tinyusb/docs/reference/getting_started.rst

***************
Getting Started
***************

Add TinyUSB to your project
---------------------------

It is relatively simple to incorporate tinyusb to your project

* Copy or ``git submodule`` this repo into your project in a subfolder. Let's say it is *your_project/tinyusb*
* Add all the .c in the ``tinyusb/src`` folder to your project
* Add *your_project/tinyusb/src* to your include path. Also make sure your current include path also contains the configuration file tusb_config.h.
* Make sure all required macros are all defined properly in tusb_config.h (configure file in demo application is sufficient, but you need to add a few more such as ``CFG_TUSB_MCU``, ``CFG_TUSB_OS`` since they are passed by IDE/compiler to maintain a unique configure for all boards).
* If you use the device stack, make sure you have created/modified usb descriptors for your own need. Ultimately you need to implement all **tud descriptor** callbacks for the stack to work.
* Add tusb_init(rhport, role) call to your reset initialization code.
* Call ``tusb_int_handler(rhport, in_isr)`` in your USB IRQ Handler
* Implement all enabled classes's callbacks.
* If you don't use any RTOSes at all, you need to continuously and/or periodically call tud_task()/tuh_task() function. All of the callbacks and functionality are handled and invoked within the call of that task runner.

.. code-block::

   int main(void) {
     tusb_rhport_init_t dev_init = {
        .role = TUSB_ROLE_DEVICE,
        .speed = TUSB_SPEED_AUTO
     };
     tusb_init(0, &dev_init); // initialize device stack on roothub port 0

     tusb_rhport_init_t host_init = {
        .role = TUSB_ROLE_HOST,
        .speed = TUSB_SPEED_AUTO
     };
     tusb_init(1, &host_init); // initialize host stack on roothub port 1

     while(1) { // the mainloop
       your_application_code();
       tud_task(); // device task
       tuh_task(); // host task
     }
   }

   void USB0_IRQHandler(void) {
     tusb_int_handler(0, true);
   }

   void USB1_IRQHandler(void) {
     tusb_int_handler(1, true);
   }

Examples
--------

For your convenience, TinyUSB contains a handful of examples for both host and device with/without RTOS to quickly test the functionality as well as demonstrate how API() should be used. Most examples will work on most of `the supported boards <boards.rst>`_. Firstly we need to ``git clone`` if not already

.. code-block::

   $ git clone https://github.com/hathach/tinyusb tinyusb
   $ cd tinyusb

Some ports will also require a port-specific SDK (e.g. RP2040) or binary (e.g. Sony Spresense) to build examples. They are out of scope for tinyusb, you should download/install it first according to its manufacturer guide.

Dependencies
^^^^^^^^^^^^

The hardware code is located in ``hw/bsp`` folder, and is organized by family/boards. e.g raspberry_pi_pico is located in ``hw/bsp/rp2040/boards/raspberry_pi_pico`` where FAMILY=rp2040 and BOARD=raspberry_pi_pico. Before building, we firstly need to download dependencies such as: MCU low-level peripheral driver and external libraries e.g FreeRTOS (required by some examples). We can do that by either ways:

1. Run ``tools/get_deps.py {FAMILY}`` script to download all dependencies for a family as follow. Note: For TinyUSB developer to download all dependencies, use FAMILY=all.

.. code-block::

   $ python tools/get_deps.py rp2040

2. Or run the ``get-deps`` target in one of the example folder as follow.

.. code-block::

   $ cd examples/device/cdc_msc
   $ make BOARD=raspberry_pi_pico get-deps

You only need to do this once per family. Check out `complete list of dependencies and their designated path here <dependencies.rst>`_

Build
^^^^^

To build example, first change directory to an example folder.

.. code-block::

   $ cd examples/device/cdc_msc

Then compile with ``make BOARD={board_name} all`` , for example

.. code-block::

   $ make BOARD=raspberry_pi_pico all

Note: some examples especially those that uses Vendor class (e.g webUSB) may requires udev permission on Linux (and/or macOS) to access usb device. It depends on your OS distro, typically copy ``99-tinyusb.rules`` and reload your udev is good to go

.. code-block::

   $ cp examples/device/99-tinyusb.rules /etc/udev/rules.d/
   $ sudo udevadm control --reload-rules && sudo udevadm trigger

RootHub Port Selection
~~~~~~~~~~~~~~~~~~~~~~

If a board has several ports, one port is chosen by default in the individual board.mk file. Use option ``PORT=x`` To choose another port. For example to select the HS port of a STM32F746Disco board, use:

.. code-block::

   $ make BOARD=stm32f746disco PORT=1 all

Port Speed
~~~~~~~~~~

A MCU can support multiple operational speed. By default, the example build system will use the fastest supported on the board. Use option ``SPEED=full/high`` e.g To force F723 operate at full instead of default high speed

.. code-block::

   $ make BOARD=stm32f746disco SPEED=full all

Size Analysis
~~~~~~~~~~~~~

First install `linkermap tool <https://github.com/hathach/linkermap>`_ then ``linkermap`` target can be used to analyze code size. You may want to compile with ``NO_LTO=1`` since -flto merges code across .o files and make it difficult to analyze.

.. code-block::

   $ make BOARD=feather_nrf52840_express NO_LTO=1 all linkermap

Debug
^^^^^

To compile for debugging add ``DEBUG=1``\ , for example

.. code-block::

   $ make BOARD=feather_nrf52840_express DEBUG=1 all

Log
~~~

Should you have an issue running example and/or submitting an bug report. You could enable TinyUSB built-in debug logging with optional ``LOG=``. LOG=1 will only print out error message, LOG=2 print more information with on-going events. LOG=3 or higher is not used yet.

.. code-block::

   $ make BOARD=feather_nrf52840_express LOG=2 all

Logger
~~~~~~

By default log message is printed via on-board UART which is slow and take lots of CPU time comparing to USB speed. If your board support on-board/external debugger, it would be more efficient to use it for logging. There are 2 protocols:


* `LOGGER=rtt`: use `Segger RTT protocol <https://www.segger.com/products/debug-probes/j-link/technology/about-real-time-transfer/>`_

  * Cons: requires jlink as the debugger.
  * Pros: work with most if not all MCUs
  * Software viewer is JLink RTT Viewer/Client/Logger which is bundled with JLink driver package.

* ``LOGGER=swo``\ : Use dedicated SWO pin of ARM Cortex SWD debug header.

  * Cons: only work with ARM Cortex MCUs minus M0
  * Pros: should be compatible with more debugger that support SWO.
  * Software viewer should be provided along with your debugger driver.

.. code-block::

   $ make BOARD=feather_nrf52840_express LOG=2 LOGGER=rtt all
   $ make BOARD=feather_nrf52840_express LOG=2 LOGGER=swo all

Flash
^^^^^

``flash`` target will use the default on-board debugger (jlink/cmsisdap/stlink/dfu) to flash the binary, please install those support software in advance. Some board use bootloader/DFU via serial which is required to pass to make command

.. code-block::

   $ make BOARD=feather_nrf52840_express flash
   $ make SERIAL=/dev/ttyACM0 BOARD=feather_nrf52840_express flash

Since jlink can be used with most of the boards, there is also ``flash-jlink`` target for your convenience.

.. code-block::

   $ make BOARD=feather_nrf52840_express flash-jlink

Some board use uf2 bootloader for drag & drop in to mass storage device, uf2 can be generated with ``uf2`` target

.. code-block::

   $ make BOARD=feather_nrf52840_express all uf2

IAR Support
-----------

Use project connection
^^^^^^^^^^^^^^^^^^^^^^

IAR Project Connection files are provided to import TinyUSB stack into your project.

* A buldable project of your MCU need to be created in advance.


  * Take example of STM32F0:

    -  You need `stm32l0xx.h`, `startup_stm32f0xx.s`, `system_stm32f0xx.c`.

    - `STM32L0xx_HAL_Driver` is only needed to run examples, TinyUSB stack itself doesn't rely on MCU's SDKs.

* Open ``Tools -> Configure Custom Argument Variables`` (Switch to `Global` tab if you want to do it for all your projects)
   Click `New Group ...`, name it to `TUSB`, Click `Add Variable ...`, name it to `TUSB_DIR`, change it's value to the path of your TinyUSB stack,
   for example `C:\\tinyusb`

Import stack only
~~~~~~~~~~~~~~~~~

1. Open ``Project -> Add project Connection ...``, click `OK`, choose `tinyusb\\tools\\iar_template.ipcf`.

Run examples
~~~~~~~~~~~~

1. (Python3 is needed) Run ``iar_gen.py`` to generate .ipcf files of examples:

   .. code-block::

     cd C:\tinyusb\tools
     python iar_gen.py

2. Open `Project -> Add project Connection ...`, click `OK`, choose `tinyusb\\examples\\(.ipcf of example)`.
   For example `C:\\tinyusb\\examples\\device\\cdc_msc\\iar_cdc_msc.ipcf`

Native CMake support (9.50.1+)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

With 9.50.1 release, IAR added experimental native CMake support (strangely not mentioned in public release note). Now it's possible to import CMakeLists.txt then build and debug as a normal project.

Following these steps:

1. Add IAR compiler binary path to system ``PATH`` environment variable, such as ``C:\Program Files\IAR Systems\Embedded Workbench 9.2\arm\bin``.
2. Create new project in IAR, in Tool chain dropdown menu, choose CMake for Arm then Import ``CMakeLists.txt`` from chosen example directory.
3. Set up board option in ``Option - CMake/CMSIS-TOOLBOX - CMake``, for example :code:`-DBOARD=stm32f439nucleo -DTOOLCHAIN=iar`, **Uncheck 'Override tools in env'**.
4. (For debug only) Choose correct CPU model in ``Option - General Options - Target``, to profit register and memory view.