Expand Minimize

MmGetSystemAddressForMdl routine

The MmGetSystemAddressForMdl routine is obsolete for Windows 2000 and later versions of Windows, and for Windows Me. It is supported only for WDM drivers that must run on Windows 98. Otherwise, use MmGetSystemAddressForMdlSafe.

MmGetSystemAddressForMdl is a macro that returns a nonpaged system-space virtual address for the buffer described by the MDL. It maps the physical pages described by a given MDL into system space, if they are not already mapped to system space.

Syntax


PVOID MmGetSystemAddressForMdl(
  _In_  PMDL Mdl
);

Parameters

Mdl [in]

Pointer to a buffer whose corresponding base virtual address is to be mapped.

Return value

MmGetSystemAddressForMdl returns the base system-space virtual address that maps the physical pages described by the given MDL.

Remarks

Drivers of PIO devices call this routine to translate a virtual address range, described by the MDL at Irp->MdlAddress, for a user buffer to a system-space address range.

The MDL must describe nonpageable memory. In other words, the input MDL must describe an already locked-down user-space buffer returned by MmProbeAndLockPages, a locked-down buffer returned by MmBuildMdlForNonPagedPool, or system-space memory allocated from nonpaged pool, contiguous memory, or noncached memory.

The returned base address has the same offset as the virtual address in the MDL.

Windows 2000 issues a bug check if the attempt to map to system space fails. (Therefore, you should use MmGetSystemAddressForMdlSafe instead). In Windows 98, this routine returns NULL in case of failure.

Requirements

Version

Obsolete for Windows 2000 and later versions of Windows, and for Windows Me. This routine is supported only for WDM drivers that must run on Windows 98. Otherwise, use MmGetSystemAddressForMdlSafe.

Header

Wdm.h (include Wdm.h, Ntddk.h, or Ntifs.h)

IRQL

<=DISPATCH_LEVEL

See also

MmGetSystemAddressForMdlSafe
MmBuildMdlForNonPagedPool
MmProbeAndLockPages

 

 

Send comments about this topic to Microsoft

Show:
© 2014 Microsoft. All rights reserved.