Writing Windows WDM Device Drivers

AllocatedResources	378
AllocatedResourcesTranslated	378
Interrupt (W98)	Vector	IRQL	Affinity	Mode
AllocatedResources	7	7	1	Latched
AllocatedResourcesTranslated	37	20	1	Latched
Interrupt (W2000)	Vector	IRQL	Affinity	Mode
AllocatedResources	3	3	-1	Latched
AllocatedResourcesTranslated	33	24	1	Latched

Partial Resource Descriptors

A resource list is an array of full resource descriptors. A full resource descriptor has a partial resource list, an array of partial resource descriptors. The relevant structures (CM_RESOURCE_ LIST, CM_FULL_RESOURCE_DESCRIPTOR, CM_PARTIAL_RESOURCE_LIST, and CM_PARTIAL_ RESOURCE_DESCRIPTOR) are also covered in Chapter 18.

WDM drivers have only one full resource descriptor[21]. Therefore, inspect the array of partial resource descriptors to see what resources have been assigned. The resource descriptors are given in no particular order.

Table 9.2 shows the different types of resource information that can be found in a partial resource descriptor. The Type field specifies what resource is described. There is also a ShareDisposition field that specifies how the resource can be shared. One of the following values can be found: CmResourceShareDeviceExclusive, CmResourceShareDriverExclusive, or CmResourceShareShared.

Table 9.2 Partial resource descriptors

I/O Port	(Type==CmResourceTypePort)
PHYSICAL_ADDRESS	u.Port.Start Port Bus specific start address
ULONG u.Port.Length	Number of addresses
USHORT Flags	CM_RESOURCE_PORT_IO or CM_RESOURCE_PORT_MEMORY if you need to map the port into memory with MmMapIoSpace
Memory	(Type==CmResourceTypeMemory)
PHYSICAL_ADDRESS	u.Memory.Start Bus specific start address
ULONG u.Memory.Length	Number of addresses
USHORT Flags	CM_RESOURCE_MEMORY_READ_WRITE CM_RESOURCE_MEMORY_READ_ONLY CM_RESOURCE_MEMORY_WRITE_ONLY
Interrupt	(Type==CmResourceTypeInterrupt)