Re: Vmware crashes if compress/misc.c scrolls?

[Zachary Amsden <zach@vmware.com>]

H. Peter Anvin wrote:
> Jeremy Fitzhardinge wrote:
>   
>> H. Peter Anvin wrote:
>>     
>>> Jeremy Fitzhardinge wrote:
>>>  
>>>       
>>>> You mean "is a real failure"?  Or "is triggered by particular
>>>> instructions"?  It seems profoundly bogus (as in, surely DOS or
>>>> something reads the framebuffer).
>>>>
>>>>     
>>>>         
>>> A real failure (although only triggered from some variant of protected
>>> mode -- paging off?)
>>>   
>>>       
>> Oh, it only happens in protected mode?  So the answer to "how does the
>> shadow framebuffer get populated?" is "real mode does it before
>> switching to protected mode".
>>
>>     
>
> Sure, but that means frobbing the boot parameter structure, with
> associated problems.  I guess I'm not inherently opposed to it, but I'd
> like to understand if there is a cleaner workaround first.
>   

I'm failing to understand exactly what the failure here is.  Can you 
provide sample code that generates the problem?  Surely, it should be 
possible to read the framebuffer.

Zach