apps/interpreters README file
=============================

This apps/ directory is set aside to hold interpreters that may be
incorporated into NuttX.

ficl
----

  This is DIY port of Ficl (the "Forth Inspired Command Language").  See
  http://ficl.sourceforge.net/.  It is a "DIY" port because the Ficl source
  is not in that directory, only an environment and instructions that will
  let you build Ficl under NuttX.  The rest is up to you.

micropython
-----------

  This is a port of a build environment for Micro Python:

    https://micropython.org/

  Configuration Options:

    CONFIG_INTERPRETERS_MICROPYTHON - Enables support for the Micro Python
      interpreter
    CONFIG_INTERPRETERS_MICROPYTHON_URL - URL where Micro Python can be
      downloaded. default "https://github.com/micropython/micropython/archive".
      There are more recent snapshots at https://micropython.org/download/
    CONFIG_INTERPRETERS_MICROPYTHON_VERSION - Version number. Default "1.3.8"
    CONFIG_INTERPRETERS_MICROPYTHON_APPNAME - Executable name.  Only needed
      if CONFIG_NSH_BUILTIN_APPS=y.  Default: "micropython"
    CONFIG_INTERPRETERS_MICROPYTHON_STACKSIZE - Interpreter stack size.  Only
      needed if CONFIG_NSH_BUILTIN_APPS=y.  Default: 2048
    CONFIG_INTERPRETERS_MICROPYTHON_PRIORITY - Interpreter priority.  Only
      needed if CONFIG_NSH_BUILTIN_APPS=y.  Default: 100
    CONFIG_INTERPRETERS_MICROPYTHON_PROGNAME - Program name.  Only needed
      if CONFIG_BUILD_KERNEL=y.  Default: "micropython"

  NOTE that Micro Python is not included in this directory.  Be default,
  it will be downloaded at build time from the github .  You can avoid
  this download by pre-installing Micro Python.  Before building, just
  download Micro Python from:

    https://micropython.org/download/
    https://github.com/micropython/micropython/releases

  Or clone from the GIT repository at:

    https://github.com/micropython/
    https://github.com/micropython/micropython

  The Micro Python should be provided as a tarbll name:

    apps/interpreters/micropython/v$(CONFIG_INTERPRETERS_MICROPYTHON_VERSION).tar.gz

  and the unpacked code should reside in directory at:

    apps/interpreters/micropython/micropython-$(CONFIG_INTERPRETERS_MICROPYTHON_VERSION)

  This port was contributed by Dave Marples using Micro Python circa
  1.3.8.  It may not be compatible with other versions.

  NOTES:

  1. Micro Python will not build on Windows with a Windows native toolchain
     due to use of POSIX paths in the Micro Python build system.  It should build
     correctly on Linux or under Cygwin with the NuttX buildroot tools.

  2. Micro Python will not run correctly on a 64-bit target (such as the NuttX
     simulation on a 64-bit platfform).  In that case it generates assertions
     like:

       OverflowError: long int not supported in this build

     This change to mpconfigport.h is a partial work-around but does not solve
     all issues:

       -#define MICROPY_LONGINT_IMPL           (MICROPY_LONGINT_IMPL_MPZ)
       +#define MICROPY_LONGINT_IMPL           (MICROPY_LONGINT_IMPL_LONGLONG)

     Someday it will probably be necessary to autogenerate the mpconfigport.h
     header file with the correct properties for the target system.\

  3. Can't fine alloca.h?  With GCC compilers you may be able replace the
     inclusion of alloca.h in mkconfigport.h with:

       #define alloca(a) __builtin_alloca(a)

  4. Micro Python needs the math library libm.a.  The math library built into
     NuttX is sufficient and that can be included with CONFIG_LIBM=y.  If you
     prefer a more highly tuned math library then refer to the discussion of
     math.h in the top-level nuttx/README.txt file.  Also refer to the
     discussions in the NuttX Yahoo! forum; people have found many creative
     way to link with the newlib math library, for example.

  5. See errors like this?

       error: unknown type name 'wint_t'

     You can't include the NuttX wchar.h header file where this is defined, but
     you can add this to the mpconfigport.h header file (if it is not already
     there):

       typedef int wint_t;

     Is the missing wint_t definition coming from alloca.h?  You can either
     (1) replace alloc(a) with the #define described above, or (2) move the
     typedef of wint_t to before the inclusion of alloca.h.

  6. Micro Python is released under the MIT license which is license-compatible
     with the NuttX 3-clause BSD license.  Here is the full text of the Micro
     Python LICENSE file as of 2015-01-14:

     The MIT License (MIT)

     Copyright (c) 2013, 2014 Damien P. George

     Permission is hereby granted, free of charge, to any person obtaining a copy
     of this software and associated documentation files (the "Software"), to deal
     in the Software without restriction, including without limitation the rights
     to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     copies of the Software, and to permit persons to whom the Software is
     furnished to do so, subject to the following conditions:

     The above copyright notice and this permission notice shall be included in
     all copies or substantial portions of the Software.

     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
     AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
     THE SOFTWARE.

minibasic
---------

  The Mini Basic implementation at apps/interpreters derives from version 1.0
  by Malcolm McLean, Leeds University, and was released under the Creative
  Commons Attibution license.  I am not legal expert, but this license
  appears to be compatible with the NuttX BSD license see:
  https://creativecommons.org/licenses/ .  I, however, cannot take
  responsibility for any actions that you might take based on my
  understanding.  Please use your own legal judgement.

pcode
-----

  At present, only the NuttX Pascal add-on is supported.  This NuttX add-on
  must be downloaded separately (or is available from the Nuttx Pascal GIT
  repository).

  This Pascal add-on must be installed into the NuttX apps/ directory.  After
  unpacking the Pascal add-on package, an installation script and README.txt
  instructions can be found at pascal/nuttx.

  INSTALL.sh -- The script that performs the operation.  Usage:

     ./INSTALL.sh [-16|-32] <install-dir>

      If you are using this standard NuttX apps/ package, the correct
      location for the <install-dir> is apps/interpreters.  That is
      where the examples and build logic will expect to find the pcode
      sub-directory.

    Example:

      ./INSTALL.sh -16 $PWD/../../../apps/interpreters

    After installation, the NuttX apps/interpresters directory will contain
    the following files

      pcode
      |-- Makefile
      |-- include
      |   `-- Common header files
      |-- libboff
      |   `-- Pascal object format (POFF) library
      `--insn
          |-- include
          |   `-- model-specific header files
          `-- prun
              `-- model-specific source files

  pashello

    There is a simple Pascal example at apps/examples/pashello.  This is the
    standard "Hello, World!" example written in Pascal and interpreted from
    Pascal P-Code at runtime.  To use this example, place the following in
    your defonfig file:

      CONFIG_EXAMPLES_PASHELLO=y
      CONFIG_INTERPRETERS_PCODE=y

prun

  This directory holds some simple, convenience functions to simplify and
  standardize the interaction with the P-Code library.
