unleashed-firmware/documentation/fbt.md

# Flipper Build Tool

FBT is the entry point for firmware-related commands and utilities.
It is invoked by `./fbt` in the firmware project root directory. Internally, it is a wrapper around [scons](https://scons.org/) build system.

## Requirements

Please install Python packages required by assets build scripts: `pip3 install -r scripts/requirements.txt`

## NB

* `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
    * On \*nix, it's `$ FBT_NO_SYNC=1 ./fbt ...`
* `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.

## Invoking FBT

To build with FBT, call it specifying configuration options & targets to build. For example,

`./fbt COMPACT=1 DEBUG=0 VERBOSE=1 updater_package copro_dist`

To run cleanup (think of `make clean`) for specified targets, add `-c` option.

## VSCode integration

`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 targets

**`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.

### High-level (what you most likely need)
 
- `fw_dist` - build & publish firmware to `dist` folder. This is a default target, when no other are specified
- `fap_dist` - build external plugins & publish to `dist` folder  
- `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
- `copro_dist` - bundle Core2 FUS+stack binaries for qFlipper
- `flash` - flash attached device with OpenOCD over ST-Link
- `flash_usb`, `flash_usb_full` - build, upload and install update package to device over USB. See details on `updater_package`, `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. Allows to manually add external elf files with `add-symbol-file` in gdb
- `updater_debug` - attach gdb with updater's .elf loaded
- `blackmagic` - debug firmware with Blackmagic probe (WiFi dev board)
- `openocd` - just start OpenOCD
- `get_blackmagic` - output blackmagic address in gdb remote format. Useful for IDE integration
- `lint`, `format` - run clang-format 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 
- `cli` - start Flipper CLI session over USB

### Firmware targets

- `faps` - build all external & plugin apps as [.faps](./AppsOnSDCard.md#fap-flipper-application-package). 
- **`fbt`** also defines per-app targets. For example, for an app with `appid=snake_game` target names are:
    - `fap_snake_game`, etc - build single app as .fap by its application ID.
    - Check out [`--extra-ext-apps`](#command-line-parameters) for force adding extra apps to external build
    - `fap_snake_game_list`, etc - generate source + assembler listing for app's .fap
- `flash`, `firmware_flash` - flash current version to attached device with OpenOCD over ST-Link
- `jflash` - flash current version to attached device with JFlash using J-Link probe. JFlash executable must be on your $PATH
- `flash_blackmagic` - flash current version to attached device with Blackmagic probe
- `firmware_all`, `updater_all` - build basic set of binaries
- `firmware_list`, `updater_list` - generate source + assembler listing
- `firmware_cdb`, `updater_cdb` - generate `compilation_database.json` file for external tools and IDEs. It can be created without actually building the firmware. 

### Assets

- `resources` - build resources and their Manifest
    - `dolphin_ext` - process dolphin animations for SD card 
- `icons` - generate .c+.h for icons from png assets
- `proto` - generate .pb.c+.pb.h for .proto sources
- `proto_ver` - generate .h with protobuf version 
- `dolphin_internal`, `dolphin_blocking` - generate .c+.h for corresponding dolphin assets
 

## Command-line parameters

- `--options optionfile.py` (default value `fbt_options.py`) - load file with multiple configuration values
- `--extra-int-apps=app1,app2,appN` - forces listed apps to be built as internal with `firmware` target
- `--extra-ext-apps=app1,app2,appN` - forces listed apps to be built as external with `firmware_extapps` target
- `--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. 


## Configuration 

Default configuration variables are set in the configuration file `fbt_options.py`. 
Values set on command-line have higher precedence over configuration file.

You can find out available options with `./fbt -h`.

### Firmware application set

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`.

Check out `fbt_options.py` for details.