Re: bootloader-bios interaction

From: Craig Bergren (cbergren_at_tvbox.bergren.us)
Date: 11/24/04

  • Next message: kugle: "ppc kernel kernel access of bad area problem" 
    Date: Wed, 24 Nov 2004 22:54:10 GMT

    On Sun, 21 Nov 2004 21:11:27 +0800, du wrote:

    >
    > "Uday Mullangi" <udaymullangi@lucent.com>
    >> Hi,
    >>
    >> I am looking for the boot sequence for Linux OS (Intel P4 processor) In
    >> particular, where the BIOS finisies the POST and jumps to the
    > predefined
    >> location where the bootloader code is executed. I believe while the BIOS
    > is
    >> running the processor is configured in real mode. So when the bootloader
    >> code is executing, will the processor switch to protected mode?( i am
    >> not
    >

    For a description of the boot process, see this file in the kernel source
    distribution "linux/Documentation/i386/boot.txt". You can download a copy
    from kernel.org.

    > No,bootloader running in real mode then it do not load the whole kernel
    > image.
    > Bootloader only load part of kernel,and jump to it. In the kernel ,there
    > is a asm function named setup() switch the processor to protected mode and
    > call startup_32().The startup_32 do something and load other
    > part of kernel image

    I think this is the sequence for Windoze. I've never seen setup() and
    setup_32() in Linux.

    >> Could anyone give me some pointers about this execution ??

    Look in "linux/arch/i386/boot/setup.S" this is where the bios calls in
    real mode and the switch to protected happens.

    >>

  • Next message: kugle: "ppc kernel kernel access of bad area problem"

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