Python Python interpreter

This guide explains how to run Python on NuttX.

Yes, you heard it right. Python on NuttX. This is a port of the CPython repository for NuttX. The CPython repository is the reference implementation of the Python programming language. It is written in C and is the most widely used Python interpreter.

Warning

Python for NuttX is still in the experimental stage (thus, it requires CONFIG_EXPERIMENTAL to be enabled) It is not fully functional for all the architectures and configurations. Please check this issue in the nuttx-apps repository to know the current status.

How Does it Work?

1. Python for NuttX target initially the rv-virt (RISC-V QEMU) board.

2. Python modules are stored in pyc (byte-code format) and are loaded from a ROMFS image at startup.

3. Environment variables like PYTHONHOME and PYTHON_BASIC_REPL need to be set accordingly.

Building Python NuttX

Use the rv-virt:python config to build Python for NuttX. Note that the CMake scripts don’t work for this configuration. For now, please use the makefile build instead:

$ cd nuttx
$ make distclean
$ ./tools/configure.sh rv-virt:python
$ make -j$(nproc)
$ ls -l nuttx

This will generate a nutxx binary. This file can be run using the RISC-V QEMU.

Try Python in NSH

Before running the RISC-V QEMU, create a raw disk image with the following command:

$ dd if=/dev/zero of=./mydisk-1gb.img bs=1M count=1024

Then, run RISC-V QEMU with the following command:

$ qemu-system-riscv32 -semihosting -M virt,aclint=on -cpu rv32 -smp 8 \
   -global virtio-mmio.force-legacy=false \
   -device virtio-serial-device,bus=virtio-mmio-bus.0 \
   -chardev socket,telnet=on,host=127.0.0.1,port=3450,server=on,wait=off,id=foo \
   -device virtconsole,chardev=foo \
   -device virtio-rng-device,bus=virtio-mmio-bus.1 \
   -netdev user,id=u1,hostfwd=tcp:127.0.0.1:10023-10.0.2.15:23,hostfwd=tcp:127.0.0.1:15001-10.0.2.15:5001 \
   -device virtio-net-device,netdev=u1,bus=virtio-mmio-bus.2 \
   -drive file=./mydisk-1gb.img,if=none,format=raw,id=hd \
   -device virtio-blk-device,bus=virtio-mmio-bus.3,drive=hd \
   -bios none -kernel ./nuttx -nographic

ABC[    0.062131] board_userled: LED 1 set to 0
[    0.063269] board_userled: LED 2 set to 0
[    0.063367] board_userled: LED 3 set to 0
telnetd [4:100]

NuttShell (NSH) NuttX-10.4.0
nsh> python_mount_modules
Mounting ROMFS filesystem at target=/usr/local/lib/ with source=/dev/ram1
nsh> export PYTHONHOME /usr/local
nsh> export PYTHON_BASIC_REPL 1
nsh> python
Python 3.13.0 (main, Dec  4 2024, 17:00:42) [GCC 13.2.0] on nuttx
Type "help", "copyright", "credits" or "license" for more information.
>>>

Demo

Check the following asciinema demo to see how to run Python on NuttX. You can copy and paste the commands from the demo to try it yourself.