From 55e8c65b8d776df37e55b6fdbc629545b3d0364c Mon Sep 17 00:00:00 2001 From: Johny Mattsson Date: Thu, 22 Sep 2016 11:42:13 +1000 Subject: [PATCH] More developer notes. --- docs/en/extn-developer-faq.md | 45 +++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/docs/en/extn-developer-faq.md b/docs/en/extn-developer-faq.md index 0670a760..1a59aec2 100644 --- a/docs/en/extn-developer-faq.md +++ b/docs/en/extn-developer-faq.md @@ -2,6 +2,51 @@ **# # # Work in Progress # # #** +### Changes in IDF compared to non-OS/RTOS SDK +This is a non-exhaustive list, obviously, but some key points are: + + - **No more `c_types.h`**. Standard C types are finally the norm. + - `stdint.h` for all your `[u]intX_t` needs + - `stdbool.h` for bool (note `true`/`false` vs old `TRUE`/`FALSE`) + - `stddef.h` for `size_t` + + - **A real C library**. All the `os_`, `ets_` and `c_` prefixes for + standard library functions are gone (except for the special case + c_getenv, for now). + + - **Everything builds on at least C99 level**, with plenty of warnings + enabled. Fix the code so it doesn't produce warnings - don't turn + off the warnings! Yes, there *may* be exceptions, but they're rare. + + - **`user_config.h` is no more**. All configuration is now handled + via Kconfig (`make menuconfig` to configure). From the developer + perspective, simply include `sdkconfig.h` and test the + corresponding CONFIG_YOUR_FEATURE macro. The `platform.h` header + is guaranteed to include `sdkconfig.h`, btw. + + - **`user_modules.h` is also gone**. Module selection is now done + via Kconfig. Rather than adding a #define to `user_modules.h`, + add an option in `components/modules/Kconfig` of the form + `LUA_MODULE_XYZ`, and the existing `NODEMCU_MODULE()` macros + will take care of the rest. Example Kconfig entry: + ``` + config LUA_MODULE_XYZ + bool "Xyz module" + default "y" + help + Includes the XYZ module. Provides features X, Y and Z. + ``` + + - **Preemptive multithreading**. The network stack and other drivers + now run in their own threads with private stacks. This makes for + a more robust architecture, but does mean proper synchronization + *MUST* be employed between the threads. This includes between + API callbacks and main Lua thread. + + - **Logical flash partitions**. Rather than hardcoding assumptions of + flash area usage, there is now an actual logical partition table + kept on the flash. + ### NodeMCU task paradigm NodeMCU uses a task based approach for scheduling work to run within