Subject: Re: Map kernel as sections
To: Robert Swindells <firstname.lastname@example.org>
From: John Fremlin <email@example.com>
Date: 06/04/2001 00:09:46
Robert Swindells <firstname.lastname@example.org> writes:
> >> Why is the kernel mapped as pages not as a section?
> >playing with the pmap. In theory we could use different sized
> >sections, 1MB, 64K, 4K and 1K as appropiate, but that'd get very
> >complex, and pmap is tricky enough as it is.
> It currently works like that on arm32.
> Take a look at map_chunk() in arch/arm32/machdep.c
How often does the kernel actually get mapped as a section in
practice? I ask because I did (actually I mapped all of physical
memory to its physical address with repeated map_section) and
pmap_extract blew up due to not handling L1 sections. Testing a fix
Unfortunately it involves changing the pmap_pte_v macro to use its
argument twice: once to check if it's a section and once to
dereference it as a pointer. I'd personally like to turn it into an