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From: Paolo Ornati <javaman@katamail.com>
To: herbert@13thfloor.at
Cc: linux-kernel@vger.kernel.org
Subject: Re: [OT] Documentation for PC Architecture
Date: Mon, 18 Aug 2003 23:11:53 +0200	[thread overview]
Message-ID: <200308182244.01727.javaman@katamail.com> (raw)
In-Reply-To: <20030818185507.GB8297@www.13thfloor.at>

>
> > Curiosity: since the memory addresses from 640KB to 1MB are reserved for
> > memory mapped I/O (video memory) and BIOS ROM... the corrispondent range
> > in
>
> uh oh ...
>
> > the REAL MEMORY isn't usable and so we lost 384KB of memory. Is this
> > right?
>
> for DOS, withouth upper memory manager yes ;)

I'm talking about an OS in protected mode... in any case how can I access to 
this memory region if it's mapped for other things?

I've done some tests with a simple kernel which I wrote: all that region 
(except video memory at 0xb8000) results "read only"...

So I THINK YOU mean: "you can use more than 640KB in real mode using a memory 
manager that "remap" 0xC0000 (for example) to 0x100000 or something like it"

Right?

bye,
	Paolo


  reply	other threads:[~2003-08-18 21:12 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-08-18  9:27 Paolo Ornati
2003-08-18 18:55 ` Herbert Pötzl
2003-08-18 21:11   ` Paolo Ornati [this message]
2003-08-18 22:54     ` Herbert Pötzl
2003-08-19  1:02       ` Jamie Lokier
2003-08-18 16:34         ` Nagendra Singh Tomar
2003-08-19 16:30           ` Jamie Lokier
2003-08-19  8:01         ` Paolo Ornati
2003-08-19 15:23         ` Krzysztof Halasa
2003-08-19  0:53     ` Jamie Lokier
2003-08-18 10:14 John Bradford
2003-08-18 11:24 ` Paolo Ornati
2003-08-19  7:37 John Bradford
2003-08-19 11:48 ` Maciej W. Rozycki

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