*`fbt` constructs all referenced environments & their targets' dependency trees on startup. So, to keep startup time as low as possible, we're hiding construction of certain targets behind command-line options.
*`fbt` always performs `git submodule update --init` on start, unless you set `FBT_NO_SYNC=1` in environment:
* On Windows, that's `set "FBT_NO_SYNC=1"` in the shell you're running `fbt` from
*`fbt` builds updater & firmware in separate subdirectories in `build`, with their names depending on optimization settings (`COMPACT` &`DEBUG` options). However, for ease of integration with IDEs, latest built variant's directory is always linked as `built/latest`. Additionally, `compile_commands.json` is generated in that folder, which is used for code completion support in IDE.
FBT keeps track of internal dependencies, so you only need to build the highest-level target you need, and FBT will make sure everything they depend on is up-to-date.
-`updater_package`, `updater_minpackage` - build self-update package. Minimal version only inclues firmware's DFU file; full version also includes radio stack & resources for SD card
-`lint`, `format` - run clang-tidy on C source code to check and reformat it according to `.clang-format` specs
-`lint_py`, `format_py` - run [black](https://black.readthedocs.io/en/stable/index.html) on Python source code, build system files & application manifests
-`firmware_cdb`, `updater_cdb` - generate `compilation_database.json` file for external tools and IDEs. It can be created without actually building the firmware.
-`--with-updater` - enables updater-related targets and dependency tracking. Enabling this option introduces extra startup time costs, so use it when bundling update packages. _Explicily enabling this should no longer be required, fbt now has specific handling for updater-related targets_
You can create customized firmware builds by modifying the application list to be included in the build. Application presets are configured with the `FIRMWARE_APPS` option, which is a map(configuration_name:str -> application_list:tuple(str)). To specify application set to use in a build, set `FIRMWARE_APP_SET` to its name.
For example, to build a firmware image with unit tests, run `./fbt FIRMWARE_APP_SET=unit_tests`.