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From: Robert Kaiser <rob@sysgo.de>
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To: Pavel Machek <pavel@suse.cz>
Subject: Re: Disk is cheap?
Date: Tue, 6 Feb 2001 15:49:30 +0100
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Cc: Patrizio Bruno <patrizio@dada.it>, linux-kernel@vger.kernel.org
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On Sam, 03 Feb 2001 you wrote:
> > Usually most of the startup time is spent by the BIOS doing
> > extensive self-test stuff and for firing up services (http,
> > inetd, sendmail, ...) that many embedded systems have little use
> > for.
> 
> Actually, most of that time is spent running bash/sleep 1. Startup
> scripts tend to be poorly designed.

Yes!

> > I have a 25MHz 386EX (~2.2 Bogomips) here that boots Linux out of ROM
> > in roughly 30 seconds. Most of _that_ time however is spent decompressing
> > the kernel.
> 
> You might want to set up XIP and run kernel directly off the ROM...
> 

Hmm, that board has only 512KB ROM. I can fit a minimal Linux kernel
and root-FS in that, but only if it's compressed. ROM, in my experience,
is more expensive than RAM, so it often makes sense to save ROM space
even at the expense of using a little more RAM.

But I'm curious: is there a simple procedure to set up a linux Kernel
to execute from ROM ?


----------------------------------------------------------------
Robert Kaiser                         email: rkaiser@sysgo.de
SYSGO RTS GmbH
Am Pfaffenstein 14                    phone: (49) 6136 9948-762
D-55270 Klein-Winternheim / Germany   fax:   (49) 6136 9948-10
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