From: tsbogend@alpha.franken.de (Thomas Bogendoerfer)
To: linux-mips@linux-mips.org
Subject: IP22 64bit kernel
Date: Tue, 11 Sep 2007 23:30:48 +0200 [thread overview]
Message-ID: <20070911213048.GA20579@alpha.franken.de> (raw)
I finally figured out, why 64bit SGI IP22 kernels are broken (at
least when booted with SGI sash). Looks like sash jumps to an uncached
XPHYS address instead of the KSEG0 address indicated by the ELF start.
This messes up bogomips calculation.
I found an interesting piece of code in head.S:
.macro ARC64_TWIDDLE_PC
#if defined(CONFIG_ARC64) || defined(CONFIG_MAPPED_KERNEL)
/* We get launched at a XKPHYS address but the kernel is linked
* to
run at a KSEG0 address, so jump there. */
PTR_LA t0, \@f
jr t0
\@:
#endif
.endm
Enabling this for (CONFIG_SGI_IP22 && CONFIG_64BIT) fixes the boot problem.
It's not big deal to add this, but I'm wondering why we not just always
use this macro ? What platforms do it break with it ?
Thomas.
--
Crap can work. Given enough thrust pigs will fly, but it's not necessary a
good idea. [ RFC1925, 2.3 ]
next reply other threads:[~2007-09-11 21:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-11 21:30 Thomas Bogendoerfer [this message]
2007-09-12 23:15 ` IP22 64bit kernel Ralf Baechle
2007-09-13 7:05 ` Kumba
2007-09-13 15:50 ` Ralf Baechle
2007-09-13 18:23 ` Thomas Bogendoerfer
2007-10-17 18:36 ` Ralf Baechle
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