-
Chromium
After reading this post at “Linux Today” I decided to install the so expected Linux version of Chrome, the Google’s browser.
As I use Arch Linux, I haven’t expected to have a compiled version linked directly by the chromium’s website. Instead, I was hoping Arch’s developers already packaged it. And, with no big surprises, they did. Just to clarify a thing before continuing: Chromium is the open source projected behind Chrome (which is not opensource).
I’m not writing this post to repeat what’s already written there. So read it too. As opposed to his impression however, I’m running it without big problems: pages are rendered well formatted, without html or css problems. Sure, it’s not a browser to use everyday yet, but as a pre-alpha version it’s doing pretty good. Below, a picture with this post been written.
-
Saudade…
No final do ano passado meu amigo Fadinha Ricardo publicou um post em seu blog falando sobre saudade. Concordo com o sua afirmação. Como escrevi nos comentários daquele post, em 2004 foi feita uma sondagem a tradutores profissionais por uma empresa britânica e a palavra “saudade” do português foi eleita como uma das mais difíceis de se traduzir.
O bom porém da saudade é quando você mata ela. Que sensação boa!!
Resolvi tocar nesse assunto porque meu irmão veio me visitar. Nos últimos dois finais de semana pude estar com ele e dar uma passeada pela Itália. Tantos lugares, tantas emoções, tantas lembranças… enfim, nos divertimo à beça. A lista de lugares por onde passamos seria longa de mais pra contar, então vou deixar somente os nomes das cidades (os nomes que eu sei em português sem ficar procurando no google eu coloquei em português, caso contrário deixei em italiano):
Milão, Como, Turim e Monza no primeiro final de semana.
Eu e meu irmão... A cidade de Como lá em baixo
-
Playing with your cache
Another possible titles could be “how to really slow down your computer” or “why caches are so important in computer architectures”. I started playing with turning my cache on and off last week using Linux because there are some situations in which you have to know why a piece of software is not working as expected. A possible problem could be the well known cache trashing, in which the contents of the cache is thrown away very often. Turning it down may give an answer if this is really the problem since now even running very slowly this variable is eliminated.
For example in my stage we had some tests showing that in certain scenarios a quad-core machine is much slower than an equivalent single or dual core. Next post I’ll show how to play with your cores, activating and deactivating them, so you may create your own programs and test them against a 1, 2, 3,… cores machine.
Also I think it’s a good exercise to students of computer science/engineering who are enrolled in courses as “computer architectures” and “operating systems”. For those, two good books: “Modern Operating Systems” by Tanenbaum and “Computer Architecture: A Quantitative Approach” by Hennessy and Patterson.
-
Hello world – Again!
I’m back again!!
Soon I’ll post some news and explain why I’m changing home.
Update your RSSs as I’ll not update my past blog anymore. So, as the title says:
HELLO WORLD!!
-
Driver radio STLC2590
This is a re-post of a project I did. It’s still the same, no version upgrade. I’m putting it on this blog as I don’t update or track comments on the old one and people generally go there through google.
–First of all I’d like to thank ST Microeletronics for give us the opportunity to work on a Linux driver for their chip STLC2590. All the documentation needed to write it was given by them. Thanks also to Patrick Bellasi, our tutor, which has tough us so much in regard to Linux driver development, APIs of ST, tools used in this project etc. At last, I’d like to thank William Fornaciari, which indicated us to ST so we could do this project as part of the course “Laboratory of Operating Systems and Software Design” at Politecnico di Milano.
This is a driver intended to be used mainly on Embedded Systems and SoC. I’ve never heard about a common PC using this chip within multimedia cards. So, all the instructions and documentation were made in the scope of crosscompiling it for ARM processors.
Here I publish the code under the GPLv2 License. I remember all of you that may use this driver that it’s dependent on the I2C API of STLinux (thought this limitation can be removed with few lines of code, but it requires knownledge of the vanilla I2C API). Also, I recommend to use the kernel and tools (for crosscompiling) from Poky Linux.
Current version: 0.0.12
Description and features:
- Radio driver for chip STLC2520 using V4L2 API.
- Configure the chip through I2C.
- RDS stuff is implemented. You have to use an userspace utility to get it working: rdsd.
- Kernel Linux 2.6.20 and tools for crosscompiling from Poky Linux. Patches to kernel from STLinux that include the I2C API used.
- Tools used for debugging and testing: rdsd and rdsquery, fmtools.Still somethings to do:
- Remove the “exclusive_open” behavior (taken from V4L2) so more than one client at a time can connect to it (for example, one could control radio stations, volume, etc and the other the rds stuff, that it’d be the case of fmtools and rdsd working together).
- Review the sleep calls inside the code to render it faster and better.
- Review the need of locks on interrupt handlers of rds data.Download the source code and documentation (in italian, as a final report for my course): stlc2590-0.0.12.tar.bz2.
If you want to know more about the driver or its development, I really encourage you to:
1) Read the documentation (if you are Italian please translate it – documentation is also under GPLv2 and the .odt and image files are given);
2) Contact me (either through the comments space or by email)
3) Hire me to work with you
As an academic work I think it can also be useful for those which are learning Linux and Kernel Programming. If you want to learn more you should get this driver as example and also read books (at least some chapters) like Linux Device Drivers (available online) and Advanced Linux Programming.Enjoy it.