_fs_getfsize.c

keil arm flash fs 最新版 在Ｋｅｉｌ ａｒｍ下使用

/*----------------------------------------------------------------------------
 *      R T L  -  F l a s h   F i l e   S y s t e m
 *----------------------------------------------------------------------------
 *      Name:    _FS_GETFSIZE.C 
 *      Purpose: Low level Get File Size Function
 *      Rev.:    V3.22
 *----------------------------------------------------------------------------
 *      This code is part of the RealView Run-Time Library.
 *      Copyright (c) 2004-2008 KEIL - An ARM Company. All rights reserved.
 *---------------------------------------------------------------------------*/

#include "File_Config.h"

/*--------------------------- __getfsize ------------------------------------*/

U32 __getfsize (IOB *fcb, BOOL set_fidx) {
   /* Low level get file size function. */
   FALLOC fa;
   U32 bl,fidx,adr,prev;
   U32 i,fsize;

   if (fcb->drive == DRV_MCARD) {
      /* This info is available for Flash Card. */
      return (fcb->fsize);
   }
   if ((fcb->flags & _IOAPPEND) && (set_fidx == __FALSE)) {
      /* Size info already set in '__fopen()'. */
      return (fcb->fsize);
   }
   fidx = 0;
   fsize = 0;
   bl = fcb->_fblock;
nextbl:
   for (i = 0; i < fcb->NumSect; i++) {
      /* Search for file blocks identified with identification 'fileID' */
      adr = fs_adr_sig (bl, fcb);
      adr = fs_rd_sig (adr, &fa.end);
      if (fa.end != fcb->InitVal) {
         for (prev = 0; ; prev = fa.end) {
            adr = fs_rd_alloc (adr, &fa);
            if (fa.fileID == fcb->fileID  &&  fa.index == fidx) {
               /* All file blocks are 4-byte aligned. */
               fsize += (fa.end - ((prev + 3) & ~3));
               fidx++;
               goto nextbl;
            }
            if (fa.end == fcb->InitVal) break;
         }
      }
      if (++bl == fcb->NumSect) {
         bl = 0;
      }
   } 
   /* This File Block does not exist so this must be End Of File */
   if (set_fidx == __TRUE) {
      fcb->_fidx = fidx;
   }
   return (fsize);
} /* end of _getfsize */

/*----------------------------------------------------------------------------
 * end of file
 *---------------------------------------------------------------------------*/