.. _mpu_test:
Memory Protection Unit (MPU) TEST
#################################
Overview
********
This test provides a set options to check the correct MPU configuration
against the following security issues:
* Read at an address that is reserved in the memory map.
* Write into the boot Flash/ROM.
* Run code located in SRAM.
If the MPU configuration is correct each option selected ends up in an MPU
fault.
Building and Running
********************
This project can be built and executed as follows:
.. zephyr-app-commands::
:zephyr-app: samples/mpu/mpu_test
:board: v2m_beetle
:goals: build flash
:compact:
Reset the board and you should be able to see on the corresponding
Serial Port the following message:
.. code-block:: console
***** BOOTING ZEPHYR OS v1.7.99 - BUILD: Mar 9 2017 13:01:59 *****
*** MPU test options ***
1 - Read a reserved address in the memory map
2 - Write in to boot FLASH/ROM
3 - Run code located in RAM
Select an option:
To build the single thread version, use the supplied configuration file for
single thread: :file:`prj_single.conf`:
.. zephyr-app-commands::
:zephyr-app: samples/mpu/mpu_test
:board: v2m_beetle
:conf: prj_single.conf
:goals: run
:compact:
To build a version that allows writes to the flash device, edit
``prj.conf``, and follow the directions in the comments to enable the
proper configs.
Sample Output
=============
.. code-block:: console
***** BOOTING ZEPHYR OS v1.7.99 - BUILD: May 12 2017 09:47:02 *****
shell> select mpu_test
mpu_test> read
***** BUS FAULT *****
Executing thread ID (thread): 0x200003b8
Faulting instruction address: 0x290
Precise data bus error
Address: 0x24000000
Fatal fault in thread 0x200003b8! Aborting.
915bf989cf