MEM_DES structure (cfgmgr32.h)

The MEM_DES structure is used for specifying either a resource list or a resource requirements list that describes memory usage for a device instance. For more information about resource lists and resource requirements lists, see Hardware Resources.

Syntax

typedef struct Mem_Des_s {
  DWORD     MD_Count;
  DWORD     MD_Type;
  DWORDLONG MD_Alloc_Base;
  DWORDLONG MD_Alloc_End;
  DWORD     MD_Flags;
  DWORD     MD_Reserved;
} MEM_DES, *PMEM_DES;

Members

MD_Count

For a resource list:

Zero.

For a resource requirements list:

The number of elements in the MEM_RANGE array that is included in the MEM_RESOURCE structure.

MD_Type

Must be set to the constant value MType_Range.

MD_Alloc_Base

For a resource list:

The lowest-numbered of a range of contiguous physical memory addresses allocated to the device.

For a resource requirements list:

Zero.

MD_Alloc_End

For a resource list:

The highest-numbered of a range of contiguous physical memory addresses allocated to the device.

For a resource requirements list:

Zero.

MD_Flags

One bit flag from each of the flag sets described in the following table.

	Flag	Definition
Read-Only Flags
	fMD_ROM	The specified memory range is read-only.
	fMD_RAM	The specified memory range is not read-only.
	mMD_MemoryType	Bitmask for the bit within MD_Flags that specifies the read-only attribute.
Write-Only Flags
	fMD_ReadDisallowed	The specified memory range is write-only.
	fMD_ReadAllowed	The specified memory range is not write-only.
	mMD_Readable	Bitmask for the bit within MD_Flags that specifies the write-only attribute.
Address Size Flags
	fMD_24	24-bit addressing (not used).
	fMD_32	32-bit addressing.
	mMD_32_24	Bitmask for the bit within MD_Flags that specifies the address size.
Prefetch Flags
	fMD_PrefetchAllowed	The specified memory range can be prefetched.
	fMD_PrefetchDisallowed	The specified memory range cannot be prefetched.
	mMD_Prefetchable	Bitmask for the bit within MD_Flags that specifies the prefetch ability.
Caching Flags
	fMD_Cacheable	The specified memory range can be cached.
	fMD_NonCacheable	The specified memory range cannot be cached.
	mMD_Cacheable	Bitmask for the bit within MD_Flags that specifies the caching ability.
Combined-Write Caching Flags
	fMD_CombinedWriteAllowed	Combined-write caching is allowed.
	fMD_CombinedWriteDisallowed	Combined-write caching is not allowed.
	mMD_CombinedWrite	Bitmask for the bit within MD_Flags that specifies the combine-write caching ability.

MD_Reserved

For internal use only.

Requirements

Requirement	Value
Header	cfgmgr32.h (include Cfgmgr32.h)

See also

MEM_RANGE

MEM_RESOURCE