Subject: Re: noncontiguous memory question
To: Arthur Isaenko <isartw@yahoo.com>
From: Richard Earnshaw <rearnsha@cambridge.arm.com>
List: port-arm32
Date: 09/03/2002 14:14:00
> I'm playing with NetBSD kernel and going to port on
> Psion Revo plus (ARM710 based). 
> It has two RAM banks and I have found nothing related
> to noncontiguous memory 
> support in arch/arm/arm32/pmap.c.
> Please let me know
>  1. current noncontiguous memory support for arm port.
>  2. Is exist some useful doc related to virtual and
> physical memory mapping(in addition to UVM source) ? 
> Lawrence Kesteloot's stuff is poor and dated. 
> Also, arch/* source investigation shows several 
> approaches to memory mapping and I would like to know
> best practice. 
> Please just say that this port is better than each
> other and I will try to investigate these patterns.

NetBSD has support for multiple non-contiguous chunks of memory.  You add 
them to the VM system with uvm_page_plysload() call in your startup code.  
See for example the way the acorn32 port does this 
(acorn32/acorn32/rpc_machdep.c

R>