We need to be able to build WASM programs. This can be done by installing the ``wasi-sdk`` as shown in the `WAMR guide <https://wamr.gitbook.io/document/basics/getting-started/host_prerequsites>`_.
Make sure the installation is reachable via ``/opt/wasi-sdk`` on your host, as this is expected by the build script of the WASM hello world sample below.
Building NuttX
==============
We use the `sim/wamr` config to build WAMR with NuttX. Note that at this writing, the that CMake scripts don't work for this configuration. For now, please use the makefile build instead:
..code:: console
$ cd nuttx
$ tools/configure.sh sim/wamr
$ make -j4
$ ls -l nuttx
-rwxrwxr-x 1 yf yf 4176376 Jun 10 08:11 nuttx
This will generate a ``nutxx`` binary. Also a WASM sample is available in the folder ``apps/interpreters/wamr/wamr/product-mini/app-samples/hello-world`` folder. We build the sample as follows:
..code:: console
$ cd apps/interpreters/wamr/wamr/product-mini/app-samples/hello-world
$ ./build.sh
$ ls -l test.wasm
-rwxrwxr-x 1 yf yf 413 Jun 10 08:18 test.wasm
The ``test.wasm`` program should be accessible from NuttX later.
Try WAMR in NSH
===============
Copy the ``test.wasm`` to the folder where the ``nuttx`` program lives, then run ``./nuttx`` to kick off NuttX and run ``iwasm /data/test.wasm`` from NSH:
