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Re: what's pio.h?



On Sat, Jul 06, 2019 at 12:54:53AM +0200, Thomas Klausner wrote:
> Hi!
> 
> So I see that we install machine/pio.h which defines functions like
> these (amd64):
> 
> inb, insb, inw, insw, inl, insl; outb, outsb, ...
> 
> But I can't seem to find any documentation or implementation for this.
> 
> Is this in libc or does one need to link a library for these?
> What are they good for?
> 
> Thanks,
>  Thomas

Those are x86 assembly instruction names. For other architectures the
implementation exists as static inline.

It looks like they are implemented in the kernel but not outside.
It also appears that other architectures have implementations (e.g.
powerpc).

I know that at least linux-side, x86-sounding interfaces have turned
machine independent. that seems to be the case here.

A bunch of drivers seem to reference it, all looking very crusty.


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