:mod:`dualbank`
===============

.. py:module:: dualbank

.. autoapi-nested-parse::

   DUALBANK Module

   The `dualbank` module adds ability to update and switch
   between the two app partitions.

   There are two identical partitions, these contain different
   firmware versions.
   Having two partitions enables rollback functionality.

   The two partitions are defined as boot partition and
   next-update partition. Calling `dualbank.flash()` writes
   the next-update partition.

   After the next-update partition is written a validation
   check is performed and on a successful validation this
   partition is set as the boot partition. On next reset,
   firmware will be loaded from this partition.

   Here is the sequence of commands to follow:

   .. code-block:: python

       import dualbank

       dualbank.flash(buffer, offset)
       dualbank.switch()



.. raw:: html

    <p>
    <details>
    <summary>Available on these boards</summary>
    <ul>
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    <li> ATMegaZero ESP32-S2
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    </ul>
    </details>
    </p>




.. py:function:: flash(*buffer: _typing.ReadableBuffer, offset: int = 0) -> None

   Writes one of two app partitions at the given offset.

   This can be called multiple times when flashing the firmware
   in small chunks.


.. py:function:: switch() -> None

   Switches the boot partition.

   On next reset, firmware will be loaded from the partition
   just switched over to.