why call _level0 for idle_task - Minix

This is a discussion on why call _level0 for idle_task - Minix ; hi there seems to be no one left in this forum since my last posts went all unanswered but ill still give it another try: why does the idle_task have to do a call to _level0? afaik , idle task ...

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Thread: why call _level0 for idle_task

  1. why call _level0 for idle_task

    hi

    there seems to be no one left in this forum since my last posts went
    all unanswered but ill still give it another try:
    why does the idle_task have to do a call to _level0? afaik, idle task
    ALREADY executes with pl = 0. just look at:

    08621 privilege = (iskernelp(rp)) ? TASK_PRIVILEGE :
    USER_PRIVILEGE;

    in alloc_segments. am i getting something wrong or is this really an
    unnecessary call?

    thanx,

    martin


  2. Re: why call _level0 for idle_task

    In article <1170761161.201473.119410@a75g2000cwd.googlegroups. com>,
    sancho1980 wrote:
    >hi
    >
    >there seems to be no one left in this forum since my last posts went
    >all unanswered but ill still give it another try:
    >why does the idle_task have to do a call to _level0? afaik, idle task
    >ALREADY executes with pl = 0. just look at:
    >
    >08621 privilege = (iskernelp(rp)) ? TASK_PRIVILEGE :
    >USER_PRIVILEGE;
    >
    >in alloc_segments. am i getting something wrong or is this really an
    >unnecessary call?


    You need 0 (INTR_PRIVILEGE) for the halt instruction, and TASK_PRIVILEGE
    is at level 1.


    --
    That was it. Done. The faulty Monk was turned out into the desert where it
    could believe what it liked, including the idea that it had been hard done
    by. It was allowed to keep its horse, since horses were so cheap to make.
    -- Douglas Adams in Dirk Gently's Holistic Detective Agency

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