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.
-`blackmagic` - debug firmware with Blackmagic probe (WiFi dev board).
-`openocd` - just start OpenOCD.
-`get_blackmagic` - output the blackmagic address in the GDB remote format. Useful for IDE integration.
-`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.
-`--options optionfile.py` (default value `fbt_options.py`) - load a file with multiple configuration values
-`--extra-int-apps=app1,app2,appN` - force listed apps to be built as internal with the `firmware` target
-`--extra-ext-apps=app1,app2,appN` - force listed apps to be built as external with the `firmware_extapps` target
-`--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 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.
