Writing to external file

Jorge said:

I am trying to write the contents of an EEPROM to an external file on my computer via the UART.  I have followed the app note SPRA861 "RAMDISK: A sample user defined C i/o driver" but I keep getting linker "undefined symbol" errors.  What does this mean, thanks.  Also I am using fopen and fprintf in my code and I am running from flash and am using the TMS320F2809.

The "undefined symbol" error in the linker means that the compiler has found a definition for a symbol (such as a variable, function, etc) but the linker can not resolve it.  If the symbol is a function, there either needs to be an object file which contains the definition of this symbol included in the linker, or a library needs to be included.

If you can post the actual error, this may help highlight where you should look.

Brandon,

Here are the errors and a portion of the code I used, this is the only place I have used this peice of code.  Thanks for the help.

[Linking...] "C:\CCStudio_v3.3\C2000\cgtools\bin\cl2000" -@"Debug.lkf"
<Linking>

undefined                        first referenced
 symbol                              in file
---------                        ----------------
_RAM_rename                      C:\Work\Flash Version (Non-Bios Version)\Debug\Main.obj
_RAM_write                       C:\Work\Flash Version (Non-Bios Version)\Debug\Main.obj
_RAM_lseek                       C:\Work\Flash Version (Non-Bios Version)\Debug\Main.obj
_RAM_read                        C:\Work\Flash Version (Non-Bios Version)\Debug\Main.obj
_RAM_unlink                      C:\Work\Flash Version (Non-Bios Version)\Debug\Main.obj
_RAM_open                        C:\Work\Flash Version (Non-Bios Version)\Debug\Main.obj
_RAM_close                       C:\Work\Flash Version (Non-Bios Version)\Debug\Main.obj
>>   error: symbol referencing errors - './Debug/Control.out' not built

>> Compilation failure

Build Complete,
  2 Errors, 0 Warnings, 0 Remarks.

Portion of Main.C

//Standard Defined includes
#include <stdio.h>
#include <file.h>

//User Defined includes
#include "Main.h"

int    RAM_open(const char *path, unsigned flags, int llv_fd);
int    RAM_close(int dev_fd);
int    RAM_read(int dev_fd, char *buf, unsigned count);
int    RAM_write(int dev_fd, const char *buf, unsigned count);
fpos_t RAM_lseek(int dev_fd, fpos_t offset, int origin);
int    RAM_unlink(const char *path);
int    RAM_rename(const char *old_name, const char *new_name);

//User Defined Code
 
void main(void)
{

    add_device("ramdisk", _MSA, RAM_open, RAM_close, RAM_read, RAM_write,
  RAM_lseek, RAM_unlink, RAM_rename);

Jorge,

I downloaded the RAMDISK code and was able to compile/link it without an issue. I will send this to you through the support channel as we have been talking through there already.

Regards,

Tim Love