Humboldt Solutions Ltd » embedded

Running Linux on a PCI Add-in Card: Hardware

Adrian Cox — Fri, 28 Apr 2006 10:54:00 +0000

Every so often I see someone attempting to run the Linux kernel on a PCI add-in card. I’ve done this myself, but there are a lot of complications. This article covers the hardware, and a second article will cover software. Don’t take this as chipset selection advice: before you commit to hardware double-check both the errata [...]

SSL Handshake Overhead for Mobile Devices

Adrian Cox — Fri, 03 Mar 2006 11:05:00 +0000

If you’re designing an application where devices communicate with a server over a mobile network, there are trade-offs between implementation effort and data transfer. This may not apply to a consumer application, where the application developer doesn’t have to pay the data charges. But if the application is M2M these trade-offs matter.

First, I assume that you [...]

In the Year 2038

Adrian Cox — Wed, 15 Feb 2006 21:29:00 +0000

I have now seen my first ever year 2038 bug. An embedded Linux system that was installed two years ago became unable to acquire a network address by DHCP. The machine did not require an accurate clock, and nobody had initialised its battery-backed real-time clock. Once installed, it had started counting forward from 1st January [...]

Vorbis on DM642

Adrian Cox — Thu, 09 Feb 2006 18:59:00 +0000

Theora video on the DM642 may not be entirely successful, but Vorbis audio is a different story. I’ve been experimenting with the Tremor integer-only implementation of Vorbis decoding.

Tremor offers two modes of operation. Normal mode, and low precision mode. Normal mode requires 64-bit intermediate results in arithmetic operations, whereas low precision mode only requires 32-bit intermediates. [...]

Embedded Theora Video

Adrian Cox — Tue, 07 Feb 2006 13:59:00 +0000

Last year I did some experiments with the Theora video decoder on a Texas Instruments DM642 DSP. A royalty free video decoder is very attractive for embedded devices, but after some major restructuring for performance, some problems remained.

The main problem is that, unlike MPEG video, Theora video is not packed in the bitstream in the raster [...]