68 lines
2.0 KiB
ReStructuredText
68 lines
2.0 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 Zephyr Kernel uses the qemu_x86 board configuration to emulate pentium-class
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systems running on QEMU.
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It provides support for an x86 Minute IA CPU 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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.. note::
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This board configuration makes no claims about its suitability for use
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with actual galileo hardware, or any other hardware.
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The qemu_x86 board configuration has been tested on QEMU 2.1.
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Supported Features
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******************
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The qemu_x86 board 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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The kernel currently does not support other hardware features on this platform.
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HPET System Clock Support
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=========================
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The qemu_x86 board configuration uses an HPET clock frequency of 25 MHz.
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Serial Port
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===========
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The qemu_x86 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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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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