Subject: Re: Changing kernel base address (was: Re: Heads up: shared arm include files)
To: Chris Gilbert <chris@buzzbee.freeserve.co.uk>
From: Mike Pumford <mpumford@mpc-data.co.uk>
List: port-arm32
Date: 01/22/2001 11:28:56
> 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.
> 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.
Mike