Subject: Re: BDI and 85xx

From: Dan Malek <[email-masked]>
Date: Mon, 7 Nov 2005 12:17:46 -0500

On Nov 7, 2005, at 6:24 AM, Marcelo Tosatti wrote:

> Edson had to patch this in to get BDI to work on 85xx with 2.6.14.

How about we just change MSR_KERNEL and MSR_USER
in the include file #define instead of all of this run-time code?
Or, change the code so it preserves DE in general, so we don't
need a special kernel configuration just for the BDI?

The original reason I did the BDI_SWITCH was due to the
overhead of tracking user PTE switches in the context switch
code.  I don't like the way this has been overloaded to mean
"BDI general operation."  We should be able to attach a BDI2000
to any kernel configuration and always get kernel debugging
capability.  The BDI_SWITCH was to enable the extra feature
(with some overhead) of debugging into user applications,
it never should have affected any kernel debug operation.

It's unfortunate that Book-E is such a PITA for debuggers,
but let's please find a better way of using these features.
Separate kernel configurations to enable hardware
debugging isn't acceptable.

Thanks.

	-- Dan