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/*

 *  This file contains information pertaining to the Hitachi SH

 *  processor.

 *

 *  Authors: Ralf Corsepius (corsepiu@faw.uni-ulm.de) and

 *           Bernd Becker (becker@faw.uni-ulm.de)

 *

 *  COPYRIGHT (c) 1997-1998, FAW Ulm, Germany

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 *

 *

 *  COPYRIGHT (c) 1998.

 *  On-Line Applications Research Corporation (OAR).

 *  Copyright assigned to U.S. Government, 1994.

 *

 *  The license and distribution terms for this file may be

 *  found in the file LICENSE in this distribution or at

 *  http://www.OARcorp.com/rtems/license.html.

 *

 *  $Id: cpu.c,v 1.2 2001-09-27 11:59:30 chris Exp $

 */

#include <rtems/system.h>

#include <rtems/score/isr.h>

#include <rtems/score/sh_io.h>

#include <rtems/score/cpu.h>

#include <rtems/score/sh.h>

/* referenced in start.S */

extern proc_ptr vectab[] ;

proc_ptr vectab[256] ;

extern proc_ptr _Hardware_isr_Table[];

/*  _CPU_Initialize

 *

 *  This routine performs processor dependent initialization.

 *

 *  INPUT PARAMETERS:

 *    cpu_table       - CPU table to initialize

 *    thread_dispatch - address of disptaching routine

 */

void _CPU_Initialize(

  rtems_cpu_table  *cpu_table,

  void      (*thread_dispatch)      /* ignored on this CPU */

)

{

  register unsigned32 level = 0;

  /*

   *  The thread_dispatch argument is the address of the entry point

   *  for the routine called at the end of an ISR once it has been

   *  decided a context switch is necessary.  On some compilation

   *  systems it is difficult to call a high-level language routine

   *  from assembly.  This allows us to trick these systems.

   *

   *  If you encounter this problem save the entry point in a CPU

   *  dependent variable.

   */

  _CPU_Thread_dispatch_pointer = thread_dispatch;

  /*

   *  If there is not an easy way to initialize the FP context

   *  during Context_Initialize, then it is usually easier to

   *  save an "uninitialized" FP context here and copy it to

   *  the task's during Context_Initialize.

   */

  /* FP context initialization support goes here */

  _CPU_Table = *cpu_table;

  /* enable interrupts */

  _CPU_ISR_Set_level( level);

}

/*PAGE

 *

 *  _CPU_ISR_Get_level

 */

unsigned32 _CPU_ISR_Get_level( void )

{

  /*

   *  This routine returns the current interrupt level.

   */

  register unsigned32 _mask ;

  sh_get_interrupt_level( _mask );

  return ( _mask);

}

/*PAGE

 *

 *  _CPU_ISR_install_raw_handler

 */

void _CPU_ISR_install_raw_handler(

  unsigned32  vector,

  proc_ptr    new_handler,

  proc_ptr   *old_handler

)

{

  /*

   *  This is where we install the interrupt handler into the "raw" interrupt

   *  table used by the CPU to dispatch interrupt handlers.

   */

  volatile proc_ptr     *vbr ;

#if SH_PARANOID_ISR  

  unsigned32            level ;

  sh_disable_interrupts( level );

#endif    

  /* get vbr */

  asm ( "stc vbr,%0" : "=r" (vbr) );

  *old_handler = vbr[vector] ;

  vbr[vector]  = new_handler ;

#if SH_PARANOID_ISR

  sh_enable_interrupts( level );

#endif

}

/*PAGE

 *

 *  _CPU_ISR_install_vector

 *

 *  This kernel routine installs the RTEMS handler for the

 *  specified vector.

 *

 *  Input parameters:

 *    vector      - interrupt vector number

 *    old_handler - former ISR for this vector number

 *    new_handler - replacement ISR for this vector number

 *

 *  Output parameters:  NONE

 *

 */

void _CPU_ISR_install_vector(

  unsigned32  vector,

  proc_ptr    new_handler,

  proc_ptr   *old_handler

)

{

   proc_ptr ignored ;

   if(( vector <= 113) && ( vector >= 11))

     {

       *old_handler = _ISR_Vector_table[ vector ];

       /*

        *  If the interrupt vector table is a table of pointer to isr entry

        *  points, then we need to install the appropriate RTEMS interrupt

        *  handler for this vector number.

        */

       _CPU_ISR_install_raw_handler(vector,

                                    _Hardware_isr_Table[vector],

                                    &ignored );

       /*

        *  We put the actual user ISR address in '_ISR_Vector_table'.

        *  This will be used by __ISR_Handler so the user gets control.

        */

       _ISR_Vector_table[ vector ] = new_handler;

     }

}

/*PAGE

 *

 *  _CPU_Thread_Idle_body

 *

 *  NOTES:

 *

 *  1. This is the same as the regular CPU independent algorithm.

 *

 *  2. If you implement this using a "halt", "idle", or "shutdown"

 *     instruction, then don't forget to put it in an infinite loop.

 *

 *  3. Be warned. Some processors with onboard DMA have been known

 *     to stop the DMA if the CPU were put in IDLE mode.  This might

 *     also be a problem with other on-chip peripherals.  So use this

 *     hook with caution.

 */

#if (CPU_PROVIDES_IDLE_THREAD_BODY == TRUE)

void _CPU_Thread_Idle_body( void )

{

  for( ; ; )

    {

      asm volatile("nop");

    }

    /* insert your "halt" instruction here */ ;

}

#endif

#if (CPU_USE_GENERIC_BITFIELD_CODE == FALSE)

unsigned8 _bit_set_table[16] =

  { 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 2, 2, 1,0};

#endif

void _CPU_Context_Initialize(

  Context_Control       *_the_context,

  void                  *_stack_base,

  unsigned32            _size,

  unsigned32            _isr,

  void  (*_entry_point)(void),

  int                   _is_fp )

{

  _the_context->r15 = (unsigned32*) ((unsigned32) (_stack_base) + (_size) );

  _the_context->sr  = (_isr << 4) & 0x00f0 ;

  _the_context->pr  = (unsigned32*) _entry_point ;

}