写一个wdf驱动程序，能够访问pcie配置空间

好的，下面是一个简单的 wdf 驱动程序，可以访问 PCIe 配置空间。

#include <ntddk.h>
#include <wdf.h>

DRIVER_INITIALIZE DriverEntry;

EVT_WDF_DRIVER_UNLOAD OnDriverUnload;

EVT_WDF_DRIVER_DEVICE_ADD OnDeviceAdd;
EVT_WDF_OBJECT_CONTEXT_CLEANUP OnDeviceCleanup;

typedef struct _DEVICE_CONTEXT {
    WDFDEVICE Device;
} DEVICE_CONTEXT, *PDEVICE_CONTEXT;

WDF_DECLARE_CONTEXT_TYPE_WITH_NAME(DEVICE_CONTEXT, GetDeviceContext);

NTSTATUS DriverEntry(_In_ PDRIVER_OBJECT DriverObject, _In_ PUNICODE_STRING RegistryPath) {
    NTSTATUS status;
    WDF_DRIVER_CONFIG config;

    WDF_DRIVER_CONFIG_INIT(&config, OnDeviceAdd);
    config.EvtDriverUnload = OnDriverUnload;

    status = WdfDriverCreate(DriverObject, RegistryPath, WDF_NO_OBJECT_ATTRIBUTES, &config, WDF_NO_HANDLE);
    return status;
}

void OnDriverUnload(_In_ WDFDRIVER Driver) {
    UNREFERENCED_PARAMETER(Driver);
}

NTSTATUS OnDeviceAdd(_In_ WDFDRIVER Driver, _Inout_ PWDFDEVICE_INIT DeviceInit) {
    UNREFERENCED_PARAMETER(Driver);

    NTSTATUS status;
    WDF_OBJECT_ATTRIBUTES attributes;
    WDFDEVICE device;

    WDF_OBJECT_ATTRIBUTES_INIT_CONTEXT_TYPE(&attributes, DEVICE_CONTEXT);

    status = WdfDeviceCreate(&DeviceInit, &attributes, &device);
    if (!NT_SUCCESS(status)) {
        KdPrint(("Failed to create device (0x%08X)\n", status));
        return status;
    }

    PDEVICE_CONTEXT context = GetDeviceContext(device);
    context->Device = device;

    return status;
}

void OnDeviceCleanup(_In_ WDFOBJECT Device) {
    UNREFERENCED_PARAMETER(Device);
}

NTSTATUS AccessPcieConfigSpace(_In_ WDFDEVICE Device) {
    NTSTATUS status = STATUS_SUCCESS;
    PDEVICE_CONTEXT context = GetDeviceContext(Device);

    // 获取设备对象的 PCI 对象
    WDFDEVICE parentDevice = WdfPdoGetParent(Device);
    WDFMEMORY configSpaceMemory = NULL;
    ULONG configSpaceSize = 4096;

    // 分配内存来接收配置空间
    status = WdfMemoryCreate(
        WDF_NO_OBJECT_ATTRIBUTES,
        NonPagedPoolNx,
        0,
        configSpaceSize,
        &configSpaceMemory,
        NULL);
    if (!NT_SUCCESS(status)) {
        KdPrint(("Failed to allocate memory for config space (0x%08X)\n", status));
        goto Cleanup;
    }

    // 读取配置空间
    PHYSICAL_ADDRESS configSpaceBaseAddress = { 0 };
    configSpaceBaseAddress.QuadPart = WdfDeviceGetBusData(parentDevice, PCI_WHICHSPACE_CONFIG, WdfPdoGetAddress(Device), WdfMemoryGetBuffer(configSpaceMemory, NULL), configSpaceSize);

    // 检查是否读取成功
    if (configSpaceBaseAddress.QuadPart == 0) {
        KdPrint(("Failed to read config space\n"));
        status = STATUS_UNSUCCESSFUL;
        goto Cleanup;
    }

    // 输出配置空间
    for (ULONG i = 0; i < configSpaceSize; i += 4) {
        ULONG value = *(PULONG)((PUCHAR)WdfMemoryGetBuffer(configSpaceMemory, NULL) + i);
        KdPrint(("Config space offset 0x%04X: 0x%08X\n", i, value));
    }

Cleanup:
    if (configSpaceMemory != NULL) {
        WdfObjectDelete(configSpaceMemory);
    }
    return status;
}

这个驱动程序的主要逻辑在 `AccessPcieConfigSpace` 函数中。它分配一个内存对象来接收 PCIe 配置空间，然后使用 `WdfDeviceGetBusData` 函数读取配置空间。读取到的配置空间存储在内存对象中，并可以使用 `WdfMemoryGetBuffer` 函数获取。

要在驱动程序中调用此函数，请在 `OnDeviceAdd` 函数的末尾添加以下代码：

status = AccessPcieConfigSpace(device);
if (!NT_SUCCESS(status)) {
    KdPrint(("Failed to access PCIe config space (0x%08X)\n", status));
}

当设备被添加时，此代码将调用 `AccessPcieConfigSpace` 函数，并打印出读取到的 PCIe 配置空间。请注意，此代码仅用于演示目的，您需要根据自己的需求修改它。