X86 Emulation (QEMU)

Overview

The Zephyr Kernel uses the qemu_x86 board configuration to emulate pentium-class systems running on QEMU. It provides support for an x86 Minute IA CPU and the following devices:

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

Note

This board configuration makes no claims about its suitability for use with actual galileo hardware, or any other hardware.

The qemu_x86 board configuration has been tested on QEMU 2.1.

Supported Features

The qemu_x86 board configuration supports the following hardware features:

Interface Controller Driver/Component
HPET on-chip system clock
APIC on-chip interrupt controller
NS16550 UART on-chip serial port

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

HPET System Clock Support

The qemu_x86 board configuration uses an HPET clock frequency of 25 MHz.

Serial Port

The qemu_x86 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.

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)