_fs_fcreate.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_FCREATE.C 
 *      Purpose: Low level File Create 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 <stdio.h>
#include <rt_sys.h>
#include <rt_misc.h>
#include "File_Config.h"

/*--------------------------- _fcreate --------------------------------------*/

int _fcreate (const S8 *fname, IOB *fcb) {
   /* Low level file create function. This function creates a file */
   /* with name 'fname' for writing in the Flash File System.      */
   FALLOC fa;
   U32 i,bl,adr;
   U8  fn[32];

   bl = 0;
   for (i = 0; i < fcb->NumSect; i++) {
      adr = fs_adr_sig (i, fcb);
      adr = fs_rd_sig (adr, &fa.end);
      if ((fa.end ^ BlockUSED) == fcb->InitVal) {
         /* Check if a file already opened for writing in this Block */
         if (fs_check_fwopen (i, fcb) == __TRUE) {
            continue;
         } 
         /* Try already used Flash Block and check for free space */
         if (fs_get_freeMem (i, fcb) == 0) {
            fa.end = fcb->InitVal ^ BlockFULL;
            fs_WriteBlock (((DEVCONF *)fcb->DevCfg)[i].bEnd, &fa.end, 4, fcb);
            continue;
         }
         bl = i + 1;
         break;
      }
      if (fa.end == fcb->InitVal) {
         if (bl == 0) {
            bl = i + 1;
         }
      }
   } 
   if (bl == 0) {
      /* No Flash Blocks free. */
      return (1);
   }
   /* Write a filename to empty space in Flash Block */
   fcb->_fblock = bl - 1;
   fs_mark_freeMem (fcb);

   /* Write Block Signature (=usage) value. */
   adr = fs_adr_sig (fcb->_fblock, fcb);
   fs_rd_sig (adr, &fa.end);
   if (fa.end == fcb->InitVal) {
      fa.end = fcb->InitVal ^ BlockUSED;
      fs_WriteBlock ((adr & ~1), &fa.end, 4, fcb);
   }

   /* 'fname' must be stored 0-terminated */
   for (i = 0; fname[i] && i < 31; i++) {
      fn[i] = fname[i];
   }
   fn[i] = 0;
   i = (i + 4) & ~3;

   /* Make sure that 'fname' starts 4-byte aligned */
   fs_WriteBlock (((DEVCONF *)fcb->DevCfg)[fcb->_fblock].bStart + fcb->_fbot,
                  fn, i, fcb);
   fcb->_fbot += i;

   /* Not always correct, but 'fname' is 0-terminated anyway. */
   fa.end    = fcb->_fbot;
   fa.fileID = fcb->fileID | 0x8000;
   /* 'index' can be used later for file attributes like ReadOnly etc. */
   fa.index  = 0;
   fs_WriteBlock (((DEVCONF *)fcb->DevCfg)[fcb->_fblock].bStart + fcb->_ftop,
                   &fa, sizeof (FALLOC), fcb);
   fcb->_ftop -= sizeof (FALLOC);
   return (0);
}

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