ASM Base 10 to Base 4 (char)

void base10To4(int, char*) {
    _asm {
        mov eax, [ebp+8]
        mov ebx, 4 // new base
        mov ecx, 0
        mov esi, [ebp+12]
        _while1:
            mov edx, 0
            div ebx
            add edx, '0'
            mov [esi+ecx], dl

            inc ecx
            cmp al, 0
            je _endwhile
            jmp _while1
        _endwhile:

        mov byte ptr[esi + ecx], 0

    };
}