picobello 👌🏻

picobello is an open-source research platform focusing on AI and Machine Learning acceleration.

picobello is developed as part of the PULP (Parallel Ultra-Low Power) project, a joint effort between ETH Zurich and the University of Bologna. picobello is also supported by the EUPilot project, under the name MLS.

🚧 Getting started (currently in early development)

Environment setup for IIS-members

For IIS-members, the environment can be set up by sourcing the iis-env.sh script:

source iis-env.sh

This will set up all environment variables, and install the virtual python environment, which is needed to generate the RTL and SW sources.

Environment setup for non-IIS members

For non-IIS members, there is some additional setup required to get the environment up and running.

Bender

The first requirement you need to install is bender. Check the installation page on how to set it up.

Virtual Python environment

You need to have a python>=3.11 installed, in order to create the virtual python environment:

make python-venv
source .venv/bin/activate

By default, it will use the python in your $PATH. If you want to use a specific python version, you can set the BASE_PYTHON environment variable accordingly.

Toolchains

Picobello requires two different toolchains at the moment:

• Snitch software tests require the Clang compiler extended with Snitch-specific instructions. There are some precompiled releases available on the PULP Platform LLVM Project fork that are ready to be downloaded and unzipped.
• Cheshire requires a 64-bit GCC toolchain that can be installed from the riscv-gnu-toolchain git following the Installation (Newlib) instructions.

Once LLVM and GCC are obtained, export a LLVM_BINROOT environment variable to the binary folder of the LLVM toolchain installation. Then, add the GCC binary folder to your $PATH:

export LLVM_BINROOT=/path/to/llvm/bin
export PATH=$PATH:/path/to/gcc/bin

Verible (Optional)

For automatic formatting of generated sources, install verible. By default, the Makefile will look for a verible-verilog-format in your path, but you can also set it explicitly with the VERIBLE_FMT environment variable. This dependency is optional for normal users, but it is required to contribute to the project, since the CI will use verible to check the formatting of the code. Once installed, you can format the SV code in this repository with:

make verible-fmt

RTL code generation

After setting up the environment, you can generate all the RTL code for Cheshire, FlooNoC, and Snitch by running:

make all

or more selectively:

make floo-hw-all
make chs-hw-all
make sn-hw-all

Compile software tests

To compile the software for Cheshire and the snitch cluster, you can run the following commands:

make sw

or more selectively:

make chs-sw-tests
make snrt-tests

Platform simulation

The Picobello simulation flow currently only supports Questasim. The make vsim-compile command will build the RTL code. Tests can be executed by setting all the required command-line variable for Cheshire, see the Cheshire Docs for more details. To run a simple Chehire helloworld in Picobello, do the following:

make vsim-run CHS_BINARY=sw/cheshire/tests/helloworld.spm.elf

To run an offloading example test for Snitch, do:

make vsim-run CHS_BINARY=sw/cheshire/tests/simple_offload.spm.elf SN_BINARY=sw/snitch/tests/build/simple.elf

Use the vsim-run-batch command to run tests in batch mode with RTL optimizations to reduce the Questasim runtime.

Additional help

Additionally, you can run the following command to get a list of all available commands:

make help

🔐 License

Unless specified otherwise in the respective file headers, all code checked into this repository is made available under a permissive license. All hardware sources are licensed under the Solderpad Hardware License 0.51 (see LICENSE), and all software sources are licensed under the Apache License 2.0.