The AMD Geode LX800 CPU has an on-chip AES 128-bit crypto accelerations block and a true random number generator. Using this block for encryption and decryption is a lot faster than software implemented algorithms and it unloads the CPU. There are two main purposes where en/decryption is needed:
I'll focus on the first point in this article using LUKS (Linux Unified Key Setup).
A few days ago, while I was compiling some stuff on my ALIX.3D3, I discovered a very high CPU temperature by chance:
M/B Temp: +59 C (low = +0 C, high = +70 C) CPU Temp: +71.1 C (low = +0.0 C, high = +70.0 C) ALARM
Alix.3D3 with heat sink
I downloaded the datasheet of the AMD Geode LX800 CPU to check which temperatures are OK. On page 598 I found that my model (ALXD800EEXJ2VD) is fine for temperatures from 0 °C to 85 °C. Anyway I looked in my spare part box if I could find a suitable heat sink and fortunately I found a 40mm x 40mm x 9mm one. So I ordered some thermal adhesive and installed it.
Today I received my new Linksys Router. It's WRT610N with two wifi cards inside. One for traditional 2.4 GHz 802.11b/g/n and one for 5 GHz 802.11a/n. I'm planning to use OpenWRT or some other non standard firmware on it, so I wanted to add the RS232 console port I had on my old WRT54GS. Here's how to use it:
LEDs on ALIX.3D3
As most of the ALIX boards, the ALIX.3D3 has 3 general purpose LEDs. There is kernel support for them, but there are problems when the board has a Award BUIS as the ALIX.3D3. After reading the datasheet of the AMD CS5536 Geode companion about initialisation and use of the general purpose pins I got it finally running! Continue reading
J8: SMBus
The manual of the ALIX.3D3 board mentions a lot of pin descriptions of all pin headers on the board. J8 interfaces the SMBus of the AMD CS5536 Geode companion (which is compatible to I²C if bus speed is below 100kHz, see Maxim’s Appnote for detailed comparison). So why not add additional I²C sensors. As an example I connected an LM75 temperature sensor.
First of all we need to add some pin headers to J8 found on board next to the USB port. Continue reading