Jitu

I just read something interesting in the news and this is another reason to point out the importance of an open platform for mobiles such as openmoko. Someone who owned the G1, took this phone abroad. After coming back, he got a bill of around $100 for data roaming. Apparently the phone connects itself silently to the Internet once in a while. If you are in another country, the current provider will charge the transfered data plus the roaming tariff. Response of T-Mobile: “Leave your phone at home.” Nice solution…

APC, another magazine, also reported that, if G1 is operated with a SIM card of a local provider, it sends international SMS to an American number causing huge costs without any warning. Interesting how “user friendly” companies are in the need to generate money and to bug the customers. Which company had the motto “Don’t be evil!” again? Ah yes, Google, the identity collector.

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Finally I received the necessary Research Visa to become a PhD student at the Indian Institute of Science, Bangalore. It took almost 1.5 years at the cost of many nerves, telephone calls, office and department visits and highs and lows throughout the duration. In the end everything went very smoothly and fast. Especially if vitamin C (C for Connections) comes into the picture; such as: I know somebody, who knows somebody and his sister’s son could help in this issue.

Several times I was very close to pack everything up and just to leave this place. I already organized boxes for transferring the whole stuff back to Germany. However some of my friends (big thanks to them) managed to calm me down every time. It will definitely a new personal record my patience and persistence record.

I heard some complains from Indians regarding the delay of issuing an Indian passport. Sometimes it takes about 3 months. 3 months??!?!? Funny! This is not comparable it took for me just to get the Indian visa.

The moral of the story is: If you need something from the government, be persistent and patient. Do not forget to annoy them by frequent phone calls or to be at their door step personally quite often. Hope dies last!

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In 2.6.28 the next version of the ext3 file system became stable. In the Internet many guides are available how to upgrade from ext3 to ext4 without the need for reformatting such as the one on Kernelnewbies and Kev009.com. However the partition of which you want to upgrade the file system must be unmount which is some kind of hard, if you consider the root (/). Fortunately there are many LiveCDs from where you can boot from, without the need to mount the root file system.

Warning: Before you start, please make sure that you have the /boot directory on a partition with an ext2/3, xfs, minix, fat, jfs or reiser file system. So far grub is not able to boot from a ext4 system natively. You can change your partitions very easily with gparted.

So I downloaded the latest Ubuntu LiveCD and booted from there. To convert my root file system I simply followed one of the guides mentioned above and I will not repeat them here. This guide should give a hint what to do, if you are running on a home made kernel and you simply forgot to compile the ext4 file system or you compiled it as module and did not put it into the initrd (as it happened in my case). The kernel module for ext4 resided happily on the root partition which was, well, not accessible with my kernel anymore. So how to load a module that is needed to read the file system, if the module is stored on the file system itself? The famous hen or egg problem…

After conversion of the file system I ran into a kernel panic, because of the unknown file system of root. Unfortunately the root was not accessible from Ubuntu either. Here are the steps I performed to get the system back running:

1. Boot the LiveCD of Ubuntu. Change the sources.list in /etc/apt/ to download and install the package kernel-package. Also download the kernel sources from http://www.kernel.org/. Ensure that the kernel version is exactly the same like the one which causes the kernel panic due to the missing ext4 module.
2. Copy the config-file from /boot (which should be accessible, if you followed the warning above) and use this file to configure the kernel. Otherwise you have to recreate a working configuration.
3. Select to compile ext4 into your kernel (not as module) and built your kernel (I usually prefer make-kpkg kernel-image --append-to-version -X where X is exactly the same number as the kernel which does not boot.
4. Install the kernel (with dpkg -i). Since we are currently running on a LiveCD system, all changes are stored in RAM only and are lost by the next boot. Therefore make a backup copy of the kernel of your /boot partition and simply copy the files of the newly compiled kernel into it (vmlinuz, System.map etc) it is also wise to store the downloaded kernel source on a pen drive or similar, so that in case it does not work, you have the source available immediately).
5. Try to reboot. Since the compiler and the kernel version were exactly the same in my case, I could boot the kernel and had gained access to the file system again. There might be a chance that some modules could not be loaded (maybe due to different compiler versions). Anyway who cares, if you have access to the root partition again and are able to compile the kernel with your own compiler included all modules again?

The description might be somehow a rude way, but it worked for me and it was considered to be a temporary solution anyway which just needed to work for 30 minutes or so. My computer has 2GB RAM which was way sufficient to perform the steps above. I am not aware about the minimum requirements, but if you know an easier way, please let me know. That is the advantage of using Linux: Many ways lead to the same goal.

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