Rick's b.log - entry 2010/05/08

Neuros OSD - geeky tips and tricks

Yoo-hoo! Talk to me baby...

There are three ways to access the command line. The first is the advanced tools part of the graphical user interface (hereafter called the "UI"). It has "awesome" factor, name me anything else that lets you prod its innards right there on the telly. Now look carefully at your remote control. Can you really envisage typing out commands using that? No? Me neither.
The second way is via the serial port. It is a basic 115kbit 8N1 link with no handshaking whatsoever. Don't worry if that meant nothing, we're not touching it. Serial link will be useful in the future for some specific boot-up fiddling that is invoked before the operating system proper, but given that an ever-increasing number of computers don't even have a serial port, we'll forget about it for now.

That leaves ethernet. Most modern computers have an ethernet socket. If you are British, it is the one that looks like a bigger version of the plug on the other end of your telephone (i.e. the bit that plugs into the phone, not the wall). If you are American, it looks like a phone socket. If you are something else or confused, it may be any number of cryptic weird symbols that is supposed to represent a network. Easiest advice, look at that big socket on the back of the OSD in the middle. Now find one that looks like it on your computer...
There are several ways you can connect this to your computer, all of which are beyond the scope of this article. The simplest is an ethernet router running a DHCP server - you ought to be able to get one of these for around £20 - but note that plugging the OSD into your ADSL box may well do the exact same thing!

The screenshots/instructions assume you are running the "OSDng" firmware.
The later "Arizona" firmware should be broadly similar, I cannot say about "Torfu" (the original firmware, your OSD may have had this when shipped... it may still...).

Once you have your OSD plugged into the network, the final thing you will need to know is your OSD's IP address. You could ask your router, but it's just as easy to ask the OSD. Just look in Tools → Settings → Network ... that means from the base menu of the OSD's interface, go to the Tools option, select the Settings option, then choose the Network option. What you see will look something like this:

Talk to me - on a budget

If you do not have any wired networking on your PC, then set the OSD to say the following:

Note that WiFi interfaces, while using TCP/IP networking, are distinct to the wired network, so it is perfectly possible to specify a fixed IP address for the OSD to talk to, while using WiFi for all your internet needs. Actually, that is exactly what I'm doing right now!
If you are unsure of this networking stuff, ask a local friendly geek - it's dead easy to set up a way to get your OSD and your computer talking (in other words: if you get charged anything at all, it should be no more than the cost of a jar of Nescafé...).

Here's a photo of a back-to-back connection. The OSD is directly connected to my computer, and the other box is a video capture box (for the screenshots). All of this is on the living room table.

About the OSD and DHCP

DHCP, in case you weren't aware, is the protocol by which a computer is automatically assigned an IP address at connection time. Most low-speed dial-up modem internet access works like this, and most WiFi access works like this too.
Your OSD can work with DHCP where getting the OSD on-line is little more than "plug it in".

However, if we want to talk to it, there is a big caveat, as explained by pfft2001 on the Neuros forum:

Let me add that even though your router does give out DHCP addresses (I say this because I don't think there are any routers commercially available that don't), you should always configure the OSD to have a fixed IP address. This is because (AFAICT) the OSD doesn't broadcast a recognizable "NETBIOS" name - so if you set it up with dynamic IP, you may not be able to find it from the other machines on your LAN.

[if this paragraph seemed like gibberish, I'll summarise: static IP good, DHCP bad. ☺]

Yoo-hoo, actually talk to me!

All being well, you should see:

You should login, if for the first time, using the user name root and the password pablod

When you're in, it will look like:

Change your password NOW!

Once you're logged in, simply issue the command

Free space?

Wouldn't it be nicer to get a slightly more detailed report for everything at once?

Possible!

At the command line, simply issue the command

The two entries at the end are the important ones. I can tell, just at a glance, that my SD card (3.7Gb, so it'll be a 4Gb card) has a paltry 32.6Mb free space, in other words it is full. My USB device (7.5Gb, so it is an 8Gb flash key) has a whopping 6.7Gb free, with only 10% used. I can record stuff on this...

Pay attention to the /dev/blahblah stuff on the left, because...

Device dismount

Enter the "umount" command. You see, "mount", well, mounts devices. It's like mounting a horse really, you stick in your SD card and you tell the machine to sit on it. Actually, the sitting on part happens automatically on the OSD so you don't need to worry about that part. But to unsit on the horse, you need to unmount it.
Now, of course, you might be thinking "if it is a command to unmount, why is it called umount and not unmount?". Very good question. The answer? Because Unix is like that. (the brand of Debian Linux running on the OSD is basically a modern-day Unix-alike) It will drive you insane for the want of one letter.

Remember I said remember the slash-dev stuff from above? You'll need to tell the u(n!)mount command what to unmount by specifying a device, namely:

• SD card - /dev/mmcblk0p1 (that's zero-pee-one)
• USB device - /dev/sda

Nothing will appear to happen. Don't worry, Unix is like that too. Don't expect cute "it is now safe to remove..." messages. That would be too much like friendly. But if you issue the df -h command again, you'll see it no longer listed.

Now you can remove the device... safely.

Radio? Piece of cake...

If you wish to see the status, namely the title of the current song, just ask:

Here's a look at all of this in action:

Kawaii-Radio plays Japanese music, with a heavy emphasis on animé tunes. If that isn't your thing, you could always try:

• Sky.FM 80s - for music from the 80s!
  http://scfire-dtc-aa02.stream.aol.com:80/stream/1013
• BirdsongRadio - authentic tweety birds all day long!
  http://chill.wavestreamer.com:8062/

How to find the information for a radio channel...
The simplest way, if it is bookmarked on your PC, is to look for the link information in your player (I use WinAMP). This is usually available under something like "Edit bookmarks".
Otherwise, go to the Shoutcast website and look for interesting stations. You see those little yellow "Tune in!" buttons?
Right-click the button and "Save target as" (or similar wording) to save the resultant file to your harddisc. This is important, for if you just click it, your .pls handler will most likely load and tune to that channel automatically.
Go to where your downloads are kept, right-click the file (they're always called "tunein-station.pls") and open it in Notepad (you may need to "Open with..." and choose Notepad.

It will look like this:

   [playlist]
   numberofentries=1
   File1=http://69.162.101.49:8000
   Title1=(#1 - 94/100) AnimeNfo Radio  | Serving you the best Anime music!
   Length1=-1
   Version=2

xmms2 is capable of handling WMA, WAV, Ogg/Vorbis, MP3, MPEG audio (as in DVDs), MP4/AAC, FLAC, and reading ID3 tags, plus popular playlist files (.m3u, .pls...).

xmms2 has a number of playlist features that are woeful when accessed through the UI. I will discuss these at a later time.

Reboot your OSD

Seriously. That's it!

Wait - why not just pull the power cord? There's a simple reason for this. You wouldn't pull the plug on your computer would you? Doing that could corrupt your harddisc and cause all sorts of chaos.
Well, the thing is once you are using the CF card you are using an actual mounted filesystem instead of simply reading things from Flash. Moreso when using OSDng which resides entirely on read/write storage as a proper filesystem. Don't forget, of course, that a CF card is like a flashised form of an IDE device. So don't assume, just because it is a little thing stuck in your OSD, that is isn't a vulnerable device.
Shut down responsibly.

Schedule sanity

  15/05/2010 20:59 - 22:01 [weekly]
  13/05/2010 22:59 - 00:01 [weekly]
  13/05/2010 21:29 - 22:01 [weekly]
  10/05/2010 20:59 - 22:01 [weekly]
  08/05/2010 20:59 - 22:01 [weekly]
  08/05/2010 17:59 - 18:46 [weekly]

Using the OSD, you can assign filenames to recordings, so not only do recordings assume a logical filename (instead of either osd or osd-with-date-suffix), but when looking at the schedule you know immediately what is what...

Sadly there is (yet?) no way to interrogate or edit the schedule database via telnet.

Walk around the filesystem (the painful way)

If you're used to the likes of the DOS/Windows system, you'll need to know a few commands. The first is:

If you enter:

The left nonsense is the file permissions. You can mostly ignore this, except for the leftmost character, which is d for a directory (folder), l for a hard link, s for a symbolic link, and - for a file.
Then are numbers and something that'll probably say "root" twice. Ignore this, it's ownership information, not really relevant on the OSD.
Next, the file size. If in 'pretty' form, it will be a managable number followed by k for kilobytes or M for megabytes.
Then follows the date. The start of Unix time is the 1st of January 1970, so files that pretty much don't have a specific time will say this.
Finally, the name of the item in question. Remember, Unix is case sensitive so while "windows", "Windows" and "WINDOWS" may be the same thing on a DOS/Windows computer, it would be three different things on a Unix machine.

But wait, what's that arrow-something-else all about?
Ah... There, my friend, is a symlink (hard or symbolic link). If you've grown up used to the DOS system, this will be new to you. In a nutshell, if you look at the example above you will see that var is followed by /mnt/tmpfs/var which means that if you go to the var directory, you'll be magically teleported to the /mnt/tmpfs/var directory instead.

Wanna have some fun? You can symlink files too. There's a clever bit of software called "Busybox" that does a myriad of different things depending on what you call it. So try:

Thing is, if you just do:

There's nothing wrong. You are in the /root directory, and it's empty. You are root, /root is your home, where you go to when you log in. That's what the wiggly line (~) means.

In order to break out, try:

Grew up with DOS? Forget all about it. Under Unix there is no C: and D: and your CD-ROMs won't ever be E: and your SD cards won't be G:.
No. There is only /. That slash is God. From that point lays forth the entire filesystem. It doesn't matter if it is split across partitions or harddiscs (not uncommon) or devices or even networked to the far side of the planet. Hell, it doesn't even have to be in anything even remotely like the same physical format, never mind logical (disc) format. So long as it has files and folders and is understood by the operating system, it all comes to rest under the mighty slash. End of.

Here's a crash course to where you'll find stuff:

Walk around the filesystem (the pretty way)

Give the following commands:

You should see something more or less like this:

Move your cursor (using the arrows) until the blinking cursor is below the speech marks at the end of the word "/media/" on the second line.
Press i once. Nothing will appear to happen, but you are now in insert mode.
Press Delete until the word media is gone, and you are left with a single slash character.

Move down to the blank line under "server.follow-symlink" and press Enter once, to add a blank line. Move up so what you write next will follow on from the previous stuff.
Enter, exactly:

Your modified file should look like this:

Now go down. Down, down, off the screen (it will scroll) until you reach the line where everything else is set to "application/octet-stream".
Go and delete those words. You dont want "application/octet-stream", you want text/plain, so type that in instead. It will now look like:

Press Esc, then type in exactly:

You'll be back at the command prompt. There are two more commands to go. The first is:

Finally, issue:

Now point your browser to the OSD...

To look at what we actually did...

• Replacing "/media/" with "/" means we can see/access everything, not just a selected portion.
• Adding the "dir-listing.activate" means we now see directories when there is nothing else to serve. If you put an index.html file in there, it would be served instead.
• And finally, the "text/plain" thing is important. It attempts to force the server to send everything otherwise untyped (i.e. not a JPEG or HTML etc) to the server as plain text instead of an octet-stream.

Why does that last one matter? Because for octet streams, you will be offered a download prompt. It is a pain to download, find, and load a script when you just want to read it. By setting the type to text/plain, we are saying to the browser "just show me this". And so it does...

If you happen upon clicking an application, what happens next depends upon your browser. Some will try to show it, some will override the type specified and offer up the "save as" dialogue.
If it looks like gibberish, most likely with the word "ELF" buried in the beginning, it is probably an executable. You can't really read that (well, you can, but there's no point) so hit the back button and pick something else!

FAT device verification

Time to fix this.

This modification installs software which can alter critical parts of a FAT based device.
USE IT AT YOUR OWN RISK.

The first step is to install the dosfsck program. Now, if you don't trust me, you should look for the Debian-etch version for the ARM architecture. Then work out how to get it out of a .deb file (for the OSD has no .deb installer).
Or you can download it from here! ☺

This file should be placed in the /sbin directory. There are two ways, depending on whether or not your OSD is online...

If your OSD is online, the following should do it:

If your OSD is not online, or the above gives weird errors, then download it to your computer as normal. Copy it to the root folder of a USB flash device. Put that flash device into your OSD, then:

You're not quite ready, the OSD will refuse to run it. To fix this, say:

The final part of the puzzle is to set up some symlinks. I'm not sure what the purpose of these is, exactly, but it isn't hard to do...

Okay, you're done. Time to test drive it. If you give the options -v -n, it will simply look (and not alter anything) and report verbosely.
For example:

However, please note that this requires memory for indexing context and content, so if you hit it with a big device, it will fail...

It seems to be okay with smaller devices, say 4Mb and under, even if cluttered. To check out those large ones, you'll need to use your desktop machine. If you fancy a fun and frivolous weekend, you can install a complete live working copy of Ubuntu on to a USB device (or SD card, in my case!) and get your computer to boot from it. Geek points a-plenty for that exercise! All that to check out a storage device? Well, why not? It beats reading forums for the day...

This last little exercise is especially impressive as we've cobbled together a precompiled executable for an ARM-based version of Linux within our OSD, and got it to work.
Now, there are a myriad of potential problems as the version of Linux in the OSD runs to around 20Mb, while a real ARM install of Debian runs to 100Mb more than that. So as you can see, a lot of stuff has been pared out of the OSD's version.
That said, there's several thousand software packages. I've got one to work, what will you pick? Begin your adventure! (don't forget, ARM builds only!)

Your comments:

Please note that while I check this page every so often, I am not able to control what users write; therefore I disclaim all liability for unpleasant and/or infringing and/or defamatory material. Undesired content will be removed as soon as it is noticed. By leaving a comment, you agree not to post material that is illegal or in bad taste, and you should be aware that the time and your IP address are both recorded, should it be necessary to find out who you are. Oh, and don't bother trying to inline HTML. I'm not that stupid! ☺ ADDING COMMENTS DOES NOT WORK IF READING TRANSLATED VERSIONS.
 
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