RL-FlashFs in RTX Can't write data in file.

thank your reply.
I had done your advices, it worked very well in Keil SD_File demo for LM3S8962 board and over UART with terminal program try formatting the card;but in my project,only write data into files can't work,I search ed a meaasge in this forum,it said that "Keil SD_File demo only work none-RTX,otherwise write operation result is a enmpy file",that is right?

SD_File demo is prepared without RTX but RTX can be used without problems.
You obviously have done something wrong, I suggest you start with SD_File example for start of your application.

FINFO on the stack? It is quite large, better to do

static FINFO info;

Well it seems that you have not done retargetting, take a look to Retarget.c file, have you included it into your project?

My Retarget.c is from keil's SD_File demo,and I had included it into my project.

/*----------------------------------------------------------------------------
 *      R T L  -  F l a s h   F i l e   S y s t e m
 *----------------------------------------------------------------------------
 *      Name:    RETARGET.C
 *      Purpose: Retarget low level functions
 *      Rev.:    V3.20
 *----------------------------------------------------------------------------
 *      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 <string.h>
#include <rt_misc.h>
#include <rt_sys.h>
#include <File_Config.h>

#pragma import(__use_no_semihosting_swi)

/* The following macro definitions may be used to translate this file:

  STDIO - use standard Input/Output device
          (default is NOT used)
 */

/* Standard IO device handles. */
#define STDIN   0x8001
#define STDOUT  0x8002
#define STDERR  0x8003

/* Standard IO device name defines. */
const char __stdin_name[]  = "STDIN";
const char __stdout_name[] = "STDOUT";
const char __stderr_name[] = "STDERR";

struct __FILE { int handle; /* Add whatever you need here */ };

#ifdef STDIO
 extern int sendchar (int ch);
 extern int getkey (void);
#endif

/*--------------------------- _ttywrch --------------------------------------*/

void _ttywrch (int ch) {
#ifdef STDIO
   sendchar(ch);
#endif
}

/*--------------------------- _sys_open -------------------------------------*/

FILEHANDLE _sys_open (const char *name, int openmode) {
   /* Register standard Input Output devices. */
   if (strcmp(name, "STDIN") == 0) {
      return (STDIN);
   }
   if (strcmp(name, "STDOUT") == 0) {
      return (STDOUT);
   }
   if (strcmp(name, "STDERR") == 0) {
      return (STDERR);
   }
   return (__fopen (name, openmode));
}

/*--------------------------- _sys_close ------------------------------------*/

int _sys_close (FILEHANDLE fh) {
   if (fh > 0x8000) {
      return (0);
   }
   return (__fclose (fh));
}

/*--------------------------- _sys_write ------------------------------------*/

int _sys_write (FILEHANDLE fh, const U8 *buf, U32 len, int mode) {
#ifdef STDIO
   if (fh == STDOUT) {
      /* Standard Output device. */
      for (  ; len; len--) {
         sendchar (*buf++);
      }
      return (0);
   }
#endif
   if (fh > 0x8000) {
      return (-1);
   }
   return (__write (fh, buf, len));
}

/*--------------------------- _sys_read -------------------------------------*/

int _sys_read (FILEHANDLE fh, U8 *buf, U32 len, int mode) {
#ifdef STDIO
   if (fh == STDIN) {
      /* Standard Input device. */
      for (  ; len; len--) {
         *buf++ = getkey ();
      }
      return (0);
   }
#endif
   if (fh > 0x8000) {
      return (-1);
   }
   return (__read (fh, buf, len));
}

/*--------------------------- _sys_istty ------------------------------------*/

int _sys_istty (FILEHANDLE fh) {
   if (fh > 0x8000) {
      return (1);
   }
   return (0);
}

/*--------------------------- _sys_seek -------------------------------------*/

int _sys_seek (FILEHANDLE fh, long pos) {
   if (fh > 0x8000) {
      return (-1);
   }
   return (__setfpos (fh, pos));
}

/*--------------------------- _sys_ensure -----------------------------------*/

int _sys_ensure (FILEHANDLE fh) {
   if (fh > 0x8000) {
      return (-1);
   }
   return (__flushbuf (fh));
}

/*--------------------------- _sys_flen -------------------------------------*/

long _sys_flen (FILEHANDLE fh) {
   if (fh > 0x8000) {
      return (0);
   }
   return (__get_flen (fh));
}

/*--------------------------- _sys_tmpnam -----------------------------------*/

int _sys_tmpnam (char *name, int sig, unsigned maxlen) {
   return (1);
}

/*--------------------------- _sys_command_string ---------------------------*/

char *_sys_command_string (char *cmd, int len) {
   return (cmd);
}

/*--------------------------- _sys_exit -------------------------------------*/

void _sys_exit (int return_code) {
   /* Endless loop. */
   while (1);
}








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