windows驱动开发-resources获取与使用

参考

_CM_PARTIAL_RESOURCE_DESCRIPTOR structure

PCM_PARTIAL_RESOURCE_DESCRIPTOR

今日开发altera dma驱动，获取资源的时候得到下面的打印，显示获取的资源类型为CmResourceTypeMemoryLarge，这个资源与普通的CmResourceTypeMemory不一样，查看官网，

CmResourceTypeMemoryLarge   One of u.Memory40, u.Memory48, or u.Memory64.
The CM_RESOURCE_MEMORY_LARGE_XXX flags set in the Flags member determines which structure is used.

实际偏移和长度存储的变量由Flags位确定，

CM_RESOURCE_MEMORY_LARGE_40 The memory descriptor uses the u.Memory40 member.
CM_RESOURCE_MEMORY_LARGE_48 The memory descriptor uses the u.Memory48 member.
CM_RESOURCE_MEMORY_LARGE_64 The memory descriptor uses the u.Memory64 member.

同时，此时的长度需要左移一个偏移才是实际长度，

u.Memory40.Start

For raw resources: Specifies the bus-relative physical address of the lowest of a range of contiguous memory addresses that are allocated to the device.

For translated resources: Specifies the system physical address of the lowest of a range of contiguous memory addresses that are allocated to the device.

For more information about raw and translated resources, see Remarks.

u.Memory40.Length40

Contains the high 32 bits of the 40-bit length, in bytes, of the range of allocated memory addresses. The lowest 8 bits are treated as zero.

u.Memory48.Start

For raw resources: Specifies the bus-relative physical address of the lowest of a range of contiguous memory addresses that are allocated to the device.

For translated resources: Specifies the system physical address of the lowest of a range of contiguous memory addresses that are allocated to the device.

For more information about raw and translated resources, see Remarks.

u.Memory48.Length48

Contains the high 32 bits of the 48-bit length, in bytes, of the range of allocated memory addresses. The lowest 16 bits are treated as zero.

u.Memory64.Start

For raw resources: Specifies the bus-relative physical address of the lowest of a range of contiguous memory addresses that are allocated to the device.

For translated resources: Specifies the system physical address of the lowest of a range of contiguous memory addresses that are allocated to the device.

For more information about raw and translated resources, see Remarks.

u.Memory64.Length64

Contains the high 32 bits of the 64-bit length, in bytes, of the range of allocated memory addresses. The lowest 32 bits are treated as zero.