Tulio Magno Quites Machado Filho

Reading the serial number of a POWER server from Linux

2020-02-02T19:34:36-03:00

From time to time, I have to identify which physical server I'm connected to. That usually involves reading the manufacturer serial number of the server. That information is provided to Linux by the device tree, which is exported via procfs at `/proc/device-tree/`. However, the file that hosts the serial number of your server may vary according to the virtualization mechanism in place, e.g. bare-metal and LPARs use the file `system-id`, while KVM guests use the file `host-serial`. With that said, we can read the serial number of our server with the following command: ```find /proc/device-tree/ -name host-serial -o -name system-id | xargs cat; echo```

Updated tutorial on Optimized libraries for Linux on Power

2018-12-01T23:55:30-02:00

A while ago, David Flaherty wrote a nice tutorial about writing optimized libraries for Linux on Power. As time passed, parts of the tutorial became obsolete and needed some love. Earlier in November [I completed this update](https://developer.ibm.com/tutorials/optimized-libraries-for-linux-on-power/) and removed all the obsolete parts, added new sections mentioning glibc's `getauxval()` and GCC's `__builtin_cpu_is()` and attribute ifunc.

Subscribe and unsubscribe from Google Groups without a Google account

2018-03-29T11:33:27-03:00

Many users still prefer to interact with mailing lists via email. I'm one of them. Some of the mailing lists I follow are maintained in Google Groups, which doesn't provide a good interface for subscription for people without a Google account. Anyway, it's *still* possible to subscribe to these groups if you replace `group-name` with the name of the group you'd like to subscribe to and visit: ```https://groups.google.com/forum/#!forum/group-name/join``` In order to unsubscribe, visit the following link after replacing `group-name` with the name of the group: ```https://groups.google.com/forum/#!forum/group-name/unsubscribe```

If it's not practical to redistribute free software, it's not free...

2015-11-20T21:39:24-02:00

If it's not practical to redistribute free software, it's not free software in practice.

[Matthew Garrett](https://mjg59.dreamwidth.org/38467.html)

If you don't have full source to your firmware you don't have a system...

2015-11-20T21:40:16-02:00

If you don't have full source to your firmware you don't have a system you can trust.

[Alan Cox](https://plus.google.com/+AlanCoxLinux/posts/9bCJPSdjT4t)

OpenSUSE 12.2

2016-01-30T21:54:06-02:00

[![OpenSUSE 12.2](https://countdown.opensuse.org/medium.en.png "OpenSUSE 12.2")](http://software.opensuse.org) We're less than a week for the release of OpenSUSE 12.2.

Don’t rely on the cloud. It’s great to have online storage you can...

2015-11-10T17:22:20-02:00

Don’t rely on the cloud. It’s great to have online storage you can get at from all your various devices, but when the shit goes down and your under attack, nothing is more secure than a hard drive you can unplug and hide in a shoebox in the closet. It’s not the most convenient way to back up, but you’ll thank yourself for it.

[Gizmodo UK](http://www.gizmodo.co.uk/2012/08/how-gizmodo-got-hacked-and-how-you-should-defend-yourself/)

How much do you depend on Google?

2015-11-10T15:49:40-02:00

Have you ever thought how much do you depend on Google? I've never thought, but I'm learning about it now.

It seems that Google is +almost+ down in Brazil right now and I don't know why, because the search is the most affected. I can't access my email or chat to someone else. The social network I've been using recently isn't working. But OK. I don't need to read my email everyday, right? Let's do something else.

Maybe I could watch some videos on YouTube. Wait... Let's try again...

The last week I was planning to learn a recipe, but I forgot about it. Great! Wait... The search is down.

OK. Let's read some news. At least I host my own RSS reader instead of using Google Reader. After reading some news I found a new word in English, but I couldn't look for its meaning. I read about an "interesting project(Projet Meshnet)":https://projectmeshnet.org/ that is planning to free the Internet, but I can't search for more information.

Obviously, I could use another search engine (and in fact I "did(DuckDuckGoog)":http://duckduckgoog.com/), but it's interesting to see how dependent we're on Google and The Cloud. And I can only conclude that freeing yourself from The Cloud is the best choice we have.

Ocimum gratissimum

2012-06-23T11:08:50-03:00

Ocimum gratissimum

Sky today in Campinas

2012-05-19T18:17:56-03:00

Sky today in Campinas

OpenStreetMap and Osmand map of Brazil

2015-11-10T17:25:55-02:00

![OpenStreetMap logo](/uploads/200px-Public-images-osm_logo.png) I have been contributing to [OpenStreetMap](http://www.openstreetmap.org/) recently and most of the times I use [Osmand](http://code.google.com/p/osmand) to view/navigate the maps. The maps in Campinas are still changing a lot, so it's necessary to update them frequently. ~~As the process to convert these maps requires a lot of RAM and cpu power, I'm sharing the result "here"~~. **Edit**: this isn't necessary anymore.

Touristic steam locomotive in Campinas

2012-05-19T18:19:35-03:00

Touristic steam locomotive in Campinas

OpenSUSE 12.1

2016-01-30T21:54:58-02:00

OpenSUSE 12.1 is going to be released November, 16th. Do not forget about that!

Analisando o efeito da MP dos tablets

2012-04-29T19:16:40-03:00

Ontem, o Senado aprovou a medida provisória 540 que, dentre outras coisas, torna os tablets isentos de Cofins e de contribuição ao PIS/PASEP, conforme os trechos do texto original:

Art. 28. Ficam reduzidas a 0 (zero) as alíquotas da Contribuição para o PIS/Pasep e da Cofins incidentes sobre a receita bruta de venda a varejo: ... VI - máquinas automáticas de processamento de dados, portáteis, sem teclado, que tenham uma unidade central de processamento com entrada e saída de dados por meio de uma tela sensível ao toque de área superior a 140 cm² e inferior a 600 cm², e que não possuam função de comando remoto (Tablet PC) classificadas na subposição 8471.41 da TIPI, produzidas no País conforme processo produtivo básico estabelecido pelo Poder Executivo.

Segundo a maioria das reportagens [1] [2] [3], isto pode representar uma queda de até 31% a 36% no valor final.

Sendo assim, proponho armazenar uma lista com os preços atuais dos tablets para análise posterior. Para simplificar o trabalho de pesquisa, utilizei o Buscapé e filtrei os resultados apenas por lojas com classificação ouro. Este filtro evita ~~a inserção de produtos sem imposto~~ possíveis variações de preços típicas do mercado brasileiro.

Tablet	Preço mínimo	Preço máximo
Acer Iconia Tab A500 16GB	R$1022,11	R$1399,00
Acer Iconia Tab A500 32GB	R$1439,10	R$1599,00
Motorola Xoom 32GB	R$1.347,19	R$1999,90
Semp Toshiba MP1003G	R$999,00	R$999,00
Semp Toshiba Thrive 32 GB	R$1521,00	R$1521,00
Samsung Galaxy Tab 16 GB	R$849,15	R$1749,00
Samsung Galaxy Tab 3G 16 GB	R$1149,00	R$1661,55
Asus Eee Pad Transformer TF101 16 GB	R$1107,29	R$1424,05
Apple iPad 2 16 GB	R$1326,31	R$2465,85

Dos modelos listados, apenas os da Samsung possuem tela de 7", enquanto o restante possui tela de 10". Apenas o iPad utiliza um sistema operacional diferente do Android. Entretanto, os tablets da Samsung e da Semp Toshiba são baseados na série 2.x do Android, que foi desenvolvida para celulares.

World IPv6 Day

2012-04-30T22:38:58-03:00

Today is the World IPv6 Day. According to the website, the goal of the day is "to motivate organizations across the industry to prepare their services for IPv6 to ensure a successful transition as IPv4 addresses run out."

Unfortunately, my Internet Service Provider does not support IPv6. Anyway, this website should work fine with IPv6 only connections.

If you want to test your connection, try http://test-ipv6.com.

Realtek RTL8111/8168B on OpenSUSE (2)

2012-04-29T19:19:08-03:00

On my last post I've presented the OpenSUSE Project Drivers:NIC.

But since than I've installed OpenSUSE 11.4 and configured it to use the OpenSUSE Tumbleweed repository with the 2.6.38 kernel that has a better support to the Realtek RTL8111/8168B ethernet card with the default r8169 module. I've been using this kernel (already on 2.6.38.2) for the last weeks and I haven't gotten those problems again.

Realtek RTL8111/8168B on OpenSUSE

2012-04-29T19:19:55-03:00

I've recently installed OpenSUSE 11.3 on a computer with a Realtek Ethernet controller recognized as Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03) by lspci. Although the network worked after the installation, it couldn't connect after a reboot. The only useful messages returned by dmesg were:

r8169 0000:06:00.0: eth0: unable to apply firmware patch
r8169 0000:06:00.0: eth0: link down
r8169 0000:06:00.0: eth0: link down

After googling for this I realized that the r8169 module was wrongly chosen and it was necessary to install the r8168 module provided by Realtek and not included in the Kernel. Just after concluding this I found the OpenSUSE Project Drivers:NIC that aims to provide drivers for network interface cards, including the r8168 that I needed.

Update: I have more information in a newer post.

Festa de lançamento do KDE SC 4.6

2012-04-29T12:08:11-03:00

Com a aproximação do lançamento da versão 4.6 do KDE SC, o KDE-MG está organizando um encontro.
Todos são muito bem vindos!

Maiores informações em: http://kde-mg.org/2011/01/20/festa-de-lancamento-do-kde-sc-4-6/

Moving around

2011-01-16T20:24:44-02:00

It has been a long time since I planned to move from Blogger. Blogger offers a simple service with the basic tools to start blogging. But as time passes by you realize that you need more tools to improve the blog or to simplify your work. Most of the tools you find surfing the web. Some are third party services and you start to distribute around your data. Images are stored in Picasa Web. Files can be stored in your Dropbox account. Static pages can be stored at Google Sites. When you have a small blog, that is ok. But when things start growing, controlling all this mess is difficult. Then I started thinking who was really the owner of the information: me or Blogger? If can't do what a want to, probably I'm not the owner. The migration to a new host proved this. Blogger offers you a way to export your data, but there isn't a way to redirect visitors to the new address. According to Blogger you just have to loose them... Some people offers a javascript redirection, but this won't work with search engines. The correct redirection should return an http 301. From now on, both my website and blog will be available at http://www.quites.com.br. Feed subscribers shouldn't have problems as FeedBurner will redirect you to the new feed. If you find a problem with the new site, please contact me.

Curso introdutório de git

2012-04-30T22:41:07-03:00

No último dia 13 de Novembro eu ministrei um curso introdutório sobre git durante a Semana da Computação da Faculdade Pitágoras-Betim. O curso fala um pouco sobre a origem do git e dos comandos básicos para usá-lo. Procurei também mostrar um pouco da diferença que existe entre os sistemas de controle de versões distribuídos e centralizados, já que acredito que esta a maior causa de dificuldades ao utilizá-lo. Como sempre, os arquivos estão disponíveis na página de artigos do meu site.