stm32f429 printf/b on keil

How can i use printf in keil for my stm32f429i disc1 discovery board. I followed the steps on this link www.keil.com/.../ulink2_trace_itm_viewer.htm. i am still not able to print. Do i have to add any code. If yes where? My retarget_io.c file which gets created when i select the stdio and stdin itm is locked. Its unmodifiable. Is there a need to modify that? Blocked at this since 2 days. So need help soon.
Do i have to add this to my main file?

#include <stdio.h>
#include <rt_misc.h>

#pragma import(__use_no_semihosting_swi)

// Para utilização do saida de debug através do ULINK2
#define ITM_Port8(n) (*((volatile unsigned char *)(0xE0000000+4*n)))
#define ITM_Port16(n) (*((volatile unsigned short*)(0xE0000000+4*n)))
#define ITM_Port32(n) (*((volatile unsigned long *)(0xE0000000+4*n)))
#define DEMCR (*((volatile unsigned long *)(0xE000EDFC)))
#define TRCENA 0x01000000

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

// Escreve caractere na porta de Debug
int sendchar (int ch) { if (DEMCR & TRCENA) { while (ITM_Port32(0) == 0); ITM_Port8(0) = ch; } return(ch);
}

int fputc(int ch, FILE *f) { return (ITM_SendChar((uint32_t)ch));
}

int ferror(FILE *f) { /* Your implementation of ferror */ return EOF;
}

void _ttywrch(int ch) { sendchar(ch);
}

void _sys_exit(int return_code) {
label: goto label; /* endless loop */
}