PLEASE Show how you solve the PROBLEM!!

Learning Objectives

• Can understand simple x86 machine instructions
• Can interpret arithmetic and shift operators
• Can interpret conditional jump statements
• Can interpret looping constructs

Directions

• Show the contents of the registers and memory after each of these short programs executes.
• See https://www.felixcloutier.com/x86/ for unfamiliar instructions.
• See https://www.calculator.net/hex-calculator.html for a hex calculator

Problem #2:

1. Assume rbp initially holds address 0x48000

2. IDA set up these symbols for you

var_C = dword ptr -0Ch

var_8 = dword ptr -8

var_4 = dword ptr -4

3. Interpret this code

mov [rbp+var_C], 0Ah

mov [rbp+var_4], 6

mov [rbp+var_8], 1Eh

mov edx, [rbp+var_C]

mov eax, [rbp+var_4]

add eax, edx

cmp [rbp+var_8], eax

jle short loc_40159D

mov edx, [rbp+var_4]

mov eax, edx

add eax, eax

add eax, edx

mov [rbp+var_4], eax

jmp short loc_4015BB

loc_40159D:

mov eax, [rbp+var_4]

cmp eax, [rbp+var_8]

jle short loc_4015B0

mov eax, [rbp+var_C]

sub eax, [rbp+var_4]

mov [rbp+var_8], eax

jmp short loc_4015BB

loc_4015B0:

mov edx, [rbp+var_C]

mov eax, [rbp+var_4]

add eax, edx

mov [rbp+var_8], eax

loc_4015BB:

4. Show the results of executing the code in the registers and memory. Express your answers in hex.

Registers

eax
ebx
ecx
edx	6uh
rbp	0x48000

Memory

0x47FDC
0x47FE0
0x47FE4	05h
0x47FE8	5c2h
0x47FEC
0x47FF0	0Ah
0x47FF4	1Eh
0x47FF8
0x47FFC	0Ah
0x48000
0x48004
0x48008