/***********************************************************************************************************                                                uC/OS-II*                                          The Real-Time Kernel*                                            MEMORY MANAGEMENT**                          (c) Copyright 1992-2001, Jean J. Labrosse, Weston, FL*                                           All Rights Reserved** File : OS_MEM.C* By   : Jean J. Labrosse**********************************************************************************************************/#ifndef  OS_MASTER_FILE#include "includes.h"#endif#if (OS_MEM_EN > 0) && (OS_MAX_MEM_PART > 0)/***********************************************************************************************************                                        CREATE A MEMORY PARTITION** Description : Create a fixed-sized memory partition that will be managed by uC/OS-II.** Arguments   : addr     is the starting address of the memory partition**               nblks    is the number of memory blocks to create from the partition.**               blksize  is the size (in bytes) of each block in the memory partition.**               err      is a pointer to a variable containing an error message which will be set by*                        this function to either:**                        OS_NO_ERR            if the memory partition has been created correctly.*                        OS_MEM_INVALID_ADDR  you are specifying an invalid address for the memory *                                             storage of the partition.*                        OS_MEM_INVALID_PART  no free partitions available*                        OS_MEM_INVALID_BLKS  user specified an invalid number of blocks (must be >= 2)*                        OS_MEM_INVALID_SIZE  user specified an invalid block size*                                             (must be greater than the size of a pointer)* Returns    : != (OS_MEM *)0  is the partition was created*              == (OS_MEM *)0  if the partition was not created because of invalid arguments or, no*                              free partition is available.**********************************************************************************************************/OS_MEM  *OSMemCreate (void *addr, INT32U nblks, INT32U blksize, INT8U *err){#if OS_CRITICAL_METHOD == 3                           /* Allocate storage for CPU status register      */    OS_CPU_SR  cpu_sr;#endif        OS_MEM    *pmem;    INT8U     *pblk;    void     **plink;    INT32U     i;#if OS_ARG_CHK_EN > 0    if (addr == (void *)0) {                          /* Must pass a valid address for the memory part. */        *err = OS_MEM_INVALID_ADDR;        return ((OS_MEM *)0);    }    if (nblks < 2) {                                  /* Must have at least 2 blocks per partition      */        *err = OS_MEM_INVALID_BLKS;        return ((OS_MEM *)0);    }    if (blksize < sizeof(void *)) {                   /* Must contain space for at least a pointer      */        *err = OS_MEM_INVALID_SIZE;        return ((OS_MEM *)0);    }#endif    OS_ENTER_CRITICAL();    pmem = OSMemFreeList;                             /* Get next free memory partition                */    if (OSMemFreeList != (OS_MEM *)0) {               /* See if pool of free partitions was empty      */        OSMemFreeList = (OS_MEM *)OSMemFreeList->OSMemFreeList;    }    OS_EXIT_CRITICAL();    if (pmem == (OS_MEM *)0) {                        /* See if we have a memory partition             */        *err = OS_MEM_INVALID_PART;        return ((OS_MEM *)0);    }    plink = (void **)addr;                            /* Create linked list of free memory blocks      */    pblk  = (INT8U *)addr + blksize;    for (i = 0; i < (nblks - 1); i++) {        *plink = (void *)pblk;        plink  = (void **)pblk;        pblk   = pblk + blksize;    }    *plink = (void *)0;                               /* Last memory block points to NULL              */    OS_ENTER_CRITICAL();    pmem->OSMemAddr     = addr;                       /* Store start address of memory partition       */    pmem->OSMemFreeList = addr;                       /* Initialize pointer to pool of free blocks     */    pmem->OSMemNFree    = nblks;                      /* Store number of free blocks in MCB            */    pmem->OSMemNBlks    = nblks;    pmem->OSMemBlkSize  = blksize;                    /* Store block size of each memory blocks        */    OS_EXIT_CRITICAL();    *err   = OS_NO_ERR;    return (pmem);}/*$PAGE*//***********************************************************************************************************                                          GET A MEMORY BLOCK** Description : Get a memory block from a partition** Arguments   : pmem    is a pointer to the memory partition control block**               err     is a pointer to a variable containing an error message which will be set by this*                       function to either:**                       OS_NO_ERR           if the memory partition has been created correctly.*                       OS_MEM_NO_FREE_BLKS if there are no more free memory blocks to allocate to caller*                       OS_MEM_INVALID_PMEM if you passed a NULL pointer for 'pmem'** Returns     : A pointer to a memory block if no error is detected*               A pointer to NULL if an error is detected**********************************************************************************************************/void  *OSMemGet (OS_MEM *pmem, INT8U *err){#if OS_CRITICAL_METHOD == 3                           /* Allocate storage for CPU status register      */    OS_CPU_SR  cpu_sr;#endif        void      *pblk;#if OS_ARG_CHK_EN > 0    if (pmem == (OS_MEM *)0) {                        /* Must point to a valid memory partition         */        *err = OS_MEM_INVALID_PMEM;        return ((OS_MEM *)0);    }#endif    OS_ENTER_CRITICAL();    if (pmem->OSMemNFree > 0) {                       /* See if there are any free memory blocks       */        pblk                = pmem->OSMemFreeList;    /* Yes, point to next free memory block          */        pmem->OSMemFreeList = *(void **)pblk;         /*      Adjust pointer to new free list          */        pmem->OSMemNFree--;                           /*      One less memory block in this partition  */        OS_EXIT_CRITICAL();        *err = OS_NO_ERR;                             /*      No error                                 */        return (pblk);                                /*      Return memory block to caller            */    }    OS_EXIT_CRITICAL();    *err = OS_MEM_NO_FREE_BLKS;                       /* No,  Notify caller of empty memory partition  */    return ((void *)0);                               /*      Return NULL pointer to caller            */}/*$PAGE*//***********************************************************************************************************                                         RELEASE A MEMORY BLOCK** Description : Returns a memory block to a partition** Arguments   : pmem    is a pointer to the memory partition control block**               pblk    is a pointer to the memory block being released.** Returns     : OS_NO_ERR            if the memory block was inserted into the partition*               OS_MEM_FULL          if you are returning a memory block to an already FULL memory *                                    partition (You freed more blocks than you allocated!)*               OS_MEM_INVALID_PMEM  if you passed a NULL pointer for 'pmem'*               OS_MEM_INVALID_PBLK  if you passed a NULL pointer for the block to release.**********************************************************************************************************/INT8U  OSMemPut (OS_MEM  *pmem, void *pblk){#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */    OS_CPU_SR  cpu_sr;#endif            #if OS_ARG_CHK_EN > 0    if (pmem == (OS_MEM *)0) {                   /* Must point to a valid memory partition             */        return (OS_MEM_INVALID_PMEM);    }    if (pblk == (void *)0) {                     /* Must release a valid block                         */        return (OS_MEM_INVALID_PBLK);    }#endif    OS_ENTER_CRITICAL();    if (pmem->OSMemNFree >= pmem->OSMemNBlks) {  /* Make sure all blocks not already returned          */        OS_EXIT_CRITICAL();        return (OS_MEM_FULL);    }    *(void **)pblk      = pmem->OSMemFreeList;   /* Insert released block into free block list         */    pmem->OSMemFreeList = pblk;    pmem->OSMemNFree++;                          /* One more memory block in this partition            */    OS_EXIT_CRITICAL();    return (OS_NO_ERR);                          /* Notify caller that memory block was released       */}/*$PAGE*//***********************************************************************************************************                                          QUERY MEMORY PARTITION** Description : This function is used to determine the number of free memory blocks and the number of*               used memory blocks from a memory partition.** Arguments   : pmem    is a pointer to the memory partition control block**               pdata   is a pointer to a structure that will contain information about the memory*                       partition.** Returns     : OS_NO_ERR            If no errors were found.*               OS_MEM_INVALID_PMEM  if you passed a NULL pointer for 'pmem'*               OS_MEM_INVALID_PDATA if you passed a NULL pointer for the block to release.**********************************************************************************************************/#if OS_MEM_QUERY_EN > 0INT8U  OSMemQuery (OS_MEM *pmem, OS_MEM_DATA *pdata){#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */    OS_CPU_SR  cpu_sr;#endif            #if OS_ARG_CHK_EN > 0    if (pmem == (OS_MEM *)0) {                   /* Must point to a valid memory partition             */        return (OS_MEM_INVALID_PMEM);    }    if (pdata == (OS_MEM_DATA *)0) {             /* Must release a valid storage area for the data     */        return (OS_MEM_INVALID_PDATA);    }#endif    OS_ENTER_CRITICAL();    pdata->OSAddr     = pmem->OSMemAddr;    pdata->OSFreeList = pmem->OSMemFreeList;    pdata->OSBlkSize  = pmem->OSMemBlkSize;    pdata->OSNBlks    = pmem->OSMemNBlks;    pdata->OSNFree    = pmem->OSMemNFree;    OS_EXIT_CRITICAL();    pdata->OSNUsed    = pdata->OSNBlks - pdata->OSNFree;    return (OS_NO_ERR);}#endif                                           /* OS_MEM_QUERY_EN                                    *//*$PAGE*//***********************************************************************************************************                                    INITIALIZE MEMORY PARTITION MANAGER** Description : This function is called by uC/OS-II to initialize the memory partition manager.  Your*               application MUST NOT call this function.** Arguments   : none** Returns     : none** Note(s)    : This function is INTERNAL to uC/OS-II and your application should not call it.**********************************************************************************************************/void  OS_MemInit (void){#if OS_MAX_MEM_PART == 1    OSMemFreeList                = (OS_MEM *)&OSMemTbl[0]; /* Point to beginning of free list          */    OSMemFreeList->OSMemFreeList = (void *)0;              /* Initialize last node                     */    OSMemFreeList->OSMemAddr     = (void *)0;              /* Store start address of memory partition  */    OSMemFreeList->OSMemNFree    = 0;                      /* No free blocks                           */    OSMemFreeList->OSMemNBlks    = 0;                      /* No blocks                                */    OSMemFreeList->OSMemBlkSize  = 0;                      /* Zero size                                */#endif#if OS_MAX_MEM_PART >= 2    OS_MEM  *pmem;    INT16U   i;    pmem = (OS_MEM *)&OSMemTbl[0];                    /* Point to memory control block (MCB)           */    for (i = 0; i < (OS_MAX_MEM_PART - 1); i++) {     /* Init. list of free memory partitions          */        pmem->OSMemFreeList = (void *)&OSMemTbl[i+1]; /* Chain list of free partitions                 */        pmem->OSMemAddr     = (void *)0;              /* Store start address of memory partition       */        pmem->OSMemNFree    = 0;                      /* No free blocks                                */        pmem->OSMemNBlks    = 0;                      /* No blocks                                     */        pmem->OSMemBlkSize  = 0;                      /* Zero size                                     */        pmem++;    }    pmem->OSMemFreeList = (void *)0;                  /* Initialize last node                          */    pmem->OSMemAddr     = (void *)0;                  /* Store start address of memory partition       */    pmem->OSMemNFree    = 0;                          /* No free blocks                                */    pmem->OSMemNBlks    = 0;                          /* No blocks                                     */    pmem->OSMemBlkSize  = 0;                          /* Zero size                                     */    OSMemFreeList       = (OS_MEM *)&OSMemTbl[0];     /* Point to beginning of free list               */#endif}#endif                                           /* OS_MEM_EN                                          */