[LinuxBIOS] Overview

Richard Smith smithbone at gmail.com
Tue Apr 25 15:55:05 CEST 2006

On 4/25/06, m at de-minimis.co.uk <m at de-minimis.co.uk> wrote:

> I'm completely new to LinuxBios, and I'm trying to understand exactly what
> it does, and what it offers.  Trying to decide exactly how interested I
> am.  Could you please forgive my ignorance and clarify the following for
> me please:

Have you read all the info at linuxbios.org?  That should help.

> Does LinuxBios run on the main processor or on some auxiliary processor?

LinuxBIOS replaces the system BIOS so it rus on the "main" processor.

> What is the typical power consumption of a LinuxBios moboard running the
> minimum number of devices to do basic communication over ethernet -
> hopefully only the moboard and the network card if it isn't already on the
> moboard will require power, then I need to know processor consumption -
> here the earlier question about what does the processing becomes relevant.

The power consumption of most onboard devices will be swamped by the
power consumption of the CPU.  Next in line (or even greater) would be
a high powerd graphics card.  Since the power consumption of a
mainboard depneds on the type of the mainboard, the design of the
mainboard, and load of the CPU there is no easy answer to your
question.  Some one would actually have to measure it for a specific
mainboard setup.

For example a Dual opteron setup is going to pull way more juice than a Geode.

> Can LinuxBios be used to do complicated wake-on lan?

LinuxBIOS is GPL so it can do _whatever_ you code it to do. *grin*
Currently I don't know of any wake-on-lan implementations for the
supported mainboards.  But perhapas someone else does.

> Does LinuxBios help with running multiple operating systems
> simultaneously? (high interest)


> Does it accelerate booting,


> because where previously first the bios
> loaded, then grub, then the OS proper, now perhaps booting can go straight
> from LinuxBios to OS?

Even better than that.  LinuxBIOS can be customized to take out most
of the fat in a normal bios.  A linux prompt in 3 seconds is not
unheard of.  A lot depends on the type of media you boot from.

> How often can one typically write to the bios before it won't take any
> more changes?

I do embedded systems where we use flash parts a lot and I've never
run into a case where I've reached the write limit of a flash during
developement.  Its largely a non-issue.

> I understand it's flash, so I expect few thousand times,

The minimum I've ever seen was 10,000 cycles.  Most are 100,000
cycles. Some nowdays are 1M cycles.  This is also a worst case rating.
 ie running at the temp extreme and the lowest supply voltage.

> more if one rotates which memory blocks one uses, but on the other hand
> this isn't exactly flash that is designed to be rewritten very often, as
> far as I understand anyway!  Can one fairly easily and at a competitive
> price buy replacement chips?

Yes.  Digikey and Mouser have most of the popular parts.  And you
don't need the exact same part just one that is the same size and the
same speed and same package/pinout.

Richard A. Smith

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