The Little Things

It has been a while since I’ve maintained my site. Shame on me! Here is a little rundown of a KDE install I did on my brand new Nokia N810. This little internet tablet is a fun hack, so fun I’ve had to reflash the thing like 4 times now. Either way, the big and scary part is doing the dual boot to allow the device to not only boot from internal flash but also to the intenal 2G memory card or an external Mini (not micro) SD card. I’ve taken some information from here , here, and here. Actually you can follow most of the first link but with some changes and explanations that I’ll note below.


The very first note is if you are reading what is supported in the initfs_flasher you will not see the very most recent version of OS2008. That doesn’t matter, it still works. Secondly,when you do get to the point of booting to another partition, just reboot and hold the menu button on the keyboard of the device in the lower left corner when asked to get the boot menu. Easy as that. Scary to do but I’ll let you sweat that whole process on your own like I did.

Remember to always unmount your memory cards from your computer when you are disconnecting the usb cable.

Here are a few examples of how you may want to setup your memory cards for dual booting. Note that the partition that you dual boot or clone images to for booting are always the second on the card. Not entirely certain why it has to be this way to be honest. I think that if you modify the boot menu file you can change this, but for now lets just go with the flow. Also, if you have read anything about this whole process you know that you will need root access to the device, and a few extra programs. Finally you should know that in my examples I used a few different locations than in the other tutorials simply because that is where I ended up putting things when I was floundering around with this entire procedure. I put tar, for example, into a bin directory in /home/user/ that I created (No apt-get install tar or you are going to cause all kinds of issues I guess!).

sudo gainroot
apt-get install e2fsprogs bzip2

For 2G internal card:
Note: The external card on N810 is always /media/mmc2 (/dev/mmcblk1) and the internal will always be /media/mmc1 (/dev/mmcblk0). You can change any of the commands around to suit your needs. I also found that using the fat32 partition worked, whereas the regular fat16 did not. So you will see some different formatting commands below.

umount /media/mmc2
sfdisk /dev/mmcblk0 -uM
/dev/mmcblk0p1:0,480,0C (this is a ~480 MB FAT32 partition)
/dev/mmcblk0p2:480,, (this is a ~1.5MB Linux_83 partition)
/dev/mmcblk0p3: <return> (no partition)
/dev/mmcblk0p4: <return> (no partition)

umount /media/mmc2
mkfs.vfat /dev/mmcblk0p1 -F 32
umount/media/mmc2
mke2fs /dev/mmcblk0p2
reboot

only insert the modules below if they are not already listed (use lsmod to see)

insmod /mnt/initfs/lib/modules/2.6.21-omap1/mbcache.ko
insmod /mnt/initfs/lib/modules/2.6.21-omap1/ext2.ko


mkdir /opt/
mount /dev/mmcblk0p2 /opt
mkdir /floppy/
mount -t jffs2 -o ro /dev/mtdblock4 /floppy


Explain: mount with type jffs2 (a flash based file system) as read only (-o ro) the running file system /dev/mtdblock4 to /floppy.

Make sure that tar is installed (not through apt!) to a different location such as /home/user/bin. Find a precompiled version for maemo then do the following:

8. Disconnect from the Internet, then

cd <directory where tar is at>
./tar cf - -C /floppy . | ./tar xvf - -C /opt

Explain: create a tar file from “-” which is stdin (which is /floppy our read only mounted currently running file system) and do not include the /floppy as part of the path “-C”. Pipe this output to tar to extract it to /opt

umount /opt
umount /floppy
reboot

Hold the menu button on the keyboard to get to the boot menu and select the second partition of the internal card (it will say that it is booting to mmcblk1p2!)

Change the background image so you will always know which one you are in.

manually reboot back into the image in flash, your desktop image should return to what it was before. Then plugin the usb cable to your pc to do a backup of your file system if you like.

After I plug it in I locate the file system that automounted with all the system files in it and unmount the rest. Then in a terminal I do a df -h to find out which one is currently mounted. In my case it was /dev/sdb2 so I ran:

sudo dd if=/dev/sdb2 | gzip > /home/caesar/Projects/N810/current.gz

Here dd is making an image of the first hard drive, and piping it through the gzip compression program. The compressed image is then placed in a file on a separate folder. Give it some time, you can check on the file being created in your windows manager if you like. When it is done it will look something like this in your output:

2949120+0 records in
2949120+0 records out
1509949440 bytes (1.5 GB) copied, 366.663 s, 4.1 MB/s

To reverse the process:

gzip -dc /home/caesar/Projects/N810/current.gz | dd of=/dev/sdb2

Now log back into your cloned image and start removing applications to make as much room as possible. I shaved mine down to almost the default install. Then plugin your usb connector to your pc and copy over the KDE358v2.tar.bz2 and SUPv2.tgz files to your EXTERNAL memory card. Then open xterm up again on the device and extract the files to the root file system

cd /
<path to where you put tar>/tar xjvf /media/mmc2/KDE358v2.tar.bz2
<path to where you put tar>/tar xzvf /media/mmc2/SUPv2.tgz


And you are then done, start up KDE from the Extras menu. Beware that the sound will be at full blast and start jamming some logon tune. Scared the crap out of me the first time!