These are some assembly instructions to do reverse engineering more easy:
MOV (Move): Copies the value from one location to another.
mov eax, 42 ; Move the value 42 into the eax register
ADD: Adds two values.
add ebx, eax ; Add the value in eax to the value in ebx
SUB: Subtracts one value from another.
sub ecx, edx ; Subtract the value in edx from the value in ecx
CMP (Compare): Compares two values and sets flags based on the result.
cmp esi, edi ; Compare the values in esi and edi and set flags accordingly
JMP (Jump): Unconditionally transfers control to another instruction.
jmp label ; Unconditionally jump to the location labeled "label"
JE (Jump if Equal): Jumps to a specific location if the zero flag is set.
je equal_label ; Jump to "equal_label" if the zero flag is set (previous comparison was equal)
JNE (Jump if Not Equal): Jumps to a specific location if the zero flag is not set.
jne not_equal_label ; Jump to "not_equal_label" if the zero flag is not set (previous comparison was not equal)jz label ; Jump to "label" if the zero flag is set (eax == 0)
JZ: It's a conditional jump instruction that transfers program control to a specified label or memory location if the zero flag (ZF) is set.
jz label ; Jump to "label" if the zero flag is set (eax == 0)
CALL: Calls a subroutine or function.
call my_function ; Call the subroutine or function labeled "my_function"
RET (Return): Returns from a subroutine.
ret ; Return from a subroutine
PUSH: Pushes a value onto the stack.
push eax ; Push the value in eax onto the stack
POP: Pops a value from the stack.
pop ebx ; Pop a value from the stack into the ebx register
AND, OR, XOR: Performs logical AND, OR, and XOR operations on values.
and edx, ebx ; Perform bitwise AND between edx and ebx
or ecx, eax ; Perform bitwise OR between ecx and eax
xor esi, edi ; Perform bitwise XOR between esi and edi
SHL/SHR (Shift Left/Right): Shifts bits left or right.
shl eax, 2 ; Shift the bits in eax left by 2 positions
shr ebx, 1 ; Shift the bits in ebx right by 1 position
INC/DEC (Increment/Decrement): Increases or decreases a value by one.
inc ecx ; Increment the value in ecx by one
dec edx ; Decrement the value in edx by one
LOOP: Decrements a counter and jumps if the counter is not zero.
mov ecx, 5 ; Set ecx to 5 (loop counter)
loop loop_label ; Decrement ecx and jump to "loop_label" while ecx is not zero
NOP (No Operation): Does nothing and acts as a placeholder.
nop ; No operation, does nothing
INT (Interrupt): Triggers an interrupt or software-generated exception.
int 0x80 ; Trigger a software interrupt (Linux system call)
LEA (Load Effective Address): Loads the address of a memory location.
lea ebx, [ecx+edx] ; Load the effective address of ecx+edx into ebx
CMPXCHG (Compare and Exchange): Compares and swaps a value if conditions are met (used in multi-threading).
cmpxchg [eax], ebx ; Compare the value in eax with the value at the memory address pointed by eax and exchange with ebx if equal (used in multi-threading)
XOR: Performs bitwise XOR on two values.
xor eax, eax ; Clear the eax register by XORing it with itself
