.. _flash_partitions:

Flash partitions nodes explanation
##################################

In each of the <boards>.dts files, the flash partitions layout can be described.
It must be put inside the 'partitions' node in the 'flash0' node.

Mcuboot related partitions
**************************

**boot_partition**
  This is the partition where the bootloader is expected to be
  placed. mcuboot is linked into this partition.

**slot0_partition**
  This is the partition where the current, executable
  application image is expected to be placed. Any bootable application must be
  linked into this area.

**slot1_partition**
  This is the partition where the downloaded application image
  is collected. Mcuboot can load this image to slot0_partition and run it.
  The slot0_partition and slot1_partition must be the same size.

**scratch_partition**
  This partition is used for images swapping support.
  See the  `mcuboot documentation`_ for more details.

.. _mcuboot documentation: https://github.com/runtimeco/mcuboot/blob/master/docs/design.md#image-slots

By default a code-partition to link into is not selected.

If Zephyr code-partition is not chosen, the image will be linked into the entire
flash device. If code-partition points to an individual partition, the code will be linked
to, and be restricted to that partition.

File system related partitions
******************************
**nffs_partition**
  This is the area where NFFS expects its partition.

Example
*******

For an example of a DTS file containing such a description,
see the `nrf52840_pca10056.dts`_ file.

.. _nrf52840_pca10056.dts: https://github.com/zephyrproject-rtos/zephyr/blob/master/boards/arm/nrf52840_pca10056/nrf52840_pca10056.dts