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

#include <assert.h>
#include <errno.h>
#include <rdbg/reg.h>               
#include <rdbg/remdeb.h>
#include <rdbg/rdbg.h>
#include <rtems/score/cpu.h>    
#include <rtems/score/thread.h> 


void
CtxToRegs (const CPU_Exception_frame* ctx, xdr_regs* regs)
{
    regs->tabreg [GS]		= 0;
    regs->tabreg [FS]		= 0;
    regs->tabreg [ES]		= 0;
    regs->tabreg [DS]		= 0;
    regs->tabreg [EDI]		= ctx->edi;
    regs->tabreg [ESI]		= ctx->esi;
    regs->tabreg [EBP]		= ctx->ebp;
    regs->tabreg [ESP]		= ctx->esp0;
    regs->tabreg [EBX]		= ctx->ebx;
    regs->tabreg [EDX]		= ctx->edx;
    regs->tabreg [ECX]		= ctx->ecx;
    regs->tabreg [EAX]		= ctx->eax;
    regs->tabreg [TRAPNO]	= ctx->idtIndex;
    regs->tabreg [ERR]		= ctx->faultCode;
    regs->tabreg [EIP]		= ctx->eip;
    regs->tabreg [CS]		= ctx->cs & 0xFFFF;
    regs->tabreg [EFL]		= ctx->eflags;
}


    void
RegsToCtx (const xdr_regs* regs, CPU_Exception_frame* ctx)
{
    ctx->edi		= regs->tabreg [EDI];
    ctx->esi		= regs->tabreg [ESI];
    ctx->ebp		= regs->tabreg [EBP];
    ctx->esp0		= regs->tabreg [ESP];
    ctx->ebx		= regs->tabreg [EBX];
    ctx->edx		= regs->tabreg [EDX];
    ctx->ecx		= regs->tabreg [ECX];
    ctx->eax		= regs->tabreg [EAX];
    ctx->idtIndex 	= regs->tabreg [TRAPNO];
    ctx->faultCode	= regs->tabreg [ERR];
    ctx->eip		= regs->tabreg [EIP];
    ctx->cs		= regs->tabreg [CS];
    ctx->eflags		= regs->tabreg [EFL];
}

void
get_ctx_thread( Thread_Control *thread, CPU_Exception_frame* ctx)
{
    ctx->edi		= thread->Registers.edi;
    ctx->esi		= thread->Registers.esi;
    ctx->ebp		= (unsigned32)(thread->Registers.ebp);
    ctx->esp0		= (unsigned32)(thread->Registers.esp);
    ctx->ebx		= thread->Registers.ebx;
    ctx->edx		= 0;
    ctx->ecx		= 0;
    ctx->eax		= 0;
    ctx->idtIndex 	= 0;
    ctx->faultCode	= 0;
    ctx->eip		= *(unsigned int*)(thread->Registers.esp);
    ctx->cs		= 0;
    ctx->eflags		= thread->Registers.eflags;
}

void
set_ctx_thread( Thread_Control *thread, CPU_Exception_frame* ctx)
{
  thread->Registers.edi = ctx->edi;
  thread->Registers.esi = ctx->esi;		
  thread->Registers.ebp = (void*)(ctx->ebp);		
  thread->Registers.esp = (void*)(ctx->esp0);		
  thread->Registers.ebx = ctx->ebx;		
  thread->Registers.eflags = ctx->eflags;		
}

 

int
Single_Step(CPU_Exception_frame* ctx)
{
  /* Check if not already set */
  if ((ctx->eflags & EFLAGS_TF) != 0  ||  ExitForSingleStep != 0) {
    /* Check coherency */
    assert ((ctx->eflags & EFLAGS_TF) != 0);
    assert (ExitForSingleStep != 0);
    return 0;
  }
  ctx->eflags |= EFLAGS_TF;	/* eflags */
  ++ExitForSingleStep;
  
  return 0;
}

 int
CheckForSingleStep (CPU_Exception_frame* ctx)
{
    if (ExitForSingleStep) {
	    /*
	     *  This functions can be called both from
	     *  INT1 and INT3 handlers. In case it is
	     *  called from INT3, need to clear TF.
	     */
	ctx->eflags &= ~EFLAGS_TF;
	ExitForSingleStep = 0;
	return 1;
    }
    return 0;
}

void
CancelSingleStep (CPU_Exception_frame* ctx)
{
	/* Cancel scheduled SS */
    ctx->eflags &= ~EFLAGS_TF;
    ExitForSingleStep-- ;
}

cpuExcHandlerType old_currentExcHandler;
extern void  rtems_exception_prologue_50();

void connect_rdbg_exception()
{
  interrupt_gate_descriptor	 *currentIdtEntry;
  unsigned			 limit;
  unsigned			 level;

  /*
   *  Connect the Exception used to debug
   */
  i386_get_info_from_IDTR (&currentIdtEntry, &limit);
  
  _CPU_ISR_Disable(level);
  create_interrupt_gate_descriptor (&currentIdtEntry[50], rtems_exception_prologue_50);
  _CPU_ISR_Enable(level);

  old_currentExcHandler = _currentExcHandler;
  _currentExcHandler = BreakPointExcHdl ;

}