From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David S. Miller" Date: Tue, 21 Sep 2004 06:31:24 +0000 Subject: Re: RED State Exception on Ultra 1, 2.6.9-rc2 Message-Id: <20040920233124.1d7e79b2.davem@davemloft.net> List-Id: References: <1095742791.3421.3.camel@ori.thedillows.org> In-Reply-To: <1095742791.3421.3.camel@ori.thedillows.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: sparclinux@vger.kernel.org On 21 Sep 2004 00:59:51 -0400 David Dillow wrote: > What's a RED State exception? The CPU has storage internally for up to 5 levels of trap information, this is called the trap stack. When you take a trap at the 4th level, the cpu enters RED state and traps to a special vector in a trap table at a fixed pre-determined address, with TLBs and caches disabled, to process the trap. When that happens, what usually occurs on Sun systems is that the cpu jumps into Sun firmware code which dumps out the trap stack like you see here. > TL00.0000.0000.0005 TT00.0000.0000.0080 > TPC00.0000.0040.ec98 TnPC00.0000.0040.ec9c TSTATE00.0000.8000.9504 > TL00.0000.0000.0004 TT00.0000.0000.0010 > TPC00.0000.0040.d000 TnPC00.0000.0040.d004 TSTATE00.0000.8000.9504 > TL00.0000.0000.0003 TT00.0000.0000.0080 > TPC00.0000.0040.ec98 TnPC00.0000.0040.ec9c TSTATE00.0000.8000.9502 > TL00.0000.0000.0002 TT00.0000.0000.0010 > TPC00.0000.0040.8c00 TnPC00.0000.0040.8c04 TSTATE00.0000.8008.9402 > TL00.0000.0000.0001 TT00.0000.0000.0060 > TPC00.0000.0042.1b68 TnPC00.0000.0042.1b6c TSTATE00.0000.8000.9602 Can you match up these "TPC" and "TnPC" values to symbols in the kernel running at the time of this crash?