Re: IP32 prom crashes due to __pa() funkiness

[Kumba <kumba@gentoo.org>]

Arnaud Giersch wrote:
> 
> I don't know if it is the RightWay(TM), but I am running here a fresh
> IP32 kernel (l.m.o git updated yesterday).  It was compiled with
> CONFIG_BUILD_ELF64=n, and I am using vmlinux.
> 
> $ file /boot/vmlinux-2.6.21-rc3-g839fd555 
> /boot/vmlinux-2.6.21-rc3-g839fd555: ELF 64-bit MSB executable, MIPS, MIPS-IV version 1 (SYSV), statically linked, not stripped
> 
> If it makes a difference, I am using arcboot.

I suppose then the question is, which is better for IP32?  CONFIG_BUILD_ELF64=y 
or CONFIG_BUILD_ELF64=n.  The reason the o64 hack used to exist, if my memory 
serves me correctly, was that someone once said that when built and run as a 
pure 64bit binary converted to 32bit via objcopy, 6 extra insns were run every 
cycle (I think), introducing unneeded slowdown.  This changed to 2 insns by 
going the o64 route, which involved CONFIG_BUILD_ELF64=n.  So 4 less insns 
technically resulted in a quicker kernel, though the layman might not notice 
such.  I believe that all changed at some point, which is why 
CONFIG_BUILD_ELF64=y was an A-OK thing prior to the __pa() introduction.

Now I guess we're back to CONFIG_BUILD_ELF64=n?  I guess the real question is, 
which way is the OneWay(TM), RightWay(TM) and OnlyWay(TM)?


Cheers,

--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