If you don't need all features of `fbt` - like building the whole firmware - and only want to build and debug a single application, you can use [ufbt](https://pypi.org/project/ufbt/).
`fbt` by default downloads and unpacks a pre-built toolchain, and then modifies environment variables for itself to use it. It does not contaminate your global system's path with the toolchain.
> However, if you wish to use tools supplied with the toolchain outside `fbt`, you can open an *fbt shell*, with properly configured environment.
If your system is not supported by pre-built toolchain variants or you want to use custom versions of dependencies, you can `set FBT_NOENV=1`. `fbt` will skip toolchain & environment configuration and will expect all tools to be available on your system's `PATH`. *(this option is not available on Windows)*
If `FBT_TOOLCHAIN_PATH` variable is set, `fbt` will use that directory to unpack toolchain into. By default, it downloads toolchain into `toolchain` subdirectory repo's root.
`fbt` builds updater & firmware in separate subdirectories in `build`, and their names depend on optimization settings (`COMPACT` &`DEBUG` options). However, for ease of integration with IDEs, the latest built variant's directory is always linked as `built/latest`. Additionally, `compile_commands.json` is generated in that folder (it is used for code completion support in IDEs).
`build/latest` symlink & compilation database are only updated upon *firmware build targets* - that is, when you're re-building the firmware itself. Running other tasks, like firmware flashing or building update bundles *for a different debug/release configuration or hardware target*, does not update `built/latest` dir to point to that configuration.
`fbt` includes basic development environment configuration for VSCode. Run `./fbt vscode_dist` to deploy it. That will copy the initial environment configuration to the `.vscode` folder. After that, you can use that configuration by starting VSCode and choosing the firmware root folder in the "File > Open Folder" menu.
- On the first start, you'll be prompted to install recommended plugins. We highly recommend installing them for the best development experience. _You can find a list of them in `.vscode/extensions.json`._
- Basic build tasks are invoked in the 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 them on your system's PATH._
- Without a supported probe, you can install firmware on Flipper using the 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.
-`fw_dist` - build & publish firmware to the `dist` folder. This is a default target when no others are specified.
-`fap_dist` - build external plugins & publish to the `dist` folder.
-`updater_package`, `updater_minpackage` - build a self-update package. The minimal version only includes the firmware's DFU file; the full version also includes a radio stack & resources for the SD card.
-`copro_dist` - bundle Core2 FUS+stack binaries for qFlipper.
-`flash` - flash the attached device with OpenOCD over ST-Link.
-`flash_usb`, `flash_usb_full` - build, upload and install the update package to the device over USB. See details on `updater_package` and `updater_minpackage`.
-`debug` - build and flash firmware, then attach with gdb with firmware's .elf loaded.
-`debug_other`, `debug_other_blackmagic` - attach GDB without loading any `.elf`. It will allow you to manually add external `.elf` files with `add-symbol-file` in GDB.
-`updater_debug` - attach GDB with the updater's `.elf` loaded.
-`lint`, `format` - run clang-format on the C source code to check and reformat it according to the `.clang-format` specs.
-`lint_py`, `format_py` - run [black](https://black.readthedocs.io/en/stable/index.html) on the Python source code, build system files & application manifests.
-`firmware_cdb`, `updater_cdb` - generate a `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 the execution environment and doesn't forward all inherited environment variables. You can find the list of variables that are always forwarded in the `environ.scons` file.
You can also create a file called `fbt_options_local.py` that will be evaluated when loading default options file, enabling persisent overriding of default options without modifying default configuration.
You can create customized firmware builds by modifying the list of applications 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 an application set to use in the build, set `FIRMWARE_APP_SET` to its name.
