davrdobj.c

FDI Intel开发的FLASH文件系统,功能很强大

/* Copyright (c) 1995-2004 Intel Corporation */
/* Intel Confidential                        */

/* ###########################################################################
###  DAV - Direct Access Volume Enhancement to FDI
###
###  Module: davrdobj.c - DAV Interface Function:  Read Object Module
###
###  $Workfile: davrdobj.c $
###  $Revision: 65 $
###  $NoKeywords: $
########################################################################### */

/*                                                               
 *****************************************************************
 * NOTICE OF LICENSE AGREEMENT                                    
 *                                                                
 * This code is provided by Intel Corp., and the use is governed  
 * under the terms of a license agreement. See license agreement  
 * for complete terms of license.                                 
 *                                                                
 * YOU MAY ONLY USE THE SOFTWARE WITH INTEL FLASH PRODUCTS.  YOUR 
 * USE OF THE SOFTWARE WITH ANY OTHER FLASH PRODUCTS IS EXPRESSLY 
 * PROHIBITED UNLESS AND UNTIL YOU APPLY FOR, AND ARE GRANTED IN  
 * INTEL'S SOLE DISCRETION, A SEPARATE WRITTEN SOFTWARE LICENSE   
 * FROM INTEL LICENSING ANY SUCH USE.                             
 *****************************************************************
 */ 


/*### Include Files
#########################*/
#include "DavLib.h"

#if (DIRECT_ACCESS_VOLUME == TRUE)

#include "davext.h"
#include "davrdobj.h"

/*### Local Declarations
#########################*/

/*### Global Declarations
#########################*/

/*### Local Functions
#########################*/

#define ExitOnError(status) \
   if (status != ERR_NONE) \
   {  FDI_APIUnlock(); \
      return status;  }

/* E5.5.962 Begin */
#define CleanupAndExitOnError(status)   \
   if(status != ERR_NONE)               \
   {                                    \
      FDI_APIUnlock();                  \
      mDEBUG_CHECK_ERRCODE(status)      \
      MEM_CalcMemoryStatistics(FALSE);  \
      return status;                    \
   }
/* E5.5.962 End */  

/*### Global Functions
#########################*/

/*###################################################################
  ### FDI_ReadObject
  ###
  ### DESCRIPTION:
  ###   This function reads data from the object space of the 
  ###   object specified by obj_name and obj_type.  The number 
  ###   of bytes specified by byte_count beginning from offset 
  ###   are read to the buffer pointed to by buffer_ptr.  During
  ###   a reallocate it is possible to have two headers with the 
  ###   same name and type.  The select parameter is used to 
  ###   determine which object to read from, the first or the 
  ###   second occurrence.
  ###
  ### PARAMETERS:
  ###   obj_name    - Name of object.
  ###   name_size   - Length of the name field in bytes.
  ###   obj_type    - Type of the object.
  ###   buffer_ptr  - IN:  Physical address pointing to the beginning 
  ###                      of the buffer where the data will be placed.
  ###                 OUT: buffer will be filled with data from object space
  ###   byte_count  - Number of bytes to read from the object to 
  ###                 the buffer.
  ###   offset      - Offset from the beginning of the object in 
  ###                 object space to begin reading from.
  ###   select      - Which object to read from.  
  ###                   FDI_SELECT_FIRST  = 1st object,
  ###                   FDI_SELECT_SECOND = 2nd object  
  ###
  ### RETURNS:
  ###   When this function passes with no errors a value of 0 is
  ###   returned otherwise, it returns a status of type ERR_CODE.
  ###*/
ERR_CODE FDI_ReadObject(UINT8*  obj_name,
                        UINT8   name_size,
                        UINT32  obj_type,
                        UINT8*  buffer_ptr,
                        UINT32  byte_count,
                        UINT32  offset,
                        UINT8   select )
{
   UINT32             object_size;
   ERR_CODE           status;
   FDI_Handle         read_address;
   SEARCH_CompareInfo compare_info;

   /* Check range of ObjectType */
   if(obj_type < FDI_HT_BeginUserTypes )
   {
      return ERR_PARAM;
   }

   /* Check for invalid Namesize and if the Name pointer is pointing to NULL */
   if((name_size <= 0 ) || 
      (name_size > FDI_MaxNameLength ) || 
      (obj_name == 0))
   {
      return ERR_PARAM;
   }

   /* Multitasking API exclusivity.  (This may not be necessary to the
      full extent as it is done here, but for now it is the safest way.) */
   FDI_APILock();

   /* Search for the object from the beginning of the */
   /*  header table.                                  */
   SEARCH_Header2SearchInfo((&FDI_SearchInfo), (&FDI_SearchHeader));
   
   /* Search for the object and calculate the base address OF THE OBJECT DATA */
   compare_info.NamePtr = (HDR_NamePtr)(obj_name);   
   compare_info.NameSize = name_size;
   compare_info.CompareValue = obj_type;
   status = SEARCH_GetNextHeader(&FDI_SearchInfo, SEARCH_ByNameType, &compare_info, FALSE);
   if (status == ERR_NONE)
   {
      /* object data begins after the object header */
      read_address = FDI_SearchInfo.CurrObj.ObjectAddress + sizeof(HDR_ObjectHeader);
      object_size  = FDI_SearchInfo.CurrObj.ObjectSize    - sizeof(HDR_ObjectHeader);
      
      if (select == FDI_SELECT_SECOND)
      {
         status = SEARCH_GetNextHeader(&FDI_SearchInfo, SEARCH_ByNameType, &compare_info, FALSE);
         if ((status != ERR_NONE) && 
             (status != ERR_NO_MORE_ENTRIES) && 
             (status != ERR_PARAM))
         {
            ExitOnError(status);
         }

         if (status == ERR_NONE)
         {
            /* object data begins after the object header */
            read_address = FDI_SearchInfo.CurrObj.ObjectAddress + sizeof(HDR_ObjectHeader);
            object_size  = FDI_SearchInfo.CurrObj.ObjectSize    - sizeof(HDR_ObjectHeader);
         }
         else
         {
            status = ERR_NOTEXISTS;
            ExitOnError(status);
         }
      }
      
      /* Check upper bounds of the read, if it goes beyond the */
      /*  size of the object then return an error.             */
      if ((offset + byte_count) > object_size)
      {
         status = ERR_PARAM;
         ExitOnError(status);
      }
      
      /* read the object data from flash */
      status = OBJ_ReadObjectData(read_address+offset, buffer_ptr, byte_count);
      ExitOnError(status);
   }

   /* If the object does not exist, a value of ERR_NOTEXISTS is returned. */
   if (status == ERR_NO_MORE_ENTRIES)
   {
      status = ERR_NOTEXISTS;
      ExitOnError(status);
   }
   
   FDI_APIUnlock();
   return status;
}

#endif /* DIRECT_ACCESS_VOLUME */