Chapter goals

Problems with absolute addressing

• If a program refers to a physical memory address in the code, then OS loses ability to re-arrange application locations in memory
• Instead, programs use relative addressing

Relative addressing

• Instructions that refer to memory use a combination of registers to compute addresses
• When OS loads application into memory, OS loads starting point of application into one register
• Instruction in application that refers to memory location is using an offset (i.e. distance from beginning of application)
• OS adds offset to starting point to calculate physical memory location