/*
*********************************************************************************************************
*                                                uC/OS-II
*                                          The Real-Time Kernel
*                                            MEMORY MANAGEMENT
*
*                              (c) Copyright 1992-2009, Micrium, Weston, FL
*                                           All Rights Reserved
*
* File    : OS_MEM.C
* By      : Jean J. Labrosse
* Version : V2.91
*
* LICENSING TERMS:
* ---------------
*   uC/OS-II is provided in source form for FREE evaluation, for educational use or for peaceful research.
* If you plan on using  uC/OS-II  in a commercial product you need to contact Micri祄 to properly license
* its use in your product. We provide ALL the source code for your convenience and to help you experience
* uC/OS-II.   The fact that the  source is provided does  NOT  mean that you can use it without  paying a
* licensing fee.
*********************************************************************************************************
*/

#ifndef  OS_MASTER_FILE
#include <ucos_ii.h>
#endif

#if (OS_MEM_EN > 0u) && (OS_MAX_MEM_PART > 0u)
/*
*********************************************************************************************************
*                                        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.
*
*               perr     is a pointer to a variable containing an error message which will be set by
*                        this function to either:
*
*                        OS_ERR_NONE              if the memory partition has been created correctly.
*                        OS_ERR_MEM_INVALID_ADDR  if you are specifying an invalid address for the memory
*                                                 storage of the partition or, the block does not align
*                                                 on a pointer boundary
*                        OS_ERR_MEM_INVALID_PART  no free partitions available
*                        OS_ERR_MEM_INVALID_BLKS  user specified an invalid number of blocks (must be >= 2)
*                        OS_ERR_MEM_INVALID_SIZE  user specified an invalid block size
*                                                   - must be greater than the size of a pointer
*                                                   - must be able to hold an integral number of pointers
* 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  *perr)
{
    OS_MEM    *pmem;
    INT8U     *pblk;
    void     **plink;
    INT32U     loops;
    INT32U     i;
#if OS_CRITICAL_METHOD == 3u                          /* Allocate storage for CPU status register      */
    OS_CPU_SR  cpu_sr = 0u;
#endif



#ifdef OS_SAFETY_CRITICAL
    if (perr == (INT8U *)0) {
        OS_SAFETY_CRITICAL_EXCEPTION();
    }
#endif

#ifdef OS_SAFETY_CRITICAL_IEC61508
    if (OSSafetyCriticalStartFlag == OS_TRUE) {
        OS_SAFETY_CRITICAL_EXCEPTION();
    }
#endif

#if OS_ARG_CHK_EN > 0u
    if (addr == (void *)0) {                          /* Must pass a valid address for the memory part.*/
        *perr = OS_ERR_MEM_INVALID_ADDR;
        return ((OS_MEM *)0);
    }
    if (((INT32U)addr & (sizeof(void *) - 1u)) != 0u){  /* Must be pointer size aligned                */
        *perr = OS_ERR_MEM_INVALID_ADDR;
        return ((OS_MEM *)0);
    }
    if (nblks < 2u) {                                 /* Must have at least 2 blocks per partition     */
        *perr = OS_ERR_MEM_INVALID_BLKS;
        return ((OS_MEM *)0);
    }
    if (blksize < sizeof(void *)) {                   /* Must contain space for at least a pointer     */
        *perr = OS_ERR_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             */
        *perr = OS_ERR_MEM_INVALID_PART;
        return ((OS_MEM *)0);
    }
    plink = (void **)addr;                            /* Create linked list of free memory blocks      */
    pblk  = (INT8U *)addr;
    loops  = nblks - 1u;
    for (i = 0u; i < loops; i++) {
        pblk +=  blksize;                             /* Point to the FOLLOWING block                  */
       *plink = (void  *)pblk;                        /* Save pointer to NEXT block in CURRENT block   */
        plink = (void **)pblk;                        /* Position to  NEXT      block                  */
    }
    *plink              = (void *)0;                  /* Last memory block points to NULL              */
    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        */
    *perr               = OS_ERR_NONE;
    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
*
*               perr    is a pointer to a variable containing an error message which will be set by this
*                       function to either:
*
*                       OS_ERR_NONE             if the memory partition has been created correctly.
*                       OS_ERR_MEM_NO_FREE_BLKS if there are no more free memory blocks to allocate to caller
*                       OS_ERR_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   *perr)
{
    void      *pblk;
#if OS_CRITICAL_METHOD == 3u                          /* Allocate storage for CPU status register      */
    OS_CPU_SR  cpu_sr = 0u;
#endif



#ifdef OS_SAFETY_CRITICAL
    if (perr == (INT8U *)0) {
        OS_SAFETY_CRITICAL_EXCEPTION();
    }
#endif

#if OS_ARG_CHK_EN > 0u
    if (pmem == (OS_MEM *)0) {                        /* Must point to a valid memory partition        */
        *perr = OS_ERR_MEM_INVALID_PMEM;
        return ((void *)0);
    }
#endif
    OS_ENTER_CRITICAL();
    if (pmem->OSMemNFree > 0u) {                      /* 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();
        *perr = OS_ERR_NONE;                          /*      No error                                 */
        return (pblk);                                /*      Return memory block to caller            */
    }
    OS_EXIT_CRITICAL();
    *perr = OS_ERR_MEM_NO_FREE_BLKS;                  /* No,  Notify caller of empty memory partition  */
    return ((void *)0);                               /*      Return NULL pointer to caller            */
}
/*$PAGE*/
/*
*********************************************************************************************************
*                                   GET THE NAME OF A MEMORY PARTITION
*
* Description: This function is used to obtain the name assigned to a memory partition.
*
* Arguments  : pmem      is a pointer to the memory partition
*
*              pname     is a pointer to a pointer to an ASCII string that will receive the name of the memory partition.
*
*              perr      is a pointer to an error code that can contain one of the following values:
*
*                        OS_ERR_NONE                if the name was copied to 'pname'
*                        OS_ERR_MEM_INVALID_PMEM    if you passed a NULL pointer for 'pmem'
*                        OS_ERR_PNAME_NULL          You passed a NULL pointer for 'pname'
*                        OS_ERR_NAME_GET_ISR        You called this function from an ISR
*
* Returns    : The length of the string or 0 if 'pmem' is a NULL pointer.
*********************************************************************************************************
*/

#if OS_MEM_NAME_EN > 0u
INT8U  OSMemNameGet (OS_MEM   *pmem,
                     INT8U   **pname,
                     INT8U    *perr)
{
    INT8U      len;
#if OS_CRITICAL_METHOD == 3u                     /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr = 0u;
#endif



#ifdef OS_SAFETY_CRITICAL
    if (perr == (INT8U *)0) {
        OS_SAFETY_CRITICAL_EXCEPTION();
    }
#endif

#if OS_ARG_CHK_EN > 0u
    if (pmem == (OS_MEM *)0) {                   /* Is 'pmem' a NULL pointer?                          */