Q: What mechanism SoftICE BPR uses?

[nmotohiko@...]

Hello exelist members,

I'm interested in programming protectors.

If someone knows SoftICE BPR mechanism, or how to prevent BPR breaking,
please tell me the information.

I thought BPR changing PTE(Page Table Entry).
And if page access fault raises, SoftICE compares the address with BPR range.  

I can't find the way to get PTE information in user-level programs.
When Checking it with SoftICE, BPR command doesn't change PTE.

Is there another way to check page using?
Is there any protector preventing BPR?

regards.
Moto