Lab 4
Merge branch 'lab3' into lab4
Lab 4
Merge branch 'lab3' into lab4

Conflicts:
	kern/init.c
	kern/pmap.c
	kern/trap.c

≈
backup
my solution for lab 4 till exercise 3
my solution for lab 4 till exercise 5
my solution for lab 4 till exercise 6
My solution for lab 4 till exercise 7
my solution for lab 4 till exercise 12
 partial solution to lab 4 till exercise 15
partial solution 2 for lab 4 till exercise 15
my complete solution for lab 4
Merge pull request #3 from amisharma/lab4

Lab4