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Archive: Linux

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March 7, 2008

Run Linux apps in Windows with andLinux

andLinux is a Ubuntu distribution that used the coLinux kernel, a Windows port of the Linux kernel which allows andLinux to run natively inside Windows without any virtualization software. After downloading, you basically just run the install Wizard. When your machine reboots, an extra taskbar icon will be waiting for you to launch and install pretty much any standard Linux application.

The coLinux kernel can be launched as a service and it runs in the background with a dedicated amount of RAM allotted to it. During the install, you create a folder to house the andLinux Ubuntu installation's root directory. If you need to access the full C drive from Linux applications, it's just a quick entry in the /etc/fstab.

When you've got everything running, the end result is really seamless. The Linux applications each run in a standard window, just like your Windows apps. There's no switching between operating system windows. Xterm, Konquerer, Amarok, whatever—It basically just works.

The installation is pretty simple, and there's also a nice tutorial at Tinkernut that runs you through the installer and shows you how to use Synaptec to easily install other Linux applications. If you're primarily a Windows user, but you miss all the great open source apps and command line tools that are available in Linux, this is worth the 700MB download.

andLinux - Link
Using andLinux (video) - Link

March 4, 2008

Ram dump over Firewire

Unlike USB2, the Firewire spec allows devices to have full DMA access. By impersonating the appropriate device, a PC can essentially obtain full read/write access to another machine's RAM, just by connecting the two machines with a Firewire cable. Adding to the recent discussion about the insecurities of physical access and Princeton's cold-boot RAM dump demonstration, Adam Boileau released a Linux Firewire utility that will give you immediate Administrator to an XP machine:

It's two years later, and I think anyone who was going to get the message about Firewire has already got it, and anyone who was going to be upset about it has got over it. Besides, according to Microsoft's definition, it never was a Security Vulnerability anyway - screensavers and login prompts are - as Bruce says - about the Feeling of Security. Anyway, today's release day for Winlockpwn, the tool I demoed at Ruxcon for bypassing windows auth, or popping an admin shell at the login window.
...

Yes, you can read and write main memory over firewire on windows.
Yes, this means you can completely own any box who's firewire port you can plug into in seconds.
Yes, it requires physical access. People with physical access win in lots of ways. Sure, this is fast and easy, but it's just one of many.
Yes, it's a FEATURE, not a bug. It's the Fire in Firewire. Yes, I know this, Microsoft know this. The OHCI-1394 spec knows this. People with firewire ports generally dont.

Adam's tools include a few Python apps that can copy and impersonate Firewire device signatures, dump RAM on a remote machine, bypass Windows authentication, and extract BIOS passwords. It's not exactly comforting, but I've got a new appreciation for Firewire now. This is the sort of access that used to only be possible by creating hardware that physically connects to the PCI bus. Now all you need is a cable and a laptop.

Firewire, DMA & Windows - direct memory access over Firewire - [via] Link

March 1, 2008

Recover data from RAM after a crash

After Princeton's cold-boot encryption key recovery hack, I got to thinking about what other useful things might be lying around in memory. It's old news that passwords of logged-in users are hanging out in there, but what about something more useful to the everyday user? What about that file you were editing before accidentally closing its window without saving?

In Linux and on PPC Macs, the root user can access the machine's ram through the /dev/mem device. I'm not sure why this is unavailable on newer Intel Macs—it's a bummer.

In theory, if you're processing some words, spreading sheets, or posting a blog entry and your program crashes, it's likely that the data you were editing will still be in RAM, unharmed, waiting to be allocated to another process. If you immediately dump the entire contents of RAM to disk before starting another large process, chances are good you can find your data again. It's tricky though—writing that RAM to disk requires you start up at least one process, such as dd. It's possible that this new process, or a another process that's currently running, could allocate memory and obliterate your file. You don't really have other options, though, so you might try something like this:

dd if=/dev/mem of=/tmp/ramdump strings /tmp/ramdump | grep "some text in your file"

I found a post by David Keech where he describes exactly this process. He was able to use it to successfully recover the text from a killed vi session:

I tested this by starting vi and typing in "thisisanabsolutelyuniqueteststring", killing the vi process without saving the file and running the command above immediately with a small modification. Instead of piping the output to a file, I piped it to grep thisisanabsolutelyuniquetest. The grep command found itself, as it always does, but it also found the original string, identified by the rest of the unique string that I didn't include in the grep command. You have to be careful when search through running memory. I now remember having this problem with the Mac all those years ago. Whenever I searched for parts of my brother's letter, I would just end up finding the part of memory that contained the search string.

He also mentions scanning the swap partition, which is also a likely place for your data to be found. It's the same process, but you replace /dev/mem with /dev/hda2 or whatever your swap partition is.

Here's the fun part. Based on what we now know about DRAM holding data even a few seconds of being unpowered, you might even be able to use the method to recover program data after a full system crash and reboot. The swap data will for sure be there, but if you reboot into single user mode without starting up X or any large applications, the possibility exists that unallocated areas of /dev/mem will still contain data from before the reboot.

How to recover your data after a crash - Link
Extracting encryption keys after a cold boot - Link

February 26, 2008

Wii Linux

This is awesome news from the GameCube Linux Wiki:

24 Feb 2008: Long time, no see Although we haven't posted any news in the last 2 years, we have silently continued our work keeping the kernel patches up to date. With the latest 2.6.24 release we have added support for the USB Gecko adapter as a console and terminal, so you can now logon into your gc-linux distro using minicom or HyperTerminal (TM). And last but not least, we have finally run natively Linux on the Nintendo Wii through Team Tweezers' twilight-hack. We have released a small usbgecko-enabled Proof of Concept mini-distro to prove it. Did I say have fun? :)

On a side note, I'm trying to put some instructions together for getting a dev environment set up with libogc and devkitPro. I'm not going to be able to test without a Wii, but this looks like a good place to start. Shout out in the comments if you know of any good Wii dev howtos that have sprouted up.

GameCube Linux Wiki - [via] Link

February 21, 2008

SIXAXIS hacks

Hackszine reader IraqiGeek writes:

I made an application that uses libusb-Win32 and PPJoy to map the Sony Sixaxis into a windows joystick with the accelerometers working and mapped.
Unfortunately, the gyro on my sixaxis seems to be faulty. So, while the code is already there to read the gyro data, it can't be used for anything.

The installation process is not exactly the shortest, but I've made a step-by-step how-to describing it.

I did a little digging and there are a couple of other noteworthy SIXAXIS hacks. In addition to IraqiGeek's driver, there is another Windows SIXAXIS driver that people are using with some success. I also was able to find a third Windows driver which contains full source, in case you want to do something more interesting than play games.

Speaking of more interesting, there also exists an open source library for Linux. If you check out the above video, you can see that a gumstix embedded computer is using the SIXAXIS input to control a number of servos.

The six R/C servos are connected to a Gumstix board with built-in Bluetooth module. Inertial measurements from the SIXAXIS are received directly through a PF_BLUETOOTH socket (not through the joystick API, due to HID descriptor issues). Heuristics explicitly discriminate between two types of motion (rotation or translation).

The author was even able to use this setup to control a small helicopter. Pretty cool stuff, I must say.

Anyone know if the SIXAXIS sensor data can be easily polled with an Arduino? Maybe this could be a be a cheap option for a 6DOF IMU.

Using the PlayStation 3 controller in Bluetooth mode with Linux - Link
SixAxis source driver for Windows - Link
Use your SIXAXIS on Windows (ps3sixaxis_en.exe)- Link
WinSIXAXIS (IraqiGeek's libusb/PPJoy driver) - Link

January 25, 2008

Use an SD card as swap space on the XO laptop

Xo-Mmcsd

I posted this over at the OLPC News Forums, and decided to share it with Hackszine readers as well.

Most of the time, the 256MB in the XO Laptop is sufficient. But I use yum to install software, and it can be very memory hungry. I often run out of RAM when installing more than a few packages at once (or a single package that decides it needs a bunch of other packages to work properly). There are two things I suggest before using yum: 1) quit all activities except terminal and cross your fingers or 2) enable some swap space and not worry.

The quick and dirty way to enable swap space is to put an SD card that you don't care about into the XO, and run one of these commands:

Note that this will destroy whatever's on the SD card, and in the long run is not good for it because it puts a lot of wear and tear on it.

On the default operating system that came with your XO:

su
mkswap /dev/mmcblk0
swapon /dev/mmcblk0
exit

On a joyride, Update.1, or later:

sudo mkswap /dev/mmcblk0
sudo swapon /dev/mmcblk0

You can replace swapon /dev/mmcblk0 with swapoff /dev/mmcblk0 when you are done and want to remove the SD card, or shut down the machine then remove the SD card. Don't remove it while you're using it as a swap drive or the system will probably crash.

As with anything that has "su" or "sudo" in it, if you mistype something, you may damage the operating system. One safety tip I can suggest is that you type the command like this:

swapon /dev/mmc[TAB][TAB]

That invokes tab filename completion, where it will either type out mmcblk0 for you, or show you a bunch of options. If you see anything other than mmcblk0, or mmcblk0p1/2/3, you might have mistyped the command. (The p1, p2, etc variants may appear if the SD card has multiple partitions on it).

I use this all the time to give myself some extra memory. It is slow because it's swapspace on an SD card, but it's much better than running out of memory while running yum. (The consequence of running out of memory is that you end up with improperly installed software). This is also handy if you are going to run a ton of activities at once, or if you are planning to use memory-intensive apps that you install with Yum, such as openoffice, gnumeric, etc.

January 6, 2008

HOWTO upgrade the XO Laptop's operating system

Xo-Devbuilds

If you've visited the OLPC Wiki, you've probably noticed the box on the right hand side that shows the latest releases (stable and development builds). Although the current stable build listed is 650, there's a newer one (653) that you might want to upgrade to. But if you want the latest, greatest, bleeding edge XO builds, you need to check out the "joyrides". However, these can be extremely unstable, so be warned.
Before you upgrade, there are a few things to know:

You can have two versions of the operating system installed at any time. By default, you'll boot into the one you installed most recently. So if you start out with build 650, then install build 653 and reboot, you'll start up in build 653. If you hold down the O key (on the keypad to the right of the screen) as you boot, you'll boot the alternate operating system (in this case, 650). (At this point, I believe that 650 becomes the default and 653 the alternate.)
At boot time, the XO laptop maps a pristine (see /versions/pristine) copy of the operating system into the running system's filesystem. Any changes you make to the filesystem are in another location (see /versions/run), but it all looks like one filesystem to you. When you reboot into an alternate operating system, any changes you had previously made to it are revived.
When you use the olpc-update command to update to a new version of the operating system, the alternate operating system is wiped out (both the pristine version and any modifications to it)
Through all of this, your home directory (/home/olpc) is left unchanged.

Update: Todd Norris wrote in with some important information. Some models of the XO laptop shipped with a version of firmware that is susceptible to a significant bug: if the real-time clock battery is physically removed or otherwise runs out of power, the machine may no longer boot. Even if you don't have an affected machine, this firmware update includes numerous bug fixes and is recommended for current models of XO laptops. For more information, including installation instructions, see the page for firmware version q2d07. However, this firmware will shortly be replaced by a newer release, so be sure to check the OLPC Wiki and look for the highlighted portion shown in the screenshot above. This will show you the newest version of firmware and operating system.

If you're ready to install the upgrades, read on.

Read full story

January 1, 2008

Encyclopodia: Wikipedia on your iPod

MakeFan pointed us to a howto for installing the Encyclopodia software, an alternate iPod interface built on iPodLinux which turns your iPod into an offline Wikipedia browser.

Yes that's right. Thanks to iPodLinux, you can now have the entire Wikipedia encylopedia on your iPod. Clocking in at only 1.7 GB of space, it is a very handy tool if you have the sudden uncontrollable urge while out at the shops to discover the capital of Mongolia or the mating habits of eels. The Wikipedia file is updated approximately once every 6 months so you won't have the most up-to-date version but hey it's free and Mongolia isn't going to change their capital anytime soon.

Unfortunately, the iPod Video and Nano devices as well as the Touch and iPhone are not yet supported by iPodLinux. If you have a slightly older iPod, however, it's a simple hack to turn it into a full pocket encyclopedia.

Encyclopodia: the encyclopedia on your iPod - Link
How to Install Wikipedia on Your iPod (Windows users)- Link
Encyclopodia Installation Guide for OS X and Linux - Link

December 28, 2007

xochat.org: make new friends

Xochat-Org-In-Action-1

My friend Tom Hoffman has set up a Jabber server for XO Laptop users:

I'm having a feeling I'll regret having done this, but xochat.org is now up and running. If you've got an XO you can point it at my Jabber server by popping open a terminal and typing this:
sugar-control-panel -s jabber xochat.org

Then hit ctrl+alt+erase to restart Sugar. You should then see the other people logged in to the server in the "Neighborhood" view. That is essentially the widest view. You should be able to see other users and shared activities, and share your own activities with them, including video.

This is, however, the bleeding edge of the bleeding edge, so don't expect perfection.

This isn't group chat; once you've got it set up, start the Chat activity, share it with your neighborhood, and like magic, you'll find all sorts of people and activities in your neighborhood. Very cool! Link and update

December 23, 2007

Run a nested X11 desktop on the XO Laptop

Xo-Laptop-X11
The XO laptop continues to be very hackable. If you haven't ordered one already, you really should because you only have a few days. I've owned some pretty sweet devices in the past, but nothing compares to this. At every turn, I find something new and cool about it, and there always seems to be a way to do the things I want to do. The only thing I need to worry about is using up all my flash drive space, but that's what USB drives are for, I guess.

Because the Sugar interface includes an X11 window manager, you can't fire up your favorite window manager without killing Sugar... unless you run a nested X11 server. The Xephyr server is available in the XO's default package repository, and it can run as a client and a server at the same time: as a full-screen client of the XO's X11 server, and as an X11 server that can contain its own session, window manager and all. (Xephyr is similar to Xnest, but supports more X extensions.)
To get it up and running, I started the Terminal activity, used su to become root, and installed Xephyr and blackbox (a nice lightweight window manager):

$ su
# yum install xorg-x11-server-Xephyr blackbox

Next, exit out of the root shell, and create a file in your home directory called xephyr.xinitrc that launches the window manager of your choice:

# exit
$ echo exec /usr/bin/blackbox > ~/xephyr.xinitrc

Now, each time you want to run Xephyr, use xinit to start up Xephyr on display :1 (if you want to run more than one Xephyr session at once, use :2, then :3, etc):

$ xinit ~/xephyr.xinitrc -- /usr/bin/Xephyr :1 -ac -screen 1200x900

You should see your window manager start up; the screenshot above shows blackbox with a few clients running. I ran into a few oddities that will eventually send me running to X11 documentation; for example, arrow-up and arrow-down don't bring up my history in the bash shell (but Ctrl-P and Ctrl-N work fine). And the screen is pretty hard to read except in reflective mode... but wow, it's nice to have 1200x900 pixels on such a small screen!!!

December 21, 2007

Essential hacker stocking stuffers

Like most of us, you've probably got some last-minute shopping to take care of. Or maybe there's a special someone in your life who keeps asking you for gift ideas and you need to start dropping hints to avoid another button down and a neck tie. Whatever the reason, here's a quick and dirty hacker gift guide with a variety of gift ideas that should put a smile on someone's face.

Make sure to add your own favorites to the list in the comments area and pass it along. I'm focusing primarily on smaller items that are available in local stores, but feel free to toss in whatever you think is important and shouldn't be missed.

Reading Material:

Make: The Best Of - a killer collection of the best 75 projects from our favorite magazine.
The Dangerous Book For Boys - this is a great book for sharing with your kids. Chock-full of essential information like how to tie knots, play poker, use a compass, build a tree house, and relate to girls.
Knoppix Hacks, 2nd Edition - the swiss army knife for your computer.
Illustrated Guide To Astronomical Wonders - ideal for anyone who's interested in knowing their way around the universe.
Also check out other books from the O'Reilly Hacks Series - Link

Gadgets:

Asus Eee PC - this ultra-tiny Linux laptop is just starting to appear in stores - Hacks
Linksys WRT54GL Router - the L in the GL stands for Linux. It's a $60 router that can be customized to do more than it's thousand dollar big-brothers - Hacks
Western Digital MyBook World Edition External Hard Drive - any extra storage is really nice to have, but this network-available drive contains mirrored RAID storage and a mini Linux computer that can run a web and database server - Hacks
iPhone or iPod Touch - did I really put that here? - Hacks
Broadband Mobile Card from Verizon or Sprint - they are getting super
popular, and heck, they are cheaper than an iPhone.
Nokia N95-3 - the winner of our most hackable mobile phone survey - Hacks

Toys:

Air Hogs Havoc Heli Laser Battle - remember the Picco-Zs and their clones from last year? Here's two of them in a single package, enhanced with a trigger that let's you zap your friend's heli down.
E-Sky Lama V4 Helicopter- Yeah, I'm crazy for helicopters right now. The counter-rotating models like this one are about $100, ready (and easy) to fly, and very hackable.
WowWee RoboSapien V2 - fun for the kids. More fun with a soldering iron - Hacks

Gear:

2GB or larger micro SD card, plus various SD and USB adapters - perfect for scooting files around, the size of a finger nail, and you can put a full Linux distro, anti virus software, or a Puppy Linux virtual machine on it - Hacks
Mini Multimeter - always handy.
Bike Multitool - a good one will pack allen and hex wrenches, screw drivers, and a knife into a pretty small package. Perfect for voiding warrantees in a pinch. Oh, and there's a chain tool, too - Link, Link
Soldering Tools - whether it's a new Weller or just a pair of helping hands, it'll be welcome in any stocking - Link, Link

What have we missed here? Add your wishes to the comments. Then find a completely non-tacky way to get this list into the hands of someone who wants you to be a happy hacker.

HOWTO run Arduino on the XO Laptop

Xo-Arduino-Screenshot

The XO Laptop comes with the drivers you need to talk to an Arduino board, but you need to do a few things before you can run the Arduino environment. Once you get it running, though, it works just fine. The first step is to install Java. To install Java on the XO Laptop, check out these instructions (the version of Java that you download will be different from what's listed on that page, so you'll need to modify the commands slightly to take that into account).
Once you've got Java up and running, you need to install the GNU C and C++ compilers as well as the LIBC for the AVR chip that the Arduino uses. To do this, open up the Terminal activity, su to root, and install avr-gcc, avr-libc, and avr-gcc-c++ using yum:

$ su
# yum install avr-gcc avr-libc avr-gcc-c++

While you're root, you may as well make one of the changes you need to make; add the olpc user to the lock and uucp groups. To do this, edit the /etc/group file with the /usr/sbin/vigr command and add the olpc user to the end of the lock group:

lock::54:olpc

and to the end of the uucp group:

uucp::14:uucp,olpc

After you exit vigr (which is just a script that starts vi to safely edit the group file), decline its offer to edit the gshadow file, and type exit to get back to a normal (non-root) shell):

# /usr/sbin/vigr
You are using shadow groups on this system.
Would you like to edit /etc/gshadow now [y/n]? n
# exit
exit
$

Next, make sure you're in your home directory, download Arduino (there may be a more recent version of it, so check the Arduino page to be sure. Extract Arduino in your home directory (you'll be running it out of your home directory as well):

$ cd
$ wget http://www.arduino.cc/files/arduino-0010-linux.tgz
$ tar xvfz arduino-0010-linux.tgz

Now, you're all Arduino-fied. To run it, cd to the arduino-0010 and run the arduino script:

$ cd ~/arduino-0010
$ ./arduino

There is one last trick: you'll likely find that the Arduino user interface misbehaves quite a bit. To get it to work right, press the screen rotate button four times to get a nice 360 degree rotation. Arduino will redraw and start behaving itself as shown in the screenshot.

Update: As Seth points out in the comments, the Update.1 build that is coming out this month will do away with the su command, so you should use sudo -s instead of su (or simply prefix each superuser command with sudo).

Update 2: If you use JRE 5 from the Java technology archive instead of JRE 6, you won't need to use the screen rotation trick. You'll need to add these two lines to the .bashrc file in your home directory, and then stop and relaunch the Terminal activity:

export JAVA_HOME=/usr/java/jre1.5.0_13/
export PATH=$PATH:$JAVA_HOME/bin

You'll need to install Java and modify your ~/.bashrc before you try running ./arduino

December 20, 2007

Copy and paste (sort of) into the XO laptop's Terminal activity

Xo-Pbpaste

According to ticket #5376, you can't copy and paste text between Terminal.activity and other applications. This became a problem for me this evening when I tried to copy a script from a web page into a file on the XO laptop. Fortunately, pygtk gives you access to the clipboard, and it's really easy to create a script that blasts the contents of the clipboard to stdout. I named it pbpaste after the Mac OS X utility of the same name. Save this file somewhere in your $PATH, make it executable, and you're all set.

#!/usr/bin/python

import pygtk
import gtk
cb = gtk.clipboard_get(selection = "PRIMARY")
print cb.wait_for_text()

It's not as flexible as a middle-click button would be, but it gets the job done, as shown in the figure above. And if I need to insert the contents of the clipboard into a file I'm editing in vi, I can always use :r!pbpaste

December 19, 2007

Record more than 45 seconds of audio or video on the XO laptop

240Seconds
If you go into the Record activity on the XO laptop, you'll find that you can only record a maximum of 45 seconds of video and audio. But since almost everything in this little green wonder is written in Python, it's very easy to fix this. Open up the Terminal activity, cd to /usr/share/activities/Record.activity, and then use su to become root:

$ cd /usr/share/activities/Record.activity
$ su
#

Now, make a backup copy of constants.py:

# cp constants.py constants.py.orig

Open constants.py in vi, and look for these lines:

	DURATION_15 = 15
	DURATION_30 = 30
	DURATION_45 = 45

Add the following line right after the DURATION_45 line (you can put whatever you want instead of 240--this is the number of seconds):

	DURATION_240 =240

Next, find these lines:

	DURATIONS.append(DURATION_15)
	DURATIONS.append(DURATION_30)
	DURATIONS.append(DURATION_45)

And add the following line right after the DURATION_45 line:

	DURATIONS.append(DURATION_240)

Stop the Record activity if it's already running, restart it, and you'll now have an option to record for more than 45 seconds.

December 17, 2007

Read/write access to Linux partitions from Windows

I read today on Lifehacker about a freeware tool called Linux Reader. It provides you with read access to ext2/ext3 partitions within Windows and has an explorer-like interface that allows you to drag and drop files from a standard Linux partition.

What about full read/write access? With a little googling, I found another freeware utility called Ext2 IFS that provides full write access. It's is essentially a kernel ext2/ext3 filesystem driver for Windows, which allows the operating system to access your Linux partitions in a more native manner.

After installing, you can mount your Linux partition under a drive letter, just like you would an NTFS partition. The drive will be available in Explorer and within any file browser dialog in your favorite Windows applications.

As far as I can tell, both packages pretty much ignore the permission settings on files, so you'll have full access to files across the entire partition. One caveat is that LVM volumes are not supported by the Ext2 IFS driver (and I'm assuming the same is true for Linux Reader). ReiserFS, XFS and other filesystems are also not supported. For your plain Jane dual-boot system with an ext3 partition, however, you should have no problem accessing your Linux files from within Windows.

Ext2 Installable File System For Windows - Link
Linux Reader - [via] Link