OSPI NOR Flash
===============

This guide will show you how to access the 64MB NOR Flash featured on the phyCORE-i.MX8X development kit carrier board. The NOR Flash is accessible through the OSPI interface and can also be used as an alternative boot source.

Available NOR Partitions
--------------------------

* Make sure the NOR interface was initialized properly.

  .. code-block:: none
    :caption: Target (Linux)

    mtdinfo

  .. code-block:: none
    :caption: Expected Output

    Count of MTD devices:           1
    Present MTD devices:            mtd0
    Sysfs interface supported:      yes

* View basic partition information.

  .. code-block:: none
    :caption: Target (Linux)

    cat /proc/mtd

 .. code-block:: none
   :caption: Expected Output

   dev:    size   erasesize  name
   mtd0: 04000000 00020000 "5d120000.spi"

* More detailed information can be viewed using the "mtdinfo" command on a specific partition.


  .. code-block:: none
    :caption: Target (Linux)

    mtdinfo /dev/mtd0

 .. code-block:: none
   :caption: Expected Output

   mtd0
   Name:                           5d120000.spi
   Type:                           nor
   Eraseblock size:                131072 bytes, 128.0 KiB
   Amount of eraseblocks:          512 (67108864 bytes, 64.0 MiB)
   Minimum input/output unit size: 1 byte
   Sub-page size:                  1 byte
   Character device major/minor:   90:0
   Bad blocks are allowed:         false
   Device is writable:             true

Write to OSPI
---------------

* Create a random file equal to the size of the /dev/mtd0 partition (512 kBytes).

  .. code-block:: none
    :caption: Target (Linux)

    dd if=/dev/urandom of=test.dat bs=1k count=512

 .. code-block:: none
   :caption: Expected Output

   512+0 records in
   512+0 records out
   524288 bytes (524 kB, 512 KiB) copied, 0.0265253 s, 19.8 MB/s

* Copy the generated file to the mtd0 partition using the "flashcp" command.

  .. code-block:: none
    :caption: Target (Linux)

    flashcp -v test.dat /dev/mtd0

 .. code-block:: none
   :caption: Expected Output

   Erasing blocks: 4/4 (100%)
   Writing data: 512k/512k (100%)
   Verifying data: 512k/512k (100%)

Reading from OSPI
-------------------

* Dump the contents of /dev/mtd0 partition to a new file:

  .. code-block:: none
    :caption: Target (Linux)

    dd if=/dev/mtd0 of=read.dat bs=1k count=512

 .. code-block:: none
   :caption: Expected Output

   512+0 records in
   512+0 records out
   524288 bytes (524 kB, 512 KiB) copied, 0.167633 s, 3.1 MB/s

* Make sure the output file was not corrupted during the transfer using md5sum.

  .. code-block:: none
    :caption: Target (Linux)

    md5sum test.dat read.dat

 .. code-block:: none
   :caption: Expected Output

   3497f295076c7ef96443b109ab9be333  test.dat
   3497f295076c7ef96443b109ab9be333  read.dat