python: Add defconfig for RISC-V QEMU and Documentation entries for Python on NuttX

Documentation/applications/interpreters/python/index.rst

@@ -0,0 +1,62 @@
+=============================
+``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 <https://github.com/python/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 <https://github.com/apache/nuttx-apps/issues/2884>`_ in the `nuttx-apps <https://github.com/apache/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 <https://docs.python.org/3/glossary.html#term-bytecode>`_ (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:
+
+.. code:: console
+
+   $ 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
+=================
+
+.. code:: console
+
+   $ .qemu-system-riscv32 -semihosting -M virt,aclint=on -cpu rv32 -smp 1 -bios none -kernel nuttx -nographic
+
+   ABC
+   NuttShell (NSH) NuttX-10.4.0
+   nsh> 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 <https://asciinema.org/>`_ demo to see how to run Python on NuttX. You can copy and paste the commands from the demo to try it yourself.
+
+.. image:: https://asciinema.org/a/orkD8fKuahMEgQfBak9abliE4.svg
+   :target: https://asciinema.org/a/orkD8fKuahMEgQfBak9abliE4

Documentation/platforms/risc-v/qemu-rv/boards/rv-virt/index.rst

@@ -358,6 +358,14 @@ Configures the NuttShell (nsh) located at examples/nsh.  This NSH
 configuration is focused on low-level, command-line driver testing.
 This configuration is used for 32-bit RISC-V
 
+python
+------
+
+Enables the Python interpreter for NuttX. This configuration is based on `nsh`_.
+
+For more information on how to build and run Python on NuttX,
+please refer to the :doc:`Python Interpreter </applications/interpreters/python/index>` page.
+
 nsh64
 -----
 

boards/risc-v/qemu-rv/rv-virt/configs/python/defconfig

@@ -0,0 +1,88 @@
+#
+# This file is autogenerated: PLEASE DO NOT EDIT IT.
+#
+# You can use "make menuconfig" to make any modifications to the installed .config file.
+# You can then do "make savedefconfig" to generate a new defconfig file that includes your
+# modifications.
+#
+# CONFIG_DISABLE_OS_API is not set
+# CONFIG_NSH_DISABLE_LOSMART is not set
+CONFIG_16550_ADDRWIDTH=0
+CONFIG_16550_UART0=y
+CONFIG_16550_UART0_BASE=0x10000000
+CONFIG_16550_UART0_CLOCK=3686400
+CONFIG_16550_UART0_IRQ=37
+CONFIG_16550_UART0_SERIAL_CONSOLE=y
+CONFIG_16550_UART=y
+CONFIG_ARCH="risc-v"
+CONFIG_ARCH_BOARD="rv-virt"
+CONFIG_ARCH_BOARD_QEMU_RV_VIRT=y
+CONFIG_ARCH_CHIP="qemu-rv"
+CONFIG_ARCH_CHIP_QEMU_RV32=y
+CONFIG_ARCH_CHIP_QEMU_RV=y
+CONFIG_ARCH_CHIP_QEMU_RV_ISA_A=y
+CONFIG_ARCH_CHIP_QEMU_RV_ISA_C=y
+CONFIG_ARCH_CHIP_QEMU_RV_ISA_M=y
+CONFIG_ARCH_FLOAT_H=y
+CONFIG_ARCH_INTERRUPTSTACK=2048
+CONFIG_ARCH_RISCV=y
+CONFIG_ARCH_STACKDUMP=y
+CONFIG_BOARDCTL_POWEROFF=y
+CONFIG_BOARDCTL_ROMDISK=y
+CONFIG_BOARD_LOOPSPERMSEC=6366
+CONFIG_BUILTIN=y
+CONFIG_DEBUG_FEATURES=y
+CONFIG_DEBUG_FULLOPT=y
+CONFIG_DEBUG_SYMBOLS=y
+CONFIG_DEV_URANDOM=y
+CONFIG_DEV_ZERO=y
+CONFIG_ELF=y
+CONFIG_EVENT_FD=y
+CONFIG_EXAMPLES_HELLO=y
+CONFIG_EXPERIMENTAL=y
+CONFIG_FRAME_POINTER=y
+CONFIG_FS_HOSTFS=y
+CONFIG_FS_PROCFS=y
+CONFIG_FS_ROMFS=y
+CONFIG_FS_TMPFS=y
+CONFIG_IDLETHREAD_STACKSIZE=4096
+CONFIG_INIT_ENTRYPOINT="nsh_main"
+CONFIG_INIT_STACKSIZE=4096
+CONFIG_INTERPRETER_CPYTHON=y
+CONFIG_LIBC_ENVPATH=y
+CONFIG_LIBC_EXECFUNCS=y
+CONFIG_LIBC_LOCALE=y
+CONFIG_LIBC_LOCALE_GETTEXT=y
+CONFIG_LIBC_PERROR_STDOUT=y
+CONFIG_LIBC_STRERROR=y
+CONFIG_LIBM_NEWLIB=y
+CONFIG_LIB_SYSCALL=y
+CONFIG_LIB_ZLIB=y
+CONFIG_NFILE_DESCRIPTORS_PER_BLOCK=6
+CONFIG_NSH_ARCHINIT=y
+CONFIG_NSH_BUILTIN_APPS=y
+CONFIG_NSH_FILEIOSIZE=512
+CONFIG_NSH_LINELEN=300
+CONFIG_NSH_READLINE=y
+CONFIG_NSH_VARS=y
+CONFIG_PATH_INITIAL="/system/bin"
+CONFIG_PIPES=y
+CONFIG_PSEUDOFS_SOFTLINKS=y
+CONFIG_RAM_SIZE=33554432
+CONFIG_RAM_START=0x80000000
+CONFIG_READLINE_CMD_HISTORY=y
+CONFIG_RISCV_SEMIHOSTING_HOSTFS=y
+CONFIG_RR_INTERVAL=200
+CONFIG_SCHED_WAITPID=y
+CONFIG_SERIAL_UART_ARCH_MMIO=y
+CONFIG_STACK_COLORATION=y
+CONFIG_START_MONTH=12
+CONFIG_START_YEAR=2021
+CONFIG_SYMTAB_ORDEREDBYNAME=y
+CONFIG_SYSTEM_NSH=y
+CONFIG_TESTING_GETPRIME=y
+CONFIG_TESTING_OSTEST=y
+CONFIG_TIMER_FD=y
+CONFIG_TLS_NELEM=10
+CONFIG_TLS_TASK_NELEM=10
+CONFIG_USEC_PER_TICK=1000

tools/ci/testlist/risc-v-06.dat

@@ -1,6 +1,7 @@
 /risc-v/qemu-rv/rv-virt/configs/[d-z]*
 /risc-v/q[f-z]*
 /risc-v/[r-z]*
+-rv-virt:python
 
 # Boards build by CMake
 CMake,rv-virt:smp

tools/ci/testlist/risc-v-07.dat

@@ -0,0 +1 @@
+/risc-v/qemu-rv/rv-virt/configs/python