When built for Linux, libffi includes very bloated and workaround exec-alloc
implementation required to work around SELinux and other "sekuritee" features
which real people don't use. MicroPython has own alloc-exec implementation,
used to alloc memory for @micropython.native code. With this option enabled,
uPy's implementation will override libffi's. This saves 11K on x86_64 (and
that accounts for more than half of the libffi code size).
TODO: Possibly, we want to refactor this option to allow either use uPy's
implementation even for libffi, or allow to use libffi's implementation even
for uPy.
Native code has GC-heap pointers in it so it must be scanned. But on
unix port memory for native functions is mmap'd, and so it must have
explicit code to scan it for root pointers.
Blanket wide to all .c and .h files. Some files originating from ST are
difficult to deal with (license wise) so it was left out of those.
Also merged modpyb.h, modos.h, modstm.h and modtime.h in stmhal/.
By default mingw outputs 3 digits instead of the standard 2 so all float
tests using printf fail. Using setenv at the start of the program fixes this.
To accomodate calling platform specific initialization a
MICROPY_MAIN_INIT_FUNC macro is used which is called in mp_init()
Paul Sokolovsky
Damien George
Fabian Vogt
stijn