COREMU is a scalable and portable parallel full system emulator built on Qemu. Currently, COREMU
supports X86_64 and ARM (MPcore).
COREMU is able to boot 255 emulated cores running Linux on our testing machine which has only 4 physical
cores (Intel Core(TM)2 Quad CPU Q6600, with 2G memory).
What you need:
1. Patch Qemu source code
2. Download COREMU source code
3. Install libtopology (we used version 0.9). You can download it from:
Compile and install. (Run 'configure --help' for more options.)
cd <coremu source dir>
./configure --target=x86_64 --prefix=<install dir> <path to qemu source code>
You can now use COREMU to start a Linux system. We provide several scripts to do
this. Note that COREMU needs to be run as root, because we change thread
priority during the execution.
sudo ./x86_64-linux.sh <path to coremu> <path to image> <number of emulated cores>
sudo ./x86_64-linux.sh ../bin/bin/qemu-system-x86_64 debian.img 255
The system may take a while to start booting, please be patient.
We also provide two system images which can be used directly:
- x86_64 debian Linux image. Use root to login, no password is required.
There is a wordcount MapReduce program from Phoenix-2.0 benchmark under /root
- A ramdisk for ARM Linux based on the image provided by ARM Ltd.
IMPORTANT: COREMU rely on accurate nanosleep, so the host system's Linux kernel
must have the option ""High Resolution Timer" enabled.
You can check this by looking at the output of 'cat /proc/timer_list'. If the
resolution is 1 nsecs, it should be OK.
COREMU currently does not support Mac OS X. It should be easy to port it to run on
Mac OS X. We will provide such support soon.
We put COREMU in a separate directory and build it as library, because we want
a. Make modification to Qemu as little as possible
b. Abstract what need to be done to build a parallel emulator by using a
The Qemu source code we used are checked out from the official Qemu git
repository. Since the stable branch does not support Cortex A9 very well, we
started the development on the master branch. More specifically, we started from
the commit: 54d7cf136f040713095cbc064f62d753bff6f9d2
1. It would be better to use recent version of Linux kernel (e.g. 2.6.33) in order to
emulate more than 64 cores. (We encounter kernel crash using Linux 2.6.26
during the development.)
2. We modified seabios in order to start 255 cores. But you can't use
graphical interface using this bios.
3. We suggest not using qemu's graphic interface, it's much slower than serial
mode. (Please refer to the provided scripts.)
For more information, please visit our project web site.
You can also take a look at our research group, maybe you will be interested in
our other projects.
Feel free to contact us if you have any problem.