Drivers

[This is preliminary documentation and subject to change.]

When porting drivers to 64-bit Windows, consider the following points:

• If your device supports more than 4 GB, you can use the Mm64BitPhysicalAddresses value to determine if 64-bit addressing is needed. In addition, you can use Dma64BitAddresses member of the DEVICE_DESCRIPTION structure to indicate that 64-bit addressing is supported.
• The information field in the I/O status block is of type ULONG_PTR.
• The parameters in the IRP stack locations are of type ULONG_PTR.
• The only HalXxx functions your driver should use are the ones included in Wdm.h.