main.c

一个基于MMU的操作系统

#include 	"lib.h"

#define	GPBCON		(*(volatile unsigned long *)0x56000010)
#define	GPBDAT		(*(volatile unsigned long *)0x56000014)

#define	GPB7_out	(1<<(7*2))
#define	GPB8_out	(1<<(8*2))
#define	GPB9_out	(1<<(9*2))
#define	GPB10_out	(1<<(10*2))

void  wait(unsigned long dly)
{
	for(; dly > 0; dly--);
}

int  main(int argc, char **argv)
{
	unsigned long i = 0;
 
	GPBCON	 =GPB7_out|GPB8_out|GPB9_out|GPB10_out;

	while(1){
		GPBDAT = (~(i++))<<7;
		write("user program leds will sleep 0.5s\n\r");
		sleep(50);	//系统时钟周期为10ms，休眠0.5s
	}

	return 0;
}