interpreters/python: Add libffi package integration to enable Python's ctypes module

[tmedicci]

Summary

• interpreters/python: Add ctypes prototype patches for NuttX:

  • integrate NuttX-specific ctypes and posixmodule updates.

• system/libffi: Add libffi package integration:

  • Add Kconfig, build rules, and ignore entries required to build and package libffi as a standalone system component.

Impact

Impact on user: Allow users to import the ctypes module for Python on NuttX.

Impact on build: No.

Impact on hardware: No.

Impact on documentation: No.

Impact on security: No.

Impact on compatibility: No.

Testing

rv-virt:cpython can be used to test it.

Building

make -j distclean
./tools/configure.sh -S rv-virt:python
kconfig-tweak -e FS_TMPFS
kconfig-tweak --set-val FS_HEAPSIZE 2097152
kconfig-tweak --set-val RAM_SIZE 67108864
kconfig-tweak -e LIBC_DLFCN
kconfig-tweak -e LIB_LIBFFI
kconfig-tweak -e INTERPRETERS_CPYTHON_ENABLE_PIP
make olddefconfig
make -j$(nproc)

Running

After build, run it on the generic RISC-V QEMU:

qemu-system-riscv32 -semihosting -M virt,aclint=on -cpu rv32 -smp 8 -m 128 \
   -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

And, then, try to import ctypes on Python and check its output result to calculate the size of a C type.

Results

 nsh> python
[    2.710000] check_and_mount_romfs: Mounting ROMFS filesystem at target=/usr/local/lib with source=/dev/ram1
Python 3.13.0 (main, May 21 2026, 16:35:39) [GCC 14.2.0] on nuttx
Type "help", "copyright", "credits" or "license" for more information.
>>> import ctypes
>>> x = ctypes.sizeof(ctypes.c_longlong)
>>> x
8
>>>