What do the noapic/nolapic kernel arguments do? - Linux

This is a discussion on What do the noapic/nolapic kernel arguments do? - Linux ; Hi everyone, I have been reading Chapter 9 of the Intel Processor Manuals, Vol 3A (System Programming Guide), which details the APIC. I have noticed that we often have to add the noapic and nolapic arguments to the kernel command ...

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Thread: What do the noapic/nolapic kernel arguments do?

  1. What do the noapic/nolapic kernel arguments do?

    Hi everyone,

    I have been reading Chapter 9 of the Intel Processor Manuals, Vol 3A
    (System Programming Guide), which details the APIC.
    I have noticed that we often have to add the noapic and nolapic
    arguments to the kernel command line to make devices like the wireless
    card work. The explanation for these options simply stated that this
    is to overcome "buggy bios implementations".

    Can someone here explain what could possibly be the bug in the bios
    that necessitates the use of these arguments? Further, what does the
    kernel do differently when it sees these arguments?

    Thanks for your help,
    Mayank

  2. Re: What do the noapic/nolapic kernel arguments do?

    funkymunky writes:
    > I have been reading Chapter 9 of the Intel Processor Manuals, Vol 3A
    > (System Programming Guide), which details the APIC.
    > I have noticed that we often have to add the noapic and nolapic
    > arguments to the kernel command line to make devices like the wireless
    > card work. The explanation for these options simply stated that this
    > is to overcome "buggy bios implementations".
    >
    > Can someone here explain what could possibly be the bug in the bios
    > that necessitates the use of these arguments? Further, what does the
    > kernel do differently when it sees these arguments?


    noapic [SMP,APIC] Tells the kernel to not make use of any
    IOAPICs that may be present in the system.

    nolapic [X86-32,APIC] Do not enable or use the local APIC.

    Documentation for kernel commandline arguments can be found in
    Documentation/kernel-parameters.txt (part of the Linux-sources).


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