ARMv8-A Architecture

Question 1

The ARMv8-A architecture is?

Answer 1

Is a RISC
Is a Load/Store machine
• Register file contains 31 64-bit-wide registers
• Most instructions manipulate 64-bit or 32-bit data stored in these registers
Uses a von Neumann architecture for RAM

Question 2

What are the 4 exception levels of the ARMv8-A architecture?

Answer 2

EL0: for normal user applications with limited privileges
EL1: for the OS kernel
EL2: for a Hypervisor
EL3: Low-level firmware

Question 3

How many general purpose registers does AArch64 have?

Answer 3

31, numbered 0 to 30

Question 4

Registers x0-x7 are used for?

Answer 4

Passing arguments into a procedure and returning results

Question 5

Register x8 is a?

Answer 5

Indirect result location register

Question 6

Registers x9-x15 are?

Answer 6

Temporary registers (caller saved)

Question 7

Registers x16, x17 are?

Answer 7

Intra-procedure-call temporary registers (IP0, IP1)

Question 8

Register x18 is a?

Answer 8

Platform register

Question 9

Registers x19-x28 are?

Answer 9

Callee-Saved registers. Values are preserved by any function called

Question 10

Register x29 is the?

Answer 10

Frame Pointer Register

Question 11

Register x30 is the?

Answer 11

Procedure Link Register

Question 12

The stack pointer register is?

Answer 12

Used to point to the top of the run-time stack (SP)

Question 13

The zero register is?

Answer 13

A register that always gives 0 when read from and discards any value written to it (X/WZR)

Question 14

The program counter register does what?

Answer 14

Holds the address of the currently executing instruction and cannot be accessed directly as a named register