Re: Boot program changed

[Anders Magnusson <ragge%ludd.ltu.se@localhost>]

Den 2018-03-22 kl. 02:45, skrev Charles Dickman:
> Excellent!
>
> On Mon, Mar 19, 2018 at 11:47 AM, Anders Magnusson <ragge%ludd.ltu.se@localhost> wrote:
> > Hi all,
> >
> > I have made some changes to the boot program to allow large kernels to be
> > loaded.
> > This should solve the problems with the 8.0 boot.
> >
> > The changes are quite invasive and I haven't tested all drivers yet, but
> > after that I will request pullup to NetBSD 8.
> I struggled a few times with the stray interrupt until I figured out
> what was going on.
>
> My naive view was that anything beyond (4MB - boot loader size) for
> the kernel was going to require some major changes since there was an
> assumption in the loader that the DMA/scatter gather mapping was one
> for one with kernel memory. For the uVax qbus machines i think the
> mapping is limited to 4MB.  I will be interested in reviewing your
> solution.
The boot loader was using 1-1 mapping for qbus devices, hence the 4MB limit.
Now the map is setup for the transfers as it should.  I have tested it 
(in simh) on MV3 with ra and qe drivers and on 11/780 with ra.
hp needs more fixes to work as expected.

The MV1 do not have a map, but it cannot handle so much memory either so 
it do not matter.

If someone want to run NetBSD on a machine with less than 8MB of memory 
then boot have to be recompiled to relocate at a lower address.

-- Ragge