How does uvison get call stack infomation?

Hi,

I don't know why my debugger always has only one row in the call stack window, and especially the caller has the "prefix" of "\?C_LIB_CODE\?CO?CCASE?3_AP000006\" .
Here is my test program:

void func2(unsigned char * s)
{
	*s++;
}

void func1()
{
 	unsigned int i=0;
	unsigned char ucMyArray[9];
	for(i=0;i<9;i++)
		 ucMyArray[i] = i;
	func2(ucMyArray);
}

main()
{
	func1();
	while(1);
}