第七篇 硬件内存资源的获取，解析

 

硬件资源的获取，解析

  

1. 生成WDF的KMDFhelloWorld程序

2. 改写INF文件中硬件ID

3. 编译安装

以上三点不重复介绍，下面直接关注更新，增加的代码。

 

在DeviceADD例程中添加

首先是增加即插即用管理....  应该对应于WDM的IRP_MN_START_DEVICE

//初始化即插即用和电源管理例程配置结构

WDF_PNPPOWER_EVENT_CALLBACKS_INIT(&pnpPowerCallbacks);

pnpPowerCallbacks.EvtDevicePrepareHardware= PCISample_EvtDevicePrepareHardware;

//注册即插即用和电源管理例程

WdfDeviceInitSetPnpPowerEventCallbacks(DeviceInit, &pnpPowerCallbacks);

 

获取内存资源：

例程实现如下

NTSTATUS

PCISample_EvtDevicePrepareHardware(

IN WDFDEVICE Device,

IN WDFCMRESLIST ResourceList,

IN WDFCMRESLIST ResourceListTranslated

)

{

    PDEVICE_CONTEXT pDeviceContext;

    ULONG           i;

    PCM_PARTIAL_RESOURCE_DESCRIPTOR descriptor;

 

    PAGED_CODE();

 

    KdPrint(("EvtDevicePrepareHardware -begins\n"));

 

    pDeviceContext =DeviceGetContext(Device);

    pDeviceContext->MemBaseAddress= NULL;

 

    //

    // Parse the resource list and savethe resource information.

    //

    i = WdfCmResourceListGetCount(ResourceListTranslated);

    KdPrint(("WdfCmResourceListGetCount=%d", i));

    for (i = 0; i <WdfCmResourceListGetCount(ResourceListTranslated); i++) {

 

       

        descriptor =WdfCmResourceListGetDescriptor(ResourceListTranslated, i);

 

        KdPrint(("i=%d Type=%d", i, descriptor->Type));

        switch (descriptor->Type) {

        case CmResourceTypeInterrupt：

        case CmResourceTypeMemory:

            //MmMapIoSpace将物理地址转换成系统内核模式地址

            pDeviceContext->MemBaseAddress= MmMapIoSpace(

                descriptor->u.Memory.Start,

                descriptor->u.Memory.Length,

                MmNonCached);

            pDeviceContext->MemLength= descriptor->u.Memory.Length;

            KdPrint(("pDeviceContext->MemLength=%u", pDeviceContext->MemLength));

            break;

 

        default:

            break;

        }

 

    }

 

    KdPrint(("EvtDevicePrepareHardware -ends\n"));

 

    return STATUS_SUCCESS;

}

 

注意释放资源

 

NTSTATUS

PCISample_EvtDeviceReleaseHardware(

IN WDFDEVICE Device,

IN WDFCMRESLIST ResourceListTranslated

)

{

    PDEVICE_CONTEXT pDeviceContext;

 

    PAGED_CODE();

 

    KdPrint(("EvtDeviceReleaseHardware -begins\n"));

 

    pDeviceContext =DeviceGetContext(Device);

 

    if (pDeviceContext->MemBaseAddress){

        //MmUnmapIoSpace解除物理地址与系统内核模式地址的关联

        MmUnmapIoSpace(pDeviceContext->MemBaseAddress,pDeviceContext->MemLength);

        pDeviceContext->MemBaseAddress= NULL;

        KdPrint(("pDeviceContext->MemLength=%u",pDeviceContext->MemLength));

    }

    else

    {

        KdPrint(("pDeviceContext->MemBaseAddress=%x",pDeviceContext->MemBaseAddress));

    }

 

    KdPrint(("EvtDeviceReleaseHardware -ends\n"));

 

    return STATUS_SUCCESS;

}