[U-Boot-Users] Problem about "printf"!

[junping feng]

My uboot can run now! Through serial,prompt"=>"can be
printed,but after input"help",it don't display
commands of uboot.
It seems as if uboot can't find the standard input and
output devices.
It display below:

......
DRAM: 16 MB 
FLASH: 16 MB
*** Warning - bad CRC, using default environment
=>


I find that function "printf" (in the
/common/console.c) can't execute. WHY? Please  give me
a hand! Thanks!
As below:

#ifndef CFG_CONSOLE_INFO_QUIET
  /* Print informations */
printf ("In:    ");
if (stdio_devices[stdin] == NULL) {
printf ("No input devices available!\n");
} else {
printf ("%s\n", stdio_devices[stdin]->name);
}

printf ("Out:   ");
if (stdio_devices[stdout] == NULL) {
printf ("No output devices available!\n");
} else {
printf ("%s\n", stdio_devices[stdout]->name);
}

printf ("Err:   ");
if (stdio_devices[stderr] == NULL) {
printf ("No error devices available!\n");
} else {
printf ("%s\n", stdio_devices[stderr]->name);
}
#endif /* CFG_CONSOLE_INFO_QUIET */





	

	
		
___________________________________________________________ 
雅虎免费G邮箱－中国第一绝无垃圾邮件骚扰超大邮箱
http://cn.mail.yahoo.com/?id=77071