Subject: Re: Changing kernel base address (was: Re: Heads up: shared arm include files)
To: Mike Pumford <mpumford@mpc-data.co.uk>
From: Chris Gilbert <chris@paradox.demon.co.uk>
List: port-arm32
Date: 01/22/2001 21:39:33
On Monday 22 January 2001 11:28 am, Mike Pumford wrote:
> > Looks fine other than as a comment says you've not checked RO4.  Looks
> > like we need the bootloader to pass in current page table address. 
> > Looking in the bootloader the page table addrs are:
> > RO3: 0x02c00000
> > RO4: 0x08000000
>
> Ah right. I wondered what the RO4 effect was. IMO the bootloader should
> now be adjusted to reflect the new IOMD mappings if we want to continue
> to rely on console output at this stage. Since we still have the
> remains of RISC OS kicking around it may be possible to use RISC OS SWI
> calls to do output.The code in initarm was just a temporary debugging hack.
> Its not really the sort of code that should be in NetBSD.

Well we could try, but it could be very very messy.  I prefer that we do as 
little as possible until we've got the primary bootstrap done.  (Its not like 
there's much to be done there, just means we have to output info on DRAM etc 
later)

> > Perhaps it's easier to not start the console until we've got our page
> > tables in place?  That way we don't need to extend the bootloader, we
> > just have to hope we make it through the primary boot.  We could have a
> > debug define to allow output providing you know the booting OS version.
>
> I think this is the best approach for now. The initarm output is
> discarded from the message buffer when the console is reinitialised and
> as you say it can be easily enabled through conditional compilation if
> necessary. I'll update the patches tonight to defer the consinit call
> until after the primary bootstrap.

It's probably cleaner, and depends less on the bootloader which I believe 
someone (Dave D?) said requires a desklib version that doesn't seem to be 
around any more?

Of course this is until Reinoud's bootloader works across the board :)

Cheers,
Chris

-- 
PS Please note the change of email address.