CS460 LAB7
      1. Download samples/LAB7/lab7.tgz

      2. Will explain code in class:
      Kernel mapped HIGH to VA=2GB,
      must include lowest 1MB for vector area

      3. Umode image mapped LOW to VA=1MB

      4. vector table can be remapped to 0xFFFF0000 by MMU control register.
      5. can build new pgtable for 258MB to  VA=2GB
         with vector remapping to 0xFFFF0000, UMode VA start from 0
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      6. Figure out how to implement these. PARTIAL
      and WORK                           FULL
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