Re: Math-emu kills the kernel on Athlon64 X2

[Linus Torvalds]

On Tue, 19 Sep 2006, Jesper Juhl wrote:
> 
> If I enable the math emulator in 2.6.18-rc7-git2 (only version I've
> tried this with) and then boot the kernel with "no387" then I only get
> as far as lilo's "...Booting the kernel." message and then the system
> hangs.

I'm wondering if it tries to use the MMX/XMM stuff for memcpy and friends. 

I'm also wondering why you'd be doing what you seem to try to be doing in 
the first place ;)

Basically, "no387" doesn't seem to disable any of the fancier FPU 
features, even though it obviously should. If you ask for math emulation, 
you'll get emulation faults for _all_ of the modern MMX stuff too (which 
we don't do). 

It's entirely possible that nobody has ever tested this combination.

		Linus
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