Re: [Milkymist port] virtual memory management

[David Holland <dholland-tech%netbsd.org@localhost>]

On Wed, May 29, 2013 at 07:51:15PM +0200, Yann Sionneau wrote:
 > I am wondering how I can manage virtual memory (especially how to
 > avoid tlb miss, or deal with them) in exception handlers.
 > 
 > At first my idea was to do most of the low level stuff in exception
 > handlers with MMU turned off, I was told it was a very bad idea.
 > LM32 MMU (for now at least) turns itself off upon any CPU
 > exception, therefore I plan on turning it on right away in the
 > exception handler.
 > 
 > This leads to the following scenario I don't know how to deal with:
 > [snip]

hold on, hold on. What's the high-level picture? Does the kernel
normally run with the MMU on or off? What's the intended scheme for
TLB refill? Are the page tables supposed to be mapped in virtual
memory (mips, vax) or placed in physical memory (x86)?

-- 
David A. Holland
dholland%netbsd.org@localhost