After my latest post about the exponential size of a potential Gentoo / Portage database of binaries (indexed by use flags, build dependencies, etc) I just came up with a fairly interesting idea.
Who else (who we all know and love) has as much (and likely far more) data to index? Obviously, Google ;-) Googles method of indexing data is using their distributed filesystem.
So why couldn't binaries based on Portage ebuilds be indexed in such a fashion. Well, since the volume of data, indexed by use flags, build dependencies, etc, would be so massive, it's unlikely that any single, community-driven server could host such data alone.
If the community was involved, though, it wouldn't be too far fetched to make the binary-distribution distributed filesystem available on Peer-to-Peer networks. The same hashing technique could be used for each of the various packages that's being built. Furthermore, as has been pointed out by others already, the environmental impact that Portage has is probably intriguing, considering that every package installed by the average user is compiled from source.
And let's be honest with each other - the bottom line in using software is using it, and not building it.
++ for P2P networking AND Gentoo :)
Update [ 2007-11-30 ]: I also mentioned this once on Daniel Robbins' blog - Funtoo
20071114
Error in glibc's select() function
While doing some programming for work, I discovered that the select() function provided by glibc does not accurately describe when data is ready to read from a socket.
The purpose of select() is to block on a file descriptor until data becomes ready, unless a specified relative timeout expires or an error occurs.
When data is ready, select will return a positive number corresponding to one of the sockets contained in one of the file-descriptor sets that were passed as parameters. If a timeout occurs, zero is returned. If an error occured, -1 is returned and errno is set appropriately.
I found that if select was called, a timeout occurred, then data became ready to read on the socket, if select was called one more time (after data has obviously arrived), then select fails to notice. That implies that glibc select() only checks for socket readiness whenever the kernel signals that the socket is ready, and not when it is initially called.
From the select(2) man page, there exists no such condition stating that the data must become available after select has been called and not before.
That's a major bug if I've ever heard of one. Hmm... it's too bad my project can't wait until the next release of glibc, when someone might have corrected this.
The purpose of select() is to block on a file descriptor until data becomes ready, unless a specified relative timeout expires or an error occurs.
When data is ready, select will return a positive number corresponding to one of the sockets contained in one of the file-descriptor sets that were passed as parameters. If a timeout occurs, zero is returned. If an error occured, -1 is returned and errno is set appropriately.
I found that if select was called, a timeout occurred, then data became ready to read on the socket, if select was called one more time (after data has obviously arrived), then select fails to notice. That implies that glibc select() only checks for socket readiness whenever the kernel signals that the socket is ready, and not when it is initially called.
From the select(2) man page, there exists no such condition stating that the data must become available after select has been called and not before.
That's a major bug if I've ever heard of one. Hmm... it's too bad my project can't wait until the next release of glibc, when someone might have corrected this.
Firefox Keyboard Shortcut for CloseOtherTabs
Do you ever find yourself surfing the net with several tabs open and suddenly experiencing an overwhelming urge to un-clutter your browser?
I certainly do. The most frustrating part about it all is that one is forced to select some tab, right-click, and then select 'Close Other Tabs'.
The Default keyboard shortcuts in the en-US version of Firefox are somewhat backward in my opinion. Practically every window manager has its own 'Close Window' shortcut key. In Windows it's Alt+F4, like it is in Gnome.
So why does Firefox need to duplicate a function that the window manager most certainly has? Firefox has its own built-in 'Close Window' shortcut which is 'Ctrl+Shift+w'. This key combination would be much better suited for 'Close Other Tabs'.
I hope that they at least make a Preferences section in Firefox 3.0 so that people can customize the shortcut keys.
20071103
Upgrading to Gnome 2.20 with Gentoo
Hi Everyone,
I thought I would post my experiences upgrading to Gnome-2.20 on my Gentoo box. In general, the upgrade was painless, but there were a few pitfalls that can be easily avoided.
This post was originally written on November 3rd, 2007, and most of the Gnome-2.20 packages were marked ~x86.
[ Update: 2007-11-16 ]
Note: After performing the initial upgrade, then performing an emerge --sync at a later date, some of the package versions may have disappeared. Since all packages in the above file use absolute package versions, another attempt to do an emerge -D --with-bdeps y '>=gnome-base/gnome-2.20' could result in slot-version collisions within emerge (see bug #199359).
Lastly, I'm not sure if this will be the case for everyone, but I had to re-emerge gok, notification-daemon, gnome-applets, and gnome-python-desktop because gnome-applets was emerged in improper order, pulling in a previous gnome library. You can verify this by running revdep-rebuild -pv before re-emerging these packages.
emerge -av1 gok notification-daemon gnome-applets gnome-python-desktop
Currently, I'm not using the binary ATI drivers (ati-drivers-8.42.3), but I'll test it out and see if there are any conflicts.
Unfortunately, I would also like to upgrade to >=xorg-x11-7.3 / >=xorg-server-1.4, but ATI's current drivers for x86 will not work with >=xorg-server-1.4. Since I'm only using the open source radeon driver at the moment, I'll give that a shot before I test out ati-drivers-8.42.3.
Happy Gnome-ing :)
I thought I would post my experiences upgrading to Gnome-2.20 on my Gentoo box. In general, the upgrade was painless, but there were a few pitfalls that can be easily avoided.
This post was originally written on November 3rd, 2007, and most of the Gnome-2.20 packages were marked ~x86.
- Add these entries to /etc/portage/package.keywords.
[ Updated: 2007-11-14 ]
[ Updated: 2007-11-16 ] - Due to bug #196621, you will need to edit your yelp use flags in /etc/portage/package.use
gnome-extra/yelp -debug - emerge -avD '>=gnome-2.20'
[ Update: 2007-11-16 ]
Note: After performing the initial upgrade, then performing an emerge --sync at a later date, some of the package versions may have disappeared. Since all packages in the above file use absolute package versions, another attempt to do an emerge -D --with-bdeps y '>=gnome-base/gnome-2.20' could result in slot-version collisions within emerge (see bug #199359).
Lastly, I'm not sure if this will be the case for everyone, but I had to re-emerge gok, notification-daemon, gnome-applets, and gnome-python-desktop because gnome-applets was emerged in improper order, pulling in a previous gnome library. You can verify this by running revdep-rebuild -pv before re-emerging these packages.
emerge -av1 gok notification-daemon gnome-applets gnome-python-desktop
Currently, I'm not using the binary ATI drivers (ati-drivers-8.42.3), but I'll test it out and see if there are any conflicts.
Unfortunately, I would also like to upgrade to >=xorg-x11-7.3 / >=xorg-server-1.4, but ATI's current drivers for x86 will not work with >=xorg-server-1.4. Since I'm only using the open source radeon driver at the moment, I'll give that a shot before I test out ati-drivers-8.42.3.
Happy Gnome-ing :)
20071030
Restore-Points in Gentoo Linux
Today I was very tempted to upgrade my Gnome desktop to version 2.20, which is in the Portage tree, but not yet marked stable. Then I thought to myself - remember what happened the last time you attempted something like this? I spent the entire day simply trying to figure out which packages to downgrade.
Gentoo's Portage package management system is excellent because of the fine-grained control provided to the administrator over which packages and which options (USE flags) are installed. Again, on the plus side, a local repository of binary packages can be created (with FEATURES=buildpkg) so that packages need only to be compiled from source at least once. I write 'at least once' is because a package will need to be recompiled whenever a version number changes (obviously) or whenever the USE flags are changed. None of us really like that, but it's a fact of life.
Now, taking a slightly deeper perspective into the concept of a local repository, there are a few different ways of organizing this. If you think of all of the variables involved with the instantaneous state of a portage-based system, ignoring overlays for now, the collection of all installed packages becomes a (lengthy) one-dimensional 'tuple' at any particular point in time.
Now, lets say that each binary package stores all of its dependency and USE flags when it is created. Then, theoretically, we could do a complete re-installation of all of the packages on a system with the binary packages alone.
In this repository, for the sake of sparing disk-space, we would likely just dump unique binary packages in a position that would be written down in a massive table. From the simplest perspective, we could simply duplicate the entire table (actually, a look up table) whenever a package or USE flag had changed.
That would probably end up being a horribly inefficient waste of space. But on the completely opposite end of the spectrum, if one was to account for each package, and create variable, off-shooting dimensions of each tuple element whenever a new version was introduced, or when a USE flag was changed,
When a USE flag is changed, then so do the dimensions of each of the elements in those tuples. In fact, what we would observe is a hyper-volume of data pointers where each element is of varying dimension and size. If one was to attempt to visualize this, it would look something like a fractal hyper-image, where the residuals of each change dieing off after some amount of forking.
The obvious trade-off is complexity versus storage space... although, think since this repository would only be storing tuples of locations on disk, then the storage space might not be so high. Although, the size of the hyper-volume would increase exponentially with each new package added. On the other hand, the 'fractal' approach would be much harder to navigate (there might be some way to organize it in a hashing system). I'm not sure if it would be faster or slower.
In any event, one would need to call a tuple out of this repository and then re-install the binary files. The recorded tuple would then be a restore point.
Gentoo's Portage package management system is excellent because of the fine-grained control provided to the administrator over which packages and which options (USE flags) are installed. Again, on the plus side, a local repository of binary packages can be created (with FEATURES=buildpkg) so that packages need only to be compiled from source at least once. I write 'at least once' is because a package will need to be recompiled whenever a version number changes (obviously) or whenever the USE flags are changed. None of us really like that, but it's a fact of life.
Now, taking a slightly deeper perspective into the concept of a local repository, there are a few different ways of organizing this. If you think of all of the variables involved with the instantaneous state of a portage-based system, ignoring overlays for now, the collection of all installed packages becomes a (lengthy) one-dimensional 'tuple' at any particular point in time.
Now, lets say that each binary package stores all of its dependency and USE flags when it is created. Then, theoretically, we could do a complete re-installation of all of the packages on a system with the binary packages alone.
In this repository, for the sake of sparing disk-space, we would likely just dump unique binary packages in a position that would be written down in a massive table. From the simplest perspective, we could simply duplicate the entire table (actually, a look up table) whenever a package or USE flag had changed.
That would probably end up being a horribly inefficient waste of space. But on the completely opposite end of the spectrum, if one was to account for each package, and create variable, off-shooting dimensions of each tuple element whenever a new version was introduced, or when a USE flag was changed,
When a USE flag is changed, then so do the dimensions of each of the elements in those tuples. In fact, what we would observe is a hyper-volume of data pointers where each element is of varying dimension and size. If one was to attempt to visualize this, it would look something like a fractal hyper-image, where the residuals of each change dieing off after some amount of forking.
The obvious trade-off is complexity versus storage space... although, think since this repository would only be storing tuples of locations on disk, then the storage space might not be so high. Although, the size of the hyper-volume would increase exponentially with each new package added. On the other hand, the 'fractal' approach would be much harder to navigate (there might be some way to organize it in a hashing system). I'm not sure if it would be faster or slower.
In any event, one would need to call a tuple out of this repository and then re-install the binary files. The recorded tuple would then be a restore point.
20071020
My Ideal Laptop
It's come to the point that I'm considering upgrading my laptop - but I haven't seen anything on the market that's ideal for me. If you know me personally, you would know that I have been a bit of an environmental nut since I was 10 years old, and that I am also an electrical engineer, embedded systems engineer, and completely obsessed with Linux. As such, I have some pretty interesting ideas of what the 'ideal laptop' would mean to me.
My ideal laptop would be one that is highly portable, environmentally friendly, and energy efficient but with a fair bit of number-crunching and graphics processing power. It should not be assembled or manufactured by poorly treated employees either. My final and least-likely-to-be-realized preference is that my ideal laptop would also be one that could be tracked if stolen[2]. It also goes without saying, that my ideal laptop would utilize hardware with open-source drivers so that one would not be stuck with any inferior, proprietary operating systems.
Throwing all of those ingredients into one pot makes for a fairly difficult main course. The question is, which company will possess the techno-culinary expertise to prepare the appetizers?
There has been much more debate and demand for environmentally friendly computing products than someone from an older generation would think[1]. However, many of the Y-Generation were brought up during the 80's when the environmental movements really began to boom and, therefore, have a much more intrinsic concern about environmental impacts.
On the other hand, the anti-theft system (ATS) is still a relatively new concept. I have personally taken it opon myself to design an personal area network (PAN) ATS for valuables such as electronics or cycles, but between my engineering job, my master's education, and now my baby on the way, I no longer have a plethora of free time for dreaming up gadgets and new designs.
If you can suggest a laptop that is currently on the market today that has similar specifications to those below, please let me know.
If you would like to see a company producing laptops with the specifications below, let your voice be heard & submit a comment.
Mechanical Specs:
If you have any suggestions of something that is currently on the market that closely matches these specifications, aside from the OLPC[4], please submit a comment.
Alternatively, if you would like to hire me as an engineer to design such a laptop please let me know.
[ Update: 20071118 ]
Here is some info from the IEEE regarding standards for greener consumer electronic devices.
List of Similar Laptops & Shortcomings
Dell Latitude D430:
If one navigates to the Dell site and selects the small business / notebook links, one would notice that there is a small image that says 'Windows XP Optional'. When the visitor proceeds to customize the notebook, Windows XP is, in fact, non-optional. Dell, take off whatever the price is of Windoze these days and offer an operating system free and / or Linux installation. Then I might consider buying this notebook.
Dell, I do very much respect the step forward by offering solid-state media instead of magnetic storage. Although the $1000 jack in price seems unfounded, especially when Transcend has such excellent deals on a solid state disk at the moment, like the ones here and here. At any rate, if I could purchase this notebook without Windows and without an internal optical drive, then it would be a done deal, and I would just buy the flash disk from Transcend.
Apple MacBook:
I really like the MacBook, although the case material is plastic and I've heard horrible things about the Nazi-esque factories where Apple assembles the iPods in China... of course that hasn't stopped thousands upon thousands of people from buying Apple products in the past. I bought my iPod used ;-)
The MacBook is good because it has a dual-core Intel chip running at 2GHz. The screen-size is also a modest 13", which makes for a very portable notebook computer. A few friends of mine have one of these babies, and I very rarely ever feel the machine get hot, and the fan is as quiet as a mouse. The MacBook has a very decent battery life and also has great power management.
Putting Gentoo Linux on a MacBook is also very possible, but can cause conflicts with the Mac OS X. What I would most likely do, is completely remove the Mac Hard disk, and add a Trancend SATA solid-state-disk of 32 GB in size instead. Then I would have the original Mac disk image available if I ever needed to use it and I could format the original magnetic SATA disk and use it externally. I think that I remember reading a rumor about Apple launching a product targeting at the Japanese market with an SDD and no optical drive. Hopefully that happens soon and they decide to expand to western markets as well.
Since I am attending a university in Germany, I would receive a 10% discount at the Apple.de Educational Store. The student discount in Germany is even more of a deal than that in Canada, after considering taxes.
[1] Some articles about environmentally friendly computing, going as far back as 1998:
Toshiba Satellite 2510, Asus U5, Wal-Mart & Toshiba, OLPC, Consumer Demands
[2] I claim prior art to some of these device specifications going back for several years if a patent lawsuit ever arises.
[3] In full awareness of the current anti-DRM movement, I still feel that artists should be able to protect their works in an open, but still technologically secure manner. My position on DRM is that publically free media should still function on a system that is DRM-compatible, as should DRM-impaired media.
[4] I am in no way knocking the OLPC project, and feel that it's a pioneering endeavor that all manufacturers should strive to match, in terms of energy efficiency. The plastic casing, on the other hand, is a bit of a minus.
My ideal laptop would be one that is highly portable, environmentally friendly, and energy efficient but with a fair bit of number-crunching and graphics processing power. It should not be assembled or manufactured by poorly treated employees either. My final and least-likely-to-be-realized preference is that my ideal laptop would also be one that could be tracked if stolen[2]. It also goes without saying, that my ideal laptop would utilize hardware with open-source drivers so that one would not be stuck with any inferior, proprietary operating systems.
Throwing all of those ingredients into one pot makes for a fairly difficult main course. The question is, which company will possess the techno-culinary expertise to prepare the appetizers?
There has been much more debate and demand for environmentally friendly computing products than someone from an older generation would think[1]. However, many of the Y-Generation were brought up during the 80's when the environmental movements really began to boom and, therefore, have a much more intrinsic concern about environmental impacts.
On the other hand, the anti-theft system (ATS) is still a relatively new concept. I have personally taken it opon myself to design an personal area network (PAN) ATS for valuables such as electronics or cycles, but between my engineering job, my master's education, and now my baby on the way, I no longer have a plethora of free time for dreaming up gadgets and new designs.
If you can suggest a laptop that is currently on the market today that has similar specifications to those below, please let me know.
If you would like to see a company producing laptops with the specifications below, let your voice be heard & submit a comment.
Mechanical Specs:
- 12 or 13" Display, ACPI-compliant, with multi-level dimming capabilities
- Light-weight, aluminum chassis
- Very quiet, as quite as a MacBook
- Overall maximum weight of 3.5 lbs ( without AC adapter)
- Magnetic AC power connector
- Light-weight, biodegradeable, non-plastic casing.
- Dual-Core Processor ~ anywhere from 1 to 2 GHz (frequency stepping is a must)
- 1GB of DDR SDRAM, expandable to perhaps 4GB
- A graphics chip w/ 64 MB of dedicated DDR SDRAM
- 32 GB sold state disk (perhaps this one from Transcend)
- 802.11 a/g Wireless
- 2.1 Bluetooth
- 10/100 Mbit or Gigabit Ethernet
- 4 USB 2.0 connections, with 2 having power distribution capabilities
- s-video (or something similar) for input / output
- audio input / output connections
- Built-in microphone
- Built-in 2 mega pixel camera
- GPS receiver
- Full ACPI Compliance and sleep states for all devices
- Longer battery life ( please, no optical or magnetic drives )
- Biodegradeable, non-plastic casing ( corn-based ?)
- Lead-free chipsets ( possibly free of other toxins as well )
- AC power adapter with auto-off capabilities and magnetic connector
- Built-in RFID chip for easy component identification during recycling
- Built-in biometric sensor (BMS) for secure user authentication (i.e. thumb print)
- Built-in RFID chip, for anti-theft-system (ATS) / tracking
- Built-in GPS receiver, for ATS and user application
- Built-in GPRS data-only transceiver for ATS and user application
- Secure-bus lines (internal PCB layer, covered vias) for ATS, DRM[3], BMS
If you have any suggestions of something that is currently on the market that closely matches these specifications, aside from the OLPC[4], please submit a comment.
Alternatively, if you would like to hire me as an engineer to design such a laptop please let me know.
[ Update: 20071118 ]
Here is some info from the IEEE regarding standards for greener consumer electronic devices.
List of Similar Laptops & Shortcomings
Dell Latitude D430:
If one navigates to the Dell site and selects the small business / notebook links, one would notice that there is a small image that says 'Windows XP Optional'. When the visitor proceeds to customize the notebook, Windows XP is, in fact, non-optional. Dell, take off whatever the price is of Windoze these days and offer an operating system free and / or Linux installation. Then I might consider buying this notebook.
Dell, I do very much respect the step forward by offering solid-state media instead of magnetic storage. Although the $1000 jack in price seems unfounded, especially when Transcend has such excellent deals on a solid state disk at the moment, like the ones here and here. At any rate, if I could purchase this notebook without Windows and without an internal optical drive, then it would be a done deal, and I would just buy the flash disk from Transcend.
Apple MacBook:
I really like the MacBook, although the case material is plastic and I've heard horrible things about the Nazi-esque factories where Apple assembles the iPods in China... of course that hasn't stopped thousands upon thousands of people from buying Apple products in the past. I bought my iPod used ;-)
The MacBook is good because it has a dual-core Intel chip running at 2GHz. The screen-size is also a modest 13", which makes for a very portable notebook computer. A few friends of mine have one of these babies, and I very rarely ever feel the machine get hot, and the fan is as quiet as a mouse. The MacBook has a very decent battery life and also has great power management.
Putting Gentoo Linux on a MacBook is also very possible, but can cause conflicts with the Mac OS X. What I would most likely do, is completely remove the Mac Hard disk, and add a Trancend SATA solid-state-disk of 32 GB in size instead. Then I would have the original Mac disk image available if I ever needed to use it and I could format the original magnetic SATA disk and use it externally. I think that I remember reading a rumor about Apple launching a product targeting at the Japanese market with an SDD and no optical drive. Hopefully that happens soon and they decide to expand to western markets as well.
Since I am attending a university in Germany, I would receive a 10% discount at the Apple.de Educational Store. The student discount in Germany is even more of a deal than that in Canada, after considering taxes.
[1] Some articles about environmentally friendly computing, going as far back as 1998:
Toshiba Satellite 2510, Asus U5, Wal-Mart & Toshiba, OLPC, Consumer Demands
[2] I claim prior art to some of these device specifications going back for several years if a patent lawsuit ever arises.
[3] In full awareness of the current anti-DRM movement, I still feel that artists should be able to protect their works in an open, but still technologically secure manner. My position on DRM is that publically free media should still function on a system that is DRM-compatible, as should DRM-impaired media.
[4] I am in no way knocking the OLPC project, and feel that it's a pioneering endeavor that all manufacturers should strive to match, in terms of energy efficiency. The plastic casing, on the other hand, is a bit of a minus.
20070930
How? .. Who? .. What? ... Hippo
Hi everyone,
It's been a little while since I've written, so I thought I'd post something about this last month which has just come as an amazing and wonderful surprise.
In complete honesty, my very first reaction was that I was thrilled ... although Erin was under the impression that the world was going to end until I worked some more of my magic charm.
Actually, we're both incredibly excicted. Erin's mom was the first one in our respective families to hear, and then I told my dad, and then I told Jacob who is probably my closest friend that has already undergone the transition from 20-somthing-er to fatherhood.
Erin & I both put off telling one of our parents for some time - Erin her dad, and me, my mother - probably out of fear for being scolded. At least I don't have that fear as badly as a certain Jeff Murdock, and in case anyone didn't catch it, yes, I did steal the title of this post from Coupling.
In any event, my mom was completely ecstatic! I was so worried that she would make that wierd Marge Simpson noise when she disapproves of something politely, especially because Erin & I are not even engaged to be married. It's something we both want to put off for a while still, although we've been a pretty healthy couple for ... well... almost 5 years? It does not seem that long to tell you the truth, but I can't imagine spending the rest of my life with to anyone else.
Erin's dad was also really happy. We spoke only briefly over the thanksgiving weekend, but everything was well nevertheless.
In any event, I thought I'd change the tone of this blog for the better!! Not so much ranting about work ;-)
I still haven't told many of my friends, simply because I like the ability to pass on wicked news like this in person. Sometimes the surprise is ruined, especially if you have a Quinlan for a mother because they like to tell everyone on your behalf ( ahem, ahem ). So hopefully none of you guys in Toronto actually read my blog, LOL !!
Now I'm back in Kiel, and the next semester is starting for me. Again, it will be another first since I've made the transition from Informatik into Digital Communications, but I'm really looking forward to be studying engineering again. Some things just feel natural ;-)
This slightly changes the plan I have to take for finishing my master's degree. Ideally, I would like to be in Canada before the baby ( who we affectionately refer to as 'the chick pea') is born and for aproximately a year onward.
Ciao 4 Now
It's been a little while since I've written, so I thought I'd post something about this last month which has just come as an amazing and wonderful surprise.
I am going to be a dad !Yes, you have read the above sentence correctly ... but here it is again, just for clarification:
I am going to be a dad !It came as a complete surprise ( well not completely ) to Erin & I. She found out on the 1st of September as we were on our way back to Montreal from Toronto.
In complete honesty, my very first reaction was that I was thrilled ... although Erin was under the impression that the world was going to end until I worked some more of my magic charm.
Actually, we're both incredibly excicted. Erin's mom was the first one in our respective families to hear, and then I told my dad, and then I told Jacob who is probably my closest friend that has already undergone the transition from 20-somthing-er to fatherhood.
Erin & I both put off telling one of our parents for some time - Erin her dad, and me, my mother - probably out of fear for being scolded. At least I don't have that fear as badly as a certain Jeff Murdock, and in case anyone didn't catch it, yes, I did steal the title of this post from Coupling.
In any event, my mom was completely ecstatic! I was so worried that she would make that wierd Marge Simpson noise when she disapproves of something politely, especially because Erin & I are not even engaged to be married. It's something we both want to put off for a while still, although we've been a pretty healthy couple for ... well... almost 5 years? It does not seem that long to tell you the truth, but I can't imagine spending the rest of my life with to anyone else.
Erin's dad was also really happy. We spoke only briefly over the thanksgiving weekend, but everything was well nevertheless.
In any event, I thought I'd change the tone of this blog for the better!! Not so much ranting about work ;-)
I still haven't told many of my friends, simply because I like the ability to pass on wicked news like this in person. Sometimes the surprise is ruined, especially if you have a Quinlan for a mother because they like to tell everyone on your behalf ( ahem, ahem ). So hopefully none of you guys in Toronto actually read my blog, LOL !!
Now I'm back in Kiel, and the next semester is starting for me. Again, it will be another first since I've made the transition from Informatik into Digital Communications, but I'm really looking forward to be studying engineering again. Some things just feel natural ;-)
This slightly changes the plan I have to take for finishing my master's degree. Ideally, I would like to be in Canada before the baby ( who we affectionately refer to as 'the chick pea') is born and for aproximately a year onward.
Ciao 4 Now
20070808
Montréal: Hacking the Kernel
So I've been back in Canada for slightly longer than a week and I'm working full time for Visible Assets until the end of September.
I've decided to postpone my flight back to Hamburg until the end of September so that I can spend a bit more time with friends and also get a bit more done for work.
Right now, I'm sitting in Montréal at Erin's place. It's been nice to be back - actually, I think I'm suffering less culture shock in Montréal than I would be in Toronto. To tell you the truth, I think mon fronçais went straight down the garbage chute since October, as if German had totally displaced it in my brain. I really think that I'm going to have to work hard at it when I get back to Canada full time, and it would be nice to work towards some sort of bilingual certification or something.
A good friend of mine from the undergrad days, Ed Cote, is in Montréal at a conference presenting some of the work he's done at Queen's, in his master's program. He just finished this past semester (I'm jealous!). Today we're going to be meeting up for a 'cinque à sept', which basically means to have a few drinks at the end of the work day. I'm looking forward to getting out on a patio and having a couple of cold ones, especially in this heat!
For the next month and a half I will be porting much of the code that I've done in user space to kernel space - well, as much as possible, i suppose. Things that I won't be able to convert to kernel space are services and so on.
Particularly, one thing that I'm working on at the moment is a virtual block device that represents tracked / timed connections to the blaster device. What's particularly strange about this, is that I'm hijacking a serial device from within kernel space, albeit with a removeable module.
So far, it's going pretty well and I even have my module initializing the uart, but I've encountered a couple of segfaults. Luckily, I'm testing all of this using Qemu ;-)
Update (2007-08-09): I've managed to fix all segfault issues with serial hijacking by exporting a function init_tty_dev, which is just a wrapper for init_dev, in drivers/char/tty_io.c . Now the uart_driver->tty_driver->tty_struct array will contain a non-NULL pointer to a tty_struct which init_dev initializes. This must always be released with release_tty_dev( struct tty_struct * tty, int idx ) when the module unloads in order to return the refcount.
I've decided to postpone my flight back to Hamburg until the end of September so that I can spend a bit more time with friends and also get a bit more done for work.
Right now, I'm sitting in Montréal at Erin's place. It's been nice to be back - actually, I think I'm suffering less culture shock in Montréal than I would be in Toronto. To tell you the truth, I think mon fronçais went straight down the garbage chute since October, as if German had totally displaced it in my brain. I really think that I'm going to have to work hard at it when I get back to Canada full time, and it would be nice to work towards some sort of bilingual certification or something.
A good friend of mine from the undergrad days, Ed Cote, is in Montréal at a conference presenting some of the work he's done at Queen's, in his master's program. He just finished this past semester (I'm jealous!). Today we're going to be meeting up for a 'cinque à sept', which basically means to have a few drinks at the end of the work day. I'm looking forward to getting out on a patio and having a couple of cold ones, especially in this heat!
For the next month and a half I will be porting much of the code that I've done in user space to kernel space - well, as much as possible, i suppose. Things that I won't be able to convert to kernel space are services and so on.
Particularly, one thing that I'm working on at the moment is a virtual block device that represents tracked / timed connections to the blaster device. What's particularly strange about this, is that I'm hijacking a serial device from within kernel space, albeit with a removeable module.
So far, it's going pretty well and I even have my module initializing the uart, but I've encountered a couple of segfaults. Luckily, I'm testing all of this using Qemu ;-)
Update (2007-08-09): I've managed to fix all segfault issues with serial hijacking by exporting a function init_tty_dev, which is just a wrapper for init_dev, in drivers/char/tty_io.c . Now the uart_driver->tty_driver->tty_struct array will contain a non-NULL pointer to a tty_struct which init_dev initializes. This must always be released with release_tty_dev( struct tty_struct * tty, int idx ) when the module unloads in order to return the refcount.
20070720
Done Exams!
I've finished my exams for the 2007 summer semester here in Kiel. Both of them went pretty well. The first was Computer Vision II: Stochastic and Topological Approaches to Image Processing, and the second one was Neuroinformatik. CVII went pretty well, although I was a bit pissed about the last question. Neuro went better actually, although I like CV a bit more. CVII is actually a fairly hard course, not as hard as CVI, but still.
I had a beer, as per tradition, as soon as I got out of the last exam, and then on the walk home, the air smelled fresher, the sun felt brighter, all of the music on my iPod seemed to fit perfectly with everything - a good sign ;-) Actually, having the ability to take time and walk home was a big change all by itself ;-) Usually I have no time what so ever, and am racing to catch the next bus too hand something in, or meet up with my study groups.
Now I can focus on my work a bit more, and get a couple of big projects out of the way. I'm excited to actually be able to concentrate on one 'job' for the summer, getting new toys to play with (i.e. embedded devices), and doing some electrical design / hacking too! I'm also planning on hacking a couple of open source apps like Banshee, iPodLinux, and writing more interesting code for my various embedded devices.
Finally, I can design some image processing hardware too, once I learn about the PCI bus and interface with the new TS-7800 boards ;-) Since I tore apart my old crappy 1.3 megapixel digital camera, I'm also hoping to put linux on it.
As of next semester I'm going to be registered in the M.Sc. in Digital Communications, which is taught in english, as opposed to Informatik, which is taught in german. That should lighten my load considerably, but also provide the same type of challenges that I'm used to in areas such as DSP, communication theory, analog & digital circuit design, and so on.
Digital Communications is an engineering program, which I like better. Not to say that I didn't like all of the experiences I had in Informatik - Professor Sommer's lectures are exactly what I was looking for by travelling halfway across the world, and I can't even put a price on some of the things I learned studying with him. The things that I have yet to develop will likely be some of the most advanced in my life.
I've also learned some very interesting things in CV, Neuro, Numerische Math., and yes, even Mathematical Logic!! Unfortunately, I have to give up my office, which is a bummer, but the change to Digital Communication will surely have plenty of benefits to make up for it ;-)
The best and most important part everything now, though, is enjoying the summer!!! I'm really looking forward to meeting up with all of my friends in Canada, seeing all of my family, and of course Erin too :) woohoo!
I had a beer, as per tradition, as soon as I got out of the last exam, and then on the walk home, the air smelled fresher, the sun felt brighter, all of the music on my iPod seemed to fit perfectly with everything - a good sign ;-) Actually, having the ability to take time and walk home was a big change all by itself ;-) Usually I have no time what so ever, and am racing to catch the next bus too hand something in, or meet up with my study groups.
I'm looking forward to coming home ____SO____ much!!!
Now I can focus on my work a bit more, and get a couple of big projects out of the way. I'm excited to actually be able to concentrate on one 'job' for the summer, getting new toys to play with (i.e. embedded devices), and doing some electrical design / hacking too! I'm also planning on hacking a couple of open source apps like Banshee, iPodLinux, and writing more interesting code for my various embedded devices.
Finally, I can design some image processing hardware too, once I learn about the PCI bus and interface with the new TS-7800 boards ;-) Since I tore apart my old crappy 1.3 megapixel digital camera, I'm also hoping to put linux on it.
As of next semester I'm going to be registered in the M.Sc. in Digital Communications, which is taught in english, as opposed to Informatik, which is taught in german. That should lighten my load considerably, but also provide the same type of challenges that I'm used to in areas such as DSP, communication theory, analog & digital circuit design, and so on.
Digital Communications is an engineering program, which I like better. Not to say that I didn't like all of the experiences I had in Informatik - Professor Sommer's lectures are exactly what I was looking for by travelling halfway across the world, and I can't even put a price on some of the things I learned studying with him. The things that I have yet to develop will likely be some of the most advanced in my life.
I've also learned some very interesting things in CV, Neuro, Numerische Math., and yes, even Mathematical Logic!! Unfortunately, I have to give up my office, which is a bummer, but the change to Digital Communication will surely have plenty of benefits to make up for it ;-)
The best and most important part everything now, though, is enjoying the summer!!! I'm really looking forward to meeting up with all of my friends in Canada, seeing all of my family, and of course Erin too :) woohoo!
20070612
RPM & YUM - and why they still suck
I used to use Redhat Linux quite a long time ago - maybe in 1996 - but I was soon after persuaded to switch to Slackware Linux. Why? Redhat's package management system, RPM, is a piece of crap.
What I used to hate about RPM a long, long, time ago:
Now though, I feel as though I can blame them. The complaints that I have, are still basically the same. After over 10 years, there has been no evolution with RPM aside from this lovely thing called yum which sorts out dependencies and retrieves files as necessary.
I'm currently packaging the sun jdk, naturally without source code so that i comply with Sun's BCL or whatever. When I built this RPM and tried to install it with RPM, i got an error saying:
After some amount of frustration and searching incoherent sites for documentation on .spec file creation (required for building RPM's) I found the following option, which I thought was like the heavens opening up. I now quote from http://www.rpm.org/max-rpm-snapshot/s1-rpm-depend-auto-depend.html, which seems to be as authoritative a site on .spec file creation as any.
After inserting this magical line into my .spec file, and packaging the file without any issues, even installing the rpm file, without any issues, yum still provides me with the fantastic error code above, even when the rpm itself says that it has no dependencies.
Go team!!
What I used to hate about RPM a long, long, time ago:
- "Dependency Hell", as it is so dearly termed by many Redhat users, is when one is unable to install a package because of the exponential number of dependency packages that are necessary. The simplest way to avoid this is with the "nodep" option, but then missing dependencies become horribly difficult to trace.
- The inability to optimize or select which dependencies (--configure options) will actually be present on your system. For example, --without-alsa / --with-oss . The simple answer is - support everything, except what Redhat doesn't want to, and make the dependency tree static. This could easily be worked around by compiling all of your own sources from scratch and populating your own RPM repository, but then that defeats the purpose of RPM in the first place, unless you're intending on releasing a new distro or creating a kickstart script so that the Redhat install CD would pull rpm's from a specific location.
Now though, I feel as though I can blame them. The complaints that I have, are still basically the same. After over 10 years, there has been no evolution with RPM aside from this lovely thing called yum which sorts out dependencies and retrieves files as necessary.
I'm currently packaging the sun jdk, naturally without source code so that i comply with Sun's BCL or whatever. When I built this RPM and tried to install it with RPM, i got an error saying:
Error: Missing Dependency: libodbc.so is needed by package jdk
Error: Missing Dependency: libodbcinst.so is needed by package jdk
After some amount of frustration and searching incoherent sites for documentation on .spec file creation (required for building RPM's) I found the following option, which I thought was like the heavens opening up. I now quote from http://www.rpm.org/max-rpm-snapshot/s1-rpm-depend-auto-depend.html, which seems to be as authoritative a site on .spec file creation as any.
The autoreqprov, autoreq, and autoprov Tags — Disable Automatic Dependency Processing
There may be times when RPM's automatic dependency processing is not desired. In these cases, the autoreqprov, autoreq, and autoprov tags may be used to disable it. This tag takes a yes/no or 0/1 value. For example, to disable automatic dependency processing, the following line may be used:
The autoreq and autoprov tags can be used to disable automatic processing of requirements or "provides" only, respectively.
Go team!!
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