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/************************************************************
* mm_initialize.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name Gregory Nutt nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************/
/************************************************************
* Included Files
************************************************************/
#include "mm_environment.h"
#include "mm_internal.h"
/************************************************************
* Definitions
************************************************************/
/************************************************************
* Public Variables
************************************************************/
/* This is the size of the heap provided to mm */
size_t g_heapsize;
/* This is the first and last nodes of the heap */
FAR struct mm_allocnode_s *g_heapstart;
FAR struct mm_allocnode_s *g_heapend;
/* All free nodes are maintained in a doubly linked list. This
* array provides some hooks into the list at various points to
* speed searches for free nodes.
*/
FAR struct mm_freenode_s g_nodelist[MM_NNODES];
/************************************************************
* Public Functions
************************************************************/
/************************************************************
* Function: mm_initialize
*
* Description:
* This is an internal OS function called only at power-up
* boot time.
*
* Parameters:
* None
*
* Return Value:
* None
*
* Assumptions:
*
************************************************************/
void mm_initialize(FAR void *heapstart, size_t heapsize)
{
FAR struct mm_freenode_s *node;
size_t heapbase;
size_t heapend;
int i;
CHECK_ALLOCNODE_SIZE;
CHECK_FREENODE_SIZE;
/* Adjust the provide heap start and size so that they are
* both aligned with the MM_MIN_CHUNK size.
*/
heapbase = MM_ALIGN_UP((size_t)heapstart);
heapend = MM_ALIGN_DOWN((size_t)heapstart + (size_t)heapsize);
/* Save the size of the heap */
g_heapsize = heapend - heapbase;
/* Initialize the node array */
memset(g_nodelist, 0, sizeof(struct mm_freenode_s) * MM_NNODES);
for (i = 1; i < MM_NNODES; i++)
{
g_nodelist[i-1].flink = &g_nodelist[i];
g_nodelist[i].blink = &g_nodelist[i-1];
}
/* Create two "allocated" guard nodes at the beginning and end of
* the heap. These only serve to keep us from allocating outside
* of the heap.
*
* And create one free node between the guard nodes that contains
* all available memory.
*/
g_heapstart = (FAR struct mm_allocnode_s *)heapbase;
g_heapstart->size = SIZEOF_MM_ALLOCNODE;
g_heapstart->preceding = MM_ALLOC_BIT;
node = (FAR struct mm_freenode_s *)(heapbase + SIZEOF_MM_ALLOCNODE);
node->size = g_heapsize - 2*SIZEOF_MM_ALLOCNODE;
node->preceding = SIZEOF_MM_ALLOCNODE;
g_heapend = (FAR struct mm_allocnode_s *)(heapend - SIZEOF_MM_ALLOCNODE);
g_heapend->size = SIZEOF_MM_ALLOCNODE;
g_heapend->preceding = node->size | MM_ALLOC_BIT;
/* Add the single, large free node to the nodelist */
mm_addfreechunk(node);
/* Initialize the malloc semaphore to one (to support one-at-
* a-time access to private data sets.
*/
mm_seminitialize();
}
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