Subject: Re: Converting from physical to virtual?
To: None <, amiga-dev@NetBSD.ORG>
From: Daniel Widenfalk <>
List: amiga-dev
Date: 05/31/1995 12:52:13
> I'm working on adding disconnect/reselect logic to the sbic driver, and I 
> need to poke a few (5-10) bytes into some random part of physical memory 
> to clean up partial transfers.  What's the preferred method of converting 
> from a physical address to something the CPU can use to poke at memory 
> with?  I have some ideas, but I prefer not to create and then destroy a 
> mapping just to store a half-dozen bytes.  And I don't want to start 
> fooling around with the CPU's registers either.

I had a similar problem when I developed my Fastlane driver and the easiest
method IMHO is to create a temporary mapping using one page. It's almost
cost-efficient and it's not much work. You could take a look in my source
(sfas.c) and see what I've done. Search for NEED_VM_FIX.

/Daniel Widenfalk