Subversion Repositories openrisc_2011-10-31

/*

 *  Implementation of hooks for the CYGNUS newlib libc

 *  These hooks set things up so that:

 *       + '_REENT' is switched at task switch time.

 *

 *  COPYRIGHT (c) 1994 by Division Incorporated

 *

 *  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: newlibc.c,v 1.2 2001-09-27 12:01:15 chris Exp $

 *

 */

#define __RTEMS_VIOLATE_KERNEL_VISIBILITY__

#include <rtems.h>

#if defined(RTEMS_NEWLIB)

#include <libcsupport.h>

#include <stdlib.h>             /* for free() */

#include <string.h>             /* for memset() */

#include <sys/reent.h>          /* for extern of _REENT (aka _impure_ptr) */

#include <errno.h>

/*

 *  NOTE:

 *        There is some problem with doing this on the hpux version

 *        of the UNIX simulator (symptom is printf core dumps), so

 *        we just don't for now.

 *        Not sure if this is a problem with hpux, newlib, or something else.

 */

#if defined(RTEMS_UNIX) && !defined(hpux)

#define NEED_SETVBUF

#endif

#ifdef NEED_SETVBUF

#include <stdio.h>

#endif

static int extension_index;

/*

 *  Private routines

 */

#define set_newlib_extension( _the_thread, _value ) \

  (_the_thread)->extensions[ extension_index ] = (_value);

#define get_newlib_extension( _the_thread ) \

  (_the_thread)->extensions[ extension_index ]

int              libc_reentrant;        /* do we think we are reentrant? */

struct _reent    libc_global_reent;

/*

 * CYGNUS newlib routine that does atexit() processing and flushes

 *      stdio streams

 *      undocumented

 */

extern void _wrapup_reent(struct _reent *);

extern void _reclaim_reent(struct _reent *);

#include <stdio.h>

void libc_wrapup(void)

{

  /*

   *  In case RTEMS is already down, don't do this.  It could be

   *  dangerous.

   */

  if (!_System_state_Is_up(_System_state_Get()))

     return;

  /*

   *  This was already done if the user called exit() directly .

  _wrapup_reent(0);

   */

  if (_REENT != &libc_global_reent) {

      _wrapup_reent(&libc_global_reent);

#if 0

      /*  Don't reclaim this one, just in case we do printfs

       *  on the way out to ROM.

       */

      _reclaim_reent(&libc_global_reent);

#endif

      _REENT = &libc_global_reent;

  }

  /*

   * Try to drain output buffers.

   *

   * Should this be changed to do *all* file streams?

   *    _fwalk (_REENT, fclose);

   */

  fclose (stdin);

  fclose (stdout);

  fclose (stderr);

}

rtems_boolean libc_create_hook(

  rtems_tcb *current_task,

  rtems_tcb *creating_task

)

{

  set_newlib_extension( creating_task, NULL );

  return TRUE;

}

/*

 * Called for all user TASKS (system tasks are MPCI Receive Server and IDLE)

 */

rtems_extension libc_start_hook(

  rtems_tcb *current_task,

  rtems_tcb *starting_task

)

{

  struct _reent *ptr;

  /*  NOTE: The RTEMS malloc is reentrant without a reent ptr since

   *        it is based on the Classic API Region Manager.

   */

  ptr = (struct _reent *) calloc(1, sizeof(struct _reent));

  if (!ptr)

     rtems_fatal_error_occurred(RTEMS_NO_MEMORY);

#ifdef __GNUC__

  /* GCC extension: structure constants */

  *ptr = (struct _reent) _REENT_INIT((*ptr));

#else

  /*

   *  WARNING: THIS IS VERY DEPENDENT ON NEWLIB!!!

   *           Last visual check was against newlib 1.8.2 but last known

   *           use was against 1.7.0.  This is basically an exansion of

   *           REENT_INIT() in <sys/reent.h>.

   *  NOTE:    calloc() takes care of zeroing fields.

   */

  ptr->_stdin = &ptr->__sf[0];

  ptr->_stdout = &ptr->__sf[1];

  ptr->_stderr = &ptr->__sf[2];

  ptr->_current_locale = "C";

  ptr->_new._reent._rand_next = 1;

#endif

  set_newlib_extension( starting_task, ptr );

}

/*

 * Called for all user TASKS (system tasks are MPCI Receive Server and IDLE)

 */

#ifdef NEED_SETVBUF

rtems_extension libc_begin_hook(rtems_tcb *current_task)

{

  setvbuf( stdout, NULL, _IOLBF, BUFSIZ );

}

#endif

rtems_extension libc_switch_hook(

  rtems_tcb *current_task,

  rtems_tcb *heir_task

)

{

  /*

   *  Don't touch the outgoing task if it has been deleted.

   */

  if ( !_States_Is_transient( current_task->current_state ) ) {

    set_newlib_extension( current_task, _REENT );

  }

  _REENT = (struct _reent *) get_newlib_extension( heir_task );

}

/*

 *  Function:   libc_delete_hook

 *  Created:    94/12/10

 *

 *  Description:

 *      Called when a task is deleted.

 *      Must restore the new lib reentrancy state for the new current

 *      task.

 *

 *  Parameters:

 *

 *

 *  Returns:

 *

 *

 *  Side Effects:

 *

 *  Notes:

 *

 *

 *  Deficiencies/ToDo:

 *

 *

 */

rtems_extension libc_delete_hook(

  rtems_tcb *current_task,

  rtems_tcb *deleted_task

)

{

  struct _reent *ptr;

  /*

   * The reentrancy structure was allocated by newlib using malloc()

   */

  if (current_task == deleted_task) {

    ptr = _REENT;

  } else {

    ptr = (struct _reent *) get_newlib_extension( deleted_task );

  }

  /* if (ptr) */

  if (ptr && ptr != &libc_global_reent) {

    _wrapup_reent(ptr);

    _reclaim_reent(ptr);

    free(ptr);

  }

  set_newlib_extension( deleted_task, NULL );

  /*

   * Require the switch back to another task to install its own

   */

  if ( current_task == deleted_task ) {

    _REENT = 0;

  }

}

/*

 *  Function:   libc_init

 *  Created:    94/12/10

 *

 *  Description:

 *      Init libc for CYGNUS newlib

 *      Set up _REENT to use our global libc_global_reent.

 *      (newlib provides a global of its own, but we prefer our

 *      own name for it)

 *

 *      If reentrancy is desired (which it should be), then

 *      we install the task extension hooks to maintain the

 *      newlib reentrancy global variable _REENT on task

 *      create, delete, switch, exit, etc.

 *

 *  Parameters:

 *      reentrant               non-zero if reentrant library desired.

 *

 *  Returns:

 *

 *  Side Effects:

 *      installs libc extensions if reentrant.

 *

 *  Notes:

 *

 *

 *  Deficiencies/ToDo:

 *

 */

void

libc_init(int reentrant)

{

  rtems_extensions_table  libc_extension;

  rtems_status_code       rc;

  rtems_id                extension_id;

  libc_global_reent = (struct _reent) _REENT_INIT((libc_global_reent));

  _REENT = &libc_global_reent;

  if (reentrant) {

    memset(&libc_extension, 0, sizeof(libc_extension));

    libc_extension.thread_create  = libc_create_hook;

    libc_extension.thread_start   = libc_start_hook;

#ifdef NEED_SETVBUF

    libc_extension.thread_begin   = libc_begin_hook;

#endif

    libc_extension.thread_switch  = libc_switch_hook;

    libc_extension.thread_delete  = libc_delete_hook;

    rc = rtems_extension_create(rtems_build_name('L', 'I', 'B', 'C'),

                          &libc_extension, &extension_id);

    if (rc != RTEMS_SUCCESSFUL)

      rtems_fatal_error_occurred( rc );

    libc_reentrant = reentrant;

    extension_index = rtems_get_index( extension_id );

  }

}

/*

 *  Function:   _exit

 *  Created:    94/12/10

 *

 *  Description:

 *      Called from exit() after it does atexit() processing and stdio fflush's

 *

 *      called from bottom of exit() to really delete the task.

 *      If we are using reentrant libc, then let the delete extension

 *      do all the work, otherwise if a shutdown is in progress,

 *      then just do it.

 *

 *  Parameters:

 *      exit status

 *

 *  Returns:

 *      does not return

 *

 *  Side Effects:

 *

 *  Notes:

 *

 *

 *  Deficiencies/ToDo:

 *

 *

 */

#include <stdio.h>

#if !defined(RTEMS_UNIX) && !defined(_AM29K)

void _exit(int status)

{

  /*

   *  We need to do the exit processing on the global reentrancy structure.

   *  This has already been done on the per task reentrancy structure

   *  associated with this task.

   */

  libc_wrapup();

  rtems_shutdown_executive(status);

}

#else

void exit(int status)

{

  libc_wrapup();

  rtems_shutdown_executive(status);

}

#endif

#endif