CM_PARTIAL_RESOURCE_DESCRIPTOR structure (wdm.h)
The CM_PARTIAL_RESOURCE_DESCRIPTOR structure specifies one or more system hardware resources, of a single type, assigned to a device. This structure is used to create an array within a CM_PARTIAL_RESOURCE_LIST structure.
Syntax
typedef struct _CM_PARTIAL_RESOURCE_DESCRIPTOR {
UCHAR Type;
UCHAR ShareDisposition;
USHORT Flags;
union {
struct {
PHYSICAL_ADDRESS Start;
ULONG Length;
} Generic;
struct {
PHYSICAL_ADDRESS Start;
ULONG Length;
} Port;
struct {
#if ...
USHORT Level;
USHORT Group;
#else
ULONG Level;
#endif
ULONG Vector;
KAFFINITY Affinity;
} Interrupt;
struct {
union {
struct {
USHORT Group;
USHORT Reserved;
USHORT MessageCount;
ULONG Vector;
KAFFINITY Affinity;
} Raw;
struct {
#if ...
USHORT Level;
USHORT Group;
#else
ULONG Level;
#endif
ULONG Vector;
KAFFINITY Affinity;
} Translated;
} DUMMYUNIONNAME;
} MessageInterrupt;
struct {
PHYSICAL_ADDRESS Start;
ULONG Length;
} Memory;
struct {
ULONG Channel;
ULONG Port;
ULONG Reserved1;
} Dma;
struct {
ULONG Channel;
ULONG RequestLine;
UCHAR TransferWidth;
UCHAR Reserved1;
UCHAR Reserved2;
UCHAR Reserved3;
} DmaV3;
struct {
ULONG Data[3];
} DevicePrivate;
struct {
ULONG Start;
ULONG Length;
ULONG Reserved;
} BusNumber;
struct {
ULONG DataSize;
ULONG Reserved1;
ULONG Reserved2;
} DeviceSpecificData;
struct {
PHYSICAL_ADDRESS Start;
ULONG Length40;
} Memory40;
struct {
PHYSICAL_ADDRESS Start;
ULONG Length48;
} Memory48;
struct {
PHYSICAL_ADDRESS Start;
ULONG Length64;
} Memory64;
struct {
UCHAR Class;
UCHAR Type;
UCHAR Reserved1;
UCHAR Reserved2;
ULONG IdLowPart;
ULONG IdHighPart;
} Connection;
} u;
} CM_PARTIAL_RESOURCE_DESCRIPTOR, *PCM_PARTIAL_RESOURCE_DESCRIPTOR;
Members
Type
Identifies the resource type. The constant value specified for Type indicates which structure within the u union is valid, as indicated in the following table. (These flags are used within both CM_PARTIAL_RESOURCE_DESCRIPTOR and IO_RESOURCE_DESCRIPTOR structures, except where noted.)
| Type value | u member substructure |
|---|---|
| CmResourceTypePort | u.Port |
| CmResourceTypeInterrupt | u.Interrupt or u.MessageInterrupt.If the CM_RESOURCE_INTERRUPT_MESSAGE flag of Flags is set, use u.MessageInterrupt; otherwise, use u.Interrupt. |
| CmResourceTypeMemory | u.Memory |
| 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. |
| CmResourceTypeDma | u.Dma (if CM_RESOURCE_DMA_V3 is not set) or u.DmaV3 (if CM_RESOURCE_DMA_V3 flag is set) |
| CmResourceTypeDevicePrivate | u.DevicePrivate |
| CmResourceTypeBusNumber | u.BusNumber |
| CmResourceTypeDeviceSpecific | u.DeviceSpecificData(Not used within IO_RESOURCE_DESCRIPTOR.) |
| CmResourceTypePcCardConfig | u.DevicePrivate |
| CmResourceTypeMfCardConfig | u.DevicePrivate |
| CmResourceTypeConnection | u.Connection |
| CmResourceTypeConfigData | Reserved for system use. |
| CmResourceTypeNonArbitrated | Not used. |
ShareDisposition
Indicates whether the described resource can be shared. Valid constant values are listed in the following table:
| Value | Meaning |
|---|---|
| CmResourceShareDeviceExclusive | The device requires exclusive use of the resource. |
| CmResourceShareDriverExclusive | The driver requires exclusive use of the resource. Not supported for WDM drivers. |
| CmResourceShareShared | The resource can be shared without restriction. |
Flags
Contains flag bits that are specific to the resource type, as indicated in the following tables (flags can be bitwise-ORed together as appropriate):
CmResourceTypePort resource type
| Flag | Definition |
|---|---|
| CM_RESOURCE_PORT_MEMORY | The device is accessed in memory address space. |
| CM_RESOURCE_PORT_IO | The device is accessed in I/O address space. |
| CM_RESOURCE_PORT_10_BIT_DECODE | The device decodes 10 bits of the port address. |
| CM_RESOURCE_PORT_12_BIT_DECODE | The device decodes 12 bits of the port address. |
| CM_RESOURCE_PORT_16_BIT_DECODE | The device decodes 16 bits of the port address. |
| CM_RESOURCE_PORT_POSITIVE_DECODE | The device uses "positive decode" instead of "subtractive decode". (In general, PCI devices use positive decode and ISA buses use subtractive decode.) |
| CM_RESOURCE_PORT_PASSIVE_DECODE | The device decodes the port but the driver does not use it. |
| CM_RESOURCE_PORT_WINDOW_DECODE | Reserved for system use. |
CmResourceTypeInterrupt resource type
| Flag | Definition |
|---|---|
| CM_RESOURCE_INTERRUPT_LEVEL_SENSITIVE | The IRQ line is level-triggered. (These IRQs are usually sharable.) |
| CM_RESOURCE_INTERRUPT_LATCHED | The IRQ line is edge-triggered. |
| CM_RESOURCE_INTERRUPT_MESSAGE | If this flag is set, the interrupt is a message-signaled interrupt. Otherwise, the interrupt is a line-based interrupt. |
| CM_RESOURCE_INTERRUPT_POLICY_INCLUDED | Not used with the CM_PARTIAL_RESOURCE_DESCRIPTOR structure. For more information about this flag, see IO_RESOURCE_DESCRIPTOR. |
| CM_RESOURCE_INTERRUPT_SECONDARY_INTERRUPT | The interrupt is a secondary interrupt. This flag can be set starting with Windows 8. For more information about secondary interrupts, see GPIO Interrupts. |
| CM_RESOURCE_INTERRUPT_WAKE_HINT | The interrupt is capable of waking the operating system from a low-power idle state or a system sleep state. This flag can be set starting with Windows 8. For more information about wake capabilities, see Enabling Device Wake-Up. |
CmResourceTypeMemory resource type
| Flag | Definition |
|---|---|
| CM_RESOURCE_MEMORY_READ_WRITE | The memory range is readable and writable. |
| CM_RESOURCE_MEMORY_READ_ONLY | The memory range is read-only. |
| CM_RESOURCE_MEMORY_WRITE_ONLY | The memory range is write-only. |
| CM_RESOURCE_MEMORY_PREFETCHABLE | The memory range is prefetchable. |
| CM_RESOURCE_MEMORY_COMBINEDWRITE | Combined-write caching is allowed. |
| CM_RESOURCE_MEMORY_24 | The device uses 24-bit addressing. |
| CM_RESOURCE_MEMORY_CACHEABLE | The memory range is cacheable. |
CmResourceTypeMemoryLarge resource type
| Flag | Definition |
|---|---|
| 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. |
CmResourceTypeDma resource type
| Flag | Definition |
|---|---|
| CM_RESOURCE_DMA_8 | 8-bit DMA channel |
| CM_RESOURCE_DMA_16 | 16-bit DMA channel |
| CM_RESOURCE_DMA_32 | 32-bit DMA channel |
| CM_RESOURCE_DMA_8_AND_16 | 8-bit and 16-bit DMA channel |
| CM_RESOURCE_DMA_BUS_MASTER | The device supports bus master DMA transfers. |
| CM_RESOURCE_DMA_TYPE_A | Type A DMA |
| CM_RESOURCE_DMA_TYPE_B | Type B DMA |
| CM_RESOURCE_DMA_TYPE_F | Type F DMA |
| CM_RESOURCE_DMA_V3 | Use the DmaV3 member instead of the Dma member. The DmaV3 member is available starting with Windows 8. |
u
Defines the u union.
u.Generic
Not used.
u.Generic.Start
Not used.
u.Generic.Length
Not used.
u.Port
Specifies a range of I/O port addresses, using the following members.
Drivers for Windows Vista and later versions of the Windows operating system can use RtlCmDecodeMemIoResource and RtlCmEncodeMemIoResource to read and update the u.Port member, rather than updating it directly.
u.Port.Start
For raw resources: Specifies the bus-relative physical address of the lowest of a range of contiguous I/O port addresses allocated to the device.
For translated resources: Specifies the system physical address of the lowest of a range of contiguous I/O port addresses allocated to the device.
For more information about raw and translated resources, see Remarks.
u.Port.Length
The length, in bytes, of the range of allocated I/O port addresses.
u.Interrupt
Specifies an interrupt vector and level, using the following members:
u.Interrupt.Level
For raw resources: Specifies the device's bus-specific IRQL (if appropriate for the platform and bus).
For translated resources: Specifies the DIRQL assigned to the device.
For more information about raw and translated resources, see Remarks.
u.Interrupt.Group
Specifies the processor group number. This member exists only if the NT_PROCESSOR_GROUPS constant is defined at compile time. This member can be nonzero only on Windows 7 and later versions of Windows. The Group and Affinity members together specify a group affinity that indicates which processors the device can interrupt. To specify an affinity for any group, set Group to ALL_PROCESSOR_GROUPS.
u.Interrupt.Vector
For raw resources: Specifies the device's bus-specific interrupt vector (if appropriate for the platform and bus).
For translated resources: Specifies the global system interrupt vector assigned to the device.
For more information about raw and translated resources, see Remarks.
u.Interrupt.Affinity
Contains a KAFFINITY-typed bitmask value indicating the set of processors the device can interrupt. To indicate that the device can interrupt any processor, this member is set to -1.
u.MessageInterrupt
Specifies a message-signaled interrupt. This member is a union. Use u.MessageInterrupt.Raw for raw resources, and u.MessageInterrupt.Translated for translated resources. This type of resource is only returned on Windows Vista and later versions of the Windows operating system.
For more information about raw and translated resources, see Remarks.
u.MessageInterrupt.DUMMYUNIONNAME
Defines the DUMMYUNIONNAME union.
u.MessageInterrupt.DUMMYUNIONNAME.Raw
Defines the Raw structure.
u.MessageInterrupt.DUMMYUNIONNAME.Raw.Group
Specifies a processor group number. This member exists only if NT_PROCESSOR_GROUPS is defined at compile time. This member can be nonzero only on Windows 7 and later versions of Windows. The Group and Affinity members together specify a group affinity that indicates which processors can receive the device's interrupts. To specify an affinity for any group, set Group to ALL_PROCESSOR_GROUPS.
u.MessageInterrupt.DUMMYUNIONNAME.Raw.Reserved
Not used.
u.MessageInterrupt.DUMMYUNIONNAME.Raw.MessageCount
Specifies the number of message-signaled interrupts generated for this driver.
u.MessageInterrupt.DUMMYUNIONNAME.Raw.Vector
Specifies the device's interrupt vector.
u.MessageInterrupt.DUMMYUNIONNAME.Raw.Affinity
Specifies a KAFFINITY value that indicates the processors that receive the device's interrupts.
u.MessageInterrupt.DUMMYUNIONNAME.Translated
The u.MessageInterrupt.Translated member has the following members:
u.MessageInterrupt.DUMMYUNIONNAME.Translated.Level
Specifies the device IRQL (DIRQL) assigned to the device's interrupts.
Specifies the device IRQL (DIRQL) assigned to the device's interrupts.
u.MessageInterrupt.DUMMYUNIONNAME.Translated.Group
Specifies a processor group number. This member exists only if NT_PROCESSOR_GROUPS is defined at compile time. This member can be nonzero only on Windows 7 and later versions of Windows. The Translated.Group and Translated.Affinity members together specify a group affinity that indicates which processors can receive the device's interrupts. To specify an affinity for any group, set Translated.Group to ALL_PROCESSOR_GROUPS.
u.MessageInterrupt.DUMMYUNIONNAME.Translated.Vector
Specifies the device's interrupt vector.
u.MessageInterrupt.DUMMYUNIONNAME.Translated.Affinity
Specifies a KAFFINITY value that identifies the processors that receive the device's interrupts.
u.Memory
Specifies a range of memory addresses, using the following members.
Drivers for Windows Vista and later versions of the Windows operating system can use RtlCmDecodeMemIoResource and RtlCmEncodeMemIoResource to read and update the u.Memory member, rather than updating it directly.
u.Memory.Start
For raw resources: Specifies the bus-relative physical address of the lowest of a range of contiguous memory addresses allocated to the device.
For translated resources: Specifies the system physical address of the lowest of a range of contiguous memory addresses allocated to the device.
For more information about raw and translated resources, see Remarks.
u.Memory.Length
Specifies the length, in bytes, of the range of allocated memory addresses.
u.Dma
Specifies a DMA setting, using one of the following members:
u.Dma.Channel
Specifies the number of the DMA channel on a system DMA controller that the device can use.
u.Dma.Port
Specifies the number of the DMA port that an MCA-type device can use.
u.Dma.Reserved1
Not used.
u.DmaV3
Specifies the DMA settings for a driver that uses version 3 of the DMA_OPERATIONS structure.
The u.DmaV3 member is available starting with Windows 8.
u.DmaV3.Channel
Specifies the number of the DMA channel on the system DMA controller that is allocated to the device.
u.DmaV3.RequestLine
Specifies the number of the request line on the system DMA controller that is allocated to the device.
u.DmaV3.TransferWidth
Specifies the width, in bits, of the data bus that the system DMA controller that is allocated to the device uses to transfer data to or from the device.
u.DmaV3.Reserved1
Not used.
u.DmaV3.Reserved2
Not used.
u.DmaV3.Reserved3
Not used.
u.DevicePrivate
Reserved for system use.
u.DevicePrivate.Data[3]
u.BusNumber
Specifies bus numbers, using the following members:
u.BusNumber.Start
Specifies the lowest-numbered of a range of contiguous buses allocated to the device.
u.BusNumber.Length
Specifies the number of buses allocated to the device.
u.BusNumber.Reserved
Not used.
u.DeviceSpecificData
Specifies the size of a device-specific, private structure that is appended to the end of the CM_PARTIAL_RESOURCE_DESCRIPTOR structure. If u.DeviceSpecificData is used, the CM_PARTIAL_RESOURCE_DESCRIPTOR structure must be the last one in the CM_PARTIAL_RESOURCE_LIST array.
Examples of device-specific structures include CM_FLOPPY_DEVICE_DATA, CM_KEYBOARD_DEVICE_DATA, CM_SCSI_DEVICE_DATA, and CM_SERIAL_DEVICE_DATA.
u.DeviceSpecificData.DataSize
Specifies the number of bytes appended to the end of the CM_PARTIAL_RESOURCE_DESCRIPTOR structure.
u.DeviceSpecificData.Reserved1
Not used.
u.DeviceSpecificData.Reserved2
Not used.
u.Memory40
Specifies a range of memory addresses, using the following members.
The u.Memory40 member is available only on Windows Vista and later versions of the Windows operating system. Drivers must use RtlCmDecodeMemIoResource and RtlCmEncodeMemIoResource to read and update this member, rather than updating it directly.
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
Specifies a range of memory addresses, using the following members.
The u.Memory48 member is available only on Windows Vista and later versions of the Windows operating system. Drivers must use RtlCmDecodeMemIoResource and RtlCmEncodeMemIoResource to read and update this member, rather than updating it directly.
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
Specifies a range of memory addresses, using the following members.
The u.Memory64 member is available only on Windows Vista and later versions of the Windows operating system. Drivers must use RtlCmDecodeMemIoResource and RtlCmEncodeMemIoResource to read and update this member, rather than updating it directly.
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.
u.Connection
Specifies a connection to a serial bus or serial port, or to a set of one or more general-purpose I/O (GPIO) pins. The following members describe this connection.
The u.Connection member is available starting with Windows 8.
u.Connection.Class
Specifies the connection class. This member is set to one of the following values:
| Value | Meaning |
|---|---|
| CM_RESOURCE_CONNECTION_CLASS_GPIO | Access the device through one or more pins on a GPIO controller. |
| CM_RESOURCE_CONNECTION_CLASS_SERIAL | Access the device through a serial bus or serial port. |
u.Connection.Type
Specifies the connection type.
If Class = CM_RESOURCE_CONNECTION_CLASS_GPIO, Type is set to the following value:
| Value | Meaning |
|---|---|
| CM_RESOURCE_CONNECTION_TYPE_GPIO_IO | Access the device through GPIO pins that are configured for I/O. |
A GPIO pin that is configured as an interrupt request input is accessed as an ordinary interrupt resource (CmResourceTypeInterrupt).
If Class = CM_RESOURCE_CONNECTION_CLASS_SERIAL, Type is set to one of the following values:
| Value | Meaning |
|---|---|
| CM_RESOURCE_CONNECTION_TYPE_SERIAL_I2C | The device is connected to an I2C bus. |
| CM_RESOURCE_CONNECTION_TYPE_SERIAL_SPI | The device is connected to an SPI bus. |
| CM_RESOURCE_CONNECTION_TYPE_SERIAL_UART | The device is connected to a serial port. |
u.Connection.Reserved1
Not used.
u.Connection.Reserved2
Not used.
u.Connection.IdLowPart
Contains the lower 32 bits of the 64-bit connection ID.
u.Connection.IdHighPart
Contains the upper 32 bits of the 64-bit connection ID.
Remarks
A CM_PARTIAL_RESOURCE_DESCRIPTOR structure can describe either a raw (bus-relative) resource or a translated (system physical) resource, depending on the routine or IRP with which it is being used. For more information, see Raw and Translated Resources and IRP_MN_START_DEVICE.
There can only be 1 DeviceSpecificData block. It must be located at the end of all resource descriptors in a full descriptor block.
Requirements
| Requirement | Value |
|---|---|
| Header | wdm.h (include Wdm.h, Ntddk.h, Ntifs.h, Wudfwdm.h) |