嵌入式系统实验二.docx

1、嵌入式系统实验二 实验二 嵌入式系统程序设计实验之linux串口和网络编程 一、实验目的： 1、强化本学期所学的相关的内容。 2、掌握串口相关设置。 3、强化基于TCP网络传输的三次握手。 4、自学Linux线程的使用。二、实验内容： 本试验基于server和client的透明传输来实现类似于QQ的聊天功能。三、实验过程： 1、linux开发环境的建立 2、嵌入式linux系统的搭建 1BootLoader的移植 2linux系统的裁剪与移植 Linux内核裁剪 ./make_image生成自己的uImage2638上电验证：3根文件系统的移植修改hostname为：whmtt./mkcram

2、fsdisk_new 生成rootfs_new.cramfs大小从老师给的40000到37b00（因为有的没有用到，大小变小了）：上电验证： 3、客服端编程client.c 相关代码：#include #include #include #include #include #include #include #include #define SERVER_PORT 20000 /设置服务端口#define CLIENT_PORT (20001+rand()%65536) /设置客户端端口（随机） #define BUFFER_SIZE 256 #define LENGTH_OF_LISTEN_

3、QUEUE 10 /可窃听队列长为10#define WELCOME_MESSAGE welcome to connect the server. void usage(char* name) printf( usage: %s IpAddrn ,name); struct sockaddr_in servaddr,cliaddr;int servfd,clifd,length=0;struct sockaddr_in servaddr,cliaddr;socklen_t socklen=sizeof(servaddr);char bufBUFFER_SIZE,buf2BUFFER_SIZE;

4、pthread_t tidp,tidp2;int pth;int runflag=0;void *Thread1(void *arg) /*等待runflag为1，当为1时清空buf， 同时接收来自server的数据并输出。 但当没有清空，则break.*/ while(runflag) memset(buf,0,BUFFER_SIZE); length=recv(clifd,buf,BUFFER_SIZE,0); if(strstr(buf,$)0)runflag=0;printf(stop!n);break; if(length0) printf(from server:%s,buf);

5、void *Thread2(void *arg) /*等待发送数据给Server*/ printf(Please input your words to Server:-$ to stopn); while(runflag) memset(buf2,0,BUFFER_SIZE); scanf(%s,buf2); send(clifd,buf2,strlen(buf2),0); if(strstr(buf2,$)0)runflag=0;printf(stop!n);break; int main(int argc, char* argv) if(argc 2 ) usage(argv0); ex

6、it( 1 ); if(clifd = socket(AF_INET,SOCK_STREAM,0) 0 ) /用tcp定义socket printf( create socket error!n ); exit( 1 ); srand(time(NULL); / initialize random generator bzero( & cliaddr, sizeof (cliaddr); cliaddr.sin_family = AF_INET; cliaddr.sin_port = htons(CLIENT_PORT); cliaddr.sin_addr.s_addr = htons(INA

7、DDR_ANY); if(bind(clifd,(struct sockaddr* )&cliaddr,sizeof(cliaddr) 0 ) printf( bind to port %d failure!n ,CLIENT_PORT); exit( 1 ); /绑定的目的是让其端口是随机的，否则端口是自增1 /一般情况下client端不用绑定 bzero(&servaddr, sizeof(servaddr); servaddr.sin_family = AF_INET; inet_aton(argv1, &servaddr.sin_addr); servaddr.sin_port = h

8、tons(SERVER_PORT); if(connect(clifd,( struct sockaddr *)&servaddr, socklen) 0) printf( cant connect to %s!n, argv1); exit(1); runflag=1; pth=pthread_create(&tidp,NULL,Thread1,NULL); if(pth!=0)printf(error!);return -1; pth=pthread_create(&tidp2,NULL,Thread2,NULL); if(pth!=0)printf(error!);return -1;

9、pthread_detach(tidp); pthread_detach(tidp2); while(runflag); close(clifd); return 0; 4、服务端server.c编写 相关代码：#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define COM0 0#define BLOCK_MODE

10、 1#define NONBLK_MODE 0#define SERVER_PORT 20000#define LENGTH_OF_LISTEN_QUEUE 10#define QUEUE 20#define BUFFER_SIZE 256#define WELCOME_MESSAGE welcome to connect the server.static struct termios g_newtio,g_oldtio;static int speed_arr = B115200, B57600, B38400, B19200, B9600, B4800, B2400, B1200, B3

11、00, B115200, B57600, B38400, B19200, B9600, B4800, B2400, B1200, B300, ;static int name_arr = 115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200, 300, 115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200, 300, ;int Init_COM(int Comm,int Baudrate,int Parity,int Stopbit,int Flagblock) int ret,i; char

12、dev_buf16; if(Comm 3) printf(Com%d not existn,Comm); return -1; memset(dev_buf,0x00,sizeof(dev_buf); sprintf(dev_buf,/dev/ttyS%d,Comm); if(Flagblock) ret = open(dev_buf, O_RDWR | O_NOCTTY );/以默认阻塞方式打开 else ret = open(dev_buf, O_RDWR | O_NOCTTY | O_NONBLOCK); /以非阻塞方式打开 if(ret 0) printf(Open ttyS%d fa

13、iledn,Comm); return -1; if( tcgetattr(ret, &g_oldtio) 0 )/保存原先的端口 printf(Get Com Parameter Error.n); return -1; for ( i= 0; i =sizeof(speed_arr) / sizeof(int) printf(Unsupported Speed!n); return -1; switch (Parity) case n: case N: g_newtio.c_cflag &= PARODD; g_newtio.c_cflag &= PARENB; break; case o

14、: case O: g_newtio.c_cflag |= PARENB; g_newtio.c_cflag |= PARODD; /奇校验 break; case e: case E: g_newtio.c_cflag |= PARENB; /偶校验 g_newtio.c_cflag &= PARODD; break; default: printf(Unsupported Parityn); return -1; switch(Stopbit) /设置停止校验位是为2，否为1. case 1: g_newtio.c_cflag &= CSTOPB; break; case 2: g_new

15、tio.c_cflag |= CSTOPB; break; default: printf(Unsupported Stopbit!n); return -1; g_newtio.c_iflag = 0; g_newtio.c_oflag = 0; g_newtio.c_lflag = 0; g_newtio.c_ccVTIME = 1; /最大等待时间为1*100ms g_newtio.c_ccVMIN = 1; /最小读数为1 g_newtio.c_iflag &= INPCK; g_newtio.c_cflag &= CRTSCTS; g_newtio.c_cflag &= CSIZE;

16、/设置数据位 g_newtio.c_cflag |= CS8; / g_newtio.c_cflag |= CLOCAL; g_newtio.c_cflag |= CREAD; if( tcsetattr(ret, TCSANOW, &g_newtio) != 0 ) /激活设置 printf(Set Com Parameter Error!n); return -1; tcflush (ret, TCIOFLUSH); /刷新输入输出缓存 return ret;/以上为套接字的相关定义/一下类似与client一样设置数据接收和发送。void RestoreComConfiguration(i

17、nt fd,struct termios *ptios) if( tcsetattr(fd, TCSANOW, ptios) != 0 ) printf(Restore Com Parameter Error!n); int fd;char buf1024,buf21024;int servfd,clifd;struct sockaddr_in servaddr,cliaddr;int runflag=0;void *Thread1(void *arg) printf(Please input your words to Server:-$ to stopn); while(runflag)

18、memset(buf,0,BUFFER_SIZE); read(fd,buf,1024); send(clifd,buf,strlen(buf),0); if(strstr(buf,$)0)runflag=0;printf(stop!n);break; void *Thread2(void *arg) int length=0; while(runflag)char stdstr1024=from client:; memset(buf2,0,BUFFER_SIZE); length=recv(clifd,buf2,1024,0); if(length0) strcat(stdstr,buf2

19、);strcat(stdstr,n); if(strstr(buf2,$)0) runflag=0;printf(stop!n);break; write(fd,stdstr,strlen(stdstr); void socket_init(void) if(servfd=socket(AF_INET,SOCK_STREAM,0)0) printf(create socket error!n); exit(1); bzero(&servaddr,sizeof(servaddr); servaddr.sin_family=AF_INET; servaddr.sin_port=htons(SERV

20、ER_PORT); servaddr.sin_addr.s_addr=htons(INADDR_ANY); if(bind(servfd,(struct sockaddr*)&servaddr,sizeof(servaddr)0) printf(bind to port %d failure!n,SERVER_PORT); exit(1); if(listen(servfd,QUEUE)0) printf(call listen failure!n); exit(1); socklen_t length=sizeof(cliaddr); clifd=accept(servfd,(struct

21、sockaddr*)&cliaddr,&length); if(clifd= 0) RestoreComConfiguration(fd,&g_oldtio); runflag=1; pth=pthread_create(&tidp,NULL,Thread1,NULL); if(pth!=0)printf(error!);return -1; pth=pthread_create(&tidp2,NULL,Thread2,NULL); if(pth!=0)printf(error!);return -1; pthread_detach(tidp); pthread_detach(tidp2); while(runflag); close(clifd);close(fd);close(servfd);/全部关闭 return 0; 编译结果： 5、nfs挂载4、实验结果：5、心得体会：