wince 2440串口疑问
C/C++ code最近看2440 5.0BSP的串口驱动，发现有个地方让人不可思议，搞不清楚，特向大家请教
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串口驱动的流程是Com_Init中初始化中断，并绑定线程，等待中断产生，不过这个5.0BSP的实现方法很让人郁闷，请看。
在Com_Init：
//读注册表的DeviceArrayIndex的值
if ( RegQueryValueEx(hKey, L"DeviceArrayIndex", NULL, &kvaluetype,
(LPBYTE)&DevIndex, &datasize) ) {
DEBUGMSG (ZONE_INIT | ZONE_ERROR,
(TEXT("Failed to get DeviceArrayIndex value, COM_Init failed\r\n")));
RegCloseKey (hKey);
LocalFree(pSerialHead);
return(NULL);
}
// Initialize hardware dependent data.其实是获得那个串口
pSerialHead->pHWObj = GetSerialObject( DevIndex );
————————————————GetSerialObject源码————————————————————
// GetSerialObj : The purpose of this function is to allow multiple PDDs to be
// linked with a single MDD creating a multiport driver. In such a driver, the
// MDD must be able to determine the correct vtbl and associated parameters for
// each PDD. Immediately prior to calling HWInit, the MDD calls GetSerialObject
// to get the correct function pointers and parameters.
//
extern "C" PHWOBJ
GetSerialObject(
DWORD DeviceArrayIndex
)
{
PHWOBJ pSerObj;
// Unlike many other serial samples, we do not have a statically allocated
// array of HWObjs. Instead, we allocate a new HWObj for each instance
// of the driver. The MDD will always call GetSerialObj/HWInit/HWDeinit in
// that order, so we can do the alloc here and do any subsequent free in
// HWDeInit.
// Allocate space for the HWOBJ.
pSerObj=(PHWOBJ)LocalAlloc( LPTR ,sizeof(HWOBJ) );
if ( !pSerObj )
return (NULL);
// Fill in the HWObj structure that we just allocated.
pSerObj->BindFlags = THREAD_IN_PDD; // PDD create thread when device is first attached.
//——这个pSerObj->dwIntID 在线程中用到，奇怪的是怎么会是注册表DeviceArrayIndex的值呢？
pSerObj->dwIntID = DeviceArrayIndex; // Only it is useful when set set THREAD_AT_MDD. We use this to transfer DeviceArrayIndex
pSerObj->pFuncTbl = (HW_VTBL *) &IoVTbl; // Return pointer to appropriate functions
// Now return this structure to the MDD.
return (pSerObj);
}
//绑定线程
if ( pSerialHead->pHWObj->BindFlags & THREAD_AT_INIT ) {
// Hook the interrupt and start the associated thread.
if ( ! StartDispatchThread( pSerialHead ) ) {
// Failed on InterruptInitialize or CreateThread. Bail.
COM_Deinit(pSerialHead);
return(NULL);
}
}
——————————————————StartDispatchThread函数源码————————————————
// ****************************************************************
//
// @doc INTERNAL
// @func BOOL | StartDispatchThread | Start thread if requested by PDD.
//
// @parm ULONG | pSerialHead
//
// @rdesc TRUE if success, FALSE if failed.