upstream-layers/yocto-docs/documentation/dev-manual/bmaptool.rst

.. SPDX-License-Identifier: CC-BY-SA-2.0-UK

Flashing Images Using `bmaptool`
********************************

A fast and easy way to flash an image to a bootable device is to use
`bmaptool`, which is integrated into the OpenEmbedded build system.
`bmaptool` is a generic tool that creates a file's block map (bmap) and
then uses that map to copy the file. As compared to traditional tools
such as `dd` or `cp`, `bmaptool` can copy (or flash) large files like raw
system image files much faster.

.. note::

   -  If you are using Ubuntu or Debian distributions, you can install
      the ``bmap-tools`` package using the following command and then
      use the tool without specifying ``PATH`` even from the root
      account::

         $ sudo apt install bmap-tools

   -  If you are unable to install the ``bmap-tools`` package, you will
      need to build `bmaptool` before using it. Use the following command::

         $ bitbake bmaptool-native -caddto_recipe_sysroot

Following, is an example that shows how to flash a Wic image. Realize
that while this example uses a Wic image, you can use `bmaptool` to flash
any type of image. Use these steps to flash an image using `bmaptool`:

#. *Update your local.conf File:* You need to have the following set
   in your ``local.conf`` file before building your image::

      IMAGE_FSTYPES += "wic wic.bmap"

#. *Get Your Image:* Either have your image ready (pre-built with the
   :term:`IMAGE_FSTYPES`
   setting previously mentioned) or take the step to build the image::

      $ bitbake image

#. *Flash the Device:* Flash the device with the image by using `bmaptool`
   depending on your particular setup. The following commands assume the
   image resides in the :term:`Build Directory`'s ``deploy/images/`` area:

   -  If you installed the package for `bmaptool`, you can directly run::

         $ sudo bmaptool copy build-directory/tmp/deploy/images/machine/image.wic /dev/sdX

   -  Otherwise, if you built `bmaptool` with BitBake, run::

         $ sudo chmod a+w /dev/sdX       # get write access to the media, needed only once after booting
         $ oe-run-native bmaptool-native bmaptool copy build-directory/tmp/deploy/images/machine/image.wic /dev/sdX

For help on the ``bmaptool`` command, use the following command::

   $ bmaptool --help