If you aren't interested in webcam drivers for Centos 4 then skip this blog entry and go to the next one, you have been warned.
This week we spent some time getting a webcam working on Linux. A camera that worked fine on Debian Etch using the the Linux kernel webcam driver called gspca wouldn't work on Centos 4.4 and by extention Redhat 4.4 because the kernel is too far behind the bleeding edge. Updating kernels from 2.6.9 to the 2.16.16 just seemed like too daunting a prospect. It turned out that when we compiled the latest driver version from Linux kernel webcams Driver SPCA / SPCA5xx there was only one unsatisfied dependency. A little more digging and we came up with the equivalent call in our kernel version. To assist those others who run into this problem I have copied the required change below.
// remap_pfn_range is not in the 2.6.9 kernel
// if (remap_pfn_range
// (vma, start, page >> PAGE_SHIFT, PAGE_SIZE, PAGE_SHARED)) {
// up(&spca50x->lock);
if (remap_page_range
(vma, start, page, PAGE_SIZE, PAGE_SHARED)) {
up(&spca50x->lock);
Thanks to all the hard working people who created this driver without much support from the camera or chipset manufacturers.
To assist those who may be typing their error message into a search engine I have included the error message text below.
/home/wayne/gspcav1-20070110/gspca_core.c: In function `spca5xx_mmap':
/home/wayne/gspcav1-20070110/gspca_core.c:2502: warning: implicit declaration of function `remap_pfn_range'
LD [M] /home/wayne/gspcav1-20070110/gspca.o
Building modules, stage 2.
MODPOST
*** Warning: "remap_pfn_range" [/home/wayne/gspcav1-20070110/gspca.ko] undefined!
On Tuesday night I try to write a blog entry in the 1 hour and 15 minutes I have while my youngest son is at Timberwolves. Timberwolves is the Baden Powell Scouting version of cubs. Baden Powell Scouting, at least our version, offers a traditional scouting alternative to Scouts Canada.
A few months ago I believe I promised you a poem of sorts. Poetry is not my normal form of expression but last fall when I was on a weekend camp with the Explorers I wrote down the following. I wrote the poem down on a piece of wet scrap paper that I had in my pocket that I first dried over the fire.
The Girl with the Sad Tired Eyes
The circumstances of our meeting have faded, time and place are forgotten, but I will never forget her sad, tired eyes.
As we chatted she told me she was tired because she couldn't sleep.
I wanted to ask her if whatever made her eyes so sad was what kept her awake but I didn't.
I wanted to ask her why her eyes were so sad but I didn't.
I wanted to hold her and comfort her until she fell asleep but I didn't.
Then I was awake, the dream done.
If we ever meet again I will ask why she has such sad, tired eyes.
We build walls to keep things in.
We build walls to keep people out.
Her eyes let me she through her walls.
Walls stop us unless we ask for entry.
I didn't knock, she didn't let me in.
Maudlin and trite? perhaps, but I leave the literary judgements to you. I think it came from being reminded by the end of the football season and the departure for Edmonton of one of the members of the Argonotes that I seem to constantly be saying goodbye to people. Every year the end of the football season means that the Argonotes that sprouted like mushrooms in the spring will disappear under the snow until next year. For any number of reasons some never come back. Goodbyes can be hard but not getting a chance to say goodbye can sometimes be harder. I think I'm just getting way too introspective in my old age. I think I missed my calling, if I was half my age I'd be playing guitar in an emo punk band. Now I know why the Yahoo spell checker want to replace the word blog with bog, I am sinking in the morass of my own, hmmmm, I can't use maudlin here since I already used it previously, moroseness. Now that alliteration, maudlin moroseness.
The picture at the top of this posting is from Secret Agent Sarah's flickr photostream
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What is with the Dell Optiplex 320? A little while ago I wrote about my experience getting Linux running on this machine. The other Optiplex 320 we got at the same time gives us Windows blue screen stop errors at least once a day. Why does Dell give you an express service code when all it does is get you to a guy who tells you that you shouldn't use it and instead join the long phone queue with everyone else? After waiting a very long time on hold and being walked through a troubleshooting procedure that had no hope of identifying a n intermittent problem like this we managed to convince the Dell support guys that we weren't going to swap hardware with our happily running Linux box and the best course of action would be for them to replace the three week old computer with another one. That reminds me, I was supposed to get some emails confirming the replacment and they haven't showed up yet. I wonder if that means that my replacement computer is lost in Dell Wonderland? I guess it's time for another trip through the looking glass.
I'm finally over my cold so maybe I'll write something longer later this weekend for my loyal readers. That reminds me that I bet get my Emusic downloads done before they run out.
I am returning to my previous blogging practice of mashing two disparate topics together in one posting.
I had a combined Christmas Party/Open House just before Christmas and the afternoon of the party my kids came to me to let me know that they had broken the light fixture in our mostly unfinished basement. It's the type of light fixture with the pull chain and string attached. I didn't have time to get a new one that afternoon so I dug an old one I thought worked out of my stash of junk and installed it. It worked for about 5 minutes before it stopped working. My Home Depot phobia has prevented me from replacing it until today. I just kept forgetting to buy a new one and there are no hardware stores located on my route to and from the office. In fact there are no hardware stores in the town of 160,000 I live in. I finally felt good enough this weekend to add it to my list of Saturday chores. I decided to consciously avoid the big box home improvement warehouses and instead head to the one surviving old fashioned hardware store in my neighbourhood. It's actually 6 kms. away but I was heading that direction anyways to buy some new memory at TigerDirect. When I reached the store and walked inside I was aghast, it wasn't the cluttered warren I remembered but it was positively barren. The older couple who had ran it for years also weren't there. The store was so empty of merchandise that I asked the woman in the store if they were closing and she said no. They might as well close, there isn't any reason to go there anymore.
The reason I was going to TigerDirect was because we noticed our Windows computer was running terribly slowly recently. It would be running Linux except that Apple still hasn't released a version of iTunes for Linux. We got the computer three years ago and so far other than replacing a fan it's performed quite well except for the inevitable byte rot that seems to affect all Windows installs. The longer you keep them the slower they get. When I decided to try to fix it up I realized that it only had 256Mb of memory installed. How can a computer that worked fine three years ago be such a slow pig today? A couple of Windows service packs, a bazillion security patches, and the ever present virus scanner have rendered it under sized and underpowered. Instead of reformatting it and starting with a fresh install I decided that I should first bring it up to the minimum memory requirement for Microsoft Vista 1Gbyte. Don't worry kids I don't expect I'll ever have a machine running Vista in this house. After adding the new memory, turning off a few items in the startup list things seem to be working much better. It just goes to show that the old computer max "You can never have too much memory" is still true.
After whining at Yahoo 360 for not having a spell checker they recently introduced one. Today I finally installed the latest version of Firefox, version 2.0, which has an integrated spell checker. Another good reason to use Firefox.
I really liked Dell computers until today when I tried to install Linux on a Dell Optiplex 320. After trying 3 different distributions I finally found a posting on Lshift.net where tonyg related his success with the newest version of Debian call etch. The install went smoothly after I entered install pci=nomsi on the boot line. That's the line that comes up when you first boot the install CD. The other thing you must do is to specify lilo as the boot loader instead of grub.
When my Apple guy Steve told me I'd become addicted to podcasts when I got my iPod I didn't believe him. My current favourite is Buzz Out Loud, CNET's podcast of indeterminate length, which actually runs about 30 minutes. It's a fun mix of tech news, rumours and banter. Wikipedia describes the three hosts as Tom Merritt "the segue king," Molly Wood, "queen of the rant," and Veronica Belmont, "the serious-comic relief." If you want to see the Buzz Out Loud crew they have a video report they did at the Snakes on a Plane premiere. If it wasn't for Buzz Out Loud I might not have heard about the One Laptop per Child project. The goal of this project is to create a $100 laptop that can be given to the world's poorest children in the most remote locations. It won't be running Vista.
My cold is still hanging on so that's it for now.