Reverse Engineering Software: For Loop in Bomb2.exe

mov     eax, [ebp+arg_4] ; base
add     eax, 14h         ; count*increment

• 3-expressions for (i=0; i < 256; i++) {}
  • Initialization
  • Test
  • Counter
• Note, all parts are optional.
• In most (not all) cases there will be a common variable

This is a classic for loop. Note the 3 parts of a for loop:

• Initialization

loc_4011D1:
mov     [ebp+var_4], 1
jmp     short loc_4011E3

• Test expression

loc_4011E3:
cmp     [ebp+var_4], 6
jge     short loc_401207

• Counter

loc_4011DA:
mov     edx, [ebp+var_4]
add     edx, 1
mov     [ebp+var_4], edx