Re: [PATCH]: Remove CONFIG_BUILD_ELF64 entirely

[Kumba <kumba@gentoo.org>]

Atsushi Nemoto wrote:
> Just an optimization.  For CKSEG0 symbol, a LUI instruction can fill
> high 32-bit by sign-extention.  Either code should work for CKSEG0
> kernel.

Hmm, strange then.  It's gotta be something those four extra commands do that 
IP32 likes.  IP22 boots fine with either form, though that has a separate 
problem where it looks like serial console on the zilog chip panics the system 
after booting into a netboot.

Doing some tests, I found out that by commenting out one or more of the 
daddui/dsll instructions for IP32 produced a kernel that still booted, but hung 
at running init/freeing kernel memory.  Using the single lui booted once, but I 
suspect that was my fault on not doing something proper, cause the next time 
around, it didn't boot at all.  I tested this all on a real console, versus 
serial, case there was an early panic or something.  But I see nothing to 
indicate why IP32 dislikes the lui->ld sequence versus the 
lui->daddui->dsll->etc->ld sequence.

There's no early printk on these systems either, so doing low-level debugging is 
difficult on them as well.


--Kumba

-- 
Gentoo/MIPS Team Lead

"Such is oft the course of deeds that move the wheels of the world: small hands 
do them because they must, while the eyes of the great are elsewhere."  --Elrond