The PR removed the bulk of non-newlib headers from the NodeMCU source base.
app/libc has now been cut down to the bare minimum overrides to shadow the
corresponding functions in the SDK's libc. The old c_xyz.h headerfiles have been
nuked in favour of the standard <xyz.h> headers, with a few exceptions over in
sdk-overrides. Again, shipping a libc.a without headers is a terrible thing to do. We're
still living on a prayer that libc was configured the same was as a default-configured
xtensa gcc toolchain assumes it is. That part I cannot do anything about, unfortunately,
but it's no worse than it has been before.
This enables our source files to compile successfully using the standard header files,
and use the typical malloc()/calloc()/realloc()/free(), the strwhatever()s and
memwhatever()s. These end up, through macro and linker magic, mapped to the
appropriate SDK or ROM functions.
As with the last commit this rolls up the follwowing, but include the various
review comments on the PR.
- **Documentation changes**. I've added the taks FAQ as a stub new Extension
developer FAQ, and split the old FAQ into a Lua Developer FAQ and a Hardware
FAQ.
- **Tasking I/F**. New `app/task/Makefile`, `app/task/task.c`,
`app/include/task/task.h` and `app/Makefile` as per previous commit. Cascade
changes to `app/driver/uart.c`, `app/include/driver/uart.h`,
`app/user/user_main.c` and `app/modules/node.c`
- **GPIO Rework** to `app/modules/gpio.c` and `pin_map.[hc]`, `platform.[hc]`
in `app/platform`
- **Other Optimisations** Move the `platform_*_exists()` from
`app/platform/common.c` to static inline declarations in `platform.h` as
this generates faster, smaller code. Move lgc.a routines out of iram0.
Terry Ellison
Johny Mattsson
sergio