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Interrupts in the Protected Mode

[b][red]This message was edited by Mantaz at 2003-11-27 3:11:3[/red][/b][hr]
Hi, folks.

I've got a question here ;) When I enter the protected mode, how can I use interrupts, that are being used in the real mode, such as 10th, 13th etc? Thanks for help :)


Comments

  • cerdeirocerdeiro Member Posts: 2
    You can NOT use them. =(

    : [b][red]This message was edited by Mantaz at 2003-11-27 3:11:3[/red][/b][hr]
    : Hi, folks.
    :
    : I've got a question here ;) When I enter the protected mode, how can I use interrupts, that are being used in the real mode, such as 10th, 13th etc? Thanks for help :)
    :
    :
    :

  • octavio2octavio2 Member Posts: 16
    : You can NOT use them. =(
    :
    but you can switch back to real mode use the int service and return
    to protected mode, or use v86 mode.
    some service interrupts are also available in protected mode.

  • ryukitsuryukitsu Member Posts: 2
    : : You can NOT use them. =(
    : :
    : but you can switch back to real mode use the int service and return
    : to protected mode, or use v86 mode.
    : some service interrupts are also available in protected mode.
    :
    :
    Hi sorry. Which int service can switch it back to real mode? Do you know of any good links that teach us how to do that?
    Thank you very much in advance.
  • octavio2octavio2 Member Posts: 16
    : Hi sorry. Which int service can switch it back to real mode?
    bit 0 of cr0 sets protected/real mode (386+ required)
    this code sets real mode: eax=cr0 and eax,-2 cr0=eax
    and this code sets protected mode: eax=cr0 or eax,1 cr0=eax
    but you must also do other changes like load a real mode IDT and
    16 bits segment code descriptors its quite complex for a newbie
    because you also need real and protected mode irq handlers, and of course: set up descriptors and interrupts tables .

    :Do you know of any good links that teach us how to do that?
    No, but take a look at: alt.os.development
    The best resource for learnig assembler are the intel manuals
    at intel.com


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