(CodeSourcery) gcc link errors for hello world?

This question is answered

Posted by Jonathan Chen

on Jan 20 2012 23:50 PM

Intellectual635 points

As usual, I must be missing something totally basic here...

#include "stdio.h"
int main()
{
printf("hello world\n");
return 0;
}

Link errors say the following functions are not found:

_close
_fstat
_isatty
_lseek
_read
_sbrk
_write

Notes

The ultimate goal is to compile StarterWare's usb_bulk_dev example (not supported by CCS CGT?), so the target platform is ARM EABI (arm-none-eabi-gcc)
Linking with the flags "-lc -lgcc -lg" doesn't fix the link errors
CodeSourcery's libc.pdf (Chapter 12) says to write your own stub functions? Is there no easier way?
Is (3) really how StarterWare does it? But then why are sbrk, etc. nowhere to be found in the source code?
Or, do gcc-compiled StarterWare programs not support printf at all??

All Replies

Posted by Baskaran Chidambaram

on Jan 22 2012 22:41 PM

Verified Answer

Verified by Jonathan Chen

Expert4435 points

Chen,

In embedded environvment we need to define the printf function, Since the definition will change across platforms, the compiler library cant provide printf. In StarterWare we defined UARTPuts() which will print on the serial port.

So just comment the printf function call, you should be able to link it.

Regards

Baskaran

Posted by Jonathan Chen

on Jan 23 2012 08:41 AM

Intellectual635 points

Thank you, Baskaran!

More questions to close up loose ends:

6. printf is available with CCS/CGT/TMS470; is this via ccs/tools/compiler/tms470/lib/rts*.lib?

7. Is it at all possible to compile the code in rtssrc.zip with gcc, or maybe a "cross-compile" with tms470 to generate a library that can be linked using gcc?

Note this is all for use with the Spectrum Digital AM1707 EVM board.

-Jonathan

Posted by Baskaran Chidambaram

on Jan 25 2012 12:36 PM

Expert4435 points

6. I am not sure about this. May be the tools team (CCS) can give more info. if you are still interested in this please post a query in "code composer studio" forum.

7. i dont think code compiled with different tool chains can be linked and executed successfully on target.