129 lines
3.6 KiB
ReStructuredText
129 lines
3.6 KiB
ReStructuredText
.. _qemu_x86:
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X86 Emulation (QEMU)
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####################
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Overview
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********
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The X86 QEMU board configuration is used to emulate the X86 architecture.
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.. figure:: qemu_x86.png
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:width: 600px
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:align: center
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:alt: Qemu
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Qemu (Credit: qemu.org)
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This board configuration provides support for an x86 Minute IA (Lakemont) CPU
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and the following devices:
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* HPET
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* Advanced Programmable Interrupt Controller (APIC)
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* NS16550 UART
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Hardware
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********
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Supported Features
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==================
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This configuration supports the following hardware features:
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+--------------+------------+-----------------------+
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| Interface | Controller | Driver/Component |
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+==============+============+=======================+
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| HPET | on-chip | system clock |
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+--------------+------------+-----------------------+
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| APIC | on-chip | interrupt controller |
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+--------------+------------+-----------------------+
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| NS16550 | on-chip | serial port |
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| UART | | |
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+--------------+------------+-----------------------+
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Devices
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=======
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HPET System Clock Support
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-------------------------
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The configuration uses an HPET clock frequency of 25 MHz.
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Serial Port
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-----------
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The board configuration uses a single serial communication channel that
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uses the NS16550 serial driver operating in polling mode. To override, enable
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the UART_INTERRUPT_DRIVEN Kconfig option, which allows the system to be
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interrupt-driven.
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If SLIP networking is enabled (see below), an additional serial port will be
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used for it.
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Known Problems or Limitations
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=============================
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The following platform features are unsupported:
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* Isolated Memory Regions
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* Serial port in Direct Memory Access (DMA) mode
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* Serial Peripheral Interface (SPI) flash
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* General-Purpose Input/Output (GPIO)
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* Inter-Integrated Circuit (I2C)
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* Ethernet
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* Supervisor Mode Execution Protection (SMEP)
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Programming and Debugging
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*************************
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Applications for the ``qemu_x86`` board configuration can be built and run in
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the usual way for emulated boards (see :ref:`build_an_application` and
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:ref:`application_run` for more details).
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Flashing
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========
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While this board is emulated and you can't "flash" it, you can use this
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configuration to run basic Zephyr applications and kernel tests in the QEMU
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emulated environment. For example, with the :ref:`synchronization_sample`:
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.. zephyr-app-commands::
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:zephyr-app: samples/synchronization
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:host-os: unix
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:board: qemu_x86
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:goals: run
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This will build an image with the synchronization sample app, boot it using
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QEMU, and display the following console output:
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.. code-block:: console
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***** BOOTING ZEPHYR OS v1.8.99 - BUILD: Jun 27 2017 13:09:26 *****
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threadA: Hello World from x86!
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threadB: Hello World from x86!
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threadA: Hello World from x86!
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threadB: Hello World from x86!
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threadA: Hello World from x86!
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threadB: Hello World from x86!
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threadA: Hello World from x86!
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threadB: Hello World from x86!
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threadA: Hello World from x86!
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threadB: Hello World from x86!
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Debugging
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=========
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Refer to the detailed overview about :ref:`application_debugging`.
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Networking
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==========
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The board supports SLIP networking over an emulated serial port
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(``CONFIG_NET_SLIP_TAP=y``). The detailed setup is described in
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:ref:`networking_with_qemu`.
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It is also possible to use the QEMU built-in Ethernet adapter to connect
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to the host system. This is faster than using SLIP and is also the preferred
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way. See :ref:`networking_with_eth_qemu` for details.
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