Saturday, May 31, 2008

Jan~Apr/2008: Suwon, Korea




DTV World.

Sunday, October 28, 2007

Quote

While

Quite a while without kernel programming, just following... far away.

Friday, April 27, 2007

Clockevents patch made its way to the kernel(2.6.21-rc1)

Last week (as of 27 Feb 2007) the Clockevents patch made
its way to the kernel(2.6.21-rc1) and took along a modified
version of the kernel timertop. Click in the link of this
post title.

That is great.
The former dyntick implementation (that one mantained by
Con Colivas) was deprecated and was superseded by this new
one which was derived from the real time patch from Red Hat
and Timesys. Surprinsingly timertop was the only part that
remained. Afterwards they ended up removing timertop.c but
have kept a good acknowledge and inspiration note in the new
code, timer_stats.c, as you can see in the link above.

Thanks Ingo Molnar and Thomas Gleixner

Saturday, February 03, 2007

GnuWin32 - Porte dos utilitários GNU para Windows

Se você está passando por uma temporada em sistemas Windows e tem grande familiaridade, além de sentir falta, dos programas de linha de comando do mundo Linux/Unix, seus problemas acabaram.

Existe o porte de grande parcela desses programas disponíveis para Windows 32 bits (incluem-se ai os mais recentes e usados). A compilação é nativa, ou seja, não requer bibliotecas compartilhadas (dll) como as do Cygwin, o que os torna mais eficientes e menos dependentes de outros aplicativos. O compilador utilizado é o Mingw, que é um porte do gcc para o ambiente das janelas e os fontes são os do projeto GNU e possuem então a mesma licença dos compilados para *n[i,u]x.

Dentre os utilitátios disponíveis podemos citar:
-Fileutils (find, ls, cp, etc)
-Compactadores (zip, bzip2)
-Grep, patch, diff e muitos outros.

Cada grupo de utilitários vem com um auto-instalador e insere ícones e menus, além das conhecidas man pages - em formato pdf!

Depois de instalar é só abrir uma janela DOS e recuperar a produtividade perdida. Quem desenvolve programas vai poder usar os comandos diff e patch para backups incrementais e ganhar espaço em disco, se não usar um controlador de versão é claro.

Chega de digitar 'ls' e dar erro:

http://gnuwin32.sourceforge.net/packages.html

Tuesday, June 27, 2006

O ditador benevolente ataca de novo!

Fala ai Pessoal,

(Sorry not in english...)

Não sei se vcs estão acompanhando, na lista PM, mas caso não estejam, precisei postar isso para vcs se divertirem também ;-)

Linus Torvalds, insatisfeito com a impossibilidade de gerar saidas (traces) durante as últimas fases de suspend/resume e também pelo fato que sempre que testa STD ou STR (suspend to Disk ou RAM) em uma nova máquina eventualmente tem problemas, está intensamente ativo numa thread na lista PM copiando David Brownell e Pavel Machek.
Na maior parte da thread ele discute com Benjamim Harrenschimidt, que não conheço bem.

Eles ficam discutindo alguns pontos das rotinas suspend/resume e as pessoas não concordam muito com ele e ficam apenas respondendo inflando a discussão até um momento que o Linus decide partir para o Just-do-it e ELE mesmo cria um patch (24/06/2006) para começar a resolver o problema (que existe de fato), um tanto quanto decepcionado com os responsáveis por esta parte do driver core.

O mais engraçado é que após ele enviar o patch e após pouquíssimas modificações ele diz que já vai incluir no main-line se ninguém disser que DESTESTOU o patch. Esse patch não quebra a sequência de resume/suspend dos drivers mas estes podem se aprimorar com a nova sequência de funções, sendo um dos objetivos originar um suporte para se ter console por mais tempo permitindo melhor debug destes momentos difíceis do kernel além de uma estrutura um pouco mais consistente para STR/STD.

!

E assim evolui o Linux...

Thursday, June 22, 2006

After a Long Winter...

a post.

Greetings!
Very busy, challenging and disruptive period.
In the last three months I can say that life has turned up-side-down.
First act was the moving from Manaus back to São Paulo, after 5 years of Amazon and Informacts law experience. Very happy and meaningfull time, specially in the professional arena.
But time has come and a return to the home town turned out to be necessary for familiar reasons.
The new work in a company that develops and sells tracking systems for trucks and general transportation is pretty different and challenging as always is to enter new paths.
The first weeks here was passed at parents house while my wife and daughter kept going from São Paulo to Santa Cruz do Rio Pardo, the hometown of my wife, located about 350 Km from SP.
The Second act was the new apartment, at the Belem subdistrict of São Paulo. Pretty good, near the subway, very good state - it has been refurbished few time before we entered there. Its organization has been taking most of my time while not at work. More 2 weeks at most and I will be completely pleased with it ;-) .
The third act was the birth if my second daughter, Clara, at 8 of June. A single beauty! Photos soon.
Now the three women are in the countryside, where they have very good medical assistence - that kind of familiar doctor/medicines, very confortable to them - and to me either: whether by the security that they are felling or the idle time to clean up the apartment. They might be coming to SP in about 2 weeks and everything will be ready for them.
My plans are to resume some open source activities soon. But I don´t know when yet. Maybe look for something with emulators, mainly qemu since I don´t have access to any board now.
Cheers,
Daniel

Wednesday, March 01, 2006

USB on-the-go

Although still increasing in popularity for new devices, this USB specification is getting widely addopted, once its proposed capabilities are easing the usage of common USB devices as cameras and portable devices.
The big remark about the USB on-the-go is the ability of a device to act either as a (limited) host or a slave. It claims that you can connect your camera to your PC to download the result of your weekend and also send the photos straight to the printer. Where in the first case the device acts as a peripheral and in the second acts as a host.
The same new level of usability can be thought to your PDA or cell phone.

The on-the-go specification, OTG for short, supplements usb 2.0 spec. This means that it inherits its transfers speed: 480 Mbits/s, the so called High Speed. Don't get confused with the Low/Full Speed from 1.x spec which runs at 1.5 or 12 Mbits/s, repectively.

In the new terminology, the initial host is the A-device and the initial peripheral is the B-device. The initial configuration is determined by the extra-recently introduced ID pin, which is sampled to indicate the device's behavior as a host or peripheral, in that time of operation. This combinations of signals are accomplished by new form factor connectors, the the mini-{ab,a,b} receptacle, and the mini-a and mini-b connectors.

Finally, what about power requirements?
This issue, which can be a drawback of this specification, can be particularly annoying if you don't have the necessary tools in hand. Due to very limited constraints of portable systems, the suplied voltage in the USB bus (Vbus) has a limited electric current (8 mA against 500 mA from traditional USB) capacity so that it can not source hungry peripherals. In that case a powered hub can do the job. Furthermore, this new approach presents enhancements in power management, once detects that it is not transfering data, the devices can enter a sleep mode where power is reduced and conversely, leave this state with wake-up events.

Some useful links:

Mentor Graphics IP-core
http://www.mentor.com/products/ip/usb/usb20otg/

Everything USB
http://www.everythingusb.com/usbonthego/

USB site
http://www.usb.org/developers/onthego/

Alsa 2nd round

The alsa patches came to omap list discussions and we have now (1 week ago) some remarks to implement, being the most commented the coding style of some files and where-to-be-placed discussion of the codec files which seem condemned to stay in the sound/arm directory. Well it seems reasonably although makes the things hard to use platform devices resources to make things independent but we ought to make it work. Actually, Mika already sent me a working version with that required approach but we gave it up in favor of the current proposal. Well, now he is resurrecting it and the 2nd round will be sent soon.
Cheers.