The notification system in the newly released ubuntu 9.04 ( Jaunty) uses the notify-osd framework. This system provides a standard way of doing passive pop up notification on the desktop.The notifications are semi transparent click through bubbles. These pop ups will disappear after a short period of time. Some times these bubbles can be irritating.
You can disable the notifications with the following command.
Installing LTSP and enabling thin clients to boot from your ubuntu 9.04 machine is very easy.
I did the following steps.
a) Install ubuntu 9.04 ( aka Jaunty) desktop with a static IP. ( A static IP is needed as your ubuntu box is going to act as a server. My IP is 192.168.0.1). Set up Internet access on this machine. You need to download a lot of packages from the net to complete the installation.
b) Install the packages ltsp-server-standalone and openssh-server
c) Build the LTSP client environment.
This command will download all the necessary packages from Internet and build your environment.
Have a look at /opt/ltsp/i386. This directory will now contain the chroot environment for the thin clients. If you want to tweak any settings you cna do it here.
d) Edit the /etc/ltsp/dhcpd.conf to suit your network setting. This file will serve the ip range 192.168.0.20 192.168.0.250 by default. If your network uses this range you can leave it as it is. (The default file worked for me as my server IP is 192.168.0.1)
e) Run the following commands.
The first command above will export the ssh keys of the server to the ltsp client environment. The ltsp-update-image command will rebuild a squashfs image from the ltsp chroot environment and place it under /opt/ltsp/images directory. This image will be exported to the thin client as root file system by the NBD daemon on the server.
Your LTSP server is ready. Try booting form a client via pxe or etherboot. You can also try to boot the thin client in qemulator.
There is a sample script for this in /usr/share/doc/ltsp-server/examples/ named qemu-ltsp.
Note: If you change any thing under /opt/ltsp/i386 , you must rebuild the image for the change to be reflected on the client. Also, if you change the IP address of the server you must do an ltsp-update-sshkeys followed by ltsp-update-image.
Today I was playing with ubuntu 9.04 . I tried to install wwwoffle the off-line proxy server. At the end of installation it failed with a ” Sub process /usr/bin/dpkg failed ” message. There was some thing wrong. Fixing the system required removal of the package. I tried the following in succession in vain.
# apt-get remove wwwoffle
#dpkg -P wwwoffle
#dpkg –force-all -r wwwoffle
I was stuck. I did a manual removal of the deb package like this.
a) List out all the file of the deb package.
# dpkg -L wwwoffle
b) Removed all the files from the above list by hand. If you are smart enough you can write a script for that.
A USB boot disk is a cool idea. It allows you to carry your favorite operating system in your pocket. Since all modern PC provide USB boot from BIOS , you can use any computer and work on your on desktop. It is also possible to make data persistent. With ubuntu 9.04 Jaunty Jackalope it is very easy to make an install disk. Here is how you can do it.
Get hold of a USB disk which is large enough to hold ubuntu and your data. I used a 2 GB Jetflash disk. First, I partitioned it into two using gparted. Both were formatted to fat32 file system. See the figure below. ( You can also choose to install on a single partition).
Next click on System-> Admininstration -Create USB statrup disk. See the Screenshot below.
This will start the aplication unetbootin as shown below.
Click on other button and select the jaunty desktop iso image and then select the USB partition you want to install Ubuntu.
If you want to keep data persistent across reboots you can check that option and select the size for data block. Unetbootin will create a single file named casper-rw on the flash drive and your home directory will be mounted in that file. It is a good idea to keep data persistent as you can walk into any Internet cafe and work with your data.
Click on Make startup disk and wait for some time, your USB boot/install disk is ready.
As a part of laboratory experiments for an embedded system course being held at Model finishing School Trivandrum, 2 nos . of mini2440 arm development kits have been purchased by the them from e bay . One of the kits is presently with me . My task is to learn it and teach embedded Linux ( or what ever I learn 😀 ) to the participants of the above course. I have been playing around it for the past two days and it looks very interesting. See the pictures.
The specifications of the board looks like this.
* Processor — Samsung S3C2440 (ARM920T core) clocked at up to 533MHz
* Memory — 64MB SDRAM (up to 100MHz)
* Flash — 64MB NAND flash; 2MB NOR flash
* Flash expansion — 1 x SD card interface
* Display — LCD controller with four-wire resistive touchscreen interface; optional 3.5- or 7-inch LCD displays
* USB — 1 x USB Host; 1 x USB Slave (B-type interface)
* Serial — 3 x serial ports
* Audio — 1 x stereo audio output interface; 1 x mic interface
* Camera — 1 x 20-pin (2.0mm space) camera interface; optional CMOS or USB cameras
* Other I/O:
o 1 x 10-pin (2.0mm space) JTAG interface
o 4 x user LEDs
o 6 x user buttons
o 1 x PWM control buzzer
o 1 x adjustable resistance, for AD conversion test
o 1 x I2C bus AT24C08 chip, for I2C bus test
o 1 x 34-pin 2.0mm GPIO interface
o 1 x 40-pin 2.0mm system bus interface
* Power — RTC battery; power supply interface
* Clock — internal real-time clock and 12Mhz passive crystal system clock source
* Dimensions — 3.9 x 3.9 inches (100 x 100mm)
* Operating system — Linux 2.6.13;
The board comes with a 4 inch detachable LCD screen. The cost of the board is around $ 89 plus shipping and customs duty. The end price was around Rs 7500 in India. The kit is preloaded with Linux and the accompaining DVD has all the tools needed for development. The board can also run windows CE,
I have not yet done any serious stuff with the kit. The user interface is based on qtopia, and it provides basic GUI features.
There is handwriting recognition software and an on screen keyboard for data entry.
There are various applications for common tasks. I was able to browse Internet and access the embedded web server on the board.
I plan to rebuild the system and try to make it boot from a usb stick or SD card. Let me see how much I can hack on this. Stay tuned for furthur updates.