bspstart.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/*
 *  This set of routines starts the application.  It includes application,
 *  board, and monitor specific initialization and configuration.
 *  The generic CPU dependent initialization has been performed
 *  before any of these are invoked.
 *
 *  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.com/license/LICENSE.
 *
 *  $Id: bspstart.c,v 1.13.4.3 2004/11/22 22:30:59 jennifer Exp $
 */

#include <string.h>
#include <fcntl.h>
#include <bsp.h>
#include <bsp/irq.h>
#include <rtems/libio.h>
#include <rtems/libcsupport.h>
#include <rtems/bspIo.h>
#include <libcpu/cpuIdent.h>
#include <libcpu/spr.h>

SPR_RW(SPRG0)
SPR_RW(SPRG1)


extern unsigned long __rtems_end[];

void  initialize_exceptions(void);

/*  On psim, each click of the decrementer register corresponds
 *  to 1 instruction.  By setting this to 100, we are indicating
 *  that we are assuming it can execute 100 instructions per
 *  microsecond.  This corresponds to sustaining 1 instruction
 *  per cycle at 100 Mhz.  Whether this is a good guess or not
 *  is anyone's guess.
 */

extern int PSIM_INSTRUCTIONS_PER_MICROSECOND;

/*
 *  The original table from the application and our copy of it with
 *  some changes.
 */

extern rtems_configuration_table  Configuration;
rtems_configuration_table         BSP_Configuration;
rtems_cpu_table   Cpu_table;

/*
 *  Tells us where to put the workspace in case remote debugger is present.
 */

#if 0
extern uint32_t          rdb_start;
#endif

/*
 * PCI Bus Frequency
 */
 unsigned int BSP_bus_frequency;
 /*
  *  * Time base divisior (how many tick for 1 second).
  *   */
 unsigned int BSP_time_base_divisor;



/*
 *  Use the shared implementations of the following routines
 */

void bsp_postdriver_hook(void);
void bsp_libc_init( void *, uint32_t, int );

/*
 * system init stack and soft ir stack size
 */
#define INIT_STACK_SIZE 0x1000
#define INTR_STACK_SIZE CONFIGURE_INTERRUPT_STACK_MEMORY


void BSP_panic(char *s)
{
    printk("%s PANIC %s\n",_RTEMS_version, s);
      __asm__ __volatile ("sc");
}

void _BSP_Fatal_error(unsigned int v)
{
    printk("%s PANIC ERROR %x\n",_RTEMS_version, v);
      __asm__ __volatile ("sc");
}

/*
 *  bsp_pretasking_hook
 *
 *  BSP pretasking hook.  Called just before drivers are initialized.
 *  Used to setup libc and install any BSP extensions.
 */

void bsp_pretasking_hook(void)
{
  extern int end;
  uint32_t         heap_start;
  uint32_t         heap_size;

  heap_start = (uint32_t) &end;
  if (heap_start & (CPU_ALIGNMENT-1))
    heap_start = (heap_start + CPU_ALIGNMENT) & ~(CPU_ALIGNMENT-1);

  heap_size = BSP_Configuration.work_space_start - (void *)&end;
  heap_size &= 0xfffffff0;  /* keep it as a multiple of 16 bytes */

  bsp_libc_init((void *) heap_start, heap_size, 0);

#ifdef RTEMS_DEBUG
  rtems_debug_enable( RTEMS_DEBUG_ALL_MASK );
#endif

}

/*
 *  bsp_start
 *
 *  This routine does the bulk of the system initialization.
 */

void bsp_start( void )
{
  unsigned char     *work_space_start;
  register uint32_t  intrStack;
  register uint32_t *intrStackPtr;

  /*
   * Note we can not get CPU identification dynamically, so force current_ppc_cpu.
   */
  current_ppc_cpu = PPC_PSIM;

  /*
   * Set up our hooks
   * Make sure libc_init is done before drivers initialized so that
   * they can use atexit()
   */

  Cpu_table.pretasking_hook = bsp_pretasking_hook;    /* init libc, etc. */
  Cpu_table.postdriver_hook = bsp_postdriver_hook;

  /*
   *  Is this true?
   *
   *  PSIM does zero out memory BUT only when IT begins execution.  Thus
   *  if we want to have a clean slate in the workspace each time we
   *  begin execution of OUR application, then we must zero the workspace.
   *
   *  It is true that it takes simulated time to clear the memory.
   */

  Cpu_table.do_zero_of_workspace = FALSE;

  Cpu_table.interrupt_stack_size = CONFIGURE_INTERRUPT_STACK_MEMORY;

  BSP_bus_frequency        = (unsigned int)&PSIM_INSTRUCTIONS_PER_MICROSECOND;
  BSP_time_base_divisor    = 1;

  /*
   *  The simulator likes the exception table to be at 0xfff00000.
   */

  Cpu_table.exceptions_in_RAM = FALSE;

  BSP_Configuration.work_space_size += 1024;

  work_space_start =
    (unsigned char *)&RAM_END - BSP_Configuration.work_space_size;

  if ( work_space_start <= (unsigned char *)&end ) {
    printk( "bspstart: Not enough RAM!!!\n" );
    bsp_cleanup();
  }

  BSP_Configuration.work_space_start = work_space_start;

  /*
   * Initialize the interrupt related settings
   * SPRG1 = software managed IRQ stack
   *
   * This could be done latter (e.g in IRQ_INIT) but it helps to understand
   * some settings below...
   */
  intrStack = ((uint32_t) __rtems_end) + 
          INIT_STACK_SIZE + INTR_STACK_SIZE - CPU_MINIMUM_STACK_FRAME_SIZE;

  /* make sure it's properly aligned */
  intrStack &= ~(CPU_STACK_ALIGNMENT-1);

  /* tag the bottom (T. Straumann 6/36/2001 <[e-mail]>) */
  intrStackPtr = (uint32_t*) intrStack;
  *intrStackPtr = 0;

  _write_SPRG1(intrStack);

  /* signal them that we have fixed PR288 - eventually, this should go away */
  _write_SPRG0(PPC_BSP_HAS_FIXED_PR288);

  /*
   * Initialize default raw exception hanlders. See vectors/vectors_init.c
   */
  initialize_exceptions();

  /*
   * Initalize RTEMS IRQ system
   */
  BSP_rtems_irq_mng_init(0);

}