Building the SDK

The generator

The generator (tools/generate_native_sdk/generate_pebble_native_sdk_files.py) runs automatically as part of the firmware build (normal variant only — PRF and test builds skip it). It exports the white-listed functions, typedefs and #defines from the firmware tree and produces the files needed to build native watchapps, all under build/:

• build/sdk/<platform>/include/pebble.h — typedefs, defines and function prototypes for apps (plus pebble_worker.h for background workers and a few version/fonts headers). Exported declarations are copied verbatim and use pbl/kernel/compiler.h macros rather than raw __attribute__; the generator rewrites those into their GCC spellings, so the SDK ships no firmware headers. Only macros that alias an attribute or forward their arguments to a builtin can be exported.

• build/sdk/<platform>/lib/libpebble.a — static library containing trampolines that call the exported functions in flash

• build/fw/pebble.auto.c — g_pbl_system_tbl, the table of function pointers the trampolines use to find an exported function’s address; compiled into the firmware image

Packaging

The rest of the distribution is packaged by the firmware build’s sdk target, which fills in the same build/sdk/ tree:

pbl configure --board $BOARD
pbl build sdk

tools/cmake/sdk.py copies the common files from sdk/ into build/sdk/common/ — the app project templates under sdk/defaults/, and the tools and resource pipeline the app build shares with the firmware — and bundles sdk/waftools/ into the waf binary app developers use to build their apps. That waf is the only one left in the tree: everything it needs lives under sdk/, and it is built out of tree, so packaging leaves the checkout untouched.