ASM Instructions Flashcards
(18 cards)
ADD op1, op2
Adds op2 to op1 and stores in EAX
SUB op1, op2
Subtracts op2 from op1 and stores in EAX
XOR EAX, EAX
‘Exclusive or’ a register; clears contents of the register
INC op1
Increment op1 by 1
DEC op1
Decrement op1 by 1
CMP op1, op2
Compare (subtract) the value of op1 (register/memory address) with op2 (register/memory address/constant) and set EFLAGS; if op1 = op2 then ZF=1, CF=0; if op1 < op2 then ZF=0, CF=1; if op1 > op2 then ZF=0, CF=0
JMP location
Jumps to a new location and executes
JZ/JE location
Jumps to specified location if ZF=1 following a test; JZ usually used to test if something is explicitly 0; JE commonly found after CMP
JNZ/JLE location
Jumps to specified location if ZF=0 following a test; JNZ usually used to test if something is not set to 0; JNE commonly found after CMP
JECXZ location
Jumps to specified location if ECX=0
AND destination, value
Logical AND operation; equiv to & in python; can be used as modulo
CALL function_name
calls a function; pushes return address (address immediately after CALL) onto stack and changes EIP to destination
CLD
clears direction flag (DF=0); controls incrementing or decremeting counter
(I)DIV value
Performs division (dividend = EDX:EAX, divisor = value, following DIV EAX=quotient, EDX=remainder)
(I)MUL register, (EAX)
Signed multiplication; multiplies two registers (EAX if not specified) and stores product in EDX:EAX
LEA destination, source
Loads memory address into the destination
LODS(B|D|W) register
Loads byte/word/doubleword at register address into EAX.
LOOP arg
Decrements ECX and jumps to arg unless ECX becomes 0.
