Subject: Re: strh on a SHARK
To: Mark Brinicombe <mark@causality.com>
From: Richard Earnshaw <rearnsha@arm.com>
List: port-arm32
Date: 08/10/1998 15:57:39
> > $ uname -a
> > NetBSD shark1 1.3F NetBSD 1.3F (SHARK) #0: Fri Jun 26 10:33:59 EDT 1998    
> >  tv@nc1.home.duh.org:/usr/SRC/netbsd/src/sys/arch/arm32/compile/SHARK arm32
> > 
> > While trying to test out a snapshot of EGCS 1.1 development tree, I tried 
> > to build the Xemacs package, but the emacs binary seems to be looping 
> > infinitely into the kernel when trying to execute a strh instruction to 
> > the first word of a page (I suspect the page is newly allocated, but can't 
> > be sure).
> 
> Ok this could be a bug in the fault handler. There should not be any
> actual register fixups requires for the SA110 that some of the older ARM
> needs but the faulting instruction is disassembled to determine if the
> fault was caused by a load or a store. I suspect that this is going wrong
> for the strh and ldrh instructions and thus the page is only ever being
> mapped as read only which would explain the looping ..
> 

Poking the memory location with gdb means that the instruction will then 
execute successfully.

R.