Nasm - "real" randomness via uninitialized variables?

In NASM, uninitialized variables are typically filled with zeros or other default values by the operating system or the runtime environment. Therefore, relying on uninitialized variables for "real" randomness is not a reliable approach.

If you need to generate random numbers or obtain random data in NASM, it is recommended to use a proper random number generator or a library that provides random number generation functions. For example, you can use the rand function from the C library, which can be called from NASM using appropriate function call conventions.

Here's an example NASM code that uses the rand function to generate a random number:

assemblyCopy code
section .data

    message db "Random number: %d", 0



section .text

    extern printf

    extern rand



    global _start



_start:

    ; Initialize the random number generator

    mov eax, 0

    call srand



    ; Generate a random number

    call rand

    mov ebx, eax



    ; Print the random number

    push ebx

    push message

    call printf

    add esp, 8



    ; Exit the program

    mov eax, 1

    xor ebx, ebx

    int 0x80

Note that this example assumes a Linux environment and uses the printf and srand functions from the C library. If you're working on Windows, you would need to adapt the code accordingly and link against the appropriate libraries.

It's important to use proper random number generation techniques to ensure the randomness and security of your application. Relying on uninitialized variables is not a reliable or recommended approach.