Technical goals for this weekend May 20, 2006
Posted by spanky in Linux, programming.add a comment
Well, since I seem to have basically failed to meet every other goal I set for myself in the previous post, I'm going to make more short term ones for the time being. For starters, I'm going to set up SSH tunneling through https by the end of the weekend. It shouldn't take too long, and I think I've found a better way that doesn't involve running a full-blown apache proxy.
Technical goals to meet by the end of April March 30, 2006
Posted by spanky in Linux, carpc, programming.add a comment
- Have some kind of definite software solution for the CarPC system. As it is, I'm bouncing between distros trying to balance boot time/bloat with functionality. amaroK looks like it's going to be the backbone of the music-playing site since it has great plugins, supports ratings, and will sync with a music player/ipod with probably not too much fuss.
- Make a honeypot and look at some attack profiles the script kiddies generally use. Hopefully get a good idea of a rootkitter's MO
- Make and maintain a Linux distro (more on this later; it's contingent on progress in a project I have no control over)
Webcam Woes February 18, 2006
Posted by spanky in Linux.add a comment
I own a Logitech Quickcam Express I got for free with some promotion, and I’ve been trying to get it working with Kubuntu on my Powerbook to no avail. There’s a quickcam kernel module, which requires video4linux support, which I loaded. The problem may actually be USB-related, though I’m not sure yet. I spent an hour or two messing with it. When I tried this on my old and busted Gentoo box, it loaded up the modules, and worked right off the bat, so I’m not sure what’s going on. More later if I end up fixing it.
Optimizing Linux boot times and other kernel tuning February 5, 2006
Posted by spanky in Linux, carpc.add a comment
So as part of my CarPC project, I’m putting together a build of Linux that is very light and very fast. I didn’t start out with any particular distro or set of tools in mind. The hardware is one of the main project constraints, in this case a Duron 700 with a Riva128 (Thanks, Jon!) and a meager 128 MB of old and busted system memory.
I tried Damn Small Linux, which is a Knoppix-derived LiveCD build. It booted in about ~60 seconds from power on to X/fluxbox session accepting user input. It’s very fast, even on this system, but had a lot of quirks, and had all the disadvantages of a binary-only distro as well. Installing odd software and tweaking it is critical to my application, so this wasn’t really the direction in which I wanted to go.
Given that DSL wasn’t for me, there are two ways I could have gone. I’ve heard of people getting very fast boot times with Linux From Scratch, but that would involve building an entire distro from scratch, and having to probably install packages and such all by hand. It’d have all the advantages of a bottom-up approach, but may or may not be worth it in the end.
The second solution, which is what I’m trying now, is to do a top-down approach: install a bare Gentoo system, and pare it down to exactly what I need, and nothing more. I’m very familiar with the Gentoo install process (it still took forever, though), and yesterday I put together a working system. It went from power on to a terminal login prompt in about 45 seconds. I’ve made a lot of changes since then, the kernel is getting smaller at each recompile as I zero in on exactly what I need. Things I’ve used to help my boot time:
- Everything I need and only what I need are compiled directly into the kernel. No modules, I eliminated those module autodetect scripts from startup, and so forth. Definitely saves a few steps and at least 7 seconds.
- I noticed an inexplicable delay between the last init script starting and getting a login prompt. It’s gone away, what I *think* fixed it was changing an option in /etc/conf.d/rc that says whether or not Linux should save /dev to a tarball on shutdown and restore it on startup.
- I spent a bit of time trying to figure out why nvidia’s X drivers for the Riva128 weren’t working. I found a bit on some forums about their latest Linux driver breaking compatibility with their older cards, and that downgrading might help, but it’s really a moot point. X.org takes a decent amount of time to start up, and Xvesa takes about 1 second.
- There’s an option in /etc/conf.d/rc that allows some parallelization of bootup, but I don’t think it makes that much of a difference for a single-processor system (at least it doesn’t for me), but YMMV
Some links I found that I’ll be checking up on:
IBM Article on faster boot times
This is really sweet : Bootchart tells you where your system is spending time in the boot process. If it comes down to it, I’ll use this, though it may not be necessary.
Current boot: 25 seconds
Internet connection sharing on Linux (IP Masquerading on a Powerbook) February 2, 2006
Posted by spanky in Linux, apple.add a comment
So I left my PCI wireless card with Linux drivers at school, my wireless router is next to the TV and not a great place to setup a Linux box, and I want to install packages onto a Linux box I’m setting up. I recently put Linux on my Powerbook, so what is commonly termed “Internet Connection Sharing” is no longer as easy as it used to be, and is bound to be a pain in the ass.
Or is it?
To clarify, what I wanted to do was share my Powerbook’s wireless connection over its Ethernet port. There are quite a few good tutorials on setting up IP masquerading, but the only one I needed was here. I copied and pasted that script into init.d, made it executable, and ran it on the Powerbook. It checks for and loads modules that I’m sure are running already, changes some network settings, and then sets up the forwarding rules in iptables. Note that I had to change 2 lines in the script, since my external interface was eth1 (wireless) and my internal interface was eth0 (wired Ethernet). I ran that, set the IP address on the host Powerbook to 192.168.2.1, set the IP address on the client system to 192.168.2.2 (both via ifconfig) and then “sudo route add default 192.168.2.1″ to the client system, and done. Pings, DNS, it was all taken care of.
Installing Linux on a Powerbook G4 January 13, 2006
Posted by spanky in Linux, apple.5 comments
Since the Airport Extreme drivers have been reverse engineered, I thought now would be the perfect time to finally install Linux on the ol’ PB. The popular distro of late is Ubuntu (Ubuntu is an ancient African word meaning “I’m sick of waiting for Gentoo to finish compiling,” as the joke goes), so I thought I’d give it a try. Nothing against Gentoo, which is still my distro of choice for the desktop. Gentoo of course is named after a fast swimming species of penguin that preys primarily on small krill and n00bs who use binary-only distros. Since I’ve always been more fond of KDE than GNOME just as a matter of preference, I chose the Kubuntu flavor. Dapper Drake is the latest version of the distro, and it’s still in testing, but it had the kernel version and modules I needed (bleeding edge packages don’t hurt, either ^_^) The timing turned out to be fortuitous, since Dapper Drake release candidate 2 was just released to the public, so I grabbed myself a copy.
The install itself is far and away the least painful Linux install I have ever seen or heard of. I put the CD in, it detected things and went into a setup program, and presented me with some basic choices like language and keyboard setup. The partition setup screen had several options, one being a “suggested” partition table, one being a guided process, and one being the manual partition setup most of us are used to. At this point, I decided to let it choose for me, and it showed me what it was going to do, and asked to write the new partition table to disk. After that, the base system and related packages were all installed, which took about 20 minutes and a reboot or two, and that is basically it. Gentoo Linux has really great documentation about install and setup. Kubuntu? It doesn’t need documentation. After the progress bar hit 100% I had a Powerbook that:
- Booted straight into kdm/KDE 3.5
- Had OpenOffice installed
- Displayed battery status correctly in the panel
- Had ALSA sound working out of the box
- Touchpad worked great (had to tone down the sensitivity– cursor moved too fast)
- Frequency scaling enabled to prevent overheating
- Eject button worked to eject cds, provided they were not mounted
If Linux is going to seriously break into the desktop world, Ubuntu/Kubuntu is the distro to do it. After this, I went into the shortcuts and reassigned some functions to the Apple keys, went into KMix and mapped the volume control Powerbook buttons to work, and got wireless working. Dapper actually shipped with almost everything I needed to get Airport Extreme started. Google for fwcutter, it’s a utility you need to download, compile, and run on an Airport Extreme driver to extract the firmware, which it will then copy to the correct directory. After that, this is what I do to get my wireless connected:
sudo modprobe bcm43xx (this should also load the 80211_softmac module, if not, do it manually)
sudo ifconfig eth1 up (static IP goes here)
sudo route add default gateway (router IP, often 192.168.1.1)
sudo iwconfig eth1 essid (Wireless network name)
sudo iwconfig eth rate 11Mb
The reason for the last command is the driver currently only works for 802.11b. Another limitation is that the SoftMac layer is not complete. I read a post about devicescape, which is supposedly much more functional, though harder to get working. I’ll see if I can get more out of the wireless in terms of packet sniffing, etc. later. If the above doesn’t work for you, check the output of dmesg and see if your computer has successfully associated with the access point. I have also heard tell of WEP encryption working as well.
As for what remains to be done, the pbuttonsd that controls things like power button behavior, suspend-to-disk and so forth often seems to require reconfiguration to work properly on some Powerbooks vs. others. All in all, it was a painless experience. As is usually the case with Linux, not everything is sunshine and roses. There are projects under way to create an open source implementation of Flash, but it’s still in progress. If you want to play something that requires Flash 7+, forget about it. Macromedia does have a Linux binary available for download, but it’s x86 (The Man giveth, and The Man taketh away). So I can’t watch Google Video at the moment, but at least now I can save it to disk. There’s a petition for them to release a Linux ppc binary, but I’m not holding my breath. The petition for open sourced Airport Extreme drivers has been around for years since the first release of the product, and we’re only seeing results now because hardworking device driver people rolled up their sleeves and took matters into their own hands. And if you don’t understand, or at least respect that, I’m not sure why you’d want to run Linux in the first place.
Screenshots:
Processor Stats (1Ghz processor frequency scaled to 66%)
Showing off Katapult, a KDE launcher application like the outstanding OS X app, Quicksilver
