source: rtems/c/src/lib/libbsp/powerpc/gen83xx/startup/bspstart.c @ 112490e

/**
 * @file
 *
 * @ingroup mpc83xx
 *
 * @brief Source for BSP startup code.
 */

/*
 * Copyright (c) 2008
 * Embedded Brains GmbH
 * Obere Lagerstr. 30
 * D-82178 Puchheim
 * Germany
 * rtems@embedded-brains.de
 *
 * 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.
 *
 * $Id$
 */

#include <string.h>

#include <rtems/libio.h>
#include <rtems/libcsupport.h>
#include <rtems/score/thread.h>

#include <libcpu/powerpc-utility.h>
#include <libcpu/raw_exception.h>

#include <bsp.h>
#include <bsp/bootcard.h>
#include <bsp/irq-generic.h>
#include <bsp/ppc_exc_bspsupp.h>

#ifdef HAS_UBOOT

/*
 * We want this in the data section, because the startup code clears the BSS
 * section after the initialization of the board info.
 */
bd_t mpc83xx_uboot_board_info = { .bi_baudrate = 123 };

/* Size in words */
const size_t mpc83xx_uboot_board_info_size = (sizeof( bd_t) + 3) / 4;

#endif /* HAS_UBOOT */

/* Configuration parameters for console driver, ... */
unsigned int BSP_bus_frequency;

/* Configuration parameters for clock driver, ... */
uint32_t bsp_clicks_per_usec;

/* Default decrementer exception handler */
static int mpc83xx_decrementer_exception_handler( BSP_Exception_frame *frame, unsigned number)
{
  ppc_set_decrementer_register(UINT32_MAX);

  return 0;
}

void BSP_panic(char *s)
{
  rtems_interrupt_level level;

  rtems_interrupt_disable(level);

  printk("%s PANIC %s\n", rtems_get_version_string(), s);

  while (1) {
    /* Do nothing */
  }
}

void _BSP_Fatal_error(unsigned n)
{
  rtems_interrupt_level level;

  rtems_interrupt_disable( level);

  printk( "%s PANIC ERROR %u\n", rtems_get_version_string(), n);

  while (1) {
    /* Do nothing */
  }
}

void bsp_get_work_area(
  void   **work_area_start,
  size_t  *work_area_size,
  void   **heap_start,
  size_t  *heap_size)
{
#ifdef HAS_UBOOT
  char *ram_end = (char *) mpc83xx_uboot_board_info.bi_memstart +
                                 mpc83xx_uboot_board_info.bi_memsize;
#else /* HAS_UBOOT */
  char *ram_end = bsp_ram_end;
#endif /* HAS_UBOOT */

  *work_area_start = bsp_work_area_start;
  *work_area_size = ram_end - bsp_work_area_start;
  *heap_start = BSP_BOOTCARD_HEAP_USES_WORK_AREA;
  *heap_size = BSP_BOOTCARD_HEAP_SIZE_DEFAULT;
}

void bsp_start( void)
{
  rtems_status_code sc = RTEMS_SUCCESSFUL;
  int rv = 0;

  ppc_cpu_id_t myCpu;
  ppc_cpu_revision_t myCpuRevision;

  uint32_t interrupt_stack_start = (uint32_t) bsp_interrupt_stack_start;
  uint32_t interrupt_stack_size = (uint32_t) bsp_interrupt_stack_size;

  /*
   * Get CPU identification dynamically. Note that the get_ppc_cpu_type() function
   * store the result in global variables so that it can be used latter...
   */
  myCpu = get_ppc_cpu_type();
  myCpuRevision = get_ppc_cpu_revision();

  /* Basic CPU initialization */
  cpu_init();

  /*
   * Enable instruction and data caches. Do not force writethrough mode.
   */

#if INSTRUCTION_CACHE_ENABLE
  rtems_cache_enable_instruction();
#endif

#if DATA_CACHE_ENABLE
  rtems_cache_enable_data();
#endif

  /*
   * This is evaluated during runtime, so it should be ok to set it
   * before we initialize the drivers.
   */

  /* Initialize some device driver parameters */

#ifdef HAS_UBOOT
  BSP_bus_frequency = mpc83xx_uboot_board_info.bi_busfreq;
  bsp_clicks_per_usec = mpc83xx_uboot_board_info.bi_busfreq / 4000000;
#else /* HAS_UBOOT */
  BSP_bus_frequency = BSP_CLKIN_FRQ * BSP_SYSPLL_MF / BSP_SYSPLL_CKID;
  bsp_clicks_per_usec = BSP_bus_frequency / 4000000;
#endif /* HAS_UBOOT */

  /* Initialize exception handler */
  ppc_exc_initialize(
    PPC_INTERRUPT_DISABLE_MASK_DEFAULT,
    interrupt_stack_start,
    interrupt_stack_size
  );

  /* Install default handler for the decrementer exception */
  rv = ppc_exc_set_handler( ASM_DEC_VECTOR, mpc83xx_decrementer_exception_handler);
  if (rv < 0) {
    BSP_panic( "Cannot install decrementer exception handler!\n");
  }

  /* Initalize interrupt support */
  sc = bsp_interrupt_initialize();
  if (sc != RTEMS_SUCCESSFUL) {
    BSP_panic( "Cannot intitialize interrupt support\n");
  }

#ifdef SHOW_MORE_INIT_SETTINGS
  printk("Exit from bspstart\n");
#endif
}

/**
 * @brief Idle thread body.
 *
 * Replaces the one in c/src/exec/score/src/threadidlebody.c
 * The MSR[POW] bit is set to put the CPU into the low power mode
 * defined in HID0.  HID0 is set during starup in start.S.
 */
Thread _Thread_Idle_body( uint32_t ignored)
{

  while (1) {
    asm volatile (
      "mfmsr 3;"
      "oris 3, 3, 4;"
      "sync;"
      "mtmsr 3;"
      "isync;"
      "ori 3, 3, 0;"
      "ori 3, 3, 0"
    );
  }

  return NULL;
}