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Overview

boards/qemu/x86/doc/index.rst

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.. zephyr:board:: qemu_x86

Overview

The X86 QEMU board configuration is used to emulate the X86 architecture.

This board configuration provides support for an x86 Minute IA (Lakemont) CPU and the following devices:

  • HPET
  • Advanced Programmable Interrupt Controller (APIC)
  • NS16550 UART

Hardware

Supported Features

.. zephyr:board-supported-hw::

Devices

HPET System Clock Support

The configuration uses an HPET clock frequency of 25 MHz.

Serial Port

The board configuration uses a single serial communication channel that uses the NS16550 serial driver operating in polling mode. To override, enable the UART_INTERRUPT_DRIVEN Kconfig option, which allows the system to be interrupt-driven.

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:

  • Isolated Memory Regions
  • Serial port in Direct Memory Access (DMA) mode
  • Serial Peripheral Interface (SPI) flash
  • General-Purpose Input/Output (GPIO)
  • Inter-Integrated Circuit (I2C)
  • Ethernet
  • Supervisor Mode Execution Protection (SMEP)

Programming and Debugging

.. zephyr:board-supported-runners::

Applications for the qemu_x86 board configuration can be built and run in the usual way for emulated boards (see :ref:build_an_application and :ref:application_run for more details).

Flashing

While this board is emulated and you can't "flash" it, you can use this configuration to run basic Zephyr applications and kernel tests in the QEMU emulated environment. For example, with the :zephyr:code-sample:synchronization sample:

.. zephyr-app-commands:: :zephyr-app: samples/synchronization :host-os: unix :board: qemu_x86 :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 x86!
    threadB: Hello World from x86!
    threadA: Hello World from x86!
    threadB: Hello World from x86!
    threadA: Hello World from x86!
    threadB: Hello World from x86!
    threadA: Hello World from x86!
    threadB: Hello World from x86!
    threadA: Hello World from x86!
    threadB: Hello World from x86!

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

For qemu_x86_64 platform, it also supports to use UEFI bootable method to run Zephyr applications and kernel tests, but you need to set up some environment configurations as follows:

  • Please install uefi-run in your system environment according to this reference link https://github.com/Richard-W/uefi-run. Note that uefi-run from snapstore may not work because of strict snap confinements. The preferred method is installing with cargo.

  • Please install OVMF in your system environment according to this reference link https://github.com/tianocore/tianocore.github.io/wiki/OVMF. The easiest way is to install a special ovmf package found in many distros. For example, use the following command in Ubuntu:

    .. code-block:: console

    sudo apt install ovmf

  • Set system environment variable OVMF_FD_PATH, for example:

    .. code-block:: console

    export OVMF_FD_PATH=/usr/share/OVMF/OVMF_CODE.fd

Now you can build application, for example UEFI boot test sample found under :zephyr_file:tests/boot/uefi:

.. zephyr-app-commands:: :zephyr-app: tests/boot/uefi :host-os: unix :board: qemu_x86_64 :goals: run

This will build an image with the uefi boot test app, boot it on qemu_x86_64 using UEFI, and display the following console output:

.. code-block:: console

    UEFI Interactive Shell v2.2
    EDK II
    UEFI v2.70 (EDK II, 0x00010000)
    Mapping table
          FS0: Alias(s):F0a:;BLK0:
              PciRoot(0x0)/Pci(0x1,0x1)/Ata(0x0)
         BLK1: Alias(s):
              PciRoot(0x0)/Pci(0x1,0x1)/Ata(0x0)
    Press ESC in 1 seconds to skip startup.nsh or any other key to continue.
    Starting UEFI application...
    *** Zephyr EFI Loader ***
    Zeroing 524544 bytes of memory at 0x105000
    Copying 32768 data bytes to 0x1000 from image offset
    Copying 20480 data bytes to 0x100000 from image offset 32768
    Copying 540416 data bytes to 0x185100 from image offset 53248
    Jumping to Entry Point: 0x112b (48 31 c0 48 31 d2 48)
    *** Booting Zephyr OS build zephyr-v2.6.0-1472-g61810ec36d28  ***
    Hello World! qemu_x86_64

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

Debugging

Refer to the detailed overview about :ref:application_debugging.

Networking

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

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.