TTY terminal scroll function

void terminal_scroll()
{
    size_t index = 0;
    size_t buffer_size = VGA_WIDTH * VGA_HEIGHT;
    while (terminal_buffer[index])
    {
        if (index + VGA_WIDTH < buffer_size)
            terminal_buffer[index] = terminal_buffer[index + VGA_WIDTH];
        else
            terminal_buffer[index] = vga_entry(' ', terminal_color);
        index++;
    }
}