path: root/cpukit/score/cpu/lm32/cpu.c

/**
 *  @file
 *
 *  @brief LM32 CPU Dependent Source
 */

/*
 *  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.rtems.org/license/LICENSE.
 *
 *  Jukka Pietarinen <jukka.pietarinen@mrf.fi>, 2008,
 *  Micro-Research Finland Oy
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <rtems/score/cpuimpl.h>
#include <rtems/score/isr.h>

/*  _CPU_Initialize
 *
 *  This routine performs processor dependent initialization.
 *
 *  INPUT PARAMETERS: NONE
 *
 *  LM32 Specific Information:
 *
 *  XXX document implementation including references if appropriate
 */

void _CPU_Initialize(void)
{
  /*
   *  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 */
}

void _CPU_Fatal_halt( uint32_t source, CPU_Uint32ptr error )
{
  ISR_Level level;

  _CPU_ISR_Disable( level );
  (void) level;

  while ( true ) {
    /* Do nothing */
  }
}

uint32_t   _CPU_ISR_Get_level( void )
{
  /*
   *  This routine returns the current interrupt level.
   */

  return 0;
}

void _CPU_ISR_install_vector(
  uint32_t         vector,
  CPU_ISR_handler  new_handler,
  CPU_ISR_handler *old_handler
)
{
   *old_handler = _ISR_Vector_table[ vector ];

   /*
    *  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;
}

/*
 *  _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.
 *
 *  LM32 Specific Information:
 *
 *  XXX document implementation including references if appropriate
 */

void *_CPU_Thread_Idle_body( uintptr_t ignored )
{
  for( ; ; ) {
    /* The LM32 softcore itself hasn't any HLT instruction. But the
     * LM32 qemu target interprets this nop instruction as HLT.
     */
    __asm__ volatile("and r0, r0, r0");
 }
}