In message <[EMAIL PROTECTED]>, Mike Smith writes:
>> Hi
>>
>> Go to http://www.uspto.gov/patft/, search for patent number 5873127, and
>> you will find the description of mapping page table entries into virtual
>> memory via one page directory entry pointing to the page directory itself
>> - exactly what FreeBSD does with PTDPTDI and APTDPTDI entries on i386.
>> (including using alternate space as in get_ptbase() in i386/pmap.c to
>> access page table entries of different processes).
>
>It'd be hard to build a case on this patent, though; since it was granted
>in 1996, and the technique is as old as the hills, proving prior art
>would probably be relatively straightforward.
Well, the application date is what counts, and that's mar1992, but I'm
pretty sure that Bill Jolitz had them beat to that date already...
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
[EMAIL PROTECTED] | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-hackers" in the body of the message
