path: root/c/src/lib/librdbg/i386/excep_f.c

/*
 **************************************************************************
 *
 * Component =   
 * 
 * Synopsis  =   rdbg/i386/excep.c
 *
 * $Id$
 *
 **************************************************************************
 */

#include <rtems.h>
#include <rtems/error.h>
#include <assert.h>
#include <errno.h>
#include <rdbg/rdbg.h>
#include <rdbg/servrpc.h>

/* -----------------------------------------------------------------
   Maping of hardware exceptions into Unix-like signal numbers.
   It is identical to the one used by the PM and the AM.
   ----------------------------------------------------------------- */

    int
ExcepToSig (Exception_context *ctx)
{
    int excep = getExcNum (ctx);
  

    switch (excep) {
      
    case I386_EXCEPTION_MATH_COPROC_UNAVAIL: 
    case I386_EXCEPTION_I386_COPROC_SEG_ERR: 
    case I386_EXCEPTION_FLOAT_ERROR: 
    case I386_EXCEPTION_BOUND: 
	return SIGFPE;

    case I386_EXCEPTION_DEBUG: 
    case I386_EXCEPTION_BREAKPOINT: 
    case I386_EXCEPTION_ENTER_RDBG: 
	return SIGTRAP;

    case I386_EXCEPTION_OVERFLOW: 
    case I386_EXCEPTION_DIVIDE_BY_ZERO:
    case I386_EXCEPTION_ILLEGAL_INSTR:  
	return SIGILL;

    case I386_EXCEPTION_SEGMENT_NOT_PRESENT:
    case I386_EXCEPTION_STACK_SEGMENT_FAULT:
    case I386_EXCEPTION_GENERAL_PROT_ERR: 
    case I386_EXCEPTION_PAGE_FAULT: 
	return SIGSEGV;

    default:
	break;
    }
    return SIGKILL;
}

  
/*----- Breakpoint Exception management -----*/

    /*
     *  Handler for Breakpoint Exceptions :
     *  software breakpoints.
     */

void
BreakPointExcHdl(CPU_Exception_frame *ctx) 
{
  rtems_status_code status;
  rtems_id continueSemId;

  if ( (justSaveContext) && (ctx->idtIndex == I386_EXCEPTION_ENTER_RDBG) ) {
    PushSavedExceptCtx (_Thread_Executing->Object.id, ctx);
    justSaveContext = 0;
  }
  else {
    if (ctx->idtIndex != I386_EXCEPTION_DEBUG){
      NbSerializedCtx++;
      rtems_semaphore_obtain(serializeSemId, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
      NbSerializedCtx--;
    }
      
    currentTargetThread = _Thread_Executing->Object.id;

#ifdef DDEBUG
    printk("----------------------------------------------------------\n");
    printk("Exception %d caught at PC %x by thread %d\n",
	   ctx->idtIndex,
	   ctx->eip,
	   _Thread_Executing->Object.id);
    printk("----------------------------------------------------------\n");
    printk("Processor execution context at time of the fault was  :\n");
    printk("----------------------------------------------------------\n");
    printk(" EAX = %x	EBX = %x	ECX = %x	EDX = %x\n",
	   ctx->eax, ctx->ebx, ctx->ecx, ctx->edx);
    printk(" ESI = %x	EDI = %x	EBP = %x	ESP = %x\n",
	   ctx->esi, ctx->edi, ctx->ebp, ctx->esp0);
    printk("----------------------------------------------------------\n");
    printk("Error code pushed by processor itself (if not 0) = %x\n",
	   ctx->faultCode);
    printk("----------------------------------------------------------\n\n");
#endif

    status = rtems_semaphore_create (rtems_build_name('D', 'B', 'G', 'c'),
				     0,
				     RTEMS_FIFO |
				     RTEMS_COUNTING_SEMAPHORE |
				     RTEMS_NO_INHERIT_PRIORITY |
				     RTEMS_NO_PRIORITY_CEILING |
				     RTEMS_LOCAL,
				     0,
				     &continueSemId);
    if (status != RTEMS_SUCCESSFUL)
      rtems_panic ("Can't create continue semaphore: `%s'\n",rtems_status_text(status));

    PushExceptCtx (_Thread_Executing->Object.id, continueSemId, ctx);
  
    switch (ctx->idtIndex){
    case I386_EXCEPTION_DEBUG:
      DPRINTF((" DEBUG EXCEPTION !!!\n"));
      ctx->eflags &= ~EFLAGS_TF;
      ExitForSingleStep-- ;
      rtems_semaphore_release( wakeupEventSemId );
    break;

    case I386_EXCEPTION_BREAKPOINT:
      DPRINTF((" BREAKPOINT EXCEPTION !!!\n"));
      rtems_semaphore_release( wakeupEventSemId );
    break;

    case I386_EXCEPTION_ENTER_RDBG:
      DPRINTF((" ENTER RDBG !!!\n"));
      rtems_semaphore_release( wakeupEventSemId );
      break;

    default:
      DPRINTF((" OTHER EXCEPTION !!!\n"));
      rtems_semaphore_release( wakeupEventSemId );
      break;
    }

    rtems_semaphore_obtain(continueSemId, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
    
    PopExceptCtx (_Thread_Executing->Object.id);
    rtems_semaphore_delete(continueSemId);
  }
}