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  1. /*
  2.  * Copyright (C) 2006 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. #include <libc.h>
  30. #include <unistd.h>
  31. #include <kernel/mm/as_arg.h>
  32. #include <task.h>
  33.  
  34. /** Create address space area.
  35.  *
  36.  * @param address Virtual address where to place new address space area.
  37.  * @param size Size of the area.
  38.  * @param flags Flags describing type of the area.
  39.  *
  40.  * @return address on success, (void *) -1 otherwise.
  41.  */
  42. void *as_area_create(void *address, size_t size, int flags)
  43. {
  44.     return (void *) __SYSCALL3(SYS_AS_AREA_CREATE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
  45. }
  46.  
  47. /** Resize address space area.
  48.  *
  49.  * @param address Virtual address pointing into already existing address space area.
  50.  * @param size New requested size of the area.
  51.  * @param flags Currently unused.
  52.  *
  53.  * @return address on success, (void *) -1 otherwise.
  54.  */
  55. void *as_area_resize(void *address, size_t size, int flags)
  56. {
  57.     return (void *) __SYSCALL3(SYS_AS_AREA_RESIZE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
  58. }
  59.  
  60. /** Prepare to accept address space area.
  61.  *
  62.  * @param id Task ID of the donor task.
  63.  * @param base Destination address for the new address space area.
  64.  * @param size Size of the new address space area.
  65.  * @param flags Flags of the area TASK is willing to accept.
  66.  *
  67.  * @return 0 on success or a code from errno.h.
  68.  */
  69. int as_area_accept(task_id_t id, void *base, size_t size, int flags)
  70. {
  71.     as_area_acptsnd_arg_t arg;
  72.    
  73.     arg.task_id = id;
  74.     arg.base = base;
  75.     arg.size = size;
  76.     arg.flags = flags;
  77.    
  78.     return __SYSCALL1(SYS_AS_AREA_ACCEPT, (sysarg_t) &arg);
  79. }
  80.  
  81. /** Send address space area to another task.
  82.  *
  83.  * @param id Task ID of the acceptor task.
  84.  * @param base Source address of the existing address space area.
  85.  *
  86.  * @return 0 on success or a code from errno.h.
  87.  */
  88. int as_area_send(task_id_t id, void *base)
  89. {
  90.     as_area_acptsnd_arg_t arg;
  91.    
  92.     arg.task_id = id;
  93.     arg.base = base;
  94.     arg.size = 0;
  95.     arg.flags = 0;
  96.    
  97.     return __SYSCALL1(SYS_AS_AREA_SEND, (sysarg_t) &arg);
  98. }
  99.  
  100. static size_t heapsize = 0;
  101. /* Start of heap linker symbol */
  102. extern char _heap;
  103.  
  104. /** Sbrk emulation
  105.  *
  106.  * @param size New area that should be allocated or negative,
  107.                if it should be shrinked
  108.  * @return Pointer to newly allocated area
  109.  */
  110. void *sbrk(ssize_t incr)
  111. {
  112.     void *res;
  113.     /* Check for invalid values */
  114.     if (incr < 0 && -incr > heapsize)
  115.         return NULL;
  116.     /* Check for too large value */
  117.     if (incr > 0 && incr+heapsize < heapsize)
  118.         return NULL;
  119.     /* Check for too small values */
  120.     if (incr < 0 && incr+heapsize > heapsize)
  121.         return NULL;
  122.  
  123.     res = as_area_resize(&_heap, heapsize + incr,0);
  124.     if (!res)
  125.         return NULL;
  126.    
  127.     /* Compute start of new area */
  128.     res = (void *)&_heap + heapsize;
  129.  
  130.     heapsize += incr;
  131.  
  132.     return res;
  133. }
  134.