Install Xen Kernel on Ubuntu 9.04 Jaunty i386

I stole the kernel from debian’s pool.

sudo dpkg -i linux-modules-2.6.26-2-xen-686_2.6.26-15_i386.deb
sudo dpkg -i linux-image-2.6.26-2-xen-686_2.6.26-15_i386.deb

* It’s a good idea to look for newer version. I don’t know why we cannot search by the debian website. But you can use the FTP…

Compiling XEN Kernel on Ubuntu 9.04 32bit

I am compiling XEN Kernel on Ubuntu 9.04 32bit
GCC is 4.3.3 and some issues with new compiler’s optimization.

This is on-going memo… I have compiled the kernel but it seems not compatible with Ubuntu 9.04.
So, I switched the xen kernel version supported by debian team.




(1) undefined reference to `__udivdi3′
arch/x86/kernel/built-in.o: In function `timer_interrupt’:
/usr/src/linux- undefined reference to `__udivdi3′
make: *** [.tmp_vmlinux1] Error 1
root@ubunzzo:/usr/src/linux- vi /usr/src/linux-

My attempt after reading reference (2) was successful, I inserted the asm(“”:”+r”(delta)) to the timer_interrupt function at the while scope at line number around 500.

        /* System-wide jiffy work. */
        if (delta >= NS_PER_TICK) {
                do_div(delta, NS_PER_TICK);
                processed_system_time += delta * NS_PER_TICK;
                while (delta > HZ) {


                        delta -= HZ;

* This works because this asm fools gcc compiler not to use optimization.
I guess do_timer internally uses do_div macro?

I found the same kind of fix in linux kernel here

The AT&T assembly format still looks confusing…

Task Coach Weekly Effort Viewer

wev_screenshotI don’t usually write about my personal projects, but this project: Task Coach Weekly Effort Viewer is getting interesting and I am using it for couple weeks.
It’s made in Java Script, CSS and XHTML. It’s read-only at this moment and missing many features.

By the way, Task Coach is a simple open source todo manager to manage personal tasks and todo lists.

Here is why I started to develop this tool.
I have multiple clients, and need to keep track on how many minutes I spent for each client. So, I found Task Coach is very useful to do the job as Task Coach can keep track work hours as “efforts.”

Since the original authors claims Task Coach is at alpha stage in development. Some features are missing, especially visualization of efforts which I decided to make it by myself. I will update more on the project which everybody can make use of it at least with a simple sample data.

Coffee Grinder for Espresso: Baratza Maestro Plus

If you want to have a best cup of Espresso at home, you must have a coffee grinder for espresso.

We don’t want to use the pre-grounded coffee which processed over a months. You can grind it yourself just before you make a espresso.

Again, this grinder is not cheap but it does have a good fine control switch for espresso or anything like drip coffee.

Espresso Machine: La Pavoni Professional

I am a big fan of espresso, and was looking for a Espresso Machine to make one at home.

After researching on the web, I decided to buy this machine. It was almost 3 months ago, but I still love this machine!!

It’s expensive machine but you just count how many times you have to buy espresso everyday at your favorite coffee shop.
It is true as some reviewer comments that the initial learning curve is high to serve a good espresso but you will love this machine once you master it.

RSA Encryption + LZMA Compression

I developed a tool in C# to do RSA encryption way back, but I didn’t like the giant file size of encrypted data. The main cause is that RSA encryption takes just around max 80 bytes as input due to the limitation or Algorithm, so it almost always requires multiple blocks of encryption.

So, I’m planning to integrate the LZMA compression and RSA encryption. Once everything done, I will post a chart of file-compression ratio.

The candidate encoding Sequence will be: File Input -> LZMA -> RSA -> LZMA -> Base64 in XML format
* LZMA will be done twice because the RSA is not compression algorithm but it makes larger.

Anybody done the similar task?
I’m also interested in AES encryption.

Google Apps for own domain.

I have my own domain and have been paying $100/year for hosting services. I actually need the e-mail only…
So, I decided to cancel the hosting service and move everything to Google Apps.
I think Google Apps sounds confusing but it actually does e-mail hosting, and web hosting for free.

It’s not the same as legacy hosting service, but it does everything I want. I am thinking to dig into making my Google Apps soon.
I don’t really like the CMS for the website. I hope Google adds a option to use WordPress.

If you have your own domain and thinking about switching hosting services, why don’t you check the Google Apps.