8.0-RC2 on Rackmac3,1 - fatal kernel trap

[Nathan Whitehorn]

Peter Grehan wrote:
> Hi Nathan,
>
>> This problem should be fixed now.
>
>  Almost :) My 7,2 and 11,2 G5's now hit the panic:
>
> 7,2: 120 translations
>
> 11,2: 126 translations
>
>  If you are concerned about BSS usage for holding the translations, it 
> might be possible to bump up the loader's unit of allocation from 16 
> pages to 64 when on a G5. See the history of that at
>
> http://svn.freebsd.org/viewvc/base/head/sys/boot/ofw/libofw/ofw_copy.c?view=log 
>
Drat. I think this is something inside OF that only applies to CD 
booting, since 64 was more than enough for netbooting the kernel or 
booting from a hard drive, so changes to the loader probably won't 
affect anything. Also, it is now too late to get any changes to this 
code into 8.0, which is unfortunate. I guess the size of the buffer just 
needs to be bumped to 128 (or more?).

I'm a little concerned about bloating the kernel here. I think there is 
enough headroom in the stack that it can be moved to the local stack 
frame, so that's a possibility. It can't be allocated dynamically, since 
there is no way to add memory that OF can use at that point in the boot 
process.
-Nathan