54 lines
1.5 KiB
HTML
54 lines
1.5 KiB
HTML
<title>Homework: xv6 and Interrupts and Exceptions</title>
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<html>
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<head>
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</head>
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<body>
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<h1>Homework: xv6 and Interrupts and Exceptions</h1>
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<p>
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<b>Read</b>: xv6's trapasm.S, trap.c, syscall.c, vectors.S, and usys.S. Skim
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lapic.c, ioapic.c, and picirq.c
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<p>
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<b>Hand-In Procedure</b>
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<p>
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You are to turn in this homework during lecture. Please
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write up your answers to the exercises below and hand them in to a
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6.828 staff member at the beginning of the lecture.
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<p>
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<b>Introduction</b>
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<p>Try to understand
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xv6's trapasm.S, trap.c, syscall.c, vectors.S, and usys.S. Skim
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You will need to consult:
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<p>Chapter 5 of <a href="../readings/ia32/IA32-3.pdf">IA-32 Intel
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Architecture Software Developer's Manual, Volume 3: System programming
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guide</a>; you can skip sections 5.7.1, 5.8.2, and 5.12.2. Be aware
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that terms such as exceptions, traps, interrupts, faults and aborts
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have no standard meaning.
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<p>Chapter 9 of the 1987 <a href="../readings/i386/toc.htm">i386
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Programmer's Reference Manual</a> also covers exception and interrupt
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handling in IA32 processors.
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<p><b>Assignment</b>:
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In xv6, set a breakpoint at the beginning of <code>syscall()</code> to
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catch the very first system call. What values are on the stack at
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this point? Turn in the output of <code>print-stack 35</code> at that
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breakpoint with each value labeled as to what it is (e.g.,
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saved <code>%ebp</code> for <code>trap</code>,
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<code>trapframe.eip</code>, etc.).
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<p>
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<b>This completes the homework.</b>
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</body>
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