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  • ACPI

    日期:2010-11-13 | 分类:Linux编程

    版权声明:转载时请以超链接形式标明文章原始出处和作者信息及本声明
    http://www.blogbus.com/freakrobot-logs/83637118.html

    关掉acpi主要是禁用了从ACPI导出的表,包括中断路由表,NUMA使用的互联关系,入SRAT/SLIT等表,没有这些表,
    系统配置只能使用缺省模式,但不一定适用你的系统。另外,没有ACPI定义的中断路由表,系统会尝试寻找MPS定义的table来配置系统。
    如果连MPS也没有,系统只能使用8259了,不过此时只能有1个CPU工作,其他起不来,也就是PIT模式,virtual wire和acpi模式都被禁用。
    pci=noacpi就是说pci的中断配置不走ACPI中导出的中断路由表,而使用其他方式,如命令行参数或者是通过软件(BSP 一级)来配置。

    Thanks to: linux-kernel@zh-kernel.org

    ———

    ACPI Advanced Configuration and Power Interface(ACPI),support for Linux requies ACPI-compliant hardware and firmware, and assume the presence of OS-directed configuration and power management (OSPM) software. This option will enlarge your kernel by about 70KB.
    Linux ACPI provides a robust functional replacement for several legacy configuration and power management inferfaces, including the Plug and Play BIOS specification (PnP BIOS), the MultiProcessor specification(MPS), and the Advanced Power Management(APM) specification. if both ACPI and APM support are configured, whichever is loaded first will be used.

    ————
    NUMA

    Non-Uniform Memory Access or Non-Uniform Memory Architecture (NUMA) is a computer memory design used in multiprocessors, where the memory access time depends on the memory location relative to a processor. Under NUMA, a processor can access its own local memory faster than non-local memory, that is, memory local to another processor or memory shared between processors.

    ————


    Linux内核中的可编程间隔定时器PIT(Programmable Interval Timer)

    每个PC机中都有一个PIT,通过IRQ产生周期性的时钟中断信号来充当系统定时器。i386中使用的通常是Intel 8254 PIT芯片,它的I/O端口地址范围是40h~43h。

    8254 PIT有3个计时通道,每个通道都有其不同的用途:

    通道0用来负责更新系统时钟。它在每一个时钟滴答会通过IRQ0向系统发出一次时钟中断信号。
    通道1通常用于控制DMAC对RAM的刷新。
    通道2被连接到PC机的扬声器,以产生方波信号。

    http://blog.csdn.net/axx1611/archive/2007/09/15/1786599.aspx
    http://en.wikipedia.org/wiki/Programmable_Interval_Timer

    分享到:

    历史上的今天:

    IA-32平台 2010-11-13
    Linux Road Map 2010-11-13

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