#define hwint_master(irq)       \
call    save                    /* save interrupted process state */;\
push    (_irq_handlers+4*irq)   /* irq_handlers[irq]              */;\
call    _intr_handle            /* intr_handle(irq_handlers[irq]) */;\
pop     ecx                                                         ;\
cmp     (_irq_actids+4*irq), 0  /* interrupt still active?        */;\
jz      0f                                                          ;\
inb     INT_CTLMASK             /* get current mask */              ;\
orb     al, [1<<irq]            /* mask irq */                      ;\
outb    INT_CTLMASK             /* disable the irq                */;\
0:      movb    al, END_OF_INT                                              ;\
outb    INT_CTL                 /* reenable master 8259           */;\
ret      
    

        .align  16
 save:
         cld                     ! set direction flag to a known value
         pushad                  ! save "general" registers
   o16 push    ds              ! save ds
  o16 push    es              ! save es
  o16 push    fs              ! save fs
  o16 push    gs              ! save gs
         mov     dx, ss          ! ss is kernel data segment
         mov     ds, dx          ! load rest of kernel segments
         mov     es, dx          ! kernel does not use fs, gs
         mov     eax, esp        ! prepare to return
         incb    (_k_reenter)    ! from -1 if not reentering
         jnz     set_restart1    ! stack is already kernel stack
         mov     esp, k_stktop
         push    _restart        ! build return address for int handler
         xor     ebp, ebp        ! for stacktrace
         jmp     RETADR-P_STACKBASE(eax)
 
         .align  4
 set_restart1:
         push    restart1
         jmp     RETADR-P_STACKBASE(eax)