m5". This will invoke m5.fast, passing it the m5_kernel and a simple machine configuration taken from "m5script.py".
NB: steps 2--4 can be combined by just running "make m5". I've listed them separately here to help troubleshooting if problems emerge.
In practice the file m5script.py (and m5.fast command line) will need to be tailored to the particular kind of system that you want to simulate. These examples are intended just to help with getting started.
Feel free to contact Tim Harris with any questions.