1、 實驗二 嵌入式系統程序設計實驗之linux串口和網絡編程 一、實驗目的： 1、強化本學期所學的相關的內容。 2、掌握串口相關設置。 3、強化基于TCP網絡傳輸的三次握手。 4、自學Linux線程的使用。二、實驗內容： 本試驗基于server和client的透明傳輸來實現類似于QQ的聊天功能。三、實驗過程： 1、linux開發環境的建立 2、嵌入式linux系統的搭建 1>BootLoader的移植 2>linux系統的裁剪與移植 Linux內核裁剪 ./make_image生成自己的uImage2638上電驗證：3>根文件系統的移植修改hostname為：whmtt./mk

2、cramfsdisk_new 生成rootfs_new.cramfs大小從老師給的40000到37b00（因為有的沒有用到，大小變小了）：上電驗證： 3、客服端編程client.c 相關代碼：#include <stdio.h> #include <sys/socket.h> #include <unistd.h> #include <sys/types.h> #include <netinet/in.h> #include <stdlib.h> #include <strings.h>#include <

3、;string.h>#define SERVER_PORT 20000 /設置服務端口#define CLIENT_PORT (20001+rand()%65536) /設置客戶端端口（隨機） #define BUFFER_SIZE 256 #define LENGTH_OF_LISTEN_QUEUE 10 /可竊聽隊列長為10#define WELCOME_MESSAGE "welcome to connect the server." void usage(char* name) printf( "usage: %s IpAddrn " ,na

4、me); 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;pthread_t tidp,tidp2;int pth;int runflag=0;void *Thread1(void *arg) /*等待runflag為1，當為1時清空buf，同時接收來自server的數據并輸出。但當沒有清空，則break.*

5、/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(length>0) printf("from server:%s",buf);void *Thread2(void *arg) /*等待發送數據給Server*/printf("Please input your words to Server:

6、-$ 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); exit( 1 ); if(clifd = socket(AF_INET,SOCK

7、_STREAM,0) < 0 ) /用tcp定義socketprintf( " 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(INADDR_ANY); if(bind

8、(clifd,(struct sockaddr* )&cliaddr,sizeof(cliaddr) < 0 ) printf( "bind to port %d failure!n " ,CLIENT_PORT); exit( 1 ); /綁定的目的是讓其端口是隨機的，否則端口是自增1 /一般情況下client端不用綁定bzero(&servaddr, sizeof(servaddr); servaddr.sin_family = AF_INET; inet_aton(argv1, &servaddr.sin_addr); servaddr.

9、sin_port = htons(SERVER_PORT); if(connect(clifd,( struct sockaddr *)&servaddr, socklen) < 0) printf( "can't 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,N

10、ULL,Thread2,NULL);if(pth!=0)printf("error!");return -1;pthread_detach(tidp);pthread_detach(tidp2);while(runflag);close(clifd);return 0; 4、服務端server.c編寫 相關代碼：#include <stdio.h>#include <sys/types.h>#include <sys/socket.h>#include <unistd.h>#include <netinet/in.h&g

11、t;#include <arpa/inet.h>#include <stdlib.h>#include <time.h>#include <string.h>#include <strings.h>#include <sys/ioctl.h>#include <fcntl.h>#include <termios.h>#include <stdlib.h>#include <errno.h>#include <sys/time.h>#include <linu

12、x/rtc.h>#include <pthread.h>#define COM0 0#define BLOCK_MODE 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;stati

13、c int speed_arr = B115200, B57600, B38400, B19200, B9600, B4800, B2400, B1200, B300, 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

14、_COM(int Comm,int Baudrate,int Parity,int Stopbit,int Flagblock)int ret,i;char 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 );/以默認阻塞方

15、式打開 else ret = open(dev_buf, O_RDWR | O_NOCTTY | O_NONBLOCK); /以非阻塞方式打開 if(ret < 0) printf("Open ttyS%d failedn",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(i

16、nt); i+) if(Baudrate = name_arri) cfsetispeed(&g_newtio,speed_arri);/*設置輸入輸出波特率*/ cfsetospeed(&g_newtio,speed_arri); break; if(i>=sizeof(speed_arr) / sizeof(int) printf("Unsupported Speed!n"); return -1; switch (Parity) case 'n':case 'N': g_newtio.c_cflag &=

17、PARODD; g_newtio.c_cflag &= PARENB; break; case 'o': case 'O': g_newtio.c_cflag |= PARENB; g_newtio.c_cflag |= PARODD; /奇校驗 break; case 'e': case 'E': g_newtio.c_cflag |= PARENB; /偶校驗 g_newtio.c_cflag &= PARODD; break; default: printf("Unsupported Parityn

18、"); return -1; switch(Stopbit) /設置停止校驗位是為2，否為1.case 1:g_newtio.c_cflag &= CSTOPB;break;case 2:g_newtio.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; /最大等待時間為1*100m

19、s g_newtio.c_ccVMIN = 1; /最小讀數為1 g_newtio.c_iflag &= INPCK; g_newtio.c_cflag &= CRTSCTS; g_newtio.c_cflag &= CSIZE;/設置數據位g_newtio.c_cflag |= CS8; / g_newtio.c_cflag |= CLOCAL; g_newtio.c_cflag |= CREAD; if( tcsetattr(ret, TCSANOW, &g_newtio) != 0 )/激活設置printf("Set Com Parameter

20、Error!n");return -1;tcflush (ret, TCIOFLUSH); /刷新輸入輸出緩存return ret;/以上為套接字的相關定義/一下類似與client一樣設置數據接收和發送。void RestoreComConfiguration(int fd,struct termios *ptios)if( tcsetattr(fd, TCSANOW, ptios) != 0 )printf("Restore Com Parameter Error!n");int fd;char buf1024,buf21024;int servfd,clifd

21、;struct sockaddr_in servaddr,cliaddr;int runflag=0;void *Thread1(void *arg)printf("Please input your words to Server:-$ to stopn");while(runflag)memset(buf,0,BUFFER_SIZE);read(fd,buf,1024);send(clifd,buf,strlen(buf),0);if(strstr(buf,"$")>0)runflag=0;printf("stop!n");

22、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(length>0) strcat(stdstr,buf2);strcat(stdstr,"n");if(strstr(buf2,"$")>0)runflag=0;printf("stop!n");break

23、;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(SERVER_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);e