From: "H. Peter Anvin" <hpa@zytor.com>
To: linux-kernel@vger.kernel.org
Subject: Re: hex addresses in setup.S
Date: 16 Jan 2002 12:03:16 -0800 [thread overview]
Message-ID: <a24ma4$4ps$1@cesium.transmeta.com> (raw)
In-Reply-To: <BJEJJDPJOCEPDBLPFDKJCEACCCAA.ceswiedler@mindspring.com>
Followup to: <BJEJJDPJOCEPDBLPFDKJCEACCCAA.ceswiedler@mindspring.com>
By author: "Chris Swiedler" <ceswiedler@mindspring.com>
In newsgroup: linux.dev.kernel
>
> Why does setup.S define the default system load address as 0x1000, and the
> comment on the line explain this to be 0x10000(and gives the decimal
> translation of 65536, so it's not a typo)? This seems to be true for several
> addresss (0x9000 = 0x90000, etc). I'm sure there's something simple I'm
> missing...what is it?
>
In real mode:
linear_address := (segment << 4) + offset
Those addresses are "segment" addresses, with (implied) offset == 0.
These kinds of addresses are sometimes referred to as "paragraph
addresses" (paragraph being bigger than words but smaller than pages,
I guess.)
-hpa
--
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
http://www.zytor.com/~hpa/puzzle.txt <amsp@zytor.com>
next prev parent reply other threads:[~2002-01-16 20:04 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-01-16 19:13 hex addresses in setup.S Chris Swiedler
2002-01-16 20:03 ` H. Peter Anvin [this message]
2002-01-16 20:44 ` Richard B. Johnson
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