Disk is cheap?

Disk is cheap?

[Robert Kaiser]

> Everyone who says, disk is cheap, ought to donate me one.
> Everyone who says, memory is cheap, has to send me some.

:-)

Perhaps a more convincing argument may be that in embedded devices,
disk as well as memory and CPU power are _not_ cheap.

The more resources Linux requires, the less are it's chances of being
accepted as a viable alternative in embedded systems.

> I'm still stuck with a P-133, 56 MB RAM (60-70 ns, some EDO,
> some FPM) and not only Linux but also W2K on a 2.1 and a 0.8 GB
> HDD.

That would be _a_ _lot_ for an embedded system!

----------------------------------------------------------------
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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

Re: Disk is cheap?

[Patrizio Bruno]

I built a embedded dvd/cdda/mp3 player based on linux, using a p200mmx
with 24mb with a bus of 75mhx, but it still takes about 20 seconds to boot,
I think that an embedded device (for home use) should boot in less than
5 seconds, how could be possible with a slow p133? (I've also tried a p133
on 66mhz of bus and it takes almost 35 seconds to boot)
However, first or last old hardware will finish, and who wants to build
an embedded device should use high cost embedded hardware (high cost for me).

P.

On Wed, 31 Jan 2001, Robert Kaiser wrote:

> 
> > Everyone who says, disk is cheap, ought to donate me one.
> > Everyone who says, memory is cheap, has to send me some.
> 
> :-)
> 
> Perhaps a more convincing argument may be that in embedded devices,
> disk as well as memory and CPU power are _not_ cheap.
> 
> The more resources Linux requires, the less are it's chances of being
> accepted as a viable alternative in embedded systems.
> 
> > I'm still stuck with a P-133, 56 MB RAM (60-70 ns, some EDO,
> > some FPM) and not only Linux but also W2K on a 2.1 and a 0.8 GB
> > HDD.
> 
> That would be _a_ _lot_ for an embedded system!
> 
> ----------------------------------------------------------------
> 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
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> Please read the FAQ at http://www.tux.org/lkml/
> 

---------------------------------------------------------
Patrizio Bruno
DADA spa / Ed-IT Development Staff
Borgo degli Albizi 37/r
50122 Firenze
Italy
tel +39 05520351
fax +39 0552478143

PGP PublicKey available at: http://www.keyserver.net/en/
---------------------------------------------------------

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

Re: Disk is cheap?

[Robert Kaiser]

In article <Pine.LNX.4.10.10101311550150.3588-100000@blacksheep.at.dada.it>,
	patrizio@dada.it (Patrizio Bruno) writes:
> I built a embedded dvd/cdda/mp3 player based on linux, using a p200mmx
> with 24mb with a bus of 75mhx, but it still takes about 20 seconds to boot,
> I think that an embedded device (for home use) should boot in less than
> 5 seconds, how could be possible with a slow p133? (I've also tried a p133
> on 66mhz of bus and it takes almost 35 seconds to boot)

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.

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.

> However, first or last old hardware will finish, and who wants to build
> an embedded device should use high cost embedded hardware (high cost for me).

Hmm, since embedded devices are usually built in large scale series,
cost is quite an important factor. Neverthless, even if you leave that
aside, there is the even more important question of size, power consumption
and heat dissipation: Any processor that requires a fan is simply
unacceptable in most embedded designs. (Plus, you don't need
the speed of an 1GHz Athlon to control a washing machine...)
That is the reason why relatively low-performing chips such as
i386EX, AMD Elan SC[45][012]0  are very popular in embedded
devices. These chips are by no means "old hardware" !
Did you know that about 95% of the worldwide microprocessor
production end up in some sort of appliance/embedded system ?

I'm pretty sure these "low-end" processors will not go away as
quickly as you might think. Whether they will be running Linux
in the future will depend on Linux's resource requirements.

Cheers

Rob

----------------------------------------------------------------
Robert Kaiser                     email: rkaiser AT sysgo DOT de
SYSGO RTS GmbH                    http://www.elinos.com
Klein-Winternheim / Germany       http://www.sysgo.de

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

Re: Disk is cheap?

[Wojtek Pilorz]

On Wed, 31 Jan 2001, Robert Kaiser wrote:

> Date: Wed, 31 Jan 2001 17:12:47 +0100
> From: Robert Kaiser <rob@sysgo.de>
> To: Patrizio Bruno <patrizio@dada.it>, linux-kernel@vger.kernel.org
> Subject: Re: Disk is cheap?
> 
> In article <Pine.LNX.4.10.10101311550150.3588-100000@blacksheep.at.dada.it>,
> 	patrizio@dada.it (Patrizio Bruno) writes:
> > I built a embedded dvd/cdda/mp3 player based on linux, using a p200mmx
> > with 24mb with a bus of 75mhx, but it still takes about 20 seconds to boot,
> > I think that an embedded device (for home use) should boot in less than
> > 5 seconds, how could be possible with a slow p133? (I've also tried a p133
> > on 66mhz of bus and it takes almost 35 seconds to boot)
> 
> 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.
> 
> 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.
>
[...]
If someone would modify kernel to allow LZO compression then the
decompression would be 3 times faster at the expense of
compressed part of the image being 9..10% larger (assuming LZO1X-999/9
method used by lzop -9)
(I have done decompression speed tests on Pentium MMX 166 MHz)

Best regards,

Wojtek
--------------------
Wojtek Pilorz
Wojtek.Pilorz@bdk.pl


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

Re: Disk is cheap?

[Pavel Machek]

Hi!

> > I built a embedded dvd/cdda/mp3 player based on linux, using a p200mmx
> > with 24mb with a bus of 75mhx, but it still takes about 20 seconds to boot,
> > I think that an embedded device (for home use) should boot in less than
> > 5 seconds, how could be possible with a slow p133? (I've also tried a p133
> > on 66mhz of bus and it takes almost 35 seconds to boot)
> 
> 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.

> 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...

								Pavel
-- 
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

Re: Disk is cheap?

[Robert Kaiser]

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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

Re: Disk is cheap?

[Hacksaw]

> On Sam, 03 Feb 2001 you wrote:
> > Actually, most of that time is spent running bash/sleep 1. Startup
> > scripts tend to be poorly designed.
> 
> Yes!

I'm not so sure. I'm using RedHat 6.2, and it seems the only time a startup script calls sleep is when it gives you a chance to do interactive startup, and when you are looking for an NIS server. You could certainly remove those.

All the other calls to sleep are in the stop sections, where you want to make sure the thing died before proceeding.

But paring down the startup scripts is a good idea. For something like an embedded device, you might even want to go with a custom init, that just runs your main program. 

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

Re: Disk is cheap?

[Robert Kaiser]

On Die, 06 Feb 2001 you wrote:
> But paring down the startup scripts is a good idea. For something like an embedded 
> device, you might even want to go with a custom init, 

Yes, I'm using busybox (see busybox.lineo.com). It's a multi-call binary that
contains a simplified init, a shell and a host of other nice things.

> that just runs your main program.

Well the _very_ minimal approach is to have your main program _be_ init :-)



----------------------------------------------------------------
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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

Re: Disk is cheap?

[John Fremlin]

 Robert Kaiser <rob@sysgo.de> writes:

> On Die, 06 Feb 2001 you wrote:
> > But paring down the startup scripts is a good idea. For something like an embedded 
> > device, you might even want to go with a custom init, 

Plug: How about jinit (my init) ;-)

        http://www.penguinpowered.com/~vii/programs/linux/jinit
        http://john.snoop.dk/programs/linux/jinit

Boot script time with the supplied example scripts is 12-13 seconds to
login prompt under 2.4 on my old K6-2. Jinit has integrated service
stop/start functionality. Also on the page are links to other source
available inits.

[...]

-- 

	http://www.penguinpowered.com/~vii
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

Re: Disk is cheap?

[Ralf Baechle]

On Wed, Jan 31, 2001 at 02:29:54PM +0100, Robert Kaiser wrote:

> Perhaps a more convincing argument may be that in embedded devices,
> disk as well as memory and CPU power are _not_ cheap.
> 
> The more resources Linux requires, the less are it's chances of being
> accepted as a viable alternative in embedded systems.
> 
> > I'm still stuck with a P-133, 56 MB RAM (60-70 ns, some EDO,
> > some FPM) and not only Linux but also W2K on a 2.1 and a 0.8 GB
> > HDD.
> 
> That would be _a_ _lot_ for an embedded system!

Oh this common missconception that embedded system equals small systems.
There are embedded systems that outrun supercomputers without sweating,
have gigs of RAM and sometimes if you look at them closly even have the
names of well known big iron companies on their boards.  The whole
embedded term is just so weakly defined and everybody seem to have his
personal definition.

  Ralf

Re: Disk is cheap?

[Robert Kaiser]

On Sat, 24 Feb 2001, Ralf Baechle wrote:

> On Wed, Jan 31, 2001 at 02:29:54PM +0100, Robert Kaiser wrote:
> 
> > Perhaps a more convincing argument may be that in embedded devices,
> > disk as well as memory and CPU power are _not_ cheap.
> > 
> > The more resources Linux requires, the less are it's chances of being
> > accepted as a viable alternative in embedded systems.
> > 
> > > I'm still stuck with a P-133, 56 MB RAM (60-70 ns, some EDO,
> > > some FPM) and not only Linux but also W2K on a 2.1 and a 0.8 GB
> > > HDD.
> > 
> > That would be _a_ _lot_ for an embedded system!
> 
> Oh this common missconception that embedded system equals small systems.

I didn't say that. I'm talking about what's common in embedded systems
and it is _very_ common for an embedded system to be small both in
mechanical dimension and computational horsepower. This is not a
misconception but simply practical experience.

> There are embedded systems that outrun supercomputers without sweating,
> have gigs of RAM and sometimes if you look at them closly even have the
> names of well known big iron companies on their boards.

Sure these systems exist, but trust me, they are a very small fraction
of a very big market.

> The whole
> embedded term is just so weakly defined and everybody seem to have his
> personal definition

How about this: An embedded system is a computer system designed to
fulfill a particular purpose.

Since embedded systems are usually made in large quantities, there is a
strong pressure to make them as cheap as possible. Thus, the amount
of resources assigned to a system is usually just barely enough for
it to fulfill it's purpose. If it has gigs of RAM, you can be sure it
needs every bit of it for doing whatever it is supposed to do.

Running on low resources is symptomatic to all embedded systems.

Helau

Rob

----------------------------------------------------------------
Robert Kaiser                          email: rkaiser@sysgo.de
SYSGO RTS GmbH                         http://www.elinos.com
Am Pfaffenstein 14                     http://www.sysgo.de
D-55270 Klein-Winternheim / Germany    

Re: Disk is cheap?

[Pavel Machek]

Hi!

> Everyone who says, disk is cheap, ought to donate me one.
> Everyone who says, memory is cheap, has to send me some.
> 
> I'm still stuck with a P-133, 56 MB RAM (60-70 ns, some EDO,
> some FPM) and not only Linux but also W2K on a 2.1 and a 0.8 GB
> HDD.
> 
> I accept donations in IDE and SCSI, as well as parport devices.

Actually there's problem: you can't easily divide what you
have. Having one 30G drive is not equivalent to having 30 1G drives,
unfortunately...
								Pavel
-- 
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

Re: Disk is cheap?

[John R Lenton]

On Tue, Jan 30, 2001 at 06:58:22PM -0000, mirabilos wrote:
> I accept donations in IDE and SCSI, as well as parport devices.

I have a parport device (one of the few things left from my XT).
I can send it to you if you pay shipping.

-- 
John Lenton (john@grulic.org.ar) -- Random fortune:
Saints should always be judged guilty until they are proven innocent.
- George Orwell
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

Disk is cheap?

[mirabilos]

Everyone who says, disk is cheap, ought to donate me one.
Everyone who says, memory is cheap, has to send me some.

I'm still stuck with a P-133, 56 MB RAM (60-70 ns, some EDO,
some FPM) and not only Linux but also W2K on a 2.1 and a 0.8 GB
HDD.

I accept donations in IDE and SCSI, as well as parport devices.

-mirabilos

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12+(proprietary extensions) # Updated:20010129 nick=mirabilos
GO/S d@ s--: a--- C++ UL++++ P--- L++$(-^lang) E----(joe) W+(++) loc=.de
N? o K? w-(+$) O+>+++ M-- V- PS+++@ PE(--) Y+ PGP t+ 5? X+ R+ !tv(silly)
b++++* DI- D+ G(>++) e(^age) h! r(-) y--(!y+) /* lang=NASM;GW-BASIC;C */
------END GEEK CODE BLOCK------


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/