Welcome to the gem5-Aladdin SoC simulator!
This is a tool for end-to-end simulation of SoC workloads, including workloads with accelerated functions handled by fixed-function hardware blocks. With gem5-Aladdin, users can study the complex behaviors and interactions between general-purpose CPUs and hardware accelerators, including but not limited to cache coherency and memory consistency in heterogeneous platforms, data movement and communication, and shared resource contention, and how all these system-level effects impact overall application performance and speedup.
If you use gem5-Aladdin in your research, we would appreciate a citation to:
Co-Designing Accelerators and SoC Interfaces using gem5-Aladdin.
Yakun Sophia Shao, Sam (Likun) Xi, Vijayalakashmi Srinvisan, Gu-Yeon Wei, and David Brooks.
International Symposium on Microarchitecture (MICRO), June 2016.
PDF
To build gem5-Aladdin, you will need to satisfy the dependencies of three projects: gem5, Aladdin, and Xenon.
The main website can be found at http://www.gem5.org
A good starting point is http://www.gem5.org/Introduction, and for more information about building the simulator and getting started please see http://www.gem5.org/Documentation and http://www.gem5.org/Tutorials.
To build gem5, you will need the following software: g++ or clang, Python (gem5 links in the Python interpreter), SCons, SWIG, zlib, m4, and lastly protobuf if you want trace capture and playback support. Please see http://www.gem5.org/Dependencies for more details concerning the minimum versions of the aforementioned tools.
If you want gem5 to dump stats in SQLite databases for easy access, you
will also need the sqlalchemy
Python module.
The main Aladdin repository is here. Users are recommended to see Aladdin's README for detailed instructions on installing dependencies.
In short, Aladdin's dependencies are:
- Boost Graph Library 1.55.0+
- GCC 4.8.1 or newer (we use C++11 features).
- LLVM 3.4 and Clang 3.4, 64-bit
- LLVM-Tracer (link).
Xenon, the system we use for generating design sweep configurations, can be found here.
Xenon requires:
- Python 2.7.6+
- The pyparsing module
- Clone gem5-Aladdin.
git clone https://github.com/harvard-acc/gem5-aladdin
- Setup the Aladdin and Xenon submodules.
git submodule update --init --recursive
gem5 supports multiple architectures, but gem5-Aladdin currently only supports x86. ARM support is planned for a future release.
Type the following command to build the simulator:
scons build/X86/gem5.opt
This will build an optimized version of the gem5 binary (gem5.opt) for the
specified architecture. You do not need to build Aladdin separately, unless
you want to run Aladdin on its own. You can also replace gem5.opt
with
gem5.debug
to build a binary suitable for use with a debugger. See
http://www.gem5.org/Build_System for more details and options.
The basic source release includes these subdirectories:
- configs: example simulation configuration scripts
- ext: less-common external packages needed to build gem5
- src: source code of the gem5 simulator
- system: source for some optional system software for simulated systems
- tests: regression tests
- util: useful utility programs and files
gem5-Aladdin can be run in two ways: standalone and CPU.
In the standalone mode, there is no CPU in the system. gem5-Aladdin will simply
invoke Aladdin, but now you get access to the complete gem5 memory system
(where Aladdin alone supports private scratchpad memory only). In CPU mode,
gem5-Aladdin will execute a user-level binary, which may invoke an accelerator
after setting the necessary input data. gem5-Aladdin uses the num-cpus
command-line
parameter to distinguish between these two modes.
We have multiple integration tests that users can use as a starting point for
running the simulator. They are located in
gem5-aladdin/src/aladdin/integration-test
, with both standalone
and
with-cpu
options. To run any integration test, simply change into the
appropriate directory and execute the following command:
sh run.sh
If successful, the output of the simulator will be placed under the outputs
subdirectory, while the stdout
dump will be preserved in stdout.gz
.
For an example of how to write a program that invokes an Aladdin accelerator,
we recommend starting with the integration tests test_load_store
(which uses
caches only) and test_dma_load_store
(which uses DMA only). Both of these
tests prepare data on the CPU, transfer the data into the accelerator, and
expect the accelerator to modify the data in a particular way and write it into
the memory system.
gem5-Aladdin does not currently support full-system simulation.
Sam Xi: samxi@seas.harvard.edu
Sophia Shao: sshao@nvidia.com