P3b

New xv6 virtual memory layout


+---------------+ USERTOP = 0XA0000             high address
|               | 
|               | STACK
+---------------+ tp
|       |       |
|       v       |
|               | >= 5 pages as a gap
|       ^       |
|       |       |
+---------------+ sz
|               |
|               | HEAP
+---------------+ 0x3000  
|               |
|               | CODE + DATA   
+---------------+ 0x2000                    
|               |
|   (UNMAPPED)  |
+---------------+                               low address