Read out Canon EOS 7D shutter count on OS X

If you own a Digital single-lens reflex (DSLR) camera you might want to read out the shutter count. For my Canon EOS 7D this can be done very easily using gPhoto2. gPhoto2 is a free open-source tool which supports more than 1300 cameras. As it is written for Unix-like systems it can be compiled for OS X very easily. If you have Homebrew installed, you can install it easily via the terminal by running

brew install gphoto2

Homebrew will install some libraries and gphoto2. Now we can switch on the camera and connect it by USB. Continue reading

CHOST: i586 vs. i486 on AMD Geode LX

On my blog post about Installing Gentoo on ALIX.3D3 Mart Raudsepp made an interesting comment: He pointed out, that on AMD Geode CPUs it might be better to use i486 CHOST instead of my used i586, because the CPU is more like a i486 as far as instruction scheduling and times go.

This sounded interesting, so I googled for some benchmark test to measure differences. I found nbench, which measures performance by executing some typical algorithms and compares them to a Pentium 90 based system. So I installed it and run on the i586 CHOST system, then rebuild it completely to i486 CHOST and run it again. Continue reading

GPIO on ALIX.3D3

The AMD CS5536 Geode companion on the ALIX.3D3 board has several general purpose input/output pins. Most of them have different functions as well, and there are some registers to set if they should be used as special function GPIO pins. The ALIX.3D3 uses 4 GPIO pins for 3 LEDs and 1 mode switch. Accessing the leds is very easy using the leds-alix2 driver, but they can be addressed as GPIO as well. There is already a driver for the GPIO pins in the kernel named cs5535_gpio.c, but it uses a non standard interface to communicate with kernel. So, I wrote a new kernel driver using the GPIO interface. Continue reading