WinCE6.0 DEVICEEMULATOR BSP的CEDDK简析

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我是靠谱客的博主唠叨摩托，最近开发中收集的这篇文章主要介绍WinCE6.0 DEVICEEMULATOR BSP的CEDDK简析，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

WinCE6.0 DEVICEEMULATOR BSP的CEDDK提供了地址转换函数,位于/SRC/DRIVERS/CEDDK/下,有2个目录DDK_BUS和DLL,前者生成ddk_bus.lib,后者生成ceddk.dll,这部分的CEDDK实现了4个函数,data.c中的HalGetBusDataByOffset和HalSetBusDataByOffset,trans.c中的HalTranslateBusAddress和HalTranslateSystemAddress.下面就来看看这个函数:
1. HalGetBusDataByOffset
HalGetBusDataByOffset从IO Bus地址或者Slot的起始偏移获得信息.该函数读取总线配置数据,将输入参数转换为新的格式给内核去调用执行后续的步骤.
(1) 该函数首先定义了OAL_DDK_PARAMS和PCI_SLOT_NUMBER结构变量.OAL_DDK_PARAMS原型如下,该结构保存了IOCTL_HAL_DDK_CALL需要的信息.
typedef struct { UINT32 function; UINT32 rc; union { struct { DEVICE_LOCATION devLoc; UINT32 offset; UINT32 length; VOID *pBuffer; } busData; struct { INTERFACE_TYPE ifcType; UINT32 busNumber; UINT32 space; UINT64 address; } transAddress; struct { INTERFACE_TYPE ifcType; UINT32 busNumber; } busPower; }; } OAL_DDK_PARAMS;
(2) 设置需要调用的IOCTL代码及返回代码
params.function = IOCTL_OAL_READBUSDATA; params.rc = 0;
(3) 根据busDataType进行判断,如果是PCIConfiguration进行成员赋值,如设置总线类型(PCIBus),slotNumber,busNumber等.(这里只支持PCIConfiguration的总线类型)
switch (busDataType) { case PCIConfiguration: params.busData.devLoc.IfcType = PCIBus; slot.u.AsULONG = slotNumber; params.busData.devLoc.BusNumber = busNumber >> 8; params.busData.devLoc.LogicalLoc = (busNumber & 0xFF) << 16; params.busData.devLoc.LogicalLoc |= slot.u.bits.DeviceNumber << 8; params.busData.devLoc.LogicalLoc |= slot.u.bits.FunctionNumber; rc = TRUE; break; }
(4) 配置offset,length,pBuffer信息
params.busData.offset = offset; params.busData.length = length; params.busData.pBuffer = pBuffer;
(5) 最后调用KernelIoControl调用IOCTL_HAL_DDK_CALL的IOCTL
if (KernelIoControl( IOCTL_HAL_DDK_CALL, ¶ms, sizeof(params), NULL, 0, &outSize )) { rc = params.rc; }
2. HalSetBusDataByOffset
HalSetBusDataByOffset与HalGetBusDataByOffset相反,是写总线配置数据.代码也基本类型,仅仅params.function为IOCTL_OAL_WRITEBUSDATA:
params.function = IOCTL_OAL_WRITEBUSDATA;
具体代码如下:
ULONG HalSetBusDataByOffset( BUS_DATA_TYPE busDataType, ULONG busNumber, ULONG slotNumber, VOID *pBuffer, ULONG offset, ULONG length ) { OAL_DDK_PARAMS params; PCI_SLOT_NUMBER slot; UINT32 outSize, rc = 0; params.function = IOCTL_OAL_WRITEBUSDATA; params.rc = 0; switch (busDataType) { case PCIConfiguration: params.busData.devLoc.IfcType = PCIBus; slot.u.AsULONG = slotNumber; params.busData.devLoc.BusNumber = busNumber >> 8; params.busData.devLoc.LogicalLoc = (busNumber & 0xFF) << 16; params.busData.devLoc.LogicalLoc |= slot.u.bits.DeviceNumber << 8; params.busData.devLoc.LogicalLoc |= slot.u.bits.FunctionNumber; rc = TRUE; break; } params.busData.offset = offset; params.busData.length = length; params.busData.pBuffer = pBuffer; if (KernelIoControl( IOCTL_HAL_DDK_CALL, ¶ms, sizeof(params), NULL, 0, &outSize )) { rc = params.rc; } return rc; }
特殊情况发生或者驱动要求调用时,驱动会调用HalSetBusDataByOffset或者HalSetBusData.比如驱动可能调用这个两个函数之一来清除PCI状态寄存器的某一位,如果设备发信号给目标停止初始化.通常硬件或启动代码会正确配置这些设置.
这两个函数在我们目前接触到的驱动还没有用到.应该是和PCI设备相关,而我们的平台上没有PCI总线及设备.

3. HalTranslateBusAddress
HalTranslateBusAddress用来将物理总线地址转换为物理系统地址.
和上面两个函数一样,首先声明了OAL_DDK_PARAMS的对象params,然后对其成员进行赋值.其中function代码设为IOCTL_OAL_TRANSBUSADDRESS.
params.function = IOCTL_OAL_TRANSBUSADDRESS; params.transAddress.ifcType = ifcType; params.transAddress.busNumber = busNumber; params.transAddress.space = *pAddressSpace; params.transAddress.address = busAddress.QuadPart;
然后调用IOCTL_HAL_DDK_CALL:
if (!KernelIoControl( IOCTL_HAL_DDK_CALL, ¶ms, sizeof(params), NULL, 0, &outSize )) goto cleanUp;
最后将params中转换的地址赋值给输出参数.

rc = params.rc; *pAddressSpace = params.transAddress.space; pSystemAddress->QuadPart = params.transAddress.address;
关于HalTranslateBusAddress更详细的阐述,在网上找到如下的说明:
HalTranslateBusAddress(Isa, 0, ioPhysicalBase, &inIoSpace, &ioPhysicalBase)函数将与总线相关的地址转换为系统地址，参数1为总线类型，参数2为总线号，参数3为要转换的地址（PHYSICAL_ADDRESS类型，实际是LARGE_INTEGER型），参数4指定寄存器地址属于IO地址空间还是物理地址空间，参数5返回转换后的物理地址。观察HalTranslateBusAddress的源码得知如果是在x86平台，这个函数除了把参数3赋给了参数5其余什么都没有做，而非x86平台将inIoSpace的值置为0，表示一定是物理地址。在调用HalTranslateBusAddress前要确定从注册表中得到的寄存器地址到底是属于哪个地址空间的

这个函数也就是在battery驱动中使用的,调用完HalTranslateBusAddress后在调用MmMapIoSpace将物理地址映射到虚拟地址空间的.
在Battery驱动中加入测试代码:
PHYSICAL_ADDRESS ioPhysicalBase = { BSP_BASE_REG_PA_BATTERY, 0}; ULONG inIoSpace = 0; RETAILMSG(TRUE,(TEXT("ioPhysicalBase1=0x%x/r/n"),ioPhysicalBase.QuadPart)); if (HalTranslateBusAddress(Internal,0, ioPhysicalBase,&inIoSpace,&ioPhysicalBase)) { // Map it if it is Memeory Mapped IO. g_pBatteryRegs = (volatile DEVICEEMULATOR_BATTERY_REGS *)MmMapIoSpace(ioPhysicalBase, sizeof(DEVICEEMULATOR_BATTERY_REGS),FALSE); RETAILMSG(TRUE,(TEXT("ioPhysicalBase2=0x%x/r/n"),ioPhysicalBase.QuadPart)); }
可以发现:

转换前后的地址是一样的.也就是上问所说的inIoSpace的值置为0，表示一定是物理地址.

4.HalTranslateSystemAddress
HalTranslateSystemAddress将系统物理地址转换为逻辑总线地址,可以传递给总线控制器,如DMA总线控制器.
代码和HalTranslateBusAddress基本类似,区别就是params.function = IOCTL_OAL_TRANSSYSADDRESS
BOOLEAN HalTranslateSystemAddress( INTERFACE_TYPE ifcType, ULONG busNumber, PHYSICAL_ADDRESS systemAddress, PHYSICAL_ADDRESS *pBusAddress ) { BOOLEAN rc = FALSE; OAL_DDK_PARAMS params; UINT32 outSize; // Check input parameters if (pBusAddress == NULL) goto cleanUp; // Prepare input parameters for HAL call memset(¶ms, 0, sizeof(params)); params.function = IOCTL_OAL_TRANSSYSADDRESS; params.transAddress.ifcType = ifcType; params.transAddress.busNumber = busNumber; params.transAddress.address = systemAddress.QuadPart; // Call to HAL if (!KernelIoControl( IOCTL_HAL_DDK_CALL, ¶ms, sizeof(params), NULL, 0, &outSize )) goto cleanUp; // Get output parameters from HAL call pBusAddress->QuadPart = params.transAddress.address; // Done rc = TRUE; cleanUp: return rc; }
以上就简单看了下CEDDK实现的几个函数,基本上都是针对OAL_DDK_PARAMS的结构进行操作处理,真正核心的操作还是在IOCTL_HAL_DDK_CALL的IOCTL调用.
在C:/WINCE600/PLATFORM/COMMON/SRC/INC/oal_ioctl_tab.h中可以看到IOCTL_HAL_DDK_CALL的定义:
{ IOCTL_HAL_DDK_CALL, 0, OALIoCtlHalDdkCall },
但OALIoCtlHalDdkCall这个函数在我们的BSP中没有实现,关于这块具体的实现还需要进一步深入研究.