| 0x08 | high address |
| 0x07 | arguments and env. |
| 0x06 | stack |
| 0x05 | shared memory |
| 0x04 | heap |
| 0x03 | uninitialized data |
| 0x02 | initialized data |
| 0x01 | program text |
| 0x00 | low address |
exec() read the 8 and 7 from file.
exec() initial the 6.
program manage the 3.
programmer manage the 5.