davgetnh.c

Flash file system

         if ((HDR_GetHdrState(srch_info_ptr->HeaderPtr->Attr16) == 
                                                HDR_HA_STATE_Valid) &&
             (HDR_GetStatusAttr(srch_info_ptr->HeaderPtr->Attr16) == 
                                                HDR_HA_Valid))
         {
            found = 1;
         }
      break;
      
      case HDR_ByNextPageObject:
      if (HDR_GetAlignmentAttr((srch_info_ptr->HeaderPtr->Attr16)) == 
          HDR_HA_AlignPage)
      {
            found = 1;
      }
      break;
      
      case HDR_ByNameType:
         /* Check for matching type and non-invalid object before */
         /*  checking the name.                                   */
         if ((HDR_GetStatusAttr((srch_info_ptr->HeaderPtr->Attr16)) 
                                            != HDR_HA_Invalid) &&
                 (srch_info_ptr->HeaderPtr->ObjectType == 
                                    compare_info_ptr->CompareValue))
         {
            found = 1;
         }
         else
         {
            break;
         }
      /*lint -fallthrough*/      
      case HDR_ByName:
         /* Read in the header name. */
         status = HDR_ReadFullHeader(srch_info_ptr->CurrObj.HeaderAddress, 
                                              srch_info_ptr->HeaderPtr, restart);
         if(status)
         {
            return status;
         }
         /* If the name lengths don't match obviously the names themselves */
         /*  cannot match.  This prevents the problem of a name with       */
         /*   aaaa matching with a name of aaaaa.                          */

         if ((srch_info_ptr->HeaderPtr->NameSize == 
                                 compare_info_ptr->NameSize) &&
               ((HDR_GetStatusAttr((srch_info_ptr->HeaderPtr->Attr16)) 
                                                       != HDR_HA_Invalid)))
         {
            found = 1;
            for (ii = 0; ii < compare_info_ptr->NameSize; ii++)
            {
               if (srch_info_ptr->HeaderPtr->Name[ii] != 
                             ((UINT8_PTR)compare_info_ptr->NamePtr)[ii])
               {
                  found = 0;
                  break;
               }
            }
         }
         else
         {
            found = 0;
         }
      break;

      case HDR_ByNextParaObject:     
      default: {};
   }
   
   *found_val_ptr = found;
   return status;
}


/*#################################################################
### GetNextHeaderHandle
###
### DESCRIPTION:
###   This function provides the search routines with a fast method
###   of scanning the header table.  It only returns only the
###   HeaderId and Attributes.  The FDI_ReadFullHeader function
###   can then be used along with the handle of the header, to
###   read the entire header.  This loads the srch_info_ptr 
###   header(partial), object size, and header address.
###
### PARAMETERS:
###   srch_info_ptr  - Structure containing search information.
###      IN:  - CurrObj.HeaderAddress references a valid header 
###              and value of 0 will start the search from the 
###              beginning of the header table.
###           - HeaderPtr points to a valid header for temporary 
###              use.
###
###      OUT: - CurrObj.HeaderAddress will reference the header 
###              address of the next header matching the type of 
###              search performed.
###           - CurrObj.ObjectSize will contain the size in bytes,
###              of the object.
###           - HeaderPtr will contain the contents of the
###              minimum information necessary to locate any
###              one object in memory space.
###
### RETURNS:
###   When this function passes with no errors a value of 0 is
###   returned otherwise, it returns a status of type ERR_CODE.
###
###   ERR_NONE       - Entry was found and the search_info_ptr 
###                   contains valid header information.
###
###   ERR_NO_MORE_ENTRIES - The entry was not found after searching
###                   the entire header table.
###*/
ERR_CODE GetNextHeaderHandle(HDR_SearchInfoPtr srch_info_ptr, 
                             int special_condition, BOOLEAN restart)
{
FDI_Handle next_header = 0xffffffff; /* DAV - init to invalid value */
ERR_CODE  status = ERR_NONE;
UINT16       this_id;   
   /* Set start_addr to either the top of Flash memory or to *handle_ptr */
   if ((srch_info_ptr->CurrObj.HeaderAddress == 0) ||
                     (special_condition == GNH_SP_StartAtCurrent))
   {
      if (srch_info_ptr->CurrObj.HeaderAddress == 0)
      {
         /* Read the first header entry. */
         next_header = srch_info_ptr->CurrObj.HeaderAddress = 
                                                HDR_FirstHeaderAddr;
      }
   }
   else
   {
      if (special_condition == GNH_SP_Normal)
      {
/* Might want to make this an option to read from the */
/* flash first!                                       */

         HDR_GetObjectSize(srch_info_ptr->HeaderPtr, 
                              (&srch_info_ptr->CurrObj.ObjectSize));
                              
         next_header = HDR_CalcNextHdrAddr(srch_info_ptr->CurrObj.HeaderAddress,
             (UINT16)HDR_GetAlignmentAttr((srch_info_ptr->HeaderPtr->Attr16)),
             srch_info_ptr->HeaderPtr->NameSize,
             srch_info_ptr->CurrObj.ObjectSize);
      }
   }
   
   if (special_condition == GNH_SP_StartAtCurrent)
   {
      next_header = srch_info_ptr->CurrObj.HeaderAddress;
   }
   
   /* Read the header */
   FLASH_ReadBuffer(next_header, (MemBufferPtr)srch_info_ptr->HeaderPtr, 
                                                    HDR_SearchFieldLength);
   /*fix Header status*/
   status = UINT16_HeaderFixISF_PLR( &(srch_info_ptr->HeaderPtr->Attr16), 
   (next_header+HDR_OffsetToAttr16), restart);
   if(status)
   {
     return status;
   }  
   /*fix header ID*/
   status = UINT16_FixISF_PLR( &(srch_info_ptr->HeaderPtr->HeaderId), 
   (next_header+HDR_OffsetToHeaderId), restart);
   if(status)
   {
     return status;
   }  

                                           
   /* Calculate Next Header's Header Base Address */
   srch_info_ptr->CurrObj.HeaderAddress = next_header;
   
   this_id = srch_info_ptr->HeaderPtr->HeaderId;
   if (this_id == HDR_ID_Empty)
   {
      return ERR_NO_MORE_ENTRIES;
   }

   /* Authenticate that the header is in a good state. */
   if (HDR_AuthenticateHeader(srch_info_ptr) != HDR_STATUS_Authentic)
   {
      return (ERR_PARAM);   
   }
   
   /* Store object size */
   HDR_GetObjectSize(srch_info_ptr->HeaderPtr, 
                       (&srch_info_ptr->CurrObj.ObjectSize));
   
   return ERR_NONE;
}
                
/*### Global Functions
#########################*/
   
/*#################################################################
  ### GetNextHeader
  ###
  ### DESCRIPTION:
  ###   This function will return information about the next object
  ###   in the header table, calculate the address of the object and 
  ###   keep track of the search state using the search_info_ptr.  
  ###   Header information is returned in its raw state.
  ###
  ###   The start point is determined by the HeaderAddress in the
  ###   search_info_ptr.  This value can be from a previous call
  ###   or from previous knowledge of the location of a particular
  ###   header entry.  The next object that matches (depends on
  ###   search method) will be returned in the search_info_ptr.  
  ###   The restart parameter is used to start from and includes the 
  ###   first object in the header table without knowing the address
  ###   of the first entry.
  ###
  ### PARAMETERS:
  ###   search_info_ptr - Structure containing detailed information
  ###                     about the desired object.
  ###    IN:  The CurrObj.HeaderAddress field must contain a valid
  ###         start address to begin searching from.  A value of 0
  ###         will start the search from the beginning of the header
  ###         table.
  ###         
  ###    OUT: The state of the search will be completely stored
  ###         in this structure upon return.  This will allow
  ###         the caller to return to a previous search state
  ###         no matter what other functions might have called
  ###         it (this function is re-entrant).
  ### 
  ###         All information about an object is returned including
  ###         the entire contents of the header (minus name).  The
  ###         HDR_ReadFullHeader function must be used to get the
  ###         name and any other fields that are not essential to
  ###         the search algorithm.
  ###         
  ###   compare_method  - Search for the next object with the 
  ###                     following qualities:
  ###                     
  ###      HDR_ByNextObject       //Return next object in the header 
  ###                             // table.
  ###      HDR_ByNextValidObject  //Return the next valid object in 
  ###                             // the header table.  
  ###      HDR_ByNextParaObject   //Return next para object in the 
  ###                             // header table.
  ###      HDR_ByNextPageObject   //Return next page object in the 
  ###                             // header table.
  ###      HDR_ByValidType        //Return the next valid object with 
  ###                             // the specified type.
  ###      HDR_ByHeaderAddress    //Return the next object that matches the
  ###                             // specified header address (fast search).
  ###      HDR_ByTypeOnly         //Return the next object of the specified 
  ###                             // type.
  ###      HDR_ByNameType         //Return the next object with the specified 
  ###                             // name + type.
  ###      HDR_ByName             //Return the next object with the specified 
  ###                             // name.
  ###
  ###   compare_value   - Used to compare header values based
  ###                     on the method chosen.
  ###                     e.g. Using the SearchByHeaderAddress, 
  ###                          the calling function would place 
  ###                          the desired header address in the 
  ###                          compare_value parameter.
  ###
  ### RETURNS:
  ###   When this function passes with no errors a value of 0 is
  ###   returned otherwise, it returns a status of type ERR_CODE.
  ###
  ###   ERR_NONE       - Entry was found and the search_info_ptr 
  ###                   contains valid header information.
  ###
  ###   ERR_NO_MORE_ENTRIES - The entry was not found after searching
  ###                   the entire header table.
  ###*/
ERR_CODE GetNextHeader(HDR_SearchInfoPtr     search_info_ptr,
                       HDR_SearchMethod      compare_method, 
                       const HDR_CompareInfo *compare_info_ptr,
                       BOOLEAN restart)
{                               
UINT32      header_size;
UINT8       found_val = 0;
ERR_CODE status = ERR_NONE;

   if (search_info_ptr->CurrObj.HeaderAddress == 0)
   {
      /* Starting from beginning of header table */
      search_info_ptr->PageAccum = 0;
   }

   while (!status)
   {
      status = GetNextHeaderHandle(search_info_ptr, FALSE, restart);
      if (!status)
      {
         status = IsFound(search_info_ptr, compare_method, compare_info_ptr,
                             &found_val, restart);
         if(status)
         {
            return(status);
         }
         
         /* If the object is absorbed, don't calculate the object address.*/
         if (HDR_GetAbsorbedAttr(search_info_ptr->HeaderPtr->Attr16) == 
                                                             HDR_HA_Exists)
         {
            /* Header is not absorbed                      */
            /* Calculate Next Header's Object Base Address */
            if (HDR_GetAlignmentAttr(search_info_ptr->HeaderPtr->Attr16) ==
                                                     HDR_HA_AlignPage)
            {
               /* Header is page aligned             */
               /* Accumulate if it is a Page object. */
               search_info_ptr->CurrObj.ObjectAddress = 
                            FDI_StartAddress + (search_info_ptr->PageAccum * 
                            FDI_PageSize);
               search_info_ptr->PageAccum += 
                                       search_info_ptr->CurrObj.ObjectSize / 
                                       FDI_PageSize;
            }
            else
            {
               /* Header is a paragraph aligned object */
               header_size = HDR_CalcHeaderSize((search_info_ptr->HeaderPtr));
               search_info_ptr->CurrObj.ObjectAddress = FDI_ParagraphLength +
                              ((search_info_ptr->CurrObj.HeaderAddress -
                                header_size) -
                               search_info_ptr->CurrObj.ObjectSize);   
            }
         }
         else
         {
            /* Header is absorbed */
            search_info_ptr->CurrObj.ObjectAddress = FDI_InvalidObjAddress;
            search_info_ptr->CurrObj.ObjectSize = 0;
         }
         
         if (found_val)
         {
            return ERR_NONE;
         }
      }
   }
   
   return status;
}

#endif /* DIRECT_ACCESS_VOLUME */