基于VxWorks的内存模拟型的字符IO设备驱动程序，并实现任务间通信

admin 管理员组

文章数量: 887007

基于VxWorks的内存模拟型的字符IO设备驱动程序，并实现任务间通信

要求：基于VxWorks的内存模拟型的字符IO设备驱动程序的设计，并编写应用程序实现任务间的通信，编写makefile文件。

基于VxWorks的内存模拟型的字符IO设备驱动程序的设计

• 1 内存模拟型的字符IO设备驱动程序memDrv.c
• 2 设备驱动程序的头文件memDrv.h
• 3 IO设备驱动实现任务间的通信的程序代码memIoDemo.c
• 4 makefile文件
• 5 运行步骤
• • 5.1 在命令提示符下执行make命令
  • 5.2 在windSh下加载模块all
  • 5.3 打印任务间通信结果

1 内存模拟型的字符IO设备驱动程序memDrv.c

/* memDrv.c - pseudo memory device driver */
#include "memDrv.h"
/*memDrv - install a memory driver*/STATUS memDrv (void){/* If driver already installed, just return */	if (memDrvNum > 0)return (OK);	/* driver already installed *//* driver initialization, if any, here *//* add driver to driver table */memDrvNum = iosDrvInstall ((FUNCPTR) NULL, (FUNCPTR) NULL,(FUNCPTR) memOpen, memClose,memRead, memWrite, memIoctl);return (memDrvNum == ERROR ? ERROR : OK);}/*memDevCreate - create a memory device*/
STATUS memDevCreate (char * name,		/* device name		    */char * base,		/* where to start in memory */int  length		/* number of bytes	    */){STATUS status;FAST MEM_DEV *pMemDv;if (memDrvNum < 1){errnoSet (S_ioLib_NO_DRIVER);return (ERROR);}if ((pMemDv = (MEM_DEV *) calloc (1, sizeof (MEM_DEV))) == NULL)return (ERROR);pMemDv->MemBase=base;status = iosDevAdd ((DEV_HDR *) pMemDv, name, memDrvNum);if (status == ERROR)free ((MEM_DEV *) pMemDv);return (status);}LOCAL MEM_DEV_PER_FD  *memOpen(MEM_DEV *pMemDv,	/* pointer to memory device descriptor */char *name,		/* name of file to open (a number) */int mode		/* access mode (O_RDONLY,O_WRONLY,O_RDWR) */){MEM_DEV_PER_FD  *pMemDevPerFd = NULL;pMemDevPerFd = (MEM_DEV_PER_FD *) calloc(1,sizeof(MEM_DEV_PER_FD));if (pMemDevPerFd != NULL){pMemDevPerFd->pMemDev = (MEM_DEV *) pMemDv;pMemDevPerFd->allowOffset2 = 0;return pMemDevPerFd;}elsereturn (MEM_DEV_PER_FD *) ERROR;}/*memRead - read from a memory IO device*/LOCAL int memRead(MEM_DEV_PER_FD *pfd,	 /* file descriptor of file to read */char *buffer,	         /* buffer to receive data */int maxbytes	         /* max bytes to read in to buffer */){bcopy (pfd->pMemDev->MemBase,buffer, maxbytes);return (maxbytes);}
/*memWrite - write to a memory IO device */LOCAL int memWrite(MEM_DEV_PER_FD *pfd,	/* file descriptor of file to write */char *buffer,	/* buffer to be written */int nbytes		/* number of bytes to write from buffer */){temp=pfd->pMemDev->MemBase;/* for(count=0;count<nbytes;count++){bcopy (buffer,temp, 1);buffer=buffer+1;temp=temp+1;taskDelay(1);}    */bcopy (buffer,pfd->pMemDev->MemBase, nbytes);return (nbytes);}
/* memIoctl - do device specific control function */LOCAL STATUS memIoctl (pfd, function, arg)MEM_DEV_PER_FD *pfd;	/* descriptor to control */FAST int function;		/* function code */int	arg;			/* some argument */{return (OK);}
/*memClose - close a memory IO device */LOCAL STATUS memClose (pfd)MEM_DEV_PER_FD *pfd;	/* file descriptor of file to close */{free (pfd);return OK;}STATUS memDevDelete(char * devName){DEV_HDR *pDevHdr;char *pNameTail;pDevHdr = iosDevFind (devName, &pNameTail);if (pDevHdr == NULL || *pNameTail != '\0')return (ERROR);iosDevDelete (pDevHdr);free ((MEM_DEV *) pDevHdr);return (OK);
}STATUS memDrvRemove(){/*check device driver exist */if(memDrvNum!=-1){ if(iosDrvRemove(memDrvNum,TRUE)==ERROR){printErr("Fail to unload driver.\n");return ERROR;	}	}memDrvNum=-1;}	

2 设备驱动程序的头文件memDrv.h

#include "copyright_wrs.h"
#include "vxWorks.h"
#include "stat.h"
#include "dirent.h"
#include "memLib.h"
#include "errnoLib.h"
#include "string.h"
#include "stdlib.h"
#include "stdio.h"
#include "ioLib.h"
#include "iosLib.h"typedef struct	/* MEM_DEV - memory device descriptor */{DEV_HDR devHdr;char *MemBase; int allowOffset1;}  MEM_DEV;typedef struct		  /* MEM_DEV_PER_FD - memory deviceId */{MEM_DEV *pMemDev;int allowOffset2;   } MEM_DEV_PER_FD;/* forward declarations */
LOCAL int memDrvNum;
LOCAL char *temp;	  /* driver number of memory driver */
LOCAL int count;/*MEM_DEV_PER_FD pMemDevPerFd;*/  STATUS memDrv ();
STATUS memDevCreate();
LOCAL MEM_DEV_PER_FD *memOpen ();
LOCAL int memRead ();
LOCAL int memWrite ();
LOCAL int memClose ();
LOCAL STATUS memIoctl ();
STATUS memDevDelete();
STATUS memDrvRemove();

3 IO设备驱动实现任务间的通信的程序代码memIoDemo.c

/* includes */
#include "vxWorks.h"
#include "taskLib.h"
#include "msgQLib.h"
#include "sysLib.h"
#include "stdio.h" 
#include "ioLib.h"  
#include "memDrv.h"#define  MemIoDev_NAME      "/memIoDevice"  /* 虚拟内存IO设备的文件名*/
#define  PRODUCER_TASK_PRI          98   /* Priority of the producer task */
#define  CONSUMER_TASK_PRI          99   /* Priority of the consumer task */
#define  TASK_STACK_SIZE          5000   /* stack size for spawned tasks */
#define  PRODUCER_TASK_MSG          3
#define  CONSUMER_TASK_MSG          3struct msg {                             /* data structure for msg passing */int tid;                         /* task id */         int value;                       /* msg value */};LOCAL int  memIoFd;  
LOCAL BOOL notDone;                      /* Flag to indicate the completion of this demo *//* function prototypes */LOCAL STATUS producerTaskFunc ();           /* producer task */
LOCAL STATUS consumerTaskFunc ();           /* consumer task *//*memIoDevDemo  */int main (void){notDone = TRUE;  /* initialize the global flag */printf ("memIoDevDemo\r\n");if(memDrv()== ERROR){perror("Error in installing memory IO Device");}if (memDevCreate (MemIoDev_NAME, calloc(1,20), sizeof (struct msg)) == ERROR)  {  perror ("Error in creating memory IO Device");   }  if ((memIoFd = open (MemIoDev_NAME, O_RDWR, 0)) == ERROR)  {  perror  ("Error in opening memory IO device");  return (ERROR);  }  /* Spwan the producerTask task */if (taskSpawn ("tProducerTask", PRODUCER_TASK_PRI, 0, TASK_STACK_SIZE, (FUNCPTR) producerTaskFunc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) == ERROR){perror ("producerTask: Error in spawning demoTask");return (ERROR);} /* Spwan the consumerTask task */if (taskSpawn ("tConsumerTask", CONSUMER_TASK_PRI, 0, TASK_STACK_SIZE, (FUNCPTR) consumerTaskFunc, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) == ERROR){perror ("consumerTask: Error in spawning demoTask");return (ERROR);}return (OK);}/******************************************************************************  producerTask - produces messages, and sends messages to the consumerTask *                 using the message queue. **  RETURNS: OK or ERROR**/STATUS producerTaskFunc (void){int count;int value;struct msg producedItem;           /* producer item - produced data */ printf ("producerTask started: task id = %#x \n", taskIdSelf ());/* Produce 2 number of messages and send these messages */for (count = 1; count <= PRODUCER_TASK_MSG; count++){value = count * 20;   /* produce a value *//* Fill in the data structure for message passing */producedItem.tid = taskIdSelf ();producedItem.value = value;/* Send Messages */if ((write (memIoFd, (char *)&producedItem, sizeof (producedItem))) == ERROR)  {  perror ("Error in sending the message");  return (ERROR);  } 	elseprintf ("ProducerTask: tid = %#x, produced value = %d \n", taskIdSelf (), value);}if(PRODUCER_TASK_PRI > CONSUMER_TASK_PRI){		memDevDelete("/memIoDevice");memDrvRemove();}return (OK);}/******************************************************************************  consumerTask - consumes all the messages from the message queue. **  RETURNS: OK or ERROR**/STATUS consumerTaskFunc (void){int count;struct msg consumedItem;           /* consumer item - consumed data */printf ("\n\nConsumerTask: Started -  task id = %#x\n", taskIdSelf());/* consume 3 number of messages */for (count = 1; count <= CONSUMER_TASK_MSG; count++){if (read (memIoFd, (char *)&consumedItem, sizeof (consumedItem)) == ERROR)  {  perror ("Error in receiving the message");  return (ERROR);  } else printf ("ConsumerTask: Consuming msg of value %d from tid = %#x\n",consumedItem.value, consumedItem.tid);}if(PRODUCER_TASK_PRI < CONSUMER_TASK_PRI){		memDevDelete("/memIoDevice");memDrvRemove();}return (OK);}

4 makefile文件

CC=ccsimpc
CFLAGS=-g -O0 
all:memIoDevDemo.o memDrv.o$(CC) $(CFLAGS) memIoDevDemo.o memDrv.o -o all
memIoDevDemo.o:memIoDevDemo.c$(CC) $(CFLAGS) -c memIoDevDemo.c -o memIoDevDemo.o
memDrv.o:memDrv.c$(CC) $(CFLAGS) -c memDrv.c -o memDrv.o
.phony:clean
clean:-vxrm memIoDevDemo.o memDrv.o

5 运行步骤

5.1 在命令提示符下执行make命令

利用命令提示符执行make命令和make clean命令。

5.2 在windSh下加载模块all

在windSh下加载模块all，并执行main函数。

5.3 打印任务间通信结果

下图是打印在模拟器上的两任务间通信结果，生产者任务优先级高于消费者，生产者任务先运行，三次向同一段内存分别写入20、40、60。紧接着消费者任务运行，读取生产者写入那段内容，但三次读取到的数据均为60，因为生产者每次写入都会覆盖上一次写入的数据，所以最终只能读到数据60。

本文标签： 基于VxWorks的内存模拟型的字符IO设备驱动程序，并实现任务间通信