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 build system.

Requirements

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

NB

• fbt constructs all referenced environments and their targets' dependency trees on startup. So, to keep startup time as low as possible, we're hiding the 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 the environment:
  • On Windows, it'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, 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 (used for code completion support in IDE).

Invoking FBT

To build with FBT, call it and specify 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 the -c option.

VSCode integration

fbt includes basic development environment configuration for VS Code. 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 VS Code 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 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 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 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.
• get_stlink - output serial numbers for attached STLink probes. Used for specifying an adapter with OPENOCD_ADAPTER_SERIAL=....
• 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 on the Python source code, build system files & application manifests.
• cli - start a Flipper CLI session over USB.

Firmware targets

• faps - build all external & plugin apps as .faps.
• 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 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 the current version to the attached device with OpenOCD over ST-Link.
• jflash - flash the current version to the attached device with JFlash using a J-Link probe. The JFlash executable must be on your $PATH.
• flash_blackmagic - flash the current version to the attached device with a Blackmagic probe.
• firmware_all, updater_all - build a basic set of binaries.
• firmware_list, updater_list - generate source + assembler listing.
• firmware_cdb, updater_cdb - generate a 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 files
  • dolphin_ext - process dolphin animations for the 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 a 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 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.

Configuration

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

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

Firmware application set

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. For example, to build a firmware image with unit tests, run ./fbt FIRMWARE_APP_SET=unit_tests.

Check out fbt_options.py for details.