os_null.c

针对于arm架构的pxa270的一个boot程序,供开始学习ARM的朋友参考.

#define LED_CS4		(*((volatile unsigned char *)(0x10500000)))

#define LED_VALUE  (0xff)


int i;

void Delay(unsigned int x)
{
	unsigned int i, j, k;
	for (i =0; i <=x; i++)
		for (j = 0; j <0xff; j++)
			for (k = 0; k <0xff; k++);
}



void dummyOs(void)
{	

	while (1)
	{	
		LED_CS4 = 0xff;
		
		for (i = 0; i < 8; i++)
		{		
			LED_CS4 = (LED_VALUE << i) -1;
			Delay(200);
		}
	}
	
}