Bootable USB RAM capture

Remember the research done by Princeton on breaking hard drive encryption by reading the keys off the memory?

Hackaday has links to someone's site who has made his version of the USB RAM dumper utility, complete with instructions on creating your own. =D

UNIX tips: Learn 10 good UNIX usage habits

Good tips to learn, whether you're new or familiar with *nix systems. =)

Creating a tar.gz MyDSL extension

This HOWTO is meant to be a correction for the steps found in the DSL wiki to create a MyDSL extension for 4.2.4.

I'll be focusing on the steps to package the extension itself, assuming that the application has already been tested to work from within the /opt folder.

The program for the instructions will be called my_program ;)

Step 1:
Create working folder to hold all the needed files for the extension. Note that all commands following this step will be run from the /home/dsl/work folder, and not from the / folder.

sudo su
mkdir -p /home/dsl/work/opt
cd /home/dsl/work/

Optional:
If we want an icon on the desktop for the extension.

mkdir -p ./home/dsl/.xtdesktop

Copy in the icons to ./home/dsl/.xtdesktop!

cp [location_of_icon] ./home/dsl/.xtdesktop

Create the .lnk file neeeded.

touch ./home/dsl/.xtdesktop/my_program.lnk
nano ./home/dsl/.xtdesktop/my_program.lnk

A sample of the .lnk file:

table Icon
Type: Program
Caption: ImageMagick
Command: /opt/imagemagick/bin/display
Icon: /home/dsl/.xtdesktop/imagemagick.xpm
X: 420 (X position)
Y: 384 (Y position)
end

Optional:
If we want a menu entry in the DSL menu for the extension (most probably, unless the application is mainly run from console with parameters)

mkdir -p tmp/mydsl.menu
touch tmp/mydsl.menu/my_program

Edit the menu entry file.

nano tmp/mydsl.menu/my_program

The format for the contents of the file is as follows:

[exec] (display name) {command}

An example:

[exec] (Launch my_program) {sh /opt/my_program/launch.sh}

Just add more lines to the file using the same format for additional menu entries.

Step 2:
Copy the program files.

cp -Pr /opt/my_program ./opt/

# only if there are other files needed in /home/dsl
cp -Pr /home/dsl/whatever ./home/dsl/

Step 3:
Change ownerships.

chown -R 0.0 ./opt/
chown -R 0.0 ./tmp/
chown -R 1001.50 ./home/dsl/
chown 1001.50 ./tmp/mydsl.menu/my_program

Step 4:
Create file list.

find . > files.txt

Step 5:
Edit the file list, remove all entries that're directories &/or dot paths (refer to wiki)

nano files.txt

Step 6:
Create the archive.

tar cvf my_program.tar --no-recursion \
--numeric-owner -T files.txt

gzip -9 my_program.tar

Optional:
If this is an extension for the official DSL repository, be sure to create an info file (check some of the others for reference) and md5sum:

md5sum my_program.tar.gz > my_program.tar.gz.md5.txt

Troubleshooting:
- If the extension might not work at first, try checking the shell scripts for dot (/relative) paths and changing them to absolute paths.





PS: Do drop me a comment if you found this useful, or if you have any comments/suggestions to leave behind!

Making a new DSL cloop file

This HOWTO is meant to be a correction for the steps found in the DSL wiki to create a new cloop file for 4.2.4. I'll leave the why for your reading from that page itself. ;)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Some things to note before we start:

DSL usually represents the path and file of the KNOPPIX image as

/cdrom/knoppix/knoppix

when in MSDOS/Windows it's represented as

[drive]:\KNOPPIX\KNOPPIX

You should always type the image filenames in DSL as all caps even though it shows up otherwise, in case of any incompatibilities with syslinux/isolinux. ;)

I use /tmp as the base working folder. Feel free to use any other folder that has enough space.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Step 1:
Locate where the KNOPPIX image is stored and setup a loop device to access the image.

sudo su
losetup /dev/cloop1 /cdrom/KNOPPIX/KNOPPIX

Step 2:
Mount the cloop.

mkdir -p /mnt/loop
mount /dev/cloop1 /mnt/loop

Step 3:
Copy everything to the temporary storage.

cp -a /mnt/loop /tmp
SAND_BOX=/tmp/loop
cd $SAND_BOX

Step 4:
Do what you want with the temporary storage ;)

Step 5:
Create a new compressed image.

mkisofs -hide-rr-moved -allow-leading-dots \
-R -l -V "KNOPPIX ISO9660" \
-v -allow-multidot $SAND_BOX | \
create_compressed_fs - \
65536 > [location_for_new_image_file]/KNOPPIX2

Step 6:
Unmount and detach.

cd $HOME
umount /mnt/loop
losetup -d /dev/cloop1

Optional:
If you're storing the new image file on a USB thumb drive, remember to make sure that the file is properly written to it before unplugging it. The way I do it is to unmount the volume, wait for the command to complete, then unplug.

umount [mount_point_for_USB_thumbdrive]

Testing:
We can test the new image file using this cheat code at startup (for syslinux/isolinus) :

dsl knoppix_file=KNOPPIX2

PS: Do drop me a comment if you found this useful, or if you have any comments/suggestions to leave behind!

DSL articles

Will be writing a couple of short HOWTOs for Damn Small Linux (DSL). Both to record down the steps, and also to correct the steps as shown in the original DSL wiki.

[update]
Making a new DSL cloop file (adapted and modified from here)
Creating a tar.gz MyDSL extension (adapted and modified from here)