*`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` includes basic development environment configuration for VSCode. To deploy it, run `./fbt vscode_dist`. That will copy initial environment configuration to `.vscode` folder. After that, you can use that configuration by starting VSCode and choosing firmware root folder in "File > Open Folder" menu.
* On first start, you'll be prompted to install recommended plug-ins. Please install them for best development experience. _You can find a list of them in `.vscode/extensions.json`._
* Basic build tasks are invoked in Ctrl+Shift+B menu.
* Debugging requires a supported probe. That includes:
* Wi-Fi devboard with stock firmware (blackmagic),
* ST-Link and compatible devices,
* J-Link for flashing and debugging (in VSCode only). _Note that J-Link tools are not included with our toolchain and you have to [download](https://www.segger.com/downloads/jlink/) them yourself and put on your system's PATH._
* Without a supported probe, you can install firmware on Flipper using USB installation method.
**`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
-`debug_other`, `debug_other_blackmagic` - attach gdb without loading any .elf. Allows to manually add external elf files with `add-symbol-file` in gdb
-`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.
-`--proxy-env=VAR1,VAR2` - additional environment variables to expose to subprocesses spawned by `fbt`. By default, `fbt` sanitizes execution environment and doesn't forward all inherited environment variables. You can find list of variables that are always forwarded in `environ.scons` file.
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`.
