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.
Module creation & registration now made a lot simpler. In essence,
each module file is now self-contained and only needs a
NODEMCU_MODULE(MYNAME, "myname", myname_map, luaopen_myname);
line to both be automatically recognised by the Lua initialization
as well as honor the LUA_USE_MODULES_MYNAME #define.
As per #810 & #796, only LUA_OPTIMIZE_MEMORY=2 & MIN_OPT_LEVEL=2 are
supported when building. This commit effects that limitation.
With this change modules/auxmods.h no longer needs to be updated for
every new module, nor do module writers need to cater for a hypothetical
LUA_OPTIMIZE_MEMORY < 2 scenario.
The rtcfifo module uses RTC memory to store sensor samples across deep-sleeps,
making it possible to batch up samples for less frequent uploads. This
component uses 9 RTC memory slots for control, and a variable number of
slots for sample storage (see rtcfifo.prepare() on how to control the
size/location of the latter).
When used together with the rtctime module, it also exposes the convenience
function rtcfifo.dsleep_until_sample() which can be used to easily take
readings on a regular basis without having to manually take into account
time spent awake to get an accurate sleep time.
The format used for storing samples is quite dense, and allows for 16 bits
of data in a fixed point format (per sample).
Johny Mattsson
Terry Ellison
Johny Mattsson