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

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 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 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.
• 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 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.