 | Level: Introductory Peter Seebach (crankyuser@seebs.plethora.net), Author, Freelance
14 Dec 2004 The Kuro Box promises something fairly interesting: a usable single-board PowerPC computer, for only US$160 -- when other PowerPC development boards often cost ten times as much. Peter Seebach guides you through setup and install in this developerWorks hardware howto.
You might think the Kuro Box sounds too good to be true.
A PowerPC® development board, for roughly a tenth of the cost of other boards? And yet, the price isn't that weird. It's a little
cheaper than x86 SBCs, but
not outlandishly so. So, into the breach: Here's a report on what I
discovered from getting one of these and starting to try it out. The
name, we are told, means "expert box;" there is certainly some targeting
here at experienced users.
What's in the box
What shows up in the mail is, well, the box. There's a little stand
for it (if you want to put it standing up), a couple of screws, a CD, the
documentation, and the box itself. The Kuro Box is a small plastic box,
with little spots for diagnostic LED lights. On the back are a power
cord, an ethernet port, and a USB port. That's it for connectors. It has a
reset button, a switch which I think turns the ethernet port into an
uplink port, and a power button (in front). The raw specs are pretty
simple: 200Mhz PowerPC processor, 64MB of memory. (Which PowerPC? It's a
Freescale® 8241, sometimes known as the "G2," which is sort of like a
PowerPC 603e.)
The documentation is a bit of a surprise. It's a single folded
sheet of paper containing the instructions... in Japanese!
The only supported path is to run a setup program
from a Windows® machine, after the hard drive has been installed. But to
find that out, you have to go to the Web site (unless you read Japanese).
(Actually, an astute reader can probably guess it from the list of Windows
versions in the manual, and the text "CD (squiggle) Setup.exe" in the
instructions.)
The distributor in the U.S. appears to be forwarding pretty much
generic Japanese kits, then providing support on their Web site (see Resources).
Initial setup
The machine won't actually boot without a hard drive installed, and
none is included. It takes a standard 3.5-inch one-third height drive, the
kind you can get free in a box of cereal these days. (Expect to pay about
US$80 for the cereal.) I used a spare 40GB drive, figuring it would be
plenty. It was.
The user might be reasonably mystified. What's this "Setup" program
going to do on my Windows box? Reformat my hard drive so I can then
transfer it? Ask which hard drive to partition? No. What they've done
is much more interesting. The on-board flash ROM is used to boot the
machine in a fairly naive mode, where it will look for DHCP, or
self-assign an IP address. Once it's up, the setup program can scan your
network looking for it, and take advantage of its naturally wide-open
setup to start programming it, specifically, partitioning and formatting
the disk, and loading a minimal software install on it.
Once the setup program is run, the box should (in theory), reboot with a
possibly-updated flash, and a root file system that can be mounted and
used. In fact, the first time I ran it, it didn't do this correctly; I
don't know why. I re-ran it, and it worked fine the second time.
This is a very interesting way to run setup. It's very much oriented
at producing an end-user appliance; you get no control at all over the
setup. Don't like their partitioning scheme? Tough. Want to load
something else? You'll have to log in and do it later. The default
arrangement is simple: you get a gigabyte of root file system, 127MB of
swap, and the rest of the disk mounted as /mnt,
with a directory (/mnt/share) ready to be
shared out.
The software install is pretty minimal, in some ways: no developer
tools, and no ssh daemon (everything is done through wide-open
telnet). You
telnet in as user root (password kuro). (Obviously, you should change this immediately.) The machine comes up sharing the
bulk of the installed disk over AppleTalk and Samba, and running a Web
server interface. By the way, when you telnet in to change the password,
don't use a real password; use a dummy password that's not related to any
password you actually use, so that when you have ssh set up, and want to
set the password without sending it in plain text, you haven't given
anything away.
The Web server interface is also in Japanese. The nice
folks at Buffalo Technology distribute a set of patch files, which are discussed below,
in Getting the English Web server running.
Installing more stuff
The first big candidate for installation is the big zip file full of
binaries. However, the Kuro Box doesn't have an unzip utility. (It has
gzip, but that only handles the first file in a
zip archive.) So, you have to unzip the file on another system, and copy
the binaries over somehow. I mounted the file system over the network and
copied the files over, which went very smoothly. Then, telnet in and
extract them. They're standard gzipped tar files, and both gzip and tar are already
there.
One of the binaries is ssh. In fact, you can now set up sshd. This
is pretty simple; you just need to add a link for it to the relevant rc.d directory.
Listing 1. Enabling ssh
root@KURO-BOX:/# cd /etc/rc.d/rc2.d
root@KURO-BOX:/etc/rc.d/rc2.d# ln -s ../init.d/ssh S30ssh
root@KURO-BOX:/etc/rc.d/rc2.d# sh S30ssh start
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Of course, this won't really work. There are no pregenerated host
keys, and the ssh script won't generate new
ones by default. Edit that script, and remove the # character from line 14, right in front of the text
AUTOKEYGEN=yes. Now try again.
If you're like me, being able to use ssh to access the box makes you a
lot more comfortable. Now's a good time to change the root password to
something a little more reasonable. I'd say turn off telnet access,
but I don't trust the machine that much yet. Just keep it on a private
network for now.
Surprisingly, there's still no unzip utility! But now you have a
compiler, and you can build your own. Here's one set of instructions to
do it:
- Make a working directory, called
/mnt/unzip. Change into that directory.
- Download the unzip source from info-zip's FTP site. As of this
writing, the URL is
<ftp://ftp.info-zip.org/pub/infozip/src/unzip551.tar.gz>.
- Untar that archive. This will create a directory named "unzip-5.51".
Change into that directory.
- Configure for a UNIX® build, by copying in the Unix-specific
Makefile. The command is
mv unix/Makefile .
- Run a make. For Linux, it appears that
make
generic does the right thing.
- Install the software.
make install will
install it all in /usr/local. Since that's in
your default path, you're done!
Getting the English Web server running
This is based on the file called KuroBoxWWW.zip, found on Buffalo's Web page (see Resources for the download page). First,
you will have to install an unzip program. This gives you a directory
called WWW without htpasswd, a name reflecting
their decision not to include the .htpasswd
file for the root directory. The cgi-bin
directory still has an original copy of that file, though, so you'll have
to reset your password again if you changed that one.
There are a few other issues. All of the scripts are unzipped with
mode 666, which is particularly inauspicious in that it lacks execute
permission. However, the files are also DOS-format text files, complete with
carriage returns. While Perl is smart enough to
detect this and politely ignore them, the Linux kernel isn't, and tries to
find a program named perl^M to run them.
Oops.
If you are reading this prior to extracting the files, just use unzip -a. If you are facing a folder full of ^Ms (or
forget to use the -a option), here's how to fix
it after the fact:
Listing 2. Fixing the cgi-bin directory
root@KURO-BOX:/www/cgi-bin# for i in *
> do
> tr -d '\015' < $i > $i.new; mv $i.new $i
> done
root@KURO-BOX:/www/cgi-bin# chmod 755 *.cgi *.pl
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With this done, you can visit the front page and poke around with the
provided CGI scripts. You will probably want to set an htpasswd:
Listing 3. Assigning a Web server password
root@KURO-BOX:/# cd www
root@KURO-BOX:/www# htpasswd -b .htpasswd root newpass
Updating password for user root
root@KURO-BOX:/www# cd cgi-bin
root@KURO-BOX:/www/cgi-bin# htpasswd -b .htpasswd root newpass
Updating password for user root
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After I ran these instructions, I found that the Web server directory
had become world-writable. Furthermore, the Web server's configuration
file specifies as a CGI directory /cgi-bin*/*.
As a result, when I forgot the root password I'd set, I was able to create
a CGI script that would be run by root by creating a new directory, /www/cgi-bin2/, and putting the script there. The
original CGI directory was not world-writable, so the curious
configuration file did matter.
Note that changes to the "administrative password" made
through the Web interface do not affect the root shell account, only the
htpasswd files.
Expansion
Of particular interest is that the system thinks it has a pair of
16550 serial ports. Unfortunately, these are far from completely wired
up. I talked to someone who did it, by taking apart and desoldering a USB
to serial adapter to connect the Kuro Box's 3.3 volt, inverted, serial
signals to another chip that used these -- and soldered the missing
resistor onto the Kuro Box's motherboard. This is, perhaps, a little more
"expert" than most people are hoping, but it is a way to get ttyS0 up and running, for people who want to watch
the kernel boot, or log in on a serial console. Inexplicably, the relevant
getty is already configured and running, even
though most of the hardware you'd need to get a standard serial port out
of this machine is missing.
The real key to expansion is the USB port on the back. That's just
one port, but it's USB 2, so there's real speed there. The Kuro Box comes
with a fairly limited selection of driver modules, but the ones you're
most likely to need are present: a couple of serial port widgets and the
standard mass storage driver. So, if you can't fit a big enough hard
drive in the box, you can always add an external drive.
One other thing: one of the commands not installed is dmesg, so you have to browse /var/log/messages to see whether the system
recognized a given device you plugged in.
Summary
The Kuro Box is the same hardware as the LinkStation network attached
storage (NAS) device (see Resources). This shows
in a few places. Some of the hardware decisions that might otherwise seem
odd are perfect fits for that market. What this means is
that the Kuro Box is not very much like the evaluation boards you would
get from a PowerPC embedded systems vendor hoping to sell you on PowerPC
development.
There are a few ways to look at this. If you're used to the x86 embedded systems market, where a US$200 or so computer will have standard serial ports, a flash memory slot, and maybe not much else, the Kuro Box seems oddly limited -- especially the lack of a serial port (given that the hardware is almost all there). If you're
used to the PowerPC embedded systems market, where vendors often charge
US$1,500 for an evaluation board, then it may seem a little less
surprising that a few parts were trimmed.
The option of using a standard IDE drive is clearly part of the Kuro
Box's heritage as a black box network storage device. Likewise, the
on-board flash memory is what you'd expect from a box aimed at retail
shelves: most developer-oriented systems would have a CF slot, allowing
you to redo the flash on another system (see Resources for more on redoing Kuro flash).
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About: Zork
Zork was an early text adventure game inspired by ADVENT® (aka Colossal
Cave). It was written from 1977-1979 on a DEC PDP-10 by four members of the MIT
Dynamic Modeling Group; three of those programmers then joined with some
others to found Infocom™ in 1979. Their games were very popular, and even
spawned a ZUG (Zork User's Group) and a best-selling book series of
Invisiclues hints for their games.
Infocom launched in an era of competing hardware running competing
operating systems (from IBM® compatibles to the Apple® ][ to the Atari 800 and
Commodore's Amiga® and C64), when portability was a significant
differentiator; this inspired Infocom to run on top of a virtual machine --
the Z-machine, which was named for Zork. Thus, you can still run Zork on
virtually any system with the help of modern Z-machine interpreters like
Frotz -- or you can also run it on the older hardware for which it was
originally written.
Infocom was bought out by Activision® in 1986, and shut down in 1989. For
more on the Infocom story, see the Wiki articles Zork and Infocom.
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The box has some pluses. In a world full of SBCs with loose power
leads, giant "wall wart" power supplies, elaborate power requirements, and
exposed chips, it's nice to have a box where, once the hard drive
is in it, it takes a standard electrical outlet (two-prong, even, for
those of you in older houses) and Just Works.
An upcoming developerWorks
series will document a project that uses Kuro as a
development platform, with all of the ups and downs that may entail -- so keep an eye out for that.
In the meantime, people who read Japanese, and thus have access to
more complete
documentation, have done some awfully neat stuff. While trying to find
documentation on some parts of this box, I found dmesg output from a NetBSD kernel booting on one of
these.
The Zork Test
An embedded system might not have a graphical display, but it
generally has some kind of text console available. In a world full of
expensive but often useless benchmarks, I have found an alternative
benchmark. It is just as often useless, but it is very cheap: The Zork
Test. Zork is a game which ran on everything from the C64 to a VAX. The
way this was accomplished was a virtual machine, called the Z-machine.
This simple virtual machine has support for virtualized memory access, so
a game much larger than the C64's eponymous 64K of memory could be run.
It provides a number of abstracted features which, conveniently, map onto
modern embedded systems tolerably (see the sidebar About: Zork for
more on Zork and the Z-machine).
To run this test, you will need a Z-machine interpreter: I chose Frotz
(see About: Zork). In addition to being very
small-footprint, Frotz makes a sort of standardized litmus test of whether
a system's programming toolkit is reasonably complete. It's a good quick
sanity check: stable C compiler, <curses.h> implementation, things like that.
Frotz can be downloaded from the maintainer's Web page (see Resources). Once you've got it, unpack it (it's a
normal gzipped tar file), and just run make to
build it. A make install will install it conveniently
in /usr/local. Now, all you need is a story
file for it to interpret. I use Zork I, which Activision allows people
to copy freely these days -- a link to it can also be found in
Resources. Once
you've got the story file, just run frotz Zork1.z5
and enjoy! (I suggest you begin by examining the mailbox.)
You might expect that since the Kuro comes with a Linux environment,
that it would pass the Zork Test with flying colors. Sure enough, it did
(but this is not always the case, and it's better to know these things
earlier rather than too late). Here are the Kuro's test results:
Listing 4. Frotz output
seebs@KURO-BOX:~$ frotz Zork1.z5
[...]
ZORK I: The Great Underground Empire
Copyright (c) 1981, 1982, 1983 Infocom, Inc. All rights reserved.
ZORK is a registered trademark of Infocom, Inc.
Revision 88 / Serial number 840726
West of House
You are standing in an open field west of a white house, with a boarded front
door.
There is a small mailbox here.
>
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Resources
About the author | 
| | Peter Seebach has been using computers for years and is gradually
becoming acclimated. He still doesn't know why mice need to be cleaned
so often, though. You can contact Peter at crankyuser@seebs.plethora.net. |
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