On Mon, Nov 22, 1999, Cort Dougan [off-list ref] wrote:

I applied the patch (with some changes necessary to get it into
2.2.14pre7).  It breaks pmac netboot during the jump from
__secondary_stat() to clear_bats(). 

You mean netbooting the kernel image directly from OF without going thru
a bootloader ? Or are you talking about the xcoff piggyback bootstrap ?

There must be some I mappings we need
to preserve in order to get to non-pc relative code.  It's worth noting
that OF loads us and gives us mappings for 0xc000000 since that's where
we're linked at. 

I never managed to get OF load the kernel image directly. How did you
acheive this result (OF setting up such a mapping ?). In this specific
case, it's always possible to ask OF about our physical address and use
it for the return address of mmu_off. It should be returned by prom_init
in r3. This would be cleaner anyway. I'll look into fixing that but I'd
like to know how you did this netboot stuff so I can reproduce it here.
(Could you send me your bootptab ?)

BootX and Quik don't do that so that's probably why they
work.  Netboot is really useful so I'd prefer to not break it (definitely
not in 2.2).  Any ideas for workarounds?

Yes, as I wrote before, OF can tell us the real physical address and we
can return it from prom_init so that mmu_off does the right thing.

Chrp and prep netboot works fine.  Boot via quik on chrp works, too.

Great.


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