Below is the = code for an=20 interrupt wrapper I'm trying to get to work, along with it's setup code. = It is a=20 modified

version of the interrupt wrapper code from=20 Allegro. In theory, the wrapper allows for two different functions to be = called:

one with interrupts disabled = and the other=20 one with interrupts enabled. This is so that very long functions can=20 be

associated with an irq without = having=20 interrupts disabled long enough to mess up the = program.

That's = theory,=20 though. The truth is, this thing is WAY too erratic. I tested it with a = couple=20 of simple functions

that only set a flag when they were called. Although = the=20 functions were never actually called, the wrapper = WAS!!

That was one out of every five tries or so, the rest = of the=20 time the program simply died and locked my machine

up, and it seems that the = farthest EIP ever got was the ljump instruction below, = so I can't tell if=20 the code after that

works at all.

Please, = somebody=20 help me! I don't know what is wrong and there simply aren't any=20 experienced

ASM programmers around here! I've checked it about a = hundred=20 times and cannot find anything wrong. Any help would

be greatly appreciated.

= =20 Miguel Angel.

= =20 ordorica AT df1 DOT telmex DOT net DOT mx=

= =20 sleeptk AT geocities DOT com

P.S. If you think this is not a good approach, = please let me=20 know of any other I could use.

.text

#define=20 WRAPPER(x)          &nb= sp;           &nbs= p;            = ;            =          =20 ; \
.globl=20 __wrapper_isr_inside_##x        &= nbsp;           &n= bsp;           &nb= sp;          =20 ; \
   .align=20 4            =             &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;  =20 ;=20 \
__wrapper_isr_inside_##x:      &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;     =20 ; \
   pushw=20 %ds           &nbs= p;            = ;     =20 /* save registers=20 */            = ; ;=20 \
   pushw=20 %es           &nbs= p;            = ;            =             &= nbsp;           &n= bsp; =20 ; \
   pushw=20 %fs           &nbs= p;            = ;            =             &= nbsp;           &n= bsp; =20 ; \
   pushw=20 %gs           &nbs= p;            = ;            =             &= nbsp;           &n= bsp; =20 ; \
  =20 pushal           &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;            = ;     =20 ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;     =20 ; \
   .byte=20 0x2e           &nb= sp;           &nbs= p;    =20 /* cs: override=20 */            = ;  =20 ; \
   movw ___djgpp_ds_alias,=20 %ax           &nbs= p;            = ;            =         =20 ; \
   movw %ax,=20 %ds           &nbs= p;            = ; =20 /* set up selectors=20 */           ;=20 \
   movw %ax,=20 %es           &nbs= p;            = ;            =             &= nbsp;         =20 ; \
   movw %ax,=20 %fs           &nbs= p;            = ;            =             &= nbsp;         =20 ; \
   movw %ax,=20 %gs           &nbs= p;            = ;            =             &= nbsp;         =20 ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ; \
   movl $x,=20 %esi           &nb= sp;           &nbs= p;            = ;            =           =20 ; \
   movl __stacks(,%esi,4),=20 %ebx           &nb= sp;           &nbs= p;            = ;       =20 ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ; \
   movl %esp,=20 %ecx           &nb= sp;           =20 /* old stack in ecx + dx */      ; = \
  =20 movw %ss,=20 %dx           &nbs= p;            = ;            =             &= nbsp;         =20 ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ; \
   movl %ebx,=20 %esp           &nb= sp;           =20 /* set up our stack=20 */           ;=20 \
   movw %ax,=20 %ss           &nbs= p;            = ;            =             &= nbsp;         =20 ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ; \
   pushl=20 %edx           &nb= sp;           &nbs= p;    =20 /* push old stack onto new */    ; \
   = pushl=20 %ecx           &nb= sp;           &nbs= p;            = ;            =             &= nbsp;=20 ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;     =20       ; \
  =20 cld           &nbs= p;            = ;           =20 /* clear the direction flag */   ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ; \
   movl __addresses_isr_inside(,%esi,4),=20 %eax           &nb= sp;           &nbs= p;     =20 ; \
   call=20 *%eax           &n= bsp;           &nb= sp;    =20 /* call the C handler */         = ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ; \
  =20 cli           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;       =20 ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ; \
   popl=20 %ecx           &nb= sp;           &nbs= p;     =20 /* restore the old stack */      ; = \
  =20 popl=20 %edx           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ; \
   movw %dx,=20 %ss           &nbs= p;            = ;            =             &= nbsp;         =20 ; \
   movl %ecx,=20 %esp           &nb= sp;           &nbs= p;            = ;            =         =20 ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ; \
   orl %eax,=20 %eax           &nb= sp;           &nbs= p;=20 /* check return value */         = ;=20 \
   jz=20 get_out_##x          &n= bsp;           &nb= sp;           &nbs= p;            = ;          =20 ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ; \
  =20 popal           &n= bsp;           &nb= sp;         =20 /* chain to old handler */       ;=20 \
   popw=20 %gs           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
   popw=20 %fs           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
   popw=20 %es           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
   popw=20 %ds           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
   pushl=20 __flags           =             &= nbsp;           &n= bsp;           &nb= sp;          =20 ; \
   pushl=20 __code_sel          &nb= sp;           &nbs= p;            = ;            =         =20 ; \
   movl %esi,=20 __temp           &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;      =20 ; \
   movl $x,=20 %esi           &nb= sp;           &nbs= p;            = ;            =           =20 ; \
   pushl=20 __addresses_isr_after(,%esi,4)       &= nbsp;           &n= bsp;           &nb= sp;   =20 ; \
   movl __temp,=20 %esi           &nb= sp;           &nbs= p;            = ;            =       =20 ; \
   ljmp=20 %cs:__addresses_old_isr+4*x       &nbs= p;            = ;            =        =20 ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ;=20 \
get_out_##x:         &n= bsp;           &nb= sp;           &nbs= p;            = ;            =     =20 ; \
  =20 popal           &n= bsp;           &nb= sp;         =20 /* iret=20 */            = ;          =20 ; \
   popw=20 %gs           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
   popw=20 %fs           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
   popw=20 %es           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
   popw=20 %ds           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
   pushl=20 __flags           =             &= nbsp;           &n= bsp;           &nb= sp;          =20 ; \
   pushl=20 __code_sel          &nb= sp;           &nbs= p;            = ;            =         =20 ; \
   movl %esi,=20 __temp           &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;      =20 ; \
   movl $x,=20 %esi           &nb= sp;           &nbs= p;            = ;            =           =20 ; \
   pushl=20 __addresses_isr_after(,%esi,4)       &= nbsp;           &n= bsp;           &nb= sp;   =20 ; \
   movl __temp,=20 %esi           &nb= sp;           &nbs= p;            = ;            =       =20 ; \
  =20 sti           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;       =20 ; \
  =20 iret           &nb= sp;           &nbs= p;            = ;            =             &= nbsp;      =20 ;=20 \
           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =             &= nbsp; =20 ; \
.globl=20 __wrapper_isr_after_##x        &n= bsp;           &nb= sp;           &nbs= p;           =20 ; \
   .align=20 4            =             &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;  =20 ; \
  =20 __wrapper_isr_after_##x:        &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;  =20 ; \
   pushw=20 %ds           &nbs= p;            = ;            =             &= nbsp;           &n= bsp; =20 ; \
   pushw=20 %es           &nbs= p;            = ;            =             &= nbsp;           &n= bsp; =20 ; \
   pushw=20 %fs           &nbs= p;            = ;            =             &= nbsp;           &n= bsp; =20 ; \
   pushw=20 %gs           &nbs= p;            = ;            =             &= nbsp;           &n= bsp; =20 ; \
  =20 pushal           &= nbsp;           &n= bsp;           &nb= sp;           &nbs= p;            = ;     =20 ; \
   movl $x,=20 %esi           &nb= sp;           &nbs= p;            = ;            =           =20 ; \
   movl __addresses_isr_after(,%esi,4),=20 %eax           &nb= sp;           &nbs= p;      =20 ; \
   call=20 *%eax           &n= bsp;           &nb= sp;           &nbs= p;            = ;            = =20 ; \
  =20 cli           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;       =20 ; \
  =20 popal           &n= bsp;           &nb= sp;           &nbs= p;            = ;            =       =20 ; \
   popw=20 %gs           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
   popw=20 %fs           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
   popw=20 %es           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
   popw=20 %ds           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;  =20 ; \
  =20 sti           &nbs= p;            = ;            =             &= nbsp;           &n= bsp;       =20 ; \
   iret

WRAPPER(0);
WRAPPER(1);
WRAPPER(2);
WRAPPER(3);
WRAP= PER(4);
WRAPPER(5);
WRAPPER(6);
WRAPPER(7);

.globl=20 __wrapper_isr_inside_0_end
.align=20 4
__wrapper_isr_inside_0_end:
ret

Somewhere else...

extern void = _wrapper_isr_inside_0(),=20 _wrapper_isr_inside_1(),=20 _wrapper_isr_inside_2(),
       &nb= sp;   =20 _wrapper_isr_inside_3(), _wrapper_isr_inside_4(),=20 _wrapper_isr_inside_5(),
       &nb= sp;   =20 _wrapper_isr_inside_6(),=20 _wrapper_isr_inside_7(),
       &nb= sp;   =20 _wrapper_isr_inside_0_end(),
       = ;    =20 _wrapper_isr_after_0(), _wrapper_isr_after_1(),=20 _wrapper_isr_after_2(),
       &nbs= p;   =20 _wrapper_isr_after_3(), _wrapper_isr_after_4(),=20 _wrapper_isr_after_5(),
       &nbs= p;   =20 _wrapper_isr_after_6(), _wrapper_isr_after_7();

dword _flags, _temp,=20 _code_sel;
dword=20 _addresses_isr_inside[NO_OF_WRAPPERS],
     &= nbsp;=20 _addresses_isr_after[NO_OF_WRAPPERS],
     &n= bsp;=20 _addresses_old_isr[NO_OF_WRAPPERS];
int  =20 _int_numbers[NO_OF_WRAPPERS];
__dpmi_paddr=20 _old_handlers[NO_OF_WRAPPERS];
byte=20 *_stacks[NO_OF_WRAPPERS];

int=20 irq_handling_startup(void)
{
int counter;

for(counter=3D0;=20 counter<NO_OF_WRAPPERS; counter++)
    =20 {
      =20 _addresses_isr_inside[counter]=3DNULL;
     &= nbsp;=20 _addresses_isr_after[counter]=3DNULL;
     &n= bsp;=20 _addresses_old_isr[counter]=3D=3DNULL;
     &= nbsp;=20 _int_numbers[counter]=3D=3DNULL;
       = _stacks[counter]=3D((byte=20 *)malloc(STACK_SIZE))+STACK_SIZE-32;
     &nb= sp;=20 LOCK_ARRAY(_stacks[counter]-STACK_SIZE+32, STACK_SIZE,=20 sizeof(byte));
     }

= _code_sel=3D_my_cs();

__asm__=20 volatile
    (
    =20 "pushfl\n\t
      popl=20 %%eax\n\t
      movl %%eax,=20 __flags\n\t"
      :=20 :
      : "eax", = "memory"
   =20 );

=20 LOCK_FUNCTION(_wrapper_isr_inside_0);
=20 LOCK_ARRAY(_addresses_isr_inside, NO_OF_WRAPPERS, = sizeof(dword));
=20 LOCK_ARRAY(_addresses_isr_after, NO_OF_WRAPPERS, = sizeof(dword));
=20 LOCK_ARRAY(_addresses_old_isr, NO_OF_WRAPPERS, sizeof(dword));
= LOCK_ARRAY(_int_numbers, NO_OF_WRAPPERS, sizeof(int));
=20 LOCK_ARRAY(_old_handlers, NO_OF_WRAPPERS, = sizeof(__dpmi_paddr));
=20 LOCK_ARRAY(_stacks, NO_OF_WRAPPERS, sizeof(dword));
=20 LOCK_VARIABLE(_temp);
LOCK_VARIABLE(_flags);
=20 LOCK_VARIABLE(_code_sel);

return = 0;
}

int take_over_irq(int number, = int=20 (*inside)(void), void (*after)(void))
{
int=20 counter;
__dpmi_paddr address;

   for(counter=3D0;=20 counter<NO_OF_WRAPPERS; counter++)
     =20 {
       =20 if(_addresses_isr_inside[counter]=3D=3DNULL)
    &= nbsp;    =20 goto free1;
      }

return = -1;

free1:

  =20 _int_numbers[counter]=3Dnumber;
  =20 _old_handlers[counter].selector=3D_my_cs();
  =20 _addresses_isr_inside[counter]=3D(dword)inside;
  =20 _addresses_isr_after[counter]=3D(dword)after;

  =20 switch(counter)
    =20 {
       default: return=20 -1;
       case 0:=20 address.offset32=3D(dword)_wrapper_isr_inside_0;=20 break;
       case 1:=20 address.offset32=3D(dword)_wrapper_isr_inside_1;=20 break;
       case 2:=20 address.offset32=3D(dword)_wrapper_isr_inside_2;=20 break;
       case 3:=20 address.offset32=3D(dword)_wrapper_isr_inside_3;=20 break;
       case 4:=20 address.offset32=3D(dword)_wrapper_isr_inside_4;=20 break;
       case 5:=20 address.offset32=3D(dword)_wrapper_isr_inside_5;=20 break;
       case 6:=20 address.offset32=3D(dword)_wrapper_isr_inside_6;=20 break;
       case 7:=20 address.offset32=3D(dword)_wrapper_isr_inside_7;=20 break;
     }

  =20 address.selector=3D_my_cs();
  =20 __dpmi_get_protected_mode_interrupt_vector(number,=20 &(_old_handlers[counter]));
  =20 _addresses_old_isr[counter]=3D_old_handlers[counter].offset32;
&= nbsp;=20 if(__dpmi_set_protected_mode_interrupt_vector(number,=20 &address))
     return -1;

return = 0;
}

--Boundary_(ID_XytOd57ALm4yiMC+JoShAQ)--