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RE: New compiler tools release: cris-dist-1.56



Yes, the bug is serious but requires rather unusual circumstances:

1. The mul instruction has to be just before a fetch of a new 
cacheline i.e. in the end of a cacheline or in a delay slot
2. The source operand has to be 0xb0XXX258-0xb0XXX25f (where XXX is
an arbitrary number).
3. It only affects kernel mode

So yes, this bug may potentially have occured in the kernel and would
also disappear mysteriously when the kernel is rebuilt with other
configuration etc.

Note that the bug does not affect ETRAX 100 (because the multiplication
was added in LX).

Someone else have to answer the rest of your questions.

/Mikael

-----Original Message-----
From: owner-dev-etrax@xxxxxxx.com">mailto:owner-dev-etrax@xxxxxxx.com] On
Behalf Of Ronny L Nilsson
Sent: Monday, March 01, 2004 10:58 PM
To: Hans-Peter Nilsson; dev-etrax
Subject: Re: New compiler tools release: cris-dist-1.56



> This release contains a critical workaround for a hardware bug.
> Without the workaround there may be intermittent crashes and
> other failures.  From the NEWS file in the cris-dist-1.56.tar.gz
> file (or /usr/doc/cris-dist-1.56/NEWS for the RPM package):
>
> - There's a workaround in GCC for a hardware bug related to
>   multiplication instructions, item 5 in the errata list at>  
> <URL:http://developer.axis.com/doc/hardware/etrax100lx/des_ref/errata
>_etrax_100lx.txt> 


Hi 
This look to me like a rather serious bug. Funny it haven't been 
reported earlier. Howcome? Is it "rare enough" to live with for 
devboard_lx-R2_1_0 systems or should those be updated too (even though 
there is no later official than R2.1.0...)?

The above errata seem to have been recently updated, why hasn't there 
been any announcement on this list or at the news column at 
http://developer.axis.com? (Or have I missed it?)

Last, but not least. The updated errata seem strange to me. The 
previous revision v1.3 had as item no. 5 a description of a SDRAM bug. 
Where is that now? Can't find it at all in new rev. Also. new and old 
(CVS) revision number seem to equals (1.3).


BR
/Ronny Nilsson