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Diffstat (limited to 'nuttx/mm/mm_initialize.c')
-rw-r--r-- | nuttx/mm/mm_initialize.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/nuttx/mm/mm_initialize.c b/nuttx/mm/mm_initialize.c new file mode 100644 index 000000000..3a21d1759 --- /dev/null +++ b/nuttx/mm/mm_initialize.c @@ -0,0 +1,216 @@ +/**************************************************************************** + * mm/mm_initialize.c + * + * Copyright (C) 2007, 2009, 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * 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 NuttX 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" + +/**************************************************************************** + * Pre-processor 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[CONFIG_MM_REGIONS]; +FAR struct mm_allocnode_s *g_heapend[CONFIG_MM_REGIONS]; + +#if CONFIG_MM_REGIONS > 1 +int g_nregions; +#endif + +/* 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 + ****************************************************************************/ + +/**************************************************************************** + * Name: mm_initialize + * + * Description: + * This is an internal OS function called only at power-up boot time. + * + * Parameters: + * heapstart - Start of the initial heap region + * heapsize - Size of the initial heap region + * + * Return Value: + * None + * + * Assumptions: + * + ****************************************************************************/ + +void mm_initialize(FAR void *heapstart, size_t heapsize) +{ + int i; + + mlldbg("Heap: start=%p size=%u\n", heapstart, heapsize); + + /* The following two lines have cause problems for some ZiLog compilers + * in the past. Life is easier if we just the suppress them for those + * tools. + */ + +#ifndef __ZILOG__ + CHECK_ALLOCNODE_SIZE; + CHECK_FREENODE_SIZE; +#endif + + /* Set up global variables */ + + g_heapsize = 0; + +#if CONFIG_MM_REGIONS > 1 + g_nregions = 0; +#endif + + /* 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]; + } + + /* Initialize the malloc semaphore to one (to support one-at- + * a-time access to private data sets). + */ + + mm_seminitialize(); + + /* Add the initial region of memory to the heap */ + + mm_addregion(heapstart, heapsize); +} + +/**************************************************************************** + * Name: mm_addregion + * + * Description: + * This function gives a region of contiguous memory to the memory manager + * + * Parameters: + * heapstart - Start of the heap region + * heapsize - Size of the heap region + * + * Return Value: + * None + * + * Assumptions: + * + ****************************************************************************/ + +void mm_addregion(FAR void *heapstart, size_t heapsize) +{ + FAR struct mm_freenode_s *node; + uintptr_t heapbase; + uintptr_t heapend; +#if CONFIG_MM_REGIONS > 1 + int IDX = g_nregions; +#else +# define IDX 0 +#endif + + /* If the MCU handles wide addresses but the memory manager is configured + * for a small heap, then verify that the caller is not doing something + * crazy. + */ + +#if defined(CONFIG_MM_SMALL) && !defined(CONFIG_SMALL_MEMORY) + DEBUGASSERT(heapsize <= MMSIZE_MAX+1); +#endif + + /* Adjust the provide heap start and size so that they are both aligned + * with the MM_MIN_CHUNK size. + */ + + heapbase = MM_ALIGN_UP((uintptr_t)heapstart); + heapend = MM_ALIGN_DOWN((uintptr_t)heapstart + (uintptr_t)heapsize); + heapsize = heapend - heapbase; + + mlldbg("Region %d: base=%p size=%u\n", IDX+1, heapstart, heapsize); + + /* Add the size of this region to the total size of the heap */ + + g_heapsize += heapsize; + + /* 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[IDX] = (FAR struct mm_allocnode_s *)heapbase; + g_heapstart[IDX]->size = SIZEOF_MM_ALLOCNODE; + g_heapstart[IDX]->preceding = MM_ALLOC_BIT; + + node = (FAR struct mm_freenode_s *)(heapbase + SIZEOF_MM_ALLOCNODE); + node->size = heapsize - 2*SIZEOF_MM_ALLOCNODE; + node->preceding = SIZEOF_MM_ALLOCNODE; + + g_heapend[IDX] = (FAR struct mm_allocnode_s *)(heapend - SIZEOF_MM_ALLOCNODE); + g_heapend[IDX]->size = SIZEOF_MM_ALLOCNODE; + g_heapend[IDX]->preceding = node->size | MM_ALLOC_BIT; + +#undef IDX + +#if CONFIG_MM_REGIONS > 1 + g_nregions++; +#endif + + /* Add the single, large free node to the nodelist */ + + mm_addfreechunk(node); +} |