On Tue, 22 Feb 2000, H. Peter Anvin wrote:
> "Richard B. Johnson" wrote:
> >
> > Until you really need to boot from a floppy so you can update your
> > NVRAM (or whatever you are using to embed Linux). Think customers
> > at a remote site, no boxes to boot over the network from, etc.
> >
>
> Why the heck do you want to put something as big, clumsy, unreliable and
> expensive as a FLOPPY DRIVE on an embedded system? You're better off
> using a socketed ROM or a serial port of some sort. This is again good
> reasons to not use a BIOS ***unless you need PC compatibility***.
>
We don't. They plug in if/when you need to upgrade. The controllers
come 'free' with the embedded chip-sets. Free, meaning you couldn't
get rid of them if you wanted to.
We find that the customer(s) will completely screw up the contents of
NVRAM (their applications can write to it using our Linux driver). If they
write to the wrong page, there goes everything necessary to boot. So,
I have a "recovery-floppy" with assembly-language that re-writes NVRAM,
then reboots using NVRAM. The user's parameters are lost, but who cares.
We don't ever use DOS or anything as gross. The recovery-floppy doesn't
start Linux or anything, it 'knows' where to get the NVRAM stuff as
a physical offset and rewrites NVRAM, after which it reboots.
Cheers,
Dick Johnson
Penguin : Linux version 2.3.41 on an i686 machine (800.63 BogoMips).
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This archive was generated by hypermail 2b29 : Wed Feb 23 2000 - 21:00:31 EST