External storage on the Nokia 770

The Nokia 770 has limited storage capacity. RS-MMC cards exist up to 1Gb and phones seldom has more, most a lot less.

To watch movies or listen to music you need more storage capacity.

Looking a bit around on a 770 with an Xterm reveals that the kernel has support for both ext2 and ext3 filesystems often used on harddisks, and it has support for the nfs network file system.

On a system with limited ressources like the tablet such features would not have been enabled unless they serve a purpose.

Harddisk access via usb

While the Nokia 770 officially only supports usb peripheral mode (used for accessing the the memory card from another computer, i.e., the 770 is the peripheral) it is well known that it can be switched to run in usb host mode, having other usb peripherals attached. That could be a self-powered usb harddisk since the tablet is unable to supply the power the usb port normally supplies.

The main obstacle for doing this is the type mini-B usb socket on the tablet. All the usb disk enclosures I have seen use either the same type mini-B usb socket or the larger type B socket. I still have to find a type mini-B to mini-B usb cable. There are some type A (female) to type A (female) adapters on the market but I haven’t been able to find one around here. That would allow you to connect two type mini-B to type A cables to form a type mini-B to mini-B cable.

So it should be possible to get a harddisk on the Nokia 770, but there is a basic connectivity problem, that is, the lack of the proper cable to connect the two.

Harddisk access via NFS

As for NFS the only thing to do is to gain root on the tablet and try to mount something. After all, the network is there.

Here’s a transcript of an NFS mount. It is fairly straightforward, only the actual mount command does take some time.

$ ssh nokia
sh: /usr/X11R6/bin/xauth: not found

BusyBox v1.00 (Debian 2:20041102-11) Built-in shell (ash)
Enter 'help' for a list of built-in commands.

~ $ sudo /usr/sbin/gainroot
Root shell enabled

BusyBox v1.00 (Debian 2:20041102-11) Built-in shell (ash)
Enter 'help' for a list of built-in commands.

/home/user # mount mozia.seindal.dk:/home /media/nfs
/home/user # df
Filesystem           1k-blocks      Used Available Use% Mounted on
/dev/mtdblock4            2048      1984        64  97% /mnt/initfs
none                       512        32       480   6% /mnt/initfs/tmp
/dev/mtdblock4          126464     64612     61852  51% /
none                       512        32       480   6% /tmp
none                      1024        52       972   5% /dev
/dev/mmcblk0p1         1002656    945824     56832  94% /media/mmc1
mozia.seindal.dk:/home 33918528  16501664  15693888  51% /media/nfs
/home/user # ls /media/nfs/
cvs         guest       lost+found  seindal
ftp         httpd       mp3         share
/home/user # ls -l /media/nfs/share/tmp/
-rw-rw-rw-    1 user     users      113521 Nov 30 23:39 screen20051130-2239.png
-rw-r--r--    1 user     users      124510 Nov 30 23:41 screen20051130-2341.png
/home/user # umount /media/nfs
/home/user # ~ $
~ $ Connection to nokia closed.

So it works. If the connection to the access point is good enough, it is possible to watch movies from an NFS server.

By making a symlink from below /home/user/MyDocs/ to the mount point, the files become browsable with the File Manager.

ScreenshotNot GUI interface to NFS

There is no interface to NFS on the tablet.

You have to flash it to R&D mode, run an xterm, do weird things to become root and issue obscure mount commands.

It is probably because the Nokia 770 isn’t marketed as a toy for Linux nerds, but as an internet appliance for people on the move. How many of these have an NFS server at their disposal? Very few, probably, so for the intended user segment an interface to NFS would just complicate matters for very little gain.

It would probably be quite useful for the rest of us, who bought a Nokia 770 because it was a cool way of running Linux on a different platform.

A graphical interface to NFS mounts cannot be installed by the Application Installer which doesn’t run as root, so even with such a program it would still be necessary to flash the tablet to R&D mode and run commands as root simply to install it. Later file systems could be mounted and unmounted without needing root access, based on a couple of added lines in /etc/sudoers.

How did I get here

There are a few good spots to examing to learn about any given Linux system: /etc and /proc for starters.

The file /proc/filesystems lists all file system types supported by the kernel, and on the Nokia 770 it contains among other things these lines:

ext3
ext2
nodev   ramfs
msdos
vfat
nodev   nfs

Most of the other file system types listed in the file are actually in use on the 770, but ext2, ext3 and nfs have no use on the tablet if compared to what Nokia says it will do.

A simple mount command confirms that they’re not used by the system.

I’m quite sure they’re not left them on the system by mistake, so Nokia must have something up the sleeve here, or at least have decided to keep these options open in the future.

9 Responses to “External storage on the Nokia 770”

  1. joelja Says:

    you generally need power on most usb perhiperals so probably you plug the 770 into a usb hub (once you’ve made/purchased) with the appropiate cable. then you can hang any usb perhiperal you want off that.

  2. froobler Says:

    Cyberguys at Amazon.com seems to have all possible USB adaptors. For example:
    search for: USB TOOL BOX, FLEXIBLE USB ADAPTER KIT
    or
    FLEXIBLE USB ADAPTER BF/MINI 5P M, WHITE

  3. Henrique Says:

    It pardons my ignorance and my english. But is possible to have access hard disks of other machines of the net wireless?

  4. Badger Says:

    Why not use this?

    http://richard.jones.name/g

    Would love to know if you couls get it working?

  5. Alexander Says:

    What about self-powered devices, like an iPod? I’ve got a Maxell dock for mine that has a standard USB type B connector on it — it came with a B->B connector.

    I’m slightly worried about frying something, however…

  6. Dieter Says:

    Here are links to buy USB adapter.
    Last two links one for less than 3$. But mailing costs could be 4 to 8 $. If sb needs cables, add your

    http://www.cablestogo.com/p
    http://www.cablestogo.com/c
    http://www.cablewholesale.c
    http://www.gocables.com/Mer

  7. arivero Says:

    Hmm… Can I fool the system into having swap via NFS?

  8. Joakim Mared Says:

    the mount command finishes instantly if you install and start rpc.portmap

    see http://vidar.gimp.org/n770/

    he overdoes a little bit. just download ftp://ftp.armedslack.org/ar…, extract rpc.portmap and run it.

  9. Joakim Mared Says:

    sorry, wrong url in the above post

    ftp://ftp.armedslack.org/ar

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