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Elixir Cross Referencer

.. _qemu_cortex_m3:

ARM Cortex-M3 Emulation (QEMU)


This board configuration will use QEMU to emulate the TI LM3S6965 platform.

.. figure:: qemu_cortex_m3.png
   :width: 600px
   :align: center
   :alt: Qemu

   Qemu (Credit:

This configuration provides support for an ARM Cortex-M3 CPU and these devices:

* Nested Vectored Interrupt Controller
* System Tick System Clock
* Stellaris UART

.. note::
   This board configuration makes no claims about its suitability for use
   with an actual ti_lm3s6965 hardware system, or any other hardware system.

Supported Features

The following hardware features are supported:

| Interface    | Controller | Driver/Component     |
| NVIC         | on-chip    | nested vectored      |
|              |            | interrupt controller |
| Stellaris    | on-chip    | serial port          |
| UART         |            |                      |
| SYSTICK      | on-chip    | system clock         |

The kernel currently does not support other hardware features on this platform.

System Clock

This board configuration uses a system clock frequency of 12 MHz.

Serial Port

This board configuration uses a single serial communication channel with the

If SLIP networking is enabled (see below), an additional serial port will be
used for it.

Known Problems or Limitations

The following platform features are unsupported:

* Memory protection through optional MPU.  However, using a XIP kernel
  effectively provides TEXT/RODATA write protection in ROM.
* SRAM at addresses 0x1FFF0000-0x1FFFFFFF
* Writing to the hardware's flash memory

Programming and Debugging

Use this configuration to run basic Zephyr applications and kernel tests in the QEMU
emulated environment, for example, with the :ref:`synchronization_sample`:

.. zephyr-app-commands::
   :zephyr-app: samples/synchronization
   :host-os: unix
   :board: qemu_cortex_m3
   :goals: run

This will build an image with the synchronization sample app, boot it using
QEMU, and display the following console output:

.. code-block:: console

        ***** BOOTING ZEPHYR OS v1.8.99 - BUILD: Jun 27 2017 13:09:26 *****
        threadA: Hello World from arm!
        threadB: Hello World from arm!
        threadA: Hello World from arm!
        threadB: Hello World from arm!
        threadA: Hello World from arm!
        threadB: Hello World from arm!
        threadA: Hello World from arm!
        threadB: Hello World from arm!
        threadA: Hello World from arm!
        threadB: Hello World from arm!

Exit QEMU by pressing :kbd:`CTRL+A` :kbd:`x`.


Refer to the detailed overview about :ref:`application_debugging`.


The board supports SLIP networking over an emulated serial port
(``CONFIG_NET_SLIP_TAP=y``). The detailed setup is described in

It is also possible to use the QEMU built-in Ethernet adapter to connect
to the host system. This is faster than using SLIP and is also the preferred
way. See :ref:`networking_with_eth_qemu` for details.


1. The Definitive Guide to the ARM Cortex-M3, Second Edition by Joseph Yiu (ISBN
2. ARMv7-M Architecture Technical Reference Manual (ARM DDI 0403D ID021310)
3. Procedure Call Standard for the ARM Architecture (ARM IHI 0042E, current
   through ABI release 2.09, 2012/11/30)
4. Cortex-M3 Revision r2p1 Technical Reference Manual (ARM DDI 0337I ID072410)
5. Cortex-M3 Devices Generic User Guide (ARM DUI 0052A ID121610)