source: rtems/cpukit/score/cpu/mips/cpu.c @ 797d88ba

/*
 *  Mips CPU Dependent Source
 *
 *  Conversion to MIPS port by Alan Cudmore <alanc@linuxstart.com> and
 *           Joel Sherrill <joel@OARcorp.com>.
 *
 *  Original MIP64ORION port by Craig Lebakken <craigl@transition.com>
 *           COPYRIGHT (c) 1996 by Transition Networks Inc.
 *
 *         To anyone who acknowledges that this file is provided "AS IS"
 *         without any express or implied warranty:
 *             permission to use, copy, modify, and distribute this file
 *             for any purpose is hereby granted without fee, provided that
 *             the above copyright notice and this notice appears in all
 *             copies, and that the name of Transition Networks not be used in
 *             advertising or publicity pertaining to distribution of the
 *             software without specific, written prior permission.
 *             Transition Networks makes no representations about the 
 *             suitability of this software for any purpose.
 *
 *  Derived from c/src/exec/score/cpu/no_cpu/cpu.c:
 *
 *  COPYRIGHT (c) 1989-1999.
 *  On-Line Applications Research Corporation (OAR).
 *
 *  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.
 *
 *  $Id$
 */

/*
 *  Rather than deleting this, it is commented out to (hopefully) help
 *  the submitter send updates.
 *
 * static char _sccsid[] = "@(#)cpu.c 08/20/96     1.5\n";
 */

#include <rtems/system.h>
#include <rtems/score/isr.h>
#include <rtems/score/wkspace.h>


/*  _CPU_Initialize
 *
 *  This routine performs processor dependent initialization.
 *
 *  INPUT PARAMETERS:
 *    cpu_table       - CPU table to initialize
 *    thread_dispatch - address of disptaching routine
 */


void null_handler( void )
{
}


void _CPU_Initialize(
  rtems_cpu_table  *cpu_table,
  void      (*thread_dispatch)      /* ignored on this CPU */
)
{
   unsigned int i = ISR_NUMBER_OF_VECTORS;

   while ( i-- ) {
      _ISR_Vector_table[i] = (ISR_Handler_entry)null_handler;
   }

  /*
   *  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;

}

/*PAGE
 *
 *  _CPU_ISR_Get_level
 *
 *  This routine returns the current interrupt level.
 */
   
#if __mips == 3

/* in cpu_asm.S for now */

#elif __mips == 1
unsigned32 _CPU_ISR_Get_level( void )
{
  unsigned int sr;

  mips_get_sr(sr);

  return ((sr & SR_IEC) ? 0 : 1);
}
#else
#error "CPU ISR level: unknown MIPS level for SR handling"
#endif

/*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.
   */
/* Q: This will become necessary for Non IDT/Sim use...*/
#if 0 /* not necessary */
/* use IDT/Sim to set interrupt vector.  Needed to co-exist with debugger. */
   add_ext_int_func( vector, new_handler );
#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
)
{
   *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, _ISR_Handler, old_handler );

   /*
    *  We put the actual user ISR address in '_ISR_vector_table'.  This will
    *  be used by the _ISR_Handler so the user gets control.
    */

    _ISR_Vector_table[ vector ] = new_handler;
}

/*PAGE
 *
 *  _CPU_Install_interrupt_stack
 */

void _CPU_Install_interrupt_stack( void )
{
/* we don't support this yet */
}

/*PAGE
 *
 *  _CPU_Internal_threads_Idle_thread_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.
 */

void _CPU_Thread_Idle_body( void )
{
#if __mips == 3
   for( ; ; )
     asm volatile("wait"); /* use wait to enter low power mode */
#elif __mips == 1
   for( ; ; )
     ;
#else
#error "IDLE: __mips not set to 1 or 3"
#endif
}

extern void mips_break( int error );

#include <stdio.h>

void mips_fatal_error( int error )
{
   printf("fatal error 0x%x %d\n",error,error);
   mips_break( error );
}