Messages in this thread |  | | Subject | Re: [PATCH 2/5 -v2.1] x86: Detect CPUID support early at boot | From | "H. Peter Anvin" <> | Date | Sun, 10 Feb 2013 07:10:56 -0800 |
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Sure it does... it takes time.
Borislav Petkov <bp@alien8.de> wrote:
>On Sat, Feb 09, 2013 at 08:34:53PM -0800, H. Peter Anvin wrote: >> I wouldn't really call it a "side effect". Perhaps the right thing >> here is to say something like "we want to start out with %eflags >> unambiguously clear". >> >> (Note also we have had to CLD earlier because we have already copied >> the command line.) > >Ok, let's make it even more verbose so that people know in the future: > >"... we want to start out with EFLAGS unambiguously clear. That means >DF >in particular (even though we have cleared it earlier after copying the >command line) because GCC expects it." > >How does that sound? > >Also, I was wondering about the whole reasoning behind that: do you >know >why DF=0 is a GCC requirement? I mean, nothing hurts GCC from issuing a >CLD each time? > >Thanks.
-- Sent from my mobile phone. Please excuse brevity and lack of formatting.
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