Chapter 8 Main Memory

Ways to manage memory & Hardware support

Execution cycle -- fetch, decode, fetch operands, execute, store result
Nonetheless, memory only see a stream of addresses

Basic hardware -- base register and limit register

Address binding -- compile time, load time, execution time

Logical address vs. physical address
Address space
MMU

Relocation register, dynamic loading, dynamic linked libraries

Swapping, backing store

Contiguous memory allocation
OS partition and user partition, multiple partitions
Location of interrupt vector, start location upon boot

Internal and external fragmentation

Paging, page frame, page table
Address calculation -- address is page number and page offset
No external fragmentation, internal fragmentation about 1/2 page per process
Small vs. large page sizes

Page-table base register (PTBR)
Translation look-aside buffer (TLB)

Hierarchical paging
Two-level paging
Hashed page tables -- inverted page tables

Segmentation
Segmentation registers