1. CS 140 Lecture Notes: Virtual MemorySlide 1 Load-Time Relocation Process 1 0 ∞ Process 3 Operating System Process 6

2. Base & Bounds Example CS 140 Lecture Notes: Virtual MemorySlide 2 Virtual Address Space 2000 1420 140 62 0 66 CALL 140 RETURN... SP

3. CS 140 Lecture Notes: Virtual MemorySlide 3 x86-64 Address Translation 1216 99 9 Page Table Page Directory (PML2) Page Directory Pointer Table (PML3) PML4 Table 52-bit Physical Address OffsetPage Frame 1240 PML4 Base 9 64-bit Virtual Address not used

4. CS 140 Lecture Notes: Virtual MemorySlide 4 Accessing User Memory User Address Space (Virtual) Pages OS Address Space (Physical) buffer write(fd, buffer, length)

5. CS 140 Lecture Notes: Virtual MemorySlide 5 OS and User in Same Address Space Code 0 ∞ Data Stack Operating System

6. CS 140 Lecture Notes: Virtual MemorySlide 6