source: rtems/c/src/lib/libbsp/shared/bootcard.c @ 71d0488b

/*
 *  This is the C entry point for ALL RTEMS BSPs.  It is invoked
 *  from the assembly language initialization file usually called
 *  start.S.  It provides the framework for the BSP initialization
 *  sequence.  The basic flow of initialization is:
 *
 *  + start.S: basic CPU setup (stack, zero BSS) 
 *    + boot_card
 *      + if defined(BSP_BOOTCARD_HANDLES_RAM_ALLOCATION)
 *        - obtain information on BSP memory and allocate RTEMS Workspace
 *      + bspstart.c: bsp_start - more advanced initialization
 *      + rtems_initialize_data_structures
 *      + if defined(BSP_BOOTCARD_HANDLES_RAM_ALLOCATION)
 *        - Allocate memory to C Program Heap
 *        - initialize C Library and C Program Heap
 *      + bsp_pretasking_hook
 *      + if defined(RTEMS_DEBUG)
 *        - rtems_debug_enable( RTEMS_DEBUG_ALL_MASK );
 *      + rtems_initialize_before_drivers
 *      + bsp_predriver_hook
 *      + rtems_initialize_device_drivers
 *        - all device drivers
 *      + bsp_postdriver_hook
 *      + rtems_initialize_start_multitasking
 *        - 1st task executes C++ global constructors
 *          .... appplication runs ...
 *          - exit
 *     + back to here eventually
 *     + bspclean.c: bsp_cleanup
 *
 *  This style of initialization ensures that the C++ global
 *  constructors are executed after RTEMS is initialized.
 *  Thanks to Chris Johns <cjohns@plessey.com.au> for the idea
 *  to move C++ global constructors into the first task.
 *
 *  COPYRIGHT (c) 1989-2008.
 *  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.
 *
 *  $Id$
 */

#include <rtems.h>

#include <bsp/bootcard.h>

/*
 *  Since there is a forward reference
 */
char *rtems_progname;

/*
 * Are we using a single heap for the RTEMS Workspace and C Program Heap?
 */
extern bool rtems_unified_work_area;

/*
 *  These are the prototypes and helper routines which are used
 *  when the BSP lets the framework handle RAM allocation between
 *  the RTEMS Workspace and C Program Heap.
 */
static rtems_status_code bootcard_bsp_libc_helper(
  void    *work_area_start,
  intptr_t work_area_size,
  void    *heap_start,
  intptr_t heap_size
)
{
  intptr_t heap_size_default = 0;

  if ( !rtems_unified_work_area && 
       heap_start == BSP_BOOTCARD_HEAP_USES_WORK_AREA) {
    /* Use the work area start as heap start */
    heap_start = work_area_start;

    /* Ensure proper alignement */
    if ((uintptr_t) heap_start & (CPU_ALIGNMENT - 1)) {
      heap_start = (void *) (((uintptr_t) heap_start + CPU_ALIGNMENT)
        & ~(CPU_ALIGNMENT - 1));
    }

    /*
     * For the default heap size use the free space from the start of the
     * work area up to the work space start as heap area.
     */
    heap_size_default = (intptr_t) ((char *) Configuration.work_space_start
      - (char *) work_area_start);

    /* Keep it as a multiple of 16 bytes */
    heap_size_default &= ~((intptr_t) 0xf);

    /* Use default heap size if requested */
    if (heap_size == BSP_BOOTCARD_HEAP_SIZE_DEFAULT) {
      heap_size = heap_size_default;
    }
              
    /* Check heap size */
    if (heap_size > heap_size_default) {
      return RTEMS_INVALID_SIZE;
    }
  }

  bsp_libc_init(heap_start, heap_size, 0);

  return RTEMS_SUCCESSFUL;
}

/*
 *  This is the initialization framework routine that weaves together
 *  calls to RTEMS and the BSP in the proper sequence to initialize
 *  the system while maximizing shared code and keeping BSP code in C
 *  as much as possible.
 */
int boot_card(
  int    argc, 
  char **argv, 
  char **envp
)
{
  static char            *argv_pointer = NULL;
  static char            *envp_pointer = NULL;
  char                  **argv_p = &argv_pointer;
  char                  **envp_p = &envp_pointer;
  rtems_interrupt_level   bsp_isr_level;
  rtems_status_code       sc = RTEMS_SUCCESSFUL;
  void                   *work_area_start = NULL;
  intptr_t                work_area_size = 0;
  void                   *heap_start = NULL;
  intptr_t                heap_size = 0;

  /*
   * Special case for PowerPC: The interrupt disable mask is stored in SPRG0.
   * It must be valid before we can use rtems_interrupt_disable().
   */
  #ifdef PPC_INTERRUPT_DISABLE_MASK_DEFAULT
    ppc_interrupt_set_disable_mask( PPC_INTERRUPT_DISABLE_MASK_DEFAULT );
  #endif /* PPC_INTERRUPT_DISABLE_MASK_DEFAULT */

  /*
   *  Make sure interrupts are disabled.
   */
  rtems_interrupt_disable( bsp_isr_level );

  /*
   *  Set things up so we have real pointers for argv and envp.
   *  If the BSP has passed us something useful, then pass it on.
   *  Somehow we need to eventually make this available to
   *  a real main() in user land. :)
   */
  if ( argv ) argv_p = argv;
  if ( envp ) envp_p = envp;

  /*
   *  Set the program name in case some application cares.
   */
  if ((argc > 0) && argv && argv[0])
    rtems_progname = argv[0];
  else
    rtems_progname = "RTEMS";

  /*
   * Invoke Board Support Package initialization routine written in C.
   */
  bsp_start();

  /*
   *  Find out where the block of memory the BSP will use for
   *  the RTEMS Workspace and the C Program Heap is.
   */
  bsp_get_work_area(&work_area_start, &work_area_size, &heap_start, &heap_size);

  if ( work_area_size <= Configuration.work_space_size ) {
    printk( "bootcard: Work space too big for work area!\n");
    bsp_cleanup();
    return -1;
  }

  if ( rtems_unified_work_area ) {
    Configuration.work_space_start = work_area_start;
    Configuration.work_space_size  = work_area_size;
  } else {
    Configuration.work_space_start = (char *) work_area_start +
      work_area_size - rtems_configuration_get_work_space_size();
  }

  #if (BSP_DIRTY_MEMORY == 1)
    memset( work_area_start, 0xCF,  work_area_size );
  #endif

  /*
   *  Initialize RTEMS data structures
   */
  rtems_initialize_data_structures();

  /*
   *  Initialize the C library for those BSPs using the shared
   *  framework.
   */
  sc = bootcard_bsp_libc_helper(
    work_area_start,
    work_area_size,
    heap_start,
    heap_size
  );
  if ( sc != RTEMS_SUCCESSFUL ) {
    printk( "bootcard: Cannot initialize C library!\n");
    bsp_cleanup();
    return -1;
  }

  /*
   *  All BSP to do any required initialization now that RTEMS
   *  data structures are initialized.  In older BSPs or those
   *  which do not use the shared framework, this is the typical
   *  time when the C Library is initialized so malloc()
   *  can be called by device drivers.  For BSPs using the shared
   *  framework, this routine can be empty.
   */
  bsp_pretasking_hook();

  /*
   *  If debug is enabled, then enable all dynamic RTEMS debug 
   *  capabilities.
   *
   *  NOTE: Most debug features are conditionally compiled in
   *        or enabled via configure time plugins.
   */
  #ifdef RTEMS_DEBUG
    rtems_debug_enable( RTEMS_DEBUG_ALL_MASK );
  #endif

  /*
   *  Let RTEMS perform initialization it requires before drivers
   *  are allowed to be initialized.
   */
  rtems_initialize_before_drivers();

  /*
   *  Execute BSP specific pre-driver hook. Drivers haven't gotten
   *  to initialize yet so this is a good chance to initialize
   *  buses, spurious interrupt handlers, etc.. 
   *
   *  NOTE: Many BSPs do not require this handler and use the
   *        shared stub.
   */
  bsp_predriver_hook();

  /*
   *  Initialize all device drivers.
   */
  rtems_initialize_device_drivers();

  /*
   *  Invoke the postdriver hook.  This normally opens /dev/console
   *  for use as stdin, stdout, and stderr.
   */
  bsp_postdriver_hook();

  /*
   *  Complete initialization of RTEMS and switch to the first task.
   *  Global C++ constructors will be executed in the context of that task.
   */
  rtems_initialize_start_multitasking();

  /***************************************************************
   ***************************************************************
   *  APPLICATION RUNS HERE!!!  When it shuts down, we return!!! *
   ***************************************************************
   ***************************************************************
   */

  /*
   *  Perform any BSP specific shutdown actions which are written in C.
   */
  bsp_cleanup();

  /*
   *  Now return to the start code.
   */
  return 0;
}