Subject: Re: Re:-pmap initlialization
To: None <kamalp@acm.org>
From: Richard Earnshaw <rearnsha@netbsd.org>
List: port-arm
Date: 01/04/2005 17:35:08
On Tue, 2005-01-04 at 08:21, Kamal R. Prasad wrote:
> Hello,
>
> I found out that as soon as tlb is invalidated, the
> system goes for a toss. Does the configuration below
> look OK? The kernel is loaded at 0xa0200000 and the L1
> page table is at 0xa01fc000.
> Other than an incorrect base addr for the page table,
> what else could cause the system to go for a toss? Why
> wouldn't the system generate an exception in such an
> event? Appreciate any answers.
A good way of killing your machine stone dead is to use vectors in page
0 and then forget to map the vector page in (or to unmap it at a later
date). Then on your first interrupt or page fault you end up in a
deadly cycle of infinite page faults trying to access address zero. The
same applies with high vectors as well, but that's much less likely to
be a problem once you've got the system up and running because the high
address isn't part of 'user space'.
R.