Re: [PATCH] x86: documentation fix regarding boot protocol

From: Ian Campbell
Date: Mon Dec 15 2008 - 06:35:21 EST


On Mon, 2008-12-15 at 12:27 +0100, Philipp Kohlbecher wrote:
> Ian Campbell wrote:
> > On Sun, 2008-12-14 at 18:50 +0100, Philipp Kohlbecher wrote:
> >> Documentation/x86/boot.txt describes payload_offset as the offset
> >> from the end of the real-mode code. In fact, it is more accurately
> >> described as the offset from the beginning of the protected-mode
> >> code, as (a) this is how it is actually calculated and (b) the padding
> >> after the real-mode code is not included in the offset.
> >>
> >> Signed-off-by: Philipp Kohlbecher <xt28@xxxxxx>
> >
> > Acked-by: Ian Campbell <ijc@xxxxxxxxxxxxxx>
> >
> > The padding after the real-mode code which you mention is just the
> > implicit padding because the size of the real-mode code is specified in
> > sectors (and hence is rounded up), isn't it?
>
> Yes, it is. You can certainly view the padding as an implicit part of
> the real-mode code, which is why the current statement isn't wrong --
> there is simply room for improvement.

Agreed.

> > Is it worth saying that the payload_offset is relative to (setup_sectors
> > +1) * 512?
>
> The fact that the protected-mode code starts at that address is already
> mentioned under the heading "LOADING THE REST OF THE KERNEL" (where
> protected mode is for some reason referred to as "non-real-mode").

I'd missed/forgotten that section, I don't think anything extra is
needed then.

Ian.

--
Ian Campbell
Current Noise: Orange Goblin - Made Of Rats

Fatal Error: Found [MS-Windows] System -> Repartitioning Disk for Linux...
(By cbbrown@xxxxxx, Christopher Browne)

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