#generate 16-bit code
.code16

#hint the assembler that here is the executable code located
.text
.globl _start;
#boot code entry
_start:
      jmp _boot                           #jump to boot code
      welcome: .asciz "Hello, new World\n\r"  #here we define the string
      enter_number: .asciz "Enter a number: \n\r"
      lower_msg: .asciz "\nYour number is to low :( \n\r"   # 26
      higher_msg: .asciz "\nYour number is to high :( \n\r" # 27
      winner_msg: .asciz "\nYour are the CAMPION, :D \n\r"  # 26

     .macro mWriteString str              #macro which calls a function to print a string
          leaw  \str, %si
          call .writeStringIn
     .endm

     # function to print the string
     .writeStringIn:
          lodsb
          orb  %al, %al
          jz   .writeStringOut
          movb $0x0e, %ah
          int  $0x10
          jmp  .writeStringIn
     .writeStringOut:
     ret

.type get_number, @function
  get_number:
   
    # save state before function
    push %bp
    mov %sp, %bp

    push %bx
    push %cx
    # Start of function
    mWriteString enter_number

    mov $0, %ah
    mov $0, %al
    int $0x16 
  
    mov $0x0E, %ah
    int $0x10

    pop %cx
    pop %bx

    mov %bp, %sp
    pop %bp
    ret

    .type string_to_int, @function
      string_to_int:
        /* Converts a string to an integer. Returns the integer in %rax.
         * %rax: Address of string to convert.
         */
        push %bp
        mov %sp, %bp
       
        push %bx
        push %cx
       
        mov %ax, %dx

        cmp $47, %dx
        jl not_a_num
        cmp $57, %dx
        jg not_a_num
                              # I multiply by 10 to shift the number one placement to the right to add the newest integer.
        sub $48, %dx 
        jmp convertdone        # In ascii, numbers start at 0 = 48, 1 = 49, 2 = 50 and so on. So I subtract 48 to get the digit.
        
        not_a_num:
        xor %dx, %dx

        convertdone:
       
        pop %cx
        pop %bx
       
        mov %bp, %sp
        pop %bp
        ret


_boot:
    mWriteString welcome

  guess:
    call get_number
    xor %ah, %ah
    call string_to_int

    cmp $5, %dx

    jl if_lower
    je if_eg
    jg if_higher

  if_lower:
    mWriteString lower_msg
    jmp guess

  if_higher: 
    mWriteString higher_msg
    jmp guess

  if_eg:
    mWriteString winner_msg  

     #move to 510th byte from the start and append boot signature
     . = _start + 510
     .byte 0x55
     .byte 0xaa