Relocating bootwrapper causes kernel panic

[Shawn Jin]

>> > >> I think the cause is clear now. But how to fix it? Two questions:
>> > >> 2. If the DTLB miss exception handler is not the right guy to load a
>> > >> proper TLB entry, how can I set one entry based on the link_address
>> > >> and the address of the flat dt blob?
>> > >
>> > > Given how early in the boot process it is, it's probably going to need
>> > > to be handled specially.
>> >
>> > What APIs can I use to set up DTLBs?
>>
>> I don't think there is one that works on 8xx.  You'll could hack up
>> initial_mmu, or else write some C code to insert an 8xx TLB entry.
>
> Yup, I think he just ends up getting out of the initial mapping which is
> smallish on 8xx, no ? Might be worth sticking in one more entry during
> boot...

If CONFIG_PIN_TLB is on, two more entries are pinned down, which gives
16MB mappings. Just curious. Why is there only one entry by default?
what's the trade-off to pin down all 4 entries?

THanks,
-Shawn.