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/*! \file include/sys/mm.h
\brief Internal Interface: memory management
\author Markus L. Noga <markus@noga.de>
*/
/*
* The contents of this file are subject to the Mozilla Public License
* Version 1.0 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License
* at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and
* limitations under the License.
*
* The Original Code is legOS code, released October 17, 1999.
*
* The Initial Developer of the Original Code is Markus L. Noga.
* Portions created by Markus L. Noga are Copyright (C) 1999
* Markus L. Noga. All Rights Reserved.
*
* Contributor(s): Markus L. Noga <markus@noga.de>
*/
#ifndef __sys_mm_h__
#define __sys_mm_h__
#ifdef __cplusplus
extern "C" {
#endif
#include <config.h>
#ifdef CONF_MM
#include <mem.h>
#include <stdlib.h>
///////////////////////////////////////////////////////////////////////
//
// Definitions
//
///////////////////////////////////////////////////////////////////////
#define MM_FREE 0x0000 //!< marker: block free
#define MM_RESERVED 0xffff //!< marker: block reserved
// as data generally nees to be word aligned, 1 unit ^= 2 bytes
//
#define MM_HEADER_SIZE 2 //!< 2 words header: pid, size
#define MM_SPLIT_THRESH (MM_HEADER_SIZE+8) //!< split off if 8+ data bytes
extern size_t mm_start; //!< end of kernel code + data
extern size_t* mm_first_free; //!< ptr to first free block.
// Macros for mm_init()
// Always alternate FREE and RESERVED.
//
//! memory from addr on can be allocated
/*! Macro for mm_init().
Always alternate MM_BLOCK_FREE and MM_BLOCK_RESERVED.
*/
#define MM_BLOCK_FREE(addr) \
next=(size_t*)(addr); \
*current=((((size_t)next)-(size_t)current)-2)>>1; \
*(next++)=MM_FREE; \
current=next;
//! memory from addr on is reserved
/*! Macro for mm_init().
Always alternate MM_BLOCK_FREE and MM_BLOCK_RESERVED.
*/
#define MM_BLOCK_RESERVED(addr) \
next=(size_t*)(((size_t)addr)-4); \
*current=((((size_t)next)-(size_t)current)-2)>>1; \
*(next++)=MM_RESERVED; \
current=next;
///////////////////////////////////////////////////////////////////////
//
// Functions
//
///////////////////////////////////////////////////////////////////////
//! initialize memory management
extern void mm_init();
//! free all blocks allocated by the current process
extern void mm_reaper();
//! how many bytes of memory are free?
extern int mm_free_mem(void);
#endif // CONF_MM
#ifdef __cplusplus
}
#endif
#endif // __sys_mm_h__
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