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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file chmemcore.c
* @brief Core memory manager code.
*
* @addtogroup memcore
* @details Core Memory Manager related APIs and services.
* <h2>Operation mode</h2>
* The core memory manager is a simplified allocator that only allows
* to allocate memory blocks without the possibility to free them.<br>
* This allocator is meant as a memory blocks provider for the other
* allocators such as:
* - C-Runtime allocator (through a compiler specific adapter module).
* - Heap allocator (see @ref heaps).
* - Memory pools allocator (see @ref pools).
* .
* By having a centralized memory provider the various allocators can
* coexist and share the main memory.<br>
* This allocator, alone, is also useful for very simple applications
* that just require a simple way to get memory blocks.
* @pre In order to use the core memory manager APIs the @p CH_USE_MEMCORE
* option must be enabled in @p chconf.h.
* @{
*/
#include "ch.h"
#if CH_USE_MEMCORE || defined(__DOXYGEN__)
static uint8_t *nextmem;
static uint8_t *endmem;
/**
* @brief Low level memory manager initialization.
*
* @notapi
*/
void core_init(void) {
#if CH_MEMCORE_SIZE == 0
extern uint8_t __heap_base__;
extern uint8_t __heap_end__;
nextmem = &__heap_base__;
endmem = &__heap_end__;
#else
static stkalign_t buffer[MEM_ALIGN_SIZE(CH_MEMCORE_SIZE) /
sizeof(stkalign_t)];
nextmem = (uint8_t *)&buffer[0];
endmem = (uint8_t *)&buffer[MEM_ALIGN_SIZE(CH_MEMCORE_SIZE) /
sizeof(stkalign_t)];
#endif
}
/**
* @brief Allocates a memory block.
* @details The size of the returned block is aligned to the alignment
* type @p stkalign_t so it is not possible to allocate less
* than <code>sizeof(stkalign_t)</code>.
*
* @param[in] size the size of the block to be allocated
* @return A pointer to the allocated memory block.
* @retval NULL allocation failed, core memory exhausted.
*
* @api
*/
void *chCoreAlloc(size_t size) {
void *p;
chSysLock();
p = chCoreAllocI(size);
chSysUnlock();
return p;
}
/**
* @brief Allocates a memory block.
* @details The size of the returned block is aligned to the alignment
* type @p align_t so it is not possible to allocate less than
* <code>sizeof(align_t)</code>.
*
* @param[in] size the size of the block to be allocated.
* @return A pointer to the allocated memory block.
* @retval NULL allocation failed, core memory exhausted.
*
* @iclass
*/
void *chCoreAllocI(size_t size) {
void *p;
size = MEM_ALIGN_SIZE(size);
if ((size_t)(endmem - nextmem) < size)
return NULL;
p = nextmem;
nextmem += size;
return p;
}
/**
* @brief Core memory status.
*
* @return The size, in bytes, of the free core memory.
*
* @api
*/
size_t chCoreStatus(void) {
return (size_t)(endmem - nextmem);
}
#endif /* CH_USE_MEMCORE */
/** @} */
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