cellinfo.c

AMD公司官方版FLASH文件系统。有详细说明文档和Windows仿真测试环境。

/**
 * CellInfo.c
 *
 * This file contains methods for storing and defining
 * cell information.  It is designed to be used by Format
 * and Initialize routines. 
 *
 * CellInfo functions are used by many different functions through out the
 *   DMS software.
 *
 * Functions in this file do not read or write to the flash
 *   they only organize and store the data given to them.
 *
 * Usage durring Format is as follows:
 *   dms_CellInfoDefineCellList is called at the beginning of a
 *     where all cell information is provided.
 *   Then dms_CellInfoCheckValidity() is called to check cell values.
 *   dms_CellInfoGetCount(), dms_CellInfoGetLargestCellBlockCount()
 *     dms_CellInfoGetTotalBlockCount(), and dms_CellInfoGetBlockCount(),
 *     are used through out the format process.
 *   dms_CellInfoFinalize() is called at the end of a Format.
 *
 * Usage is as follows:
 *   Durring Initialization dms_CellInfoDefineCellCount() is called after
 *     the cell count is read from the sector header.
 *   After all blocks in all sectors are read in and inserted into the 
 *     CellTable then dms_CellInfoDefineCellBlockCount() is called for each
 *     cell.  The block count based on the number of blocks found for that cell.
 *   dms_CellInfoCheckValidity() is called at the end of Initialization.
 *   dms_CellInfoGetCount(), dms_CellInfoGetLargestCellBlockCount()
 *     dms_CellInfoGetTotalBlockCount(), and dms_CellInfoGetBlockCount(),
 *     are used through out Reading, Writing, and Finalizing.
 *   dms_CellInfoFinalize() is called at the end of a Shutdown.
 *
 */

#include "CellInfo.h"
#include <malloc.h>

/* locally used variables */
static WORD lwCellCount = 0;
static WORD *lpwCellBlockCount = NULL;


/**
 * dms_CellInfoDefineCellList
 * Creates a local copy of the cell information.  Performs some
 * basic validity checks on the cell information.
 * This function or dms_CellInfoDefineCellCount, 
 *   dms_CellInfoDefineIncrementCellBlockCount, and dms_CellInfoCheckValidity
 *   must be called before any other functions in this file are called.
 *
 * Prerequisites:
 *   None. 
 * Uses:
 *   dms_CellInfoDefineCellCount()
 *   dms_CellInfoCheckValidity()
 * Used By:
 *   dms_CellFormat()
 *   
 */
DMS_STATUS dms_CellInfoDefineCellList(DWORD *apdwCellSize, WORD awCellCount){
  DMS_STATUS eTmpStatus;
  WORD wCellIndex;

  eTmpStatus = dms_CellInfoDefineCellCount(awCellCount);
  if (eTmpStatus != No_Error){
    return eTmpStatus;
  }

  for (wCellIndex = 0; wCellIndex < awCellCount; wCellIndex++){
    if (apdwCellSize[wCellIndex] % sizeof(DATABLOCK) != 0) {
      return Uneven_Cell_Size;
    }
    lpwCellBlockCount[wCellIndex] = (WORD) (apdwCellSize[wCellIndex] / sizeof(DATABLOCK));
  }

  eTmpStatus = dms_CellInfoCheckValidity();
  if (eTmpStatus != No_Error){
    return eTmpStatus;
  }
  return No_Error;
}
    
/**
 * dms_CellInfoFinalize
 * Frees memory used by these functions.
 *
 * Prerequisites:
 *   None. 
 * Uses:
 *   dms_CellInfoDefineCellCount()
 *   dms_CellInfoCheckValidity()
 * Used By:
 *   dms_CellFormat()
 *   dms_CellTableInitialize()
 *   dms_CellTableFinalize()
 */
DMS_STATUS dms_CellInfoFinalize(void){
  if (lpwCellBlockCount != NULL){
    free(lpwCellBlockCount);
    lpwCellBlockCount = NULL;
  }
  lwCellCount = 0;
  return No_Error;
}

/**
 * dms_CellInfoDefineCellCount
 * Allocates memory for the local copy of the cell info.
 * This function is designed to be called by the Initializion
 *   routine before reading the sector block table.
 *
 * Prerequisites:
 *   None. 
 * Uses:
 *   malloc()
 *   dms_CellInfoFinalize()
 * Used By:
 *   dms_CellTableInitialize(WORD awCellCount){
 *
 */
DMS_STATUS dms_CellInfoDefineCellCount(WORD awCellCount){
  WORD wCellIndex;
  if (lpwCellBlockCount != NULL) {
    /* assume memory from old needs freed */
    dms_CellInfoFinalize();
  }
  lpwCellBlockCount = (WORD*) malloc(sizeof(WORD) * awCellCount);
  if (lpwCellBlockCount == NULL) {
    return Out_Of_Memory_Error;
  }
  for (wCellIndex = 0; wCellIndex < awCellCount; wCellIndex++){
    lpwCellBlockCount[wCellIndex] = 0;
  }
  lwCellCount = awCellCount;
  return No_Error;
}

/**
 * dms_CellInfoDefineCellBlockCount
 * This function is designed to be called by initialization.
 * NOTE: dms_CellInfoCheckValidity should be called after all
 *   calls to this function are complete.  (ie after all 
 *   sectors are read.
 *
 * Prerequisites:
 *   dms_CellInfoDefineCellCount()
 * Uses:
 *   Nothing outside this file.
 * Used By:
 *   dms_CellTableCheckValidity()
 */
void dms_CellInfoDefineCellBlockCount(WORD awCellIndex, WORD awBlockCount){
  lpwCellBlockCount[awCellIndex] = awBlockCount;
}

/**
 * dms_CellInfoCheckValidity()
 * Performs some basic checks on the cells.
 * Checks for total cell size verse sector size are
 *   done by initialization software.
 *
 * Prerequisites:
 *   dms_CellInfoDefineCellCount()
 *   dms_CellInfoDefineCellBlockCount()
 * Uses:
 *   Nothing outside this file.
 * Used By:
 *   dms_CellTableCheckValidity(void)
 */
DMS_STATUS dms_CellInfoCheckValidity(void){
  WORD wCellIndex;

  /* check that block count for each cell >= 0 */
  for (wCellIndex = 0; wCellIndex < lwCellCount; wCellIndex++){
    if (lpwCellBlockCount[wCellIndex] <= 0) {
      return Cell_Size_Too_Small;
    }
  }
  return No_Error;
}

/**
 * dms_CellInfoGetCount()
 * Returns the number of cells.
 *
 * Prerequisites:
 *   dms_CellInfoDefineCellCount()
 * Uses:
 *   Nothing outside this file.
 * Used By:
 *   dms_CellTableCheckValidity()
 *   dms_CellTableFinalize()
 *   dms_CellRead ()
 *   dms_CellWrite()
 *   dms_CellFormat ()
 *   dms_SectorInitialize()
 *   dms_SectorCleanup()
 */
WORD dms_CellInfoGetCount(void){
  return lwCellCount;
}

/**
 *  dms_CellInfoGetBlockCount()
 *  Returns the number of blocks in the requested cell.
 *  NOTE: Cell Index must be valid otherwise result
 *    is undefined or function may crash.
 *  A valid index is >= 0 and < dms_CellInfoGetCount()
 *
 * Prerequisites:
 *   dms_CellInfoDefineCellCount()
 *   dms_CellInfoDefineCellBlockCount()
 * Uses:
 *   Nothing outside this file.
 * Used By:
 *   dms_CellWrite()
 *   dms_CellFormat()
 *   dms_CellInfoGetLargestCellBlockCount()
 *   dms_CellInfoGetTotalBlockCount()
 */
WORD dms_CellInfoGetBlockCount(WORD awCellIndex){
  return lpwCellBlockCount[awCellIndex];
}
 
/**
 * dms_CellInfoGetTotalBlockCount
 * Returns the sum of dms_CellInfoGetBlockCount for
 * all cells.
 *
 * Prerequisites:
 *   dms_CellInfoDefineCellCount()
 *   dms_CellInfoDefineCellBlockCount()
 * Uses:
 *   dms_CellInfoGetBlockCount()
 * Used By:
 *   dms_CellTableCheckValidity()
 */
WORD dms_CellInfoGetTotalBlockCount(void){
  WORD wCellIndex;
  WORD wTotalBlockCount = 0;
  for (wCellIndex = 0; wCellIndex < lwCellCount; wCellIndex++){
    wTotalBlockCount = (WORD) (wTotalBlockCount + dms_CellInfoGetBlockCount(wCellIndex));
  }
  return wTotalBlockCount;
}

/**
 * dms_CellInfoGetLargestCellBlockCount
 * Returns the size in blocks of the largest cell.
 *
 * Prerequisites:
 *   dms_CellInfoDefineCellCount()
 *   dms_CellInfoDefineCellBlockCount()
 * Uses:
 *   dms_CellInfoGetBlockCount()
 * Used By:
 *   dms_CellTableCheckValidity()
 */
WORD dms_CellInfoGetLargestCellBlockCount(void){
  WORD wCellIndex;
  WORD wLargestCellBlockCount = 0;
  WORD wCellBlockCount;
  for (wCellIndex = 0; wCellIndex < lwCellCount; wCellIndex++){
    wCellBlockCount = dms_CellInfoGetBlockCount(wCellIndex);
    if (wCellBlockCount > wLargestCellBlockCount) {
      wLargestCellBlockCount = wCellBlockCount;
    }
  }
  return wLargestCellBlockCount;
}