On Wed, Nov 12, 2003 at 06:10:23PM +0000, Charles M. Hannum wrote:
> Such as using JMP TSS to do task switches, which avoids manually saving state 
> and patching the GDT, and is faster.  And as I mentioned some time ago, will 
> eventually allow switching directly to user-level without needing a kernel 
> stack.

What exactly is the latter about? Sure, you can store the register state
in a TSS (though I doubt it's faster, it seems like TSS supoort has
bitrotted a bit in later CPUs, as nobody seems to use it). However, I don't
understand the "without needing a kernel stack" part. Yes, the register
state will not be on the kernel stack in that case, but obviously you
do need a kernel stack in general.

- Frank

-- 
Frank van der Linden                                            fvdl@netbsd.org
===============================================================================
NetBSD. Free, Unix-like OS. > 45 different platforms.    http://www.netbsd.org/