Convert binary to hexadecimal in the 80x86 assembly

I'm looking for a program that coverts a String of 1's and 0's to hexadecimal string in assembly, where the binary string comes from a code that I write in 'C'.

for example:

10111111100-> "5 F C"

The problem is that for more than 12 chars input , the output is wrong , and my mission demands at most 32 chars.

for example given 110010101111-> "CAF" it works ok! but giving 10010001101000101011001111000 should be "12345678" but i only get "123" debugging with gdb tool i see that the values are being override . how to take care of this with minimal changes in the code? Thanks

The idea is to transform the string pointed by ecx to a value in eax. now i want to take the 4 most right each time and convert them , and them put them in edx .

So far, I have:

section .rodata
  DB    "The result is:  %s", 10, 0 ; Format string

section .bss

  RESB  32

section .text
  align 16

  global my_func
  extern printf

  push  ebp
  mov   ebp, esp            ; Entry code - set up ebp and esp
  pusha                   ; Save registers
  mov ecx, dword [ebp+8]    ; Get argument (pointer to string)
  mov ebx, 0              ; counter for length
  mov eax, 0              ; will hold the string as a value
  mov edx, 0              ; manipulation helper
  mov edi, 0              ; counter for ehile_length loop

  inc ebx
  cmp byte [ecx+ebx], 0x00
  jne length
  dec ebx


  inc ecx
  cmp byte [ecx], 0x0
  JNE bring_ecx_to_end
    dec ecx
    dec ecx
    or edi ,ebx
    add esi,1

  mov  dl,byte [ecx]      ; gets 1 char into edx
  cmp DL, 0x31            ; the right character
  JE inc1                 ; if it  a '1'    

  shl esi,1 ; multiply by 2
  dec ecx
  sub edi,1
  cmp edi,0
  jne while_length

;;;;;;;;;;NOW EAX CONSISTS THE STRING ;;;;;;;;;;;;;;

mov dword edx,0 ;target register

        mov dword edi ,0
        add edi ,15 ; masking

        and edi,eax
        cmp di , 10
         jl less_than_10

          add di ,55
          jmp resume

     add di ,48

     or edx,edi
     shl edx,8
     shr eax,4
     cmp al ,0
      jne while

      shr edx , 8


  mov dword [LC1],edx

  push LC1                ; Call printf with 2 arguments: pointer to str
  push LC0                ; and pointer to format string.
  call printf
  add esp, 8              ; Clean up stack after call

  popa                    ; Restore registers
  mov   esp, ebp            ; Function exit code
  pop   ebp

  or eax, esi
  jmp resume_loop

If it is the task to convert a string of zeroes and ones into a string of hexcharacters ("10111111100" -> "000005FC") then the first thing to do is to put the value of the source string in a register. You need to setup ECX to point to the string LC1 .

mov ecx,[ebp+8]  ;Pointer to an ASCIIZ string of zero and one characters.
xor ebx,ebx
rcl ebx,1
mov al,[ecx]
inc ecx
shr al,1
jnz First
mov ecx,LC1  ;Buffer to recieve 8 hexcharacters.
rol ebx,4

You can simplify the code shl al,4 shr al,4 to and al,15 .

shr ebx, 4
inc ecx                             ; increment pointer
cmp byte [ecx], 0                   ; check if byte pointed to is zero
jnz while_ebx_not_zero              ; keep looping until it is null

The end part should not change EBX and jump back 8 times precisely.

inc ecx
cmp ecx,LC1+8
jb Again