Take a look at Mike Anderson and JTAGs. This is a really enlightening explanation of how to debug embedded linux devices w/ JTAG support, and it gives some great pointers for writing linux device drivers.
Mike Anderson is the Chief Scientist for The PTR Group, Inc. and really knows embedded linux devices. I didn’t get to attend the conference, actually I stumbled across this while working with the Linksys WRT54G-TM device.
The 54G-TM is a T-Mobile branded device, that apparently was (or maybe still is) sold by T-Mobile along w/ their WiFi capable phones. I guess the idea was that if you were within range of your 54G-TM, the call would run ala VOIP, otherwise it would use the actual cell network.
The device is great – the board layout has pads that male headers can be easily soldered onto. HairyDairyMaid includes schematics for a parallel port based JTAG cable, which can then be used to install DD-WRT, or whatever.
(If you look at the lower portion of the board you’ll see where JTAG headers are soldered)
As far as I can tell, using JTAG to directly write to flash is the only way to upload the firmware to the device. (TFTP and HTTP both fail). This 54G-TM also has a cpu fan soldered to the board and a heatsink installed on the CPU. (I didn’t do this myself, I actually bought this one that way. I have added headers to the other 4 I have, and flashing a 7.7M image of DD-WRT took 25423 seconds to complete on each device.)
Watch the video, it’s enlightening and Mike’s got a good sense of humor.
So, I’m in the process of moving – again.
I found it rather amusing the other day to see my current apartment listed on Craigslist as being “cozy”. A quick google search to define “cozy” returns an appropriate definition of “oversized dog house”.
Yeah, it’s small. Really small. So small that when I bought a small love-seat, it took forever to squeeze it through the entryway and up the flight of stairs to the ONE ROOM abode. And that room was basically the size of a large walk-in closet.
Ok, whine, whine, whine… what does this have to do with software or hardware projects? Well, getting the love-seat OUT of the apartment turned into a hard project. A REALLY HARD PROJECT. Here’s what happened:
I paid the guy that helped me move it in $40.00 to help me get it out. “If we got it in, we can get it out.” But after 45+ minutes of trying to get the P.O.S. back to the stairway, it became evident that this was a task that required some serious mathematics.
I’m not like John Nash in “A Beautiful Mind”. I’m more like Son in “Shotgun Stories”. (“I can divide up to 4 decimal spaces”.) So when the suggestion “Well, I’ve got a circular saw in the truck” came up, I knew we only had 1 solution.
And so now I’ve got to pay another $40.00 to have the carcass disposed of. (BTW, I love how it appears that Dylan is sadly walking thru some sort of furniture holocaust)
Being the nostalgic person I am, over the past 10 years I’ve accumulated a large number of old computers – everything from the Timex Sinclair 1000, TRS-80 COCO’s, and of course a Commodore 64 or 128…
The Commodore was interesting – I remember playing Exodus Ultima III, and BC’s Quest for Tires/Grogs revenge – and using this amazing “Turtle Graphics”(?) animation tool. Years before my last long-distance move, I got my hands on 5+ boxes of Commodore software from an old collector.
There’s a lot of stuff there, A LOT. A lot of games, but one of the more interesting items was the entire COMAL suite, with full documentation.
I’m using the past-tense because I found a new home for the C128 this weekend. I also offloaded an Amiga 2000. I’m tired of moving around and lugging all kinds of stuff I never use. So… anyone interested in a PowerMac 7215 running Yellow Dog Linux – it’s in need of a new home as well – AND SOON.
Long, long, long ago I worked in the realm of Tech Support…. take a look over at the links for “Toad Hall Ancient” (it’s a reference to the very first ISP, many, many years ago)
While I tend to think that most everything over there is old and outdated, the sad fact is that there are a number (4, maybe 5) of people out there still running Windows 2000, 98, or CP/M. The screenshot project (which isn’t my work, aside from a couple small additions), provides a good visual layout of these OS GUI’s.
Still have a Dialup modem? There’s init strings over there somewhere too.
I’m sure something over there is of interest to someone. Enjoy.