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If a program was built with Safe Structured Exception Handling (SafeSEH), then software-enforced DEP
can determine if the exception handler is registered in the function table located within the program
image file before an exception is dispatched. If a program is not built with SafeSEH, then software-
enforced DEP checks whether the exception handler is located within a memory region marked as execut-
able before an exception is dispatched.
Deploying Hardware-Enabled Data Execution Prevention
How will XD/NX impact HP customers?
HP tests its images and deliverables for XD/NX compatibility, including:
•
Shipping HP applications
•
Operating system image
•
Shipping peripheral drivers
•
Popular applications and games
Ideally, you should test both hardware and software-enforced DEP. Unfortunately, at this time you can only
test hardware-enforced DEP, because Microsoft has not yet supplied the tools to test software-enforced
DEP.
You can test hardware-enforced DEP with specialized tests that actively try to execute from data memory
space or real world applications. For information about applications that do not function when XD/NX is
disabled, see “Known Issues” on page 13.
What about customers who create their own software image?
HP encourages you to perform your own validation if you plan to use proprietary images or software. You
should test the following areas to ensure compatibility with DEP:
•
Third party drivers
• Video
• Network
• Printer
• Modem
•
Third party applications
• Benchmarks
• Productivity Software
• Games
Customers who set the policy level in BOOT.INI to
AlwaysOn
may encounter multiple software incom-
patibilities. You cannot exclude applications and drivers from DEP with the
AlwaysOn
policy level.
