cli_serial.c

来自「一个简单的小型操作系统」· C语言 代码 · 共 143 行

/*****************************************************************************
 *
 * Module       : cli_serial.c
 * Descriptions : Provides serial API functions. 
 * OS           : SLOS 0.09
 * Platform     : e7t
 * History      :
 *
 * 1st June 2002 Andrew N. Sloss
 * - added header information
 *
 *****************************************************************************/

/*****************************************************************************
 * IMPORT
 *****************************************************************************/

#include "../headers/api_types.h"
#include "../devices/ddf_io.h"
#include "../e7t/devices/ddf_types.h"

#include "../e7t/events/swis.h"
#include "../headers/api_device.h"

/*****************************************************************************
 * STATICS
 *****************************************************************************/

device_treestr *host;
UID serial;

/*****************************************************************************
 * ROUTINES
 *****************************************************************************/

/* -- openHost ----------------------------------------------------------------
 *
 * Description : opens the communication port for the host
 *               command line.
 *
 * Parameters  : UINT COM
 * Return      : BOOLean 0 
 * Notes       :
 *
 */

BOOL openHost(UINT com) 
{ 
/* --------------------------------------------------------------
 * eventIODeviceOpen - 
 * open the serial driver node...
 * --------------------------------------------------------------
 */

  if (com>1) {return FALSE;}

host = eventIODeviceOpen(&serial,DEVICE_SERIAL_E7T,com);

  /* check that a device driver is found ... */

  if (host==0) {return FALSE;}

  /* check the UID .................. */

  switch (serial) 
  {
  case DEVICE_IN_USE:
  case DEVICE_UNKNOWN:

	return FALSE;
  } 
  	
return TRUE; 
}

/* -- writeCharToHost ---------------------------------------------------------
 *
 * Description : write a character to host port
 *
 * Parameter   : char c - character to be sent to host port
 * Return      : none...
 * Notes       :
 *
 */

void writeCharToHost(char c)
{
eventIODeviceWriteByte(host,serial,(UINT)c);
}

/* -- printToHost -------------------------------------------------------------
 *
 * Description : print a string to the host port
 *
 * Parameter   : char *s - zero terminated string
 * Return      : none...
 * Notes       :
 *
 */

void printToHost(char *s)
{
  while (*s!=0)
  {
  writeCharToHost (*s++);
  }
}

/* -- readCharFromHost --------------------------------------------------------
 *
 * Description  : read a character from host port
 *
 * Parameter    : none...
 * Return       : char - character to be sent to host port
 * Notes	:
 *
 */

char readCharFromHost(void)
{
return (char)eventIODeviceReadByte(host,serial);
}

/* -- closeHost ---------------------------------------------------------------
 *
 * Description  : closes the host port but this code should never be 
 *                executed.
 *
 * Parameter    : none...
 * Return       : char c - character to be sent to host port
 * Notes	:
 *
 */

int closeHost(void)
{
  if (host==0) return FALSE;

return eventIODeviceClose(host,serial);
}