.global _start

_start: // in the beginning...

//push %ebx // do we need to persist them???
//push %ecx

//cmp $0,_impure_ptr
//jne skipzero

//movl $0xf5000000, _impure_ptr
//mov  $0xf5000000,%ebx

//allzero: 
//movl $0, (%ebx)
//add $4, %ebx
//cmp $0xf5001000,%ebx
//jne allzero

//skipzero:

///////////////////////////////////////////////////////////////////////
// move impure pointer to our special page (todo: check if not htere already!)
mov _impure_ptr,%eax
mov $0xf5000000,%ebx
copy: 
mov (%eax),%ecx
mov %ecx,(%ebx)
add $4, %ebx
add $4, %eax
cmp $0xf5001000,%ebx
jne copy
movl $0xf5000000, _impure_ptr
////////////////////////////////////////////////////////////////////////

call _init // constructors from .ctors

///////////////////////////////////////////////////////////////////////
// constructors from array_init ////////////////////////////
mov $__init_array_start,%eax

nextctor: 
//cmp (__init_array_end),%eax
cmp $__init_array_end,%eax
je finctor

push %eax
call *(%eax)
pop %eax

add $4, %eax
jmp nextctor

finctor: // ready with global ctors
////////////////////////////////////////////////////////////////////////

//pop %ecx
//pop %ebx

###############################################
# environment adress was passed on stack
pop %eax                      
mov %eax, environ
###############################################

pop %ecx        //argc
pop %ebx        //& argv

and $-16,%esp   //align stack
sub $8,%esp

push %ebx      //argv
push %ecx      //& argc

# call main (argc and argv are on the (realigned) tack)
call main

// ALIGN stack again (todo: do we need this!??!!)
and $-16,%esp
sub $4,%esp

push %eax // preserve main return value

call _fini //desctructors from .dtors

call _flushing // force stdout flushin

// pop programmm return value
pop %eax

// ALIGN stack (???)
and $-16,%esp
sub $4,%esp

# push exit code and pass to _exit syscall
push %eax
call exit

# and this should never be reached!!
.wait:
    hlt
jmp .wait