S3C2440是三星的一款32位以ARM9为核心的ARM芯片，主频高达400MHz，有MMU，支持LINUX，初始化程序如下：

/******************************
*文件名：main.c				  *
*功能:   主程序				  *
*创建者: 潘星宇				  *
*最后修改:2017.04.28		  *
*备注:						  *
*							  *
*******************************/

#include "main.h"
extern int get_bit_port_f (char port_bit);
int main(void)
{
//	static U8 str[30] = {0};		   //串口寄存数组
//static	U8 ch;				                 //串口用变量
//	static U8 UART_i = 0; 			   //串口数组计数用
	U8 hour_i;		                 //画小时刻度计数用的变量
	U8 minute_i;			             //画分钟刻度计数用的变量
	U32 hour;				               //从RTC读取的小时
	U32 minute;				             //分钟
	U32 second;				             //秒
	U32 second_ch;                 //秒控制变量，用于控制每秒才显示一次
	static U32 hour_register;		   //小时寄存器，用于储存上一次画时针的位置，用于清屏
	static U32 minute_register;		 //分钟寄存器
	static U32 second_register;		 //秒寄存器
	
	U8 first_location = 30;         //欢迎界面第一行字起始位置
	U8 second_location = 120;       //欢迎界面第二行字起始位置
  U8 name_location = 50;
	
	rWTCON &= 0;
	MMU_Init();			               //初始化内存管理
	LCD_Init();		                 //LCD初始化
	
	cal_cpu_bus_clk();	           //获取时钟频率
	Uart_Init(0,115200);           //初始化串口
	Uart_Select(0);			             //选择串口0
	UART_INT_initialize ();
	
  TouchpanelInit();		           //触摸屏初始化
	IIC_init();                    //初始化IIC
	touchpanelRevise(0);	         //触摸屏校正
	INT_initialize_key ();         //初始化按键中断
	ini_lock();
   
//	 NRF24L01Int();
//   while(1)
//    {
//		NRFSetRXMode();//设置为接收模式
//		GetDate();//开始接受数
//		}
	//Brush_Background(COLOR_CYAN);//绘制青色背景
	
	//绘制初始化信息介绍界面
	Brush_Background(COLOR_WHITE);          //绘制背景品白色

	
	Draw_ASCII(350,200,COLOR_BLACK,COLOR_OFF ,letter_K);           //K3:开始
	Draw_ASCII(350+8,200,COLOR_BLACK,COLOR_OFF ,number_three);
	Draw_ASCII(350+8*2,200,COLOR_BLACK,COLOR_OFF,symbol_colon);
	Draw_Text16(350+8*3, 200, COLOR_BLACK, COLOR_OFF, word_kai);
	Draw_Text16(350+8*5, 200, COLOR_BLACK, COLOR_OFF, word_shi);
	
	while(function_flag==0);
	Draw_ASCII(350,200,COLOR_BLACK,COLOR_ON,letter_K);           //K3:开始 按下变色
	Draw_ASCII(350+8,200,COLOR_BLACK,COLOR_ON,number_three);
	Draw_ASCII(350+8*2,200,COLOR_BLACK,COLOR_ON,symbol_colon);
	Draw_Text16(350+8*3, 200, COLOR_BLACK, COLOR_ON, word_kai);
	Draw_Text16(350+8*5, 200, COLOR_BLACK, COLOR_ON, word_shi);	
	delay(16000000);
	delay(16000000);
	
	RTC_time_set (0x17, 0x04, 0x21, 0x05, 0x22, 0x48, 0x25);
	while(1)
	{
		//main_interface();
		Brush_Background(COLOR_WHITE);          //绘制背景白色
		

		draw_circle(180,136,123,0xfea0);   //表外框金黄色

		//绘制返回
		//draw_return(400, 130, COLOR_BLACK, COLOR_LIGHT_GREEN);	//背景浅绿色
		
		draw_square(COLLATE_SQURE_START_X,COLLATE_SQURE_START_Y,60,COLOR_OFF,COLOR_OFF);
	//绘制 K3: 校准										
		Draw_ASCII(COLLATE_START_X,COLLATE_START_Y,COLOR_BLACK, COLOR_OFF,letter_K);
		Draw_ASCII(COLLATE_START_X+8,COLLATE_START_Y,COLOR_BLACK, COLOR_OFF,number_three);
		Draw_ASCII(COLLATE_START_X+8*2,COLLATE_START_Y,COLOR_BLACK, COLOR_OFF,symbol_colon);
		Draw_Text16(COLLATE_START_X+8*3,COLLATE_START_Y, COLOR_BLACK, COLOR_OFF, word_collate);
		Draw_Text16(COLLATE_START_X+8*5,COLLATE_START_Y, COLOR_BLACK, COLOR_OFF, word_norm);
		
		draw_square(DOOR_SQURE_START_X,DOOR_SQURE_START_Y,60,COLOR_OFF,COLOR_OFF);
	//绘制 K1: 开锁										
		Draw_ASCII(DOOR_START_X,DOOR_START_Y,COLOR_BLACK, COLOR_OFF,letter_K);
		Draw_ASCII(DOOR_START_X+8,DOOR_START_Y,COLOR_BLACK, COLOR_OFF,number_one);
		Draw_ASCII(DOOR_START_X+8*2,DOOR_START_Y,COLOR_BLACK, COLOR_OFF,symbol_colon);
		Draw_Text16(DOOR_START_X+8*3,DOOR_START_Y, COLOR_BLACK, COLOR_OFF, word_door);
		Draw_Text16(DOOR_START_X+8*5,DOOR_START_Y, COLOR_BLACK, COLOR_OFF, word_prohibit);
		
		draw_square(CIRCLE_SQURE_START_X,CIRCLE_SQURE_START_Y,60,COLOR_OFF,COLOR_OFF);
	//绘制 K2: 气泡									
		Draw_ASCII(CIRCLE_START_X ,CIRCLE_START_Y,COLOR_BLACK, COLOR_OFF,letter_K);
		Draw_ASCII(CIRCLE_START_X +8,CIRCLE_START_Y,COLOR_BLACK, COLOR_OFF,number_two);
		Draw_ASCII(CIRCLE_START_X +8*2,CIRCLE_START_Y,COLOR_BLACK, COLOR_OFF,symbol_colon);
		Draw_Text16(CIRCLE_START_X +8*3,CIRCLE_START_Y, COLOR_BLACK, COLOR_OFF, word_gas);
		Draw_Text16(CIRCLE_START_X +8*5,CIRCLE_START_Y, COLOR_BLACK, COLOR_OFF, word_froth);

		draw_square(SNAKE_SQURE_START_X,SNAKE_SQURE_START_Y,60,COLOR_OFF,COLOR_OFF);
	//绘制 K4: 吃蛇									
		Draw_ASCII(SNAKE_START_X,SNAKE_START_Y,COLOR_BLACK, COLOR_OFF,letter_K);
		Draw_ASCII(SNAKE_START_X+8,SNAKE_START_Y,COLOR_BLACK, COLOR_OFF,number_four);
		Draw_ASCII(SNAKE_START_X+8*2,SNAKE_START_Y,COLOR_BLACK, COLOR_OFF,symbol_colon);
		Draw_Text16(SNAKE_START_X+8*3,SNAKE_START_Y, COLOR_BLACK, COLOR_OFF, word_eat);
		Draw_Text16(SNAKE_START_X+8*5,SNAKE_START_Y, COLOR_BLACK, COLOR_OFF, word_snake);
		
		Paint_Bmp(340,170,96,96,logo);  //电专logo
		/**********************************************
		 *已知起始点、两点距离和角度画线的参数分别为：*
		 *第一点坐标x1,y1；							  *
		 *长度；									  *
		 *角度(不是弧度)；							  *
		 *颜色；                                      *
		 *希望保留起始的点的个数；					  *
		 *希望保留最后的点的个数                      *
		 **********************************************/
		//画小时刻度
		for (hour_i=0; hour_i<12; hour_i++)
		{
			one_point_to_another(180, 136, 120, hour_i*30, 0xfb00, 0, 15);    //从0点画到11点 橙色
		}

		//画分钟刻度
		for (minute_i=0; minute_i<60; minute_i++)
		{
			if (minute_i % 5)				       //整点处不画刻度
			{
				one_point_to_another(180, 136, 120, minute_i*6, 0xfc00, 0, 1 );	//从1分画到59分 橘黄色
			}
		}

		while (function_flag==1)
		{
			hour = rBCDHOUR;    //获取小时
			minute = rBCDMIN;   //获取分钟
			second = rBCDSEC;   //获取秒
			hour = ((hour / 16)*10 + hour % 16) % 12;//由于从RTC读出的都是16进制的，先转成10进制，再将24小时格式转化为12小时格式
			minute = (minute / 16)*10 + minute % 16; 	   
			second = (second / 16)*10 + second % 16;	    				     
			if (second != second_ch)
			{
				//先清除掉上次画的时针，分针，秒针，长度暂分别定为35，60，90
				if ((hour_register*30 + (minute_register / 10)*5) != (hour*30 + (minute / 10)*5)) //为了消除分针和时针闪屏的问
				{																				  //只有当分针或时针确实移动了位置才消除上一次画的的值
					one_point_to_another(180, 136, 120, hour_register*30 + (minute_register / 10)*5, 0xffff, 35, 0);	 
				}
				if (minute_register != minute)
				{
					one_point_to_another(180, 136, 120, minute_register*6, 0xffff, 60, 0);	
				}
				one_point_to_another(180, 136, 120, second_register*6, 0xffff, 90, 0);

				second_ch = second;      //使秒控制变量等于当前时钟的秒值，这样直到秒变化，才再次进入这个内部来
				one_point_to_another(180, 136, 120, hour*30 + (minute /10)*5, COLOR_BLACK, 35, 0);	  //时针每小时走30°，分钟动10分钟，时钟动5°
				one_point_to_another(180, 136, 120, minute*6, 0x001f, 60, 0);  //蓝色
				one_point_to_another(180, 136, 120, second*6, 0xf800, 90, 0);  //红色
				rtc_display_lcd(320,150,0xb1dd,0x08a8); //显示电子钟，参数分别为横坐标、纵坐标、颜色、背景色
				hour_register = hour;	             //将时分秒的值储存起来，用于下一秒清除上一秒的变化
				minute_register = minute;
				second_register = second;
			}
			
//			while (rUTRSTAT0 & 0x1)			  //当串口接收缓冲器有数据时
//			{
//				ch = rURXH0;				  //接收数据
//				str[UART_i++] = ch;
//				Uart_SendByte(ch);
//				if((ch == 0xff)||(UART_i == 29 ))	  //接收数据完成
//				{
//					RTC_time_set (str[0], str[1], str[2], str[3], str[4], str[5], str[6]);
//					UART_i = 0;
//					}
//			}
		}
//		while(!function_flag)
//		{
//		}
		switch(function_flag)    //是否有模块申请
		{
//			case 1:              //欲显示样例1
//			{
//				draw_example1_led(COLOR_WHITE,COLOR_DARK_GREEN);  //背景变为深绿色
//				delay(16000000);
//				led();
//				Brush_Background(COLOR_CYAN);//绘制青色背景
//				function_flag = 0;
//				break;	
//			}
//			case 2:              //欲显示样例2
//			{
//				draw_example2_clock(COLOR_WHITE,COLOR_DARK_GREEN);
//				delay(16000000);
//				clock();
//				Brush_Background(COLOR_CYAN);//绘制青色背景
//				function_flag = 0;
//				break;	
//			}	
			case 3:             //欲显示样例3
			{
				draw_square(CIRCLE_SQURE_START_X,CIRCLE_SQURE_START_Y,60,COLOR_ON,COLOR_ON);
			//绘制 K2: 气泡									
				Draw_ASCII(CIRCLE_START_X,CIRCLE_START_Y,COLOR_BLACK, COLOR_ON,letter_K);
				Draw_ASCII(CIRCLE_START_X+8,CIRCLE_START_Y,COLOR_BLACK, COLOR_ON,number_two);
				Draw_ASCII(CIRCLE_START_X+8*2,CIRCLE_START_Y,COLOR_BLACK, COLOR_ON,symbol_colon);
				Draw_Text16(CIRCLE_START_X+8*3,CIRCLE_START_Y, COLOR_BLACK, COLOR_ON, word_gas);
				Draw_Text16(CIRCLE_START_X+8*5,CIRCLE_START_Y, COLOR_BLACK, COLOR_ON, word_froth);
				delay(16000000);
				delay(16000000);
				random_circle();
				Brush_Background(COLOR_WHITE);//绘制青色背景
				function_flag = 1;
				break;	
			}
			case 4:             //欲显示样例4
			{
				draw_square(410,85,60,COLOR_ON,COLOR_ON);
			//绘制 K4: 吃蛇									
				Draw_ASCII(412,105,COLOR_BLACK, COLOR_ON,letter_K);
				Draw_ASCII(412+8,105,COLOR_BLACK, COLOR_ON,number_four);
				Draw_ASCII(412+8*2,105,COLOR_BLACK, COLOR_ON,symbol_colon);
				Draw_Text16(412+8*3,105, COLOR_BLACK, COLOR_ON, word_eat);
				Draw_Text16(412+8*5,105, COLOR_BLACK, COLOR_ON, word_snake);
				delay(16000000);
				delay(16000000);
				snake();
				Brush_Background(COLOR_WHITE);//绘制青色背景
				function_flag = 1;
				break;	
			}
			case 5:             //欲显示样例5
			{
				draw_square(DOOR_SQURE_START_X,DOOR_SQURE_START_Y,60,COLOR_ON,COLOR_ON);
			//绘制 K1: 开锁										
				Draw_ASCII(DOOR_START_X,DOOR_START_Y,COLOR_BLACK, COLOR_ON,letter_K);
				Draw_ASCII(DOOR_START_X+8,DOOR_START_Y,COLOR_BLACK, COLOR_ON,number_one);
				Draw_ASCII(DOOR_START_X+8*2,DOOR_START_Y,COLOR_BLACK, COLOR_ON,symbol_colon);
				Draw_Text16(DOOR_START_X+8*3,DOOR_START_Y, COLOR_BLACK, COLOR_ON, word_door);
				Draw_Text16(DOOR_START_X+8*5,DOOR_START_Y, COLOR_BLACK, COLOR_ON, word_prohibit);
				delay(16000000);
				delay(16000000);
				door();
				Brush_Background(COLOR_WHITE);//绘制青色背景
				function_flag = 1;
				break;	
			}
			case 20:
			{
				draw_square(COLLATE_SQURE_START_X,COLLATE_SQURE_START_Y,60,COLOR_ON,COLOR_ON);
			//绘制 K3: 校准										
				Draw_ASCII(COLLATE_START_X,COLLATE_START_Y,COLOR_BLACK, COLOR_ON,letter_K);
				Draw_ASCII(COLLATE_START_X+8,COLLATE_START_Y,COLOR_BLACK, COLOR_ON,number_three);
				Draw_ASCII(COLLATE_START_X+8*2,COLLATE_START_Y,COLOR_BLACK, COLOR_ON,symbol_colon);
				Draw_Text16(COLLATE_START_X+8*3,COLLATE_START_Y, COLOR_BLACK, COLOR_ON, word_collate);
				Draw_Text16(COLLATE_START_X+8*5,COLLATE_START_Y, COLOR_BLACK, COLOR_ON, word_norm);
				delay(16000000);
				delay(16000000);
				touchpanelRevise(1);
				Brush_Background(COLOR_WHITE);
				function_flag = 1;
				break;					
			}
			default:
			{
				function_flag = 1;
				break;
			}
		}
	}
}

稍后再分别介绍各个外设。

头文件如下

#ifndef MAIN_H
#define MAIN_H
#include "mmu.h"
#include "interface.h"
#include "LCD.h"
#include "LED.h"
#include "global_value.h"
#include "clock.h"
#include "UART.h"
#include "random_circle.h"
#include "snake.h"
#include "touch.h"
#include "IIC.h"
#include "door.h"
#include "common_functions.h"
#include "key.h"
#include "NRF.h"
#endif