punxa 2025.1

Python-based RISC-V Full System Simulator.

punxa

Python-based RISC-V Full System Simulator.

Punxa provides HDL models of different parts of a full RISC-V system designed in different design styles using py4hw.

For the processor, we currently support two 64-bit models :

• Behavioral Model of a single-cycle execution processor without pipeline
• Microprogrammed structural design with an algorithmic Control Unit implementation

The single-cycle version suppports full system simulation and proxy-kernel simulation (as in Spike). We also introduce a Linux proxy-kernel to simulate applications compiled with riscv64-unknown-linux-gnu-gcc.

We also support two 32-bit models:

• Behavioral Model of a single-cycle execution processor without pipeline
• Microprogrammed structural design with an algorithmic Control Unit implementation

Testing

We started focussing on RV64 and Baremetal applications (compiled with risc64-unknown-elf-gcc). Then, we moved to RV32. When completed, next goal is Linux boot.

RISC-V ISA Tests

RV64 ISA tests progress:

Version	Progress
Single Cycle	99.7 % |█████████████████████████████████████████████|
Microprogrammed	30.1 % |██████████████░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░|

RV32 ISA tests progress:

Version	Progress
Single Cycle	99.6 % |█████████████████████████████████████████████|
Microprogrammed	53.8 % |█████████████████████████░░░░░░░░░░░░░░░░░░░░|

check riscv-tests for a complete list

Proxy-kernel Apps

• Hello World
• Mandelbrot
• File sort
• Paranoia

Publications

Cite as

@INPROCEEDINGS{castells2024educational,
  author={Castells-Rufas, David and Novo, David and Martorell, Xavier},
  booktitle={2024 39th Conference on Design of Circuits and Integrated Systems (DCIS)}, 
  title={An Educational Tool to Analyze the Hardware/Software Integration in RISC-V Systems}, 
  year={2024},
  pages={1-6},
  doi={10.1109/DCIS62603.2024.10769201}}