RE: NetBSD File Systems

[amaya <amaya%idiom.com@localhost>]

On Mon, Mar 05, 2001 at 11:41:17PM -0500, Ken Hornstein wrote:
> >If you're not building a host that performs a critical security
function,
> >much of this may not apply to you -- but I thought it might be useful
to
> >you to know what I did.  Another benefit of using ATA flash is that
with
> >the right cable, any machine that can boot from an IDE *disk* can boot
from
> >them; ATA flash parts all act like IDE disks if connected to an IDE bus
or
> >PCMCIA IDE *controllers* if you put them in a PCMCIA slot.  This can
let
>
> Just curious: where do you get the IDE->CompactFlash cable from?  I've
> seen the PCMCIA "sleds", of course ...

>The same company that makes the PCMCIA "sleds", Adtron (one "d") also
>makes
>IDE sleds.  Of course, to use those, you need to put the card in a PCMCIA
>form-factor adapter, so they aren't suited for very small systems.

>At least one manufacturer of motherboards (flytech) puts a CompactFlash
>socket on the motherboard, wired up to the IDE controller appropriately.

>I discussed building custom "sleds" (of course, they wouldn't be much
>like
>the big "sleds" since they'd be quite small) to fit into the front of 1U
>cases and directly accept CompactFlash cards with someone at Adtron once.
>They said they could do it, though IIRC the prices they were tossing
>around weren't great.  For one-off embedded systems where hot swap of the
>flash wasn't required, I think I'd just use a Radio-Shack etch kit to
>make
>a tiny PCB with an IDE pin header and a CF socket or even just a
>compatible
>set of pins on it; for more volume or if I needed to swap cards without
>opening the case (that is, I needed "clean" access to the card from the
>front of the machine) I'd have a custom cable house make me up some
>cables
>with a CF socket on one end and an IDE cable on the other; it'd still be
>cheaper by far than having a whole custom circuit board made until you
>hit
>huge volumes.  Remember, 4MB and even now 8MB CF cards are now really,
>REALLY cheap.

        We (my company) make such an adapter - 40 and 44 pin ide header
--> CF socket with ejector - master/slave jumper and drive LED. Its a
simple 2" square circuit card (4 layers but could easily be 2) I'll post
schematics if anyone is interested...

        I can also donate some reasonable quantity of these adapters (say
10 or 20 total) to people using them for NetBSD development (I'd like to
help anyone making NetBSD more suited to embedded systems...)

>Incidentally, be careful of some off-brand CF cards that don't write
>reliably without 12V, or even, in "drive mode", at all.  I had a lot
>of trouble until I switched to SanDisk brand only, which have always
>worked very reliably for me.

        Actually CF cards dont use 12v at all (some PCMCIA cards do), they
_must_ work on +5v or +3.3V only according to the CF spec, you probably
just has some bad cards...



> nice hack if building a bunch of machines that boot/run from CF is to
>have a "burner machine" with a shell script for building images from
>directory trees or config files and a *PCMCIA* sled in it; then you can
>hot-swap the cards as you burn them without needing to whack your IDE
>disk driver to deal with disks going away and coming back (which is
>highly nonstandard) or rebooting your machine between each burn.

>I wish I could provide the shell scripts I use for this kind of bulk
>burning but unfortunately they may belong to a former consulting client
>of mine and I've never bothered to clarify their status.  Not hard to
>rewrite, however.

>If someone in the right group at Intel is reading this, gawsh, it
>would be nice if your next generation of "server" motherboards or
>StrongARM/
>Xscale mainboards just had CF sockets on them... hint hint. :-)

>--
>Thor Lancelot Simon
>tls%rek.tjls.com@localhost
>    And now he couldn't remember when this passion had flown, leaving him
>so
>  foolish and bewildered and astray: can any man?
>                                                   William Styron