Linksys NSLU2 NAS hardware/firmware questions...

I'm sure that some of you are aware of the Linksys NSLU2 NAS and the fact
that is runs Linux as it's OS. There is a third party firmware (Unslung)
that enables users to upgrade the functionality of these devices. I'm a newb
in this area so I thought I'd ask the experts...

(for those who don't know what I'm talking about, please visit
http://www.nslu2-linux.org/wiki/Main/HomePage )

When this device has the Unslung firmware installed, it is able to boot and
load packages from one of the attached USB hard drives. This unit also has
support three more USB ports in hardware. It would be a simple matter of
mounting a USB memory stick inside the unit, hardwired to one of the extra
USB ports to add some permanent storage. What I'd like to know is - Could
the NSLU2 boot from this memory stick, eliminating the need for ANY files
other than user data on the USB drives?

The other thing I was wondering is, this unit can have it's RAM upgraded by
swapping out the current chips, or piggybacking a matching set of chips.
Unfortunately, the battery covers part of the memory chips. Has anyone
successfully done the memory upgrade? Does anyone have photos?

Finally, I'm looking for any forum or tech pages regarding this subject, so
please reply if you know of more websites discussing this topic.

Thx!

On Mon, 20 Mar 2006 10:15:55 GMT, "Noozer"
wrote:

I'm sure that some of you are aware of the Linksys NSLU2 NAS and the fact
that is runs Linux as it's OS. There is a third party firmware (Unslung)
that enables users to upgrade the functionality of these devices. I'm a newb
in this area so I thought I'd ask the experts...

(for those who don't know what I'm talking about, please visit
http://www.nslu2-linux.org/wiki/Main/HomePage )

When this device has the Unslung firmware installed, it is able to boot and
load packages from one of the attached USB hard drives. This unit also has
support three more USB ports in hardware. It would be a simple matter of
mounting a USB memory stick inside the unit, hardwired to one of the extra
USB ports to add some permanent storage. What I'd like to know is - Could
the NSLU2 boot from this memory stick, eliminating the need for ANY files
other than user data on the USB drives?


No idea but I'd expect you need a new bootloader. IOW, it
is meant to only boot from it's own firmware and the drives
are only storage, as would a USB thumbdrive be. That's in
it's default configuration but you've referenced a large
project that can conceivably alter it's default
configuration completely. It would depend entirely on what
you flash to it, wheither it's capable of that. I would
wonder though, do you "need" it to boot from the thumbdrive
at all when you do still have the control over and option to
write the firmware, the OS to the integrated onboard flash?
Once you have the OS booted enough to access the
external/added USB flashdrive, it would be able to use files
from it if set up to do so.


Have you read through the forums dedicated to these?
There's probably been a few people who have tried to use USB
thumbdrives and that would be the best source for this info.


The other thing I was wondering is, this unit can have it's RAM upgraded by
swapping out the current chips, or piggybacking a matching set of chips.
Unfortunately, the battery covers part of the memory chips.

Compared to adding the memory, the battery is a relatively
trivial issue. Typical battery holder (as that appears to
be) just solders down at the two electrical contacts on each
end. Remove the battery, the holder should be desoldered
fairly easily if you are reasonably adept with a soldering
iron. IF adding memory results in less (not enough)
clearance between the battery holder and the memory, such
that the holder needed to sit a little further away from the
board then you'd have easy options:

- Source another battery holder with longer pins on the
bottom (search Digikey, mouser, alliedelectronics, etc),
remotely mount the battery (need not even be same
cell/holder, just same voltage and good/low self-discharge
rate type of battery chemistry) with wire leads going back
to the contact spots on the PCB (or pins as-in pin-header
for easy disconnect battery leads)

- Take typical SIP/DIP/whatever socket pins and solder them
onto the pins of the original battery holder so it sits a
few mm taller than originally.

- Take a smal gauge piece of sold core wire, bend a
right-angle loop in the end of it and solder the battery
holder pins into the loops, the wire being an extension to
do as the socket pins above would, cause the battery holder
to sit a few mm higher up.

How good are you are soldering? Soldering/desoldering
memory chips with that lead pitch is fairly precise work.
It'll be easier to resolder than desolder.

Has anyone
successfully done the memory upgrade? Does anyone have photos?


Do you have links detailing these memory upgrades?
For a limited purpose device, 32MB might be enough for many
tasks.


Finally, I'm looking for any forum or tech pages regarding this subject, so
please reply if you know of more websites discussing this topic.


Well, if you hadn't provided that link above, that's what
I'd have pasted he [ ]
Otherwise, good ole Google is golden,
http://www.google.com/search?hl=en&q=NSLU2+mod

When this device has the Unslung firmware installed, it is able to boot
and
load packages from one of the attached USB hard drives. This unit also has
support three more USB ports in hardware. It would be a simple matter of
mounting a USB memory stick inside the unit, hardwired to one of the extra
USB ports to add some permanent storage. What I'd like to know is - Could
the NSLU2 boot from this memory stick, eliminating the need for ANY files
other than user data on the USB drives?

No idea but I'd expect you need a new bootloader. IOW, it
is meant to only boot from it's own firmware and the drives
are only storage, as would a USB thumbdrive be. That's in
it's default configuration but you've referenced a large
project that can conceivably alter it's default
configuration completely. It would depend entirely on what
you flash to it, wheither it's capable of that. I would
wonder though, do you "need" it to boot from the thumbdrive
at all when you do still have the control over and option to
write the firmware, the OS to the integrated onboard flash?
Once you have the OS booted enough to access the
external/added USB flashdrive, it would be able to use files
from it if set up to do so.

What I'd like is to be able to swap any USB HDD on the device without having
to worry that I'm removing any packages/dependencies/etc.

Have you read through the forums dedicated to these?

Yup, but I'm not finding anything really related.

There's probably been a few people who have tried to use USB
thumbdrives and that would be the best source for this info.

I'm hoping to find some. I know that folks are plugging a memory stick into
the external USB ports and booting fine. I just want to have a permanently
installed flash disk within the unit itself.

Much more info here, BTW:
http://groups.yahoo.com/group/nslu2-general/

Eventually, I plan to use this little box as a mail server, ftp server,
media server and print server.

On Mon, 20 Mar 2006 12:09:35 GMT, "Noozer"
wrote:

When this device has the Unslung firmware installed, it is able to boot
and
load packages from one of the attached USB hard drives. This unit also has
support three more USB ports in hardware. It would be a simple matter of
mounting a USB memory stick inside the unit, hardwired to one of the extra
USB ports to add some permanent storage. What I'd like to know is - Could
the NSLU2 boot from this memory stick, eliminating the need for ANY files
other than user data on the USB drives?

No idea but I'd expect you need a new bootloader. IOW, it
is meant to only boot from it's own firmware and the drives
are only storage, as would a USB thumbdrive be. That's in
it's default configuration but you've referenced a large
project that can conceivably alter it's default
configuration completely. It would depend entirely on what
you flash to it, wheither it's capable of that. I would
wonder though, do you "need" it to boot from the thumbdrive
at all when you do still have the control over and option to
write the firmware, the OS to the integrated onboard flash?
Once you have the OS booted enough to access the
external/added USB flashdrive, it would be able to use files
from it if set up to do so.

What I'd like is to be able to swap any USB HDD on the device without having
to worry that I'm removing any packages/dependencies/etc.

Have you read through the forums dedicated to these?

Yup, but I'm not finding anything really related.

There's probably been a few people who have tried to use USB
thumbdrives and that would be the best source for this info.

I'm hoping to find some. I know that folks are plugging a memory stick into
the external USB ports and booting fine. I just want to have a permanently
installed flash disk within the unit itself.

Much more info here, BTW:
http://groups.yahoo.com/group/nslu2-general/

Eventually, I plan to use this little box as a mail server, ftp server,
media server and print server.



It should be attainable, just put whatever functions won't
fit in the onboard memory, on the thumbdrive. Does it
matter if you're "removing packages/dependencies/etc" if
this is an internal drive? I'd think if you're making it
internal, it would be so it's a permanent drive- or at least
permanently installed while it's running.

One of the pictures I saw showed someone who put another USB
port on, but it was mounted funny with it sideways and
soldered to the crystal. That seems a bad looking mod to me
but a slightly different implementation might work well-
take a fully enclosed USB port (some have springy friction
tabs stamped out of the outer shell but others have an
entirely solid outer shell around them), turn it upside down
and epoxy the top of it onto the top of the existing USB
port, but have it pointing inwards, inside the case instead
of out so it sits entirely behind the shell.

Then just wire it up following the examples others used for
the additional USB port, support. However, I'd probably be
more interested in putting a slot in the casing and mounting
a USB SD Card reader just inside. "Some" of those are
bootable as well, but IMO, you might have better luck (IF
you tried to) boot from a single-slot type reader than one
of those 25-in-1 multi-slotted combo card reader widgets. I
don't recall which motherboards I've tried but I do remember
single-purpose SD Card readers worked on some boards to boot
while the multi-in-one readers didn't.