[Charlug] Meeting Idea: Modding a simple Linux NAS

[Dennis Clark]

Does anyone here have a soldering iron and know how to use it? If so, I
would like your help in adding pins to the PCB of a Linux-based NAS I
own so I can connect a serial console to it. It would also be nice if a
multimeter were available during the process to check the pin signals.

Assuming that one or more of this group's members can help me, I think
the next CharLUG meeting would make a good time and place to get
together to work on my NAS. I believe the modification can be completed
in an hour. Afterwards we can have a discussion on what such a device
might be useful for.

If you want to know more about why I want to mod my NAS, read on...

Late last year I bought a KuroBox HG on eBay. A Kuro Box is a NAS
manufactured from similar components as the Buffalo Linkstation, but
modified to make it easier for the owner to replace the firmware with
custom Linux firmware. You can read more about the Kuro Box at
http://buffalo.nas-central.org/wiki/Category:Kurobox.

A few weeks ago I was successful in replacing the box's proprietary
bootloader with Das U-Boot, an open-source bootloader that supports my
Kuro Box. This was a significant step because U-Boot is required to run
2.6-based kernels on my NAS. U-Boot also provides a console accessible
via netcat to help with troubleshooting if a serial console is not
available.

I then proceeded to follow the instructions for installing the 2007 PPC
Gentoo distribution. After extracting the distribution files onto the
NAS and rebooting the device I opened the netconsole and watched its
output. I saw the messages for loading the kernel and watched the kernel
detect and initialize the various devices on the Kurobox until the point
when it resets the NIC, which forces the netconsole to disconnect.

All this was normal behaviour according to the instructions: I just had
to wait a minute or two for the NAS to finish booting and I would be
able to connect. So I waited, and waited, and waited ... nothing. The
NAS was supposed to use DHCP to get an address and fall back to
192.168.11.150 if it failed, but it appeared to do neither of those
things. Rebooting into Emergency Mode gave me a shell prompt again, so I
know the device was still functioning. Rebooting normally showed the
same messages as before on the netconsole, with the same final result:
nothing.

At this point, the only way for me to see what the device is doing after
it resets the NIC is to attach a serial console. I have an old Windows
CE tablet which works well as a serial terminal, and I also have an
RS232-to-TTL converter to perform the proper signal conversion.
Unfortunately the PCB for my Kuro Box has 4 holes where the TTL pinouts
normally go, so I need to solder pins or wires at those points before I
can connect a serial console to the Kuro Box. Since this mod is for
troubleshooting only, I'm not looking for modding the case to add an
RS232 connector: I'll leave the case off the NAS while I'm debugging,
and disconnect the wires before putting the case back on when I'm done.

Once I know what the problem is, I can boot into Emergency Mode, make
the required changes to the system, and reboot. With a little bit of
skill and luck I should have a working Linux OS running on my NAS.

-- Dennis