Daily Report

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2017-01-28T15:20:00.001-10:00

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Apple Losing the Patent War Against Samsung In UK

2012-10-19T21:50:00.000-10:00

Apple (AAPL) lost again in its epic war against Samsung (005930) concerning the design and utility patents on its smartphone and tablet. The UK appeals court has upheld the previous ruling that Samsung did not infringe upon Apple's iPhone and iPad designs. In July, the UK judge Colin Birss made headlines around the world, saying Samsung products were “not as cool” as Apple's despite similarities, therefore no copyright infringement. Now, Apple has to publicly announce on select newspapers and its Web site that Samsung didn't copy its products.

Apple publicly denouncing its previous claim that Samsung copied its designs would be quite humiliating and a blow to its reputation. Therefore, I think Apple will once again burn its huge cash to go all the way to the UK supreme court and avoid humiliation. To me, it's just an amusing circus that's meaningless to watch. Apple is desperate to keep its stronghold in the lucrative smartphone and tablet market that is rapidly taken over by Android appliances.

I honestly hope Apple could put its ample cash to better uses, such as helping needy people around the world by donating its luxury iPhones and iPads. Perhaps, I am dreaming.

via Reuters

To Install the Same Set of Packages as Another Debian Machine

2012-10-17T22:15:00.000-10:00

I know this is a well-known trick with the Debian package system, but I'm going to sum it up here. Suppose that you want to install the same set of packages on box A as box B. At box B, type the following command to get the list of installed packages.

dpkg --get-selections > select.txt

Then, take select.txt to box A and run on box A:

apt-get update
dpkg --set-selections < select.txt
apt-get -u dselect-upgrade

Share your Linux desktop with x11vnc

2012-10-16T16:05:00.000-10:00

x11vnc is a pretty useful program that you can use to share your Linux desktop with someone far away. To start x11vnc while using X11 windows, issue the following command:

x11vnc -display :0

This command will work in most cases, assuming there is only one instance of X11 Windows server running. However, the display number could be different. To be sure, type the following command:

xdpyinfo | head

x11vnc will output a lot of information, including the port number it runs on:

The VNC desktop is:      bootcd:2
PORT=5902

Subtracting 5900 from the port number (5902), you'll get the display number (2). Use this number to connect to your desktop remotely. I use gvncviewer.

gvncviewer 192.168.200.83:2

Administrator To Monitor Someone's Desktop with X11VNC

Let's assume that you are a system administrator with root privilege and want to monitor a user's X11 Windows desktop. You can't just run “x11vnc -display :0” because you are not the user currently using display :0. In that case, you need access to the X11 Windows' xauth file which is located at one of the following locations:

/var/lib/gdm
/var/lib/kdm
/var/lib/xdm/authdir/authfiles
/home/USER/.Xauthority

Once you locate the xauth file associated with the user's X11 desktop, you can use x11vnc to monitor his desktop activity.

x11vnc -display :0 -auth /var/lib/gdm/\:0.Xauth

Then, on your desktop as administrator, connect to the user's desktop with a vnc client.

gvncviewer 192.168.200.83:2

x11vnc with SSL

x11vnc supports various connection schemes, including SSL. On Debian and Ubuntu, type the following command to create a SSL certificate for use with x11vnc.

cat /etc/ssl/private/ssl-cert-snakeoil.key /etc/ssl/certs/ssl-cert-snakeoil.pem > /tmp/x11vnc.pem

Then, start x11vnc with -ssl option to run x11vnc in secure mode.

x11vnc -display :0 -auth /var/lib/gdm/\:0.Xauth -ssl /tmp/x11vnc.pem

ssvnc and gvncviewer can be used to connect to x11vnc via SSL connection. The following example command starts x11vnc in anonymous SSL mode that doesn't require X509 exchange.

x11vnc -display :0 -xauth /var/lib/xdm/authdir/authfiles/A\:0-R2x5Db -xkb -nopw -nc_cr -ssl /tmp/x11vnc.pem -vencrypt newdh:nox509:support

Setting Up XDM on Debian/Ubuntu Linux

2012-10-16T11:09:00.000-10:00

XDM, short for X Display Manager, is my favorite login manager for its simplicity. Sure, gdm and kdm are visually pleasant, but why do I have to install all the dependencies if xdm provides the same functionality as them? After all, xdm can launch GNOME and KDE for you — you just need to fix your ~/.xsession file. This post will serve as my notes on installation, configuration and customization of xdm.

All configuration of xdm, except for distribution-specific settings, is done by modifying the files in the /etc/X11/xdm directory. For now, I'll just go over what I have in my xdm files.

/etc/X11/xdm/Xaccess

This file is used to tell xdm who can use xdm. Therefore, if you are happy to let anyone access the X-Windows desktop locally or remotely, then you would just put an asterisk (*) in Xaccess as I did.

If you are very keen on security, you would put only the following in Xaccess. This only allows local users to have access to xdm.

localhost
127.0.0.1

However, even if Xaccess is set up as above, remote xdm login may still be possible with SSH X11 forwarding.

/etc/X11/xdm/Xresources

Xresources file is used to fine-tune the behavior and appearance of XDM. Here is what I put in my Xresources file:

Xcursor.theme: redglass

xlogin*login.translations: #override \
 Ctrl<Key>R: abort-display()\n\
 <Key>F1: set-session-argument(failsafe) finish-field()\n\
 <Key>Delete: delete-character()\n\
 <Key>Left: move-backward-character()\n\
 <Key>Right: move-forward-character()\n\
 <Key>Home: move-to-begining()\n\
 <Key>End: move-to-end()\n\
 Ctrl<Key>KP_Enter: set-session-argument(failsafe) finish-field()\n\
 <Key>KP_Enter: set-session-argument() finish-field()\n\
 Ctrl<Key>Return: set-session-argument(failsafe) finish-field()\n\
 <Key>Return: set-session-argument() finish-field()

xlogin*greeting: Welcome to CLIENTHOST
xlogin*namePrompt: Login:\040
xlogin*passwdPrompt: Password:\040
xlogin*fail: Login incorrect

xlogin*greetFace: Serif-21:bold:italic
xlogin*face: Sans-15
xlogin*promptFace: Sans-15:bold
xlogin*failFace: Sans-16:bold

xlogin*geometry: 600x400
xlogin*borderWidth: 1
xlogin*frameWidth: 5
xlogin*innerFramesWidth: 2
xlogin*shdColor: grey30
xlogin*hiColor: grey90
xlogin*background: grey
xlogin*greetColor: Blue3
xlogin*failColor: red
*Foreground: black
*Background: #fffff0

xlogin*logoFileName: /usr/share/X11/xdm/pixmaps/penguin_doll_200x300.xpm
xlogin*useShape: true
xlogin*logoPadding: 10

I think the settings are self-explanatory. This is how xdm would look with the above settings. The penguin image was taken from here.

/etc/X11/xdm/Xresources

The Xresources file allows you to specify how many X servers to run and their command arguments. In my case, I run Xorg and Xvfb. Xorg is the standard X server, and Xvfb is a server that runs totally in memory without depending on the video hardware. To see what's going on with Xvfb, I use x11vnc and gvncviewer.

# Default X.org server
:0 local /usr/bin/Xorg :0 vt7 -br -dpi 96 -nolisten TCP

:1 local /usr/local/bin/Xvfb :1 -dpi 96 -screen 0 1024x768x16

/etc/X11/xdm/Xsetup

Xsetup allows you to write any command to run when xdm displays the login screen. In my case, I run gm to set up the background image and run x11vnc to remotely access Xvfb via VNC.

#!/bin/sh
#
# This script is run as root before showing login widget.

gm display -window root /usr/share/wallpapers/Board_Tile_Gray.jpg
xkbcomp -dflts -I/usr/share/X11/xkb /etc/X11/xkb/server-0.xkm $DISPLAY

PID_XVFB=$(pidof Xvfb)
PID_X11VNC=$(pidof x11vnc)
if [ -n "$PID_XVFB" -a -z "$PID_X11VNC" ]; then
  x11vnc -display :1 -bg -xkb -nopw -nc_cr -forever -listen localhost -auth $(find /var/lib/xdm/authdir/authfiles -name \*:1\*) > /var/log/x11vnc.log 2>&1
fi

/etc/X11/xdm/xdm-config

In xdm-config, there is only one line that I bother to change. This line enables remote xdm logins.

! SECURITY: do not listen for XDMCP or Chooser requests
! Comment out this line if you want to manage X terminals with xdm
DisplayManager.requestPort:     177

/etc/X11/xdm/xdm-options

I think xdm-options is Debian specific. I don't think I made any change in this file.

# configuration options for xdm
# See xdm.options(5) for an explanation of the available options.

no-ignore-nologin
no-restart-on-upgrade
no-start-on-install
use-sessreg

Resetting XDM

There are other files in /etc/X11/xdm directory that you can safely leave as is. After you make any change with the files, have xdm reread the config files.

kill -1 $(pidof xdm)

If you want to force xdm to kill all running sessions and restart, enter the following command.

/etc/init.d/xdm restart

That's all I have to write about xdm for now. In summary, xdm is a simple, yet functional login manager that is easy to set up.

To Create SSL Certificates for Personal / Intranet Use

2012-10-15T14:01:00.000-10:00

I'm not a security guru, but I'm writing this as a personal note. Normally, I'll have to pay some company to have my SSL certificate digitally signed for commercial uses. That's because people and businesses won't acknowledge or recognize my SSL certificate in transactions unless it is signed by a reputable company. However, I can create SSL certificates myself for personal / intranet use.

On Debian and Ubuntu systems, after the ssl-cert package is installed, a SSL certificate is automatically created at /etc/ssl/certs/ssl-cert-snakeoil.pem, and the corresponding key is created at /etc/ssl/private/ssl-cert-snakeoil.key. You can just distribute ssl-cert-snakeoil.pem to other peer machines to set up SSL connections. To manually create your own SSL certificates, follow these steps. In this guide, we will use the arbitrary filenames: my-site.key, my-site.crt and my-site.pem.

Generate a public/private key pair:
```
openssl genrsa -out my-site.key 1024
```

Generate a self signed certificate:

openssl req -new -key my-site.key -x509 -days 3653 -out my-site.crt

Generate the PEM file by just appending the key and certificate files:
```
cat my-site.key my-site.crt > my-site.pem
```
The private key should be kept secret, so change the file permission.

chmod 600 my-site.key my-site.pem

You can distribute the trust certificate server.crt to your SSL client hosts that will connect securely to the SSL-enabled server. The server may need *.crt files from clients for proper client authentication.

Linux: Transmitting a Bunch of Files using socat

2012-10-15T02:26:00.000-10:00

socat is a nifty, versatile tool for establishing a secure data channel between two computers. To install socat on Debian, use apt-get:

apt-get install socat

I was trying to use socat and tar to duplicate the contents of an entire filesystem securely between two computers. In this case, I copied all files in partition /dev/sda5 on box A to partition /dev/sdb6 on box B (IP 192.168.200.83).

Using the SCTP protocol

This method does not involve encryption, so it is relatively simple to follow.

First, I opened a terminal at box B (192.168.200.83) and changed the current directory to /mnt/sdb6 where I will unpack the incoming stream of files.
```
cd /mnt/sdb6
```
Then, I typed the following command to have socat establish a SCTP connection listening on port 7749. tar would be expecting to receive incoming files.
```
socat EXEC:"tar xzf -" SCTP4-LISTEN:7749
```
Then, I opened a terminal at box A. Here I would transmit a bunch of files to box B (192.168.200.83). I changed directory to /mnt/sda5 containing files to send.
```
cd /mnt/sda5
```
Then, I typed the following command to transmit all the files in the current directory.
```
socat EXEC:"tar czf - ." SCTP4-CONNECT:192.168.200.83:7749
```

Using the SSL connection

This method involves encrypted connection and requires SSL certicates on both sides of the link. Read this post to learn how to create self-signed SSL certificates if you don't already have one.

Debian and Ubuntu automatically create a local SSL certificate at /etc/ssl/certs/ssl-cert-snakeoil.pem. Both parties of an SSL connection — box A and box B — should exchange each other's ssl-cert-snakeoil.pem in order to have SSL connections between them.

On box B, I typed the following command to run socat in SSL listening mode at port 7749.

cd /mnt/sdb6
socat EXEC:"tar xzf -" OPENSSL-LISTEN:7749,reuseaddr,cert=/etc/ssl/certs/ssl-cert-snakeoil.pem,key=/etc/ssl/private/ssl-cert-snakeoil.key,cafile=box-A.pem

On box A, I typed the following command to run socat in SSL mode while running tar to pack all the files and send them through the pipeline.

cd /mnt/sda5
socat EXEC:"tar czf - ." OPENSSL:192.168.200.83:7749,cert=/etc/ssl/certs/ssl-cert-snakeoil.pem,key=/etc/ssl/private/ssl-cert-snakeoil.key,cafile=box-B.pem

Thus I have duplicated the whole directory tree from Box A to Box B. Using socat and tar, I was able to mirror a filesystem over the network. As shown above, socat alone can be a good substitute in situations where ssh, scp and/or netcat are needed. socat has many other features I have yet to explore.

How to Extract Boot Images from Acronis Bootable CD

2012-10-11T21:45:00.000-10:00

Acronis Backup and Restore is a great software to purchase for any business that wants to protect and preserve their digital assets from natural or accidental loss. After you purchase Acronis software and deploy it on your computers, you have a chance to create a bootable CD for emergency purpose. The Acronis boot CD will prove useful when you need to restore backups on a compromised or corrupted system.

However, you may want to incorporate Acronis software into your own custom boot CD. The custom CD can be a live Linux CD or live Windows CD. In that case, your ideal CD will have a menu of choices to run Acronis in addition to booting Linux or Windows. To create such a disc, you need to extract boot images from Acronis Boot CD. This post illustrates the steps needed to creat a custom CD containing Acronis software.

Bring your Acronis emergency CD and use the following command to create an ISO file. This assumes that you are using Linux. On Windows, you can use the readom program from my cdrkit build.
```
readom dev=/dev/sr0 f=ABR11.5AWUR_en-US.iso speed=8 retries=16 -nocorr -noerror
```
Acronis uses a special bootloader called BootWiz. To extract the boot image, you need to find the location of area that begins with BOOTWIZ0 string inside the ISO file. This is a hit-or-miss process. hexedit can be used here.
```
hexedit ABR11.5AWUR_en-US.iso
```
In hexedit, press Ctrl+S, then enter 424F4F5457495A30, which translates to BOOTWIZ0. Hit Enter.
Hexedit will find the given string (BOOTWIZ0). Note the address of the line
(0x1A000). The address (0x1A000) is equivalent to 106496 in decimal, and 208 sectors. After you write down the address, quit Hexedit by pressing Ctrl+C.

Use dd to extract the FAT filesystem image.

dd if=ABR11.5AWUR_en-US.iso of=abr11.bin skip=208

Use WinImage to convert the image file (abr11.bin) — actually a FAT filesystem image — to a hard disk image format with MBR.

Normally, you can just put the hard disk image on the CD and boot it using isolinux & memdisk.
```
LABEL abr11
MENU LABEL Acronis Backup & Restore 11
KERNEL memdisk
INITRD abr11.bin
```
Alternatively, you can mount the image file (abr11.bin) and extract only the kernel and initramfs.
```
mount -t msdos -o loop,ro abr11.bin /mnt
cd /mnt
cp dat*.dat /boot
```
The following is an example boot entry for isolinux that starts 64-bit Acronis Backup & Restore.
```
LABEL abr11x
MENU LABEL Acronis Backup & Restore 11 (64-bit)
KERNEL dat5.dat
INITRD dat4.dat
APPEND video=vesa:mtrr vga=0x317 product=bootagent media_for_windows quiet
```
The kernel parameters to put as APPEND string can be taken from the efi/boot/bootx64.xml.

Aria2 shell script and batch file

2012-10-11T00:17:00.000-10:00

I wrote a BASH shell script and a DOS batch file that can be used to download files using aria2 — Aria2 is a command-line tool for downloading files. The script and the batch file take 2 arguments; the first one is for the bittorrent hash in 40-digit hexadecimal number and the second one is for arbitrary one-word description.

aria2.bat can be used on Windows, and aria2.sh can be used on Linux and *BSD. Make sure that aria2c is in PATH. For example, if you want to download an ISO file for the OpenSUSE DVD, you would type something like:

aria2.bat 198472f5217d843cceb1a4c82233f009ed6608af opensuse-dvd-586

To find the value of a bittorrent hash (that long hex number), you can cut it from a magnet link you find on a Web site — Magnet links allow you to download actual files without first having to download bittorrent files (*.torrent). When you see a magnet sign, right-click on it to display the shortcut menu and select Copy Link Location.

Then, paste it somewhere, for example, inside the URL address bar. The hash value comes after the btih: string.

After you find the bittorrent hash, use it as the first argument to the script and make up anything for the second argument, as shown in the example above.

isolinux.cfg for a live CD

2012-10-09T16:34:00.000-10:00

isolinux is a bootloader included in the syslinux package and is used to boot a CD or DVD. isolinux is one of several popular bootloaders used to create a bootable CD for open-source operating systems, including Linux and FreeDOS. Another bootloader is GRUB, which I rarely use except for booting Windows 7 with BIOS emulation.

To create a bootable CD with isolinux, just copy the file isolinux.bin to a folder that will hold CD contents for ISO mastering. On Debian or Ubuntu, the file is located at the /usr/lib/syslinux folder.

A file named isolinux.cfg needs to be created in order to provide a menu or boot entries. A sample isolinux.cfg is shown below. It makes use of vesamenu.c32 which helps display a nice graphical menu with a background picture. Vesamenu.c32 is also located in /usr/lib/syslinux and needs to be copied too.

# isolinux.cfg
# Configuration for ISOLINUX

# Wait for 60 seconds before booting up the default entry.
TIMEOUT 600
F1 help.txt #ff702640

UI vesamenu.c32
MENU RESOLUTION 640 480
MENU BACKGROUND back642.jpg
MENU COLOR border 30;44 #40dfdfdf #00000000 std
MENU COLOR title 1;36;43 #e0fdff49 #804206ef none
MENU COLOR sel 7;37;40 #e0000000 #40ffffff all
MENU COLOR hotsel 1;7;37;40 #e0af0000 #40ffffff all
MENU COLOR disabled 1;30;44 #ffe4de6f #00000000 std
MENU COLOR scrollbar 30;44 #40000000 #e0af0000 std
MENU TITLE Boot Menu
MENU CLEAR

MENU ROWS 14
MENU TABMSGROW 20
MENU CMDLINEROW 20
MENU TIMEOUTROW 22
MENU HELPMSGROW 24
MENU VSHIFT 1

# The default is to boot the first hard drive.
DEFAULT hd0
ONERROR hd1

MENU BEGIN livecd_menu

  MENU TITLE Linux Live CD Menu

  LABEL livecd_heading
  MENU LABEL Boot Linux live CD
  MENU DISABLE

  LABEL livecd_640x480
  MENU LABEL 640x480 screen
  MENU INDENT 1
  KERNEL 360.lnx
  INITRD initram.lzm 
  APPEND root=/dev/sr0 edd=off vmode=640x480

  LABEL livecd_800x600
  MENU LABEL 800x600 screen
  MENU INDENT 1
  KERNEL 360.lnx
  INITRD initram.lzm
  APPEND root=/dev/sr0 edd=off vmode=800x600

  LABEL livecd_1024x768
  MENU LABEL 1024x768 screen
  MENU INDENT 1
  KERNEL 360.lnx
  INITRD initram.lzm
  APPEND root=/dev/sr0 edd=off vmode=1024x768

  MENU SEPARATOR

  LABEL livecd_console_heading
  MENU LABEL Boot Linux live CD into text console
  MENU DISABLE

  LABEL livecd_console
  MENU LABEL text-mode console
  MENU INDENT 1
  KERNEL 360.lnx
  INITRD initram.lzm
  APPEND root=/dev/sr0 nox

  LABEL livecd_console_old
  MENU LABEL text-mode console for an old computer
  MENU INDENT 1
  KERNEL 360.lnx
  INITRD initram.lzm
  APPEND root=/dev/sr0 acpi=off irqpoll nox

  MENU SEPARATOR

  LABEL exit0
  MENU LABEL Return to the main menu.
  MENU EXIT

MENU END

MENU BEGIN cdram_menu

  MENU TITLE Linux on RAMdisk Menu

  LABEL cdram_heading
  MENU LABEL Boot Linux on RAMdisk
  MENU DISABLE

  LABEL cdram_640x480
  MENU LABEL 640x480 screen
  MENU INDENT 1
  KERNEL 360.lnx
  INITRD initram.lzm 
  APPEND boot=cdrom root=/dev/ram ramdisk_size=573440 edd=off vmode=640x480

  LABEL cdram_800x600
  MENU LABEL 800x600 screen
  MENU INDENT 1
  KERNEL 360.lnx
  INITRD initram.lzm
  APPEND boot=cdrom root=/dev/ram ramdisk_size=573440 edd=off vmode=800x600

  LABEL cdram_1024x768
  MENU LABEL 1024x768 screen
  MENU INDENT 1
  KERNEL 360.lnx
  INITRD initram.lzm
  APPEND boot=cdrom root=/dev/ram ramdisk_size=573440 edd=off vmode=1024x768

  MENU SEPARATOR

  LABEL cdram_console_heading
  MENU LABEL Boot Linux RAMdisk into text console
  MENU DISABLE

  LABEL cdram_console
  MENU LABEL text-mode console
  MENU INDENT 1
  KERNEL 360.lnx
  INITRD initram.lzm
  APPEND boot=cdrom root=/dev/ram ramdisk_size=573440 nox

  LABEL cdram_console_old
  MENU LABEL text-mode console for an old computer
  MENU INDENT 1
  KERNEL 360.lnx
  INITRD initram.lzm
  APPEND boot=cdrom root=/dev/ram ramdisk_size=573440 acpi=off irqpoll nox

  MENU SEPARATOR

  LABEL exit1
  MENU LABEL Return to the main menu.
  MENU EXIT

MENU END

LABEL hd0
  MENU LABEL First Hard Drive
  LOCALBOOT 0x80

LABEL hd1
  MENU LABEL Second Hard Drive
  KERNEL chain.c32
  APPEND hd1 swap

MENU BEGIN hd0_menu

  MENU TITLE Partition in First Hard Drive

  LABEL hd0_part1
  MENU LABEL 1st partition
  KERNEL chain.c32
  APPEND hd0 1

  LABEL hd0_part2
  MENU LABEL 2nd partition
  KERNEL chain.c32
  APPEND hd0 2

  LABEL hd0_part3
  MENU LABEL 3rd partition
  KERNEL chain.c32
  APPEND hd0 3

  LABEL hd0_part4
  MENU LABEL 4th partition
  KERNEL chain.c32
  APPEND hd0 4

  LABEL hd0_part5
  MENU LABEL 5th partition
  KERNEL chain.c32
  APPEND hd0 5

  LABEL hd0_part6
  MENU LABEL 6th partition
  KERNEL chain.c32
  APPEND hd0 6

  LABEL hd0_part7
  MENU LABEL 7th partition
  KERNEL chain.c32
  APPEND hd0 7

  LABEL hd0_part8
  MENU LABEL 8th partition
  KERNEL chain.c32
  APPEND hd0 8

  LABEL hd0_part9
  MENU LABEL 9th partition
  KERNEL chain.c32
  APPEND hd0 9

  LABEL hd0_part10
  MENU LABEL 10th partition
  KERNEL chain.c32
  APPEND hd0 10

  MENU SEPARATOR

  LABEL exit3
  MENU LABEL Return to the main menu
  MENU EXIT

MENU END

LABEL fd0
  MENU LABEL Floppy Drive
  LOCALBOOT 0x00

LABEL next
  MENU LABEL Next in boot sequence
  LOCALBOOT -1

LABEL memtest
  MENU LABEL Test your computer memory
  LINUX memtest.bin
  TEXT HELP
  Run Memtest86 to test your computer memory
  ENDTEXT

LABEL help
  MENU LABEL Help
  MENU HELP help.txt #ff702640

The example above is one that I use for my live CD, so some settings are specific to my situation. Thus, KERNEL and APPEND settings may have to be adapted for other users. However, all the keywords shown above is standard and acceptable.

Linux: Building X.org Kdrive Server Xfbdev on Debian Wheezy

2012-10-08T11:11:00.000-10:00

Kdrive is a minimal X11 server that runs as a single executable with little dependencies. I use Kdrive for my Web-only/Rescue Linux systems. Before compiling Kdrive, I installed the following packages on my box running Debian Sid — which will be eventually rolled into Wheezy release:

bison

g++-4.7

libexpat1-dev

libpciaccess-dev

libpixman-1-dev

libssl-dev

libudev-dev
libxdamage-dev

libxfont-dev

libxi-dev

libxkbfile-dev

libxmu-dev

libxxf86vm-dev

make

pkg-config

x11proto-bigreqs-dev

x11proto-composite-dev

x11proto-randr-dev

x11proto-render-dev

x11proto-resource-dev

x11proto-scrnsaver-dev

x11proto-video-dev

x11proto-xcmisc-dev

x11proto-xf86dga-dev

x11proto-xinerama-dev

xkb-data

Installing X Protocol Headers

The current RandR protocol headers from Debian didn't meet the required version, so I had to download the latest one from freedesktop.org. I installed randrproto like this.

tar xjvf randrproto-1.4.0.tar.bz2
cd randrproto-1.4.0
./configure --prefix=/usr
make install

Compiling Xfbdev

I got the latest X.org release from freedesktop.org. The following commands will build Xfbdev:

tar xjf xorg-server_1.13.0.tar.bz2

cd xorg-server-1.13.0/

./configure --prefix=/usr --disable-xorg --enable-kdrive --enable-kdrive-evdev --enable-config-udev --disable-aiglx --disable-glx --disable-dri --disable-dri2 --disable-drm --disable-record --with-xkb-path=/usr/share/X11/xkb --with-xkb-output=/var/lib/xkb --with-xkb-bin-directory=/usr/bin --with-default-xkb-rules=xorg --with-default-xkb-model=pc105 --with-default-xkb-layout=us

make

make install

Installed Files

The following files are installed after successfully building a Kdrive server.

/usr/bin/Xfbdev

/usr/bin/Xnest

/usr/bin/Xvfb

/usr/lib/xorg/protocol.txt

/usr/share/man/man1/Xnest.1

/usr/share/man/man1/Xserver.1

/usr/share/man/man1/Xvfb.1

/var/lib/xkb/README.compiled

To Use Xfbdev

An executable file Xfbdev will be created in /usr/bin. To be able to use the Xfbdev server, framebuffer video must be enabled either in the kernel or as a module. If CONFIG_FB_VESA option was enabled in the kernel, you can use the syslinux bootloader in the following way to boot Linux into a framebuffer video mode:

LABEL minimal
KERNEL vmlinuz-2.6.31.5
INITRD initramfs.lzma
APPEND vga=0x314 video=vesafb:mtrr

Once the framebuffer video has been activated, Xfbdev can be started in the following way:

Xfbdev :0 vt7 dpms -ac -br +bs -dpi 96 -mouse evdev,5,device=/dev/input/event2 -2button -keybd evdev,,device=/dev/input/event3 -fp /usr/local/share/fonts,/usr/share/fonts/X11/Type1,/usr/share/fonts/truetype/ttf-dejavu -nolisten TCP

Download my X.org build 1.13.0

Here you can obtain my compiled binaries Xfbdev, Xnest and Xvfb:

Xfbdev

Xnest
Xvfb

My Live CD based on Debian Linux Sid

2012-10-06T17:54:00.000-10:00

I created a Live CD from my Debian Linux installation. It is based on the unstable version (Sid). However, the live CD still lacks the capability to automatically configure X-Windows and the network, and uses IceWM for minimalist desktop. It can be downloaded from Google Drive. This Live CD has many uses, such as:

To troubleshoot and fix computer problems
To create backups and restore them
To partition a hard drive before installing Windows or Linux
To set up GRUB bootloader or enter boot commands
To install Debian, Ubuntu or Fedora
To access a Windows partition when it is unbootable
To survey and diagnose wireless and wired networks
To enjoy the Internet with the Web, IM, IRC and VoIP
To run a simple FTP or HTTP server
To participate in peer-to-peer networks
To do basic word processing and spreadsheet
To listen to music or watch movies
To rip CD's and DVD's

The snapshot above shows idesk icons on the desktop. Idesk is a neat application that displays icons on the desktop for you to quickly launch. Currently, I use IceWM instead of GNOME or KDE desktop to save space on the CD. So idesk is used to provide desktop icons for IceWM.

The snapshot above shows mlterm running. mlterm is my favorite terminal application. It allows me to use many languages.

Gparted is a cool application to have on a live CD. It lets you divide the hard drive into many partitions so you can run multiple operating systems.

IceWeasel is rebranded Firefox from Debian. Sorry, Chrome is not included.

LibreOffice is a fork of OpenOffice.org suite. I use it to create documents or read Microsoft Office documents.

Specifying the locale at boot time

To see your own language with the live CD, select an entry from the menu, click Tab and append LANG= option to the command line. For example, if you speak French, append LANG=fr_FR.UTF-8.

Using GraphicsMagick to Set the Background

2012-10-05T23:44:00.000-10:00

GraphicsMagick is a powerful graphics tool that can be used to set the background on Linux. I've been using xsetbg from the xloadimage package to set X-Windows background. However, I realized that GraphicsMagick can replace xloadimage and netpbm that I've used for setting background and converting images.

So far I just learned a few tricks for setting background with GraphicsMagick. To tile an image on the background, type a command like this:

gm display -window root background.jpg

To fill the background with an image smaller than the screen size, use the -geometry option:

gm display -window root -geometry 1440x960 Background.jpg

You can also use the percentage (%) sign to zoom in or out the image and place it on the background.

gm display -window root -geometry 300x200% background.jpg

You can add the -gamma option to darken or brighten the image. If gamma is less than 1, the output image will be darker. If gamma is greater than 1, the image will be brighter.

gm display -window root -gamma 0.5 BG_pix.jpg

There are many more options that you can use with GraphicsMagick, for example, -crop, -dither, -trim etc. Read the manual page of GraphicsMagick and documentation for further information.

Setting the Locale on Linux

2012-10-05T12:48:00.000-10:00

A locale is a system setting that allows users to configure the operating system for their own language, date, currency, etc. on Linux. There are slightly different ways to set up locales on different Linux distributions. Here I write how I would normally set up locales on Linux.

To set the system-wide default locale, I would append the LANG= variable to the Linux kernel. The kernel will happily accept the LANG= variable and pass it to the operating system. With syslinux, I would have an entry in syslinux.cfg as follows.

LABEL debian
KERNEL vmlinuz-3.6.0
INITRD /boot/initramfs.lzma
APPEND LANG=en_US.UTF-8 TERM=vt100 root=/dev/sda9

On Debian, Ubuntu, Mint and MEPIS, the system-wide locale may be specified in /etc/environment or /etc/default/locale.

LANG=C.UTF-8

To set your own locale different from the system-wide locale, just add a line to your .bashrc or .xsession:

export LANG=zh_CN.UTF-8

Generating locale-archive Again

The number of locales available on the system may be incomplete in order to save disk space. To see which locales are available, run the following command:

locale -a

If you want to add or remove locales, edit /etc/locale.gen. The following is a sample locale.gen.

ar_SA.UTF-8 UTF-8
bn_IN UTF-8
de_DE.UTF-8 UTF-8
en_US ISO-8859-1
en_US.UTF-8 UTF-8
es_MX.UTF-8 UTF-8
fa_IR UTF-8
fr_FR.UTF-8 UTF-8
gu_IN UTF-8
hi_IN UTF-8
id_ID.UTF-8 UTF-8
it_IT.UTF-8 UTF-8
ja_JP.UTF-8 UTF-8
kn_IN UTF-8
ko_KR.UTF-8 UTF-8
ml_IN UTF-8
mr_IN UTF-8
or_IN UTF-8
pa_PK UTF-8
pt_BR.UTF-8 UTF-8
ru_RU.UTF-8 UTF-8
ta_IN UTF-8
te_IN UTF-8
th_TH.UTF-8 UTF-8
tr_TR.UTF-8 UTF-8
vi_VN UTF-8
zh_CN.UTF-8 UTF-8
zh_TW.UTF-8 UTF-8

After changing the file locale.gen, you need to run locale-gen to regenerate the file /usr/lib/locale/locale-archive.

locale-gen

Enabling All Possible Locales

If you have plenty disk space, then you can enable all locales supported by the current glibc implementation. The list of supported locales is at /usr/share/i18n/SUPPORTED. Just copy it to /etc/locale.gen and rebuild the locales. It will regenerate the file /usr/lib/locale/locale-archive to about 100MB.

cp /usr/share/i18n/SUPPORTED /etc/locale.gen
locale-gen

Running Applications In Different Locales

Use the env command to run an application in a different locale. For example, to run pidgin in Chinese on an English desktop, I would issue:

env LANG=zh_CN.UTF-8 pidgin

Disk Cloning / Imaging over Network with SSH, Netcat, DD and XZ

2012-10-04T15:27:00.000-10:00

Today we have affordable, ample storage and faster bandwidth to facilitate partition imaging and disk cloning over network. Nowadays, it's common and feasible to take the image of a whole partition for various reasons. Compared to file-based backups using tar, disk imaging provides the following advantages.

The boot sector is preserved so that it's easy to make it bootable after the restore.
Information such as UUID and LABEL is presered, which helps identify the partition in booting and mounting.
Information such as ACL and XATTR is preserved, which helps restrict file access and secure the system.
Every bit in the unused sectors is preserved, which may assist in digital forensics to uncover deleted or hidden information.

There are commercial programs for disk imaging and backup (Norton Ghost, Acronis True Image). However, Linux users can use readily available tools to get things done. For disk cloning/imaging, we can use ssh, netcat, dd and xz. Note that dd will fail on physically damaged disks. For such disks, use ddrescue instead.

For security and compression, we are going to use ssh and xz in this tutorial. If you don't like xz, feel free to substitute xz with gzip, bzip2 or lzop. Also, netcat is used to stream the dd output over the network. On Debian and Ubuntu derivatives, you need the following packages.

bzip2, gzip, lzop, lzma OR xz-utils
dd
netcat
ssh

We are making these assumptions in the following scenarios.

Sending computer S

This computer has IP address 192.168.1.1 and needs to back up partition /dev/sda1.
Sending Port

We'll send using port 5525.
Receiving computer T

This computer has IP address 192.168.1.2 and needs to restore partition /dev/sda2.
Receiving Port

We'll receive at port 7749.

Disk Cloning using dd, xz, netcat and ssh

In this scenario, we will clone a disk partition, simultaneously sending an image of the source partition /dev/sda1 from computer S (192.168.1.1) and restoring it at /dev/sda2 on computer T (192.168.1.2). Make sure that the source partition is not mounted or is mounted read-only. Also, make sure that the target partition size is greater than or equal to the source partition size.

At the sending computer, compress the source partition /dev/sda1 with xz and set up netcat to send it at port 5525:
```
dd if=/dev/sda1 bs=16M | xz | nc -l 5525
```
At the receiving computer, set up a SSH tunnel to the sending computer (192.168.1.1):
```
ssh -f -N -L 7749:127.0.0.1:5525 username@192.168.1.1
```
At the receiving computer, type the following command to receive the partition image and restore it at /dev/sda2:
```
nc 127.0.0.1 7749 | xz -d | dd of=/dev/sda2 bs=16M
```

Alternatively, we could take the following steps to achieve the same thing. However, we start at the receiving computer.

At the receiving computer with the target partition /dev/sda2, type the following command to receive the partition image:
```
nc -l 7749 | xz -d | dd of=/dev/sda2 bs=16M
```
At the sending computer with the source partition /dev/sda1, set up a SSH tunnel to the receiving computer (192.168.1.2):
```
ssh -f -N -L 5525:127.0.0.1:7749 username@192.168.1.2
```
At the sending computer, type the following command to compress the source partition /dev/sda1 and transmit it over the SSH tunnel:
```
dd if=/dev/sda1 bs=16M | xz | nc 127.0.0.1 5525
```
Note that the transfer may take many hours for a large partition.

Disk Imaging using dd, xz, netcat and ssh

In this scenario, we will just send an image of the source partition /dev/sda1 to the receiving computer T (192.168.1.2) without restoring it. Make sure that the source partition is not mounted or is mounted read-only. A question remains whether to compress the image at the sending or receiving computer. The answer depends on which computer is more powerful. For this example, we'll compress at the sending computer (for network bandwidth reason).

At the sending computer, compress the source partition /dev/sda1 with xz and stream it using netcat:
```
dd if=/dev/sda1 bs=16M | xz | nc -l 5525
```
At the receiving computer, set up a SSH tunnel to the sending computer (192.168.1.1):
```
ssh -f -N -L 7749:127.0.0.1:5525 username@192.168.1.1
```
At the receiving computer, type the following command to receive the file:
```
nc 127.0.0.1 7749 > partimg.xz
```

Alternatively, we could take the following steps to achieve the same thing.

At the receiving computer, set up netcat to listen at port 7749 and save the incoming data to a file partimg.xz.
```
nc -l 7749 | dd of=partimg.xz bs=16M
```
At the sending computer, establish a SSH tunnel to the receiving computer (192.168.1.2) first:
```
ssh -f -N -L 5525:192.168.1.2:7749 username@192.168.1.2
```
At the sending computer, type the following command to compress the source partition /dev/sda1 and transmit it over the SSH tunnel:
```
dd if=/dev/sda1 bs=16M | xz | nc 127.0.0.1 5525
```
Note that the transfer may take many hours for a large partiiton.

Alternative Simple Commands for Disk Cloning / Imaging

I don't like these methods for some reason, but here I show the simpler methods where netcat is not needed. For disk cloning, type something like this:

dd if=/dev/sda1 bs=16M | xz | ssh username@192.168.1.2 "xz -d | dd of=/dev/sda2 bs=16M"

Just to send an image file, run a command as follows:

dd if=/dev/sda1 bs=16M | xz | ssh username@192.168.1.2 "dd of=partimg.xz bs=16M"

Bittorrent Info Hash Values for Windows 8 ISO

2012-10-01T00:33:00.000-10:00

Windows 8 ISO files have the following BTIH hash values. Use them with my aria2 script to download Windows 8.

en_windows_8_x86_dvd_915417.iso

C5D92B32277685436DEDE9957B80083D26062C03
en_windows_8_x64_dvd_915440.iso

144C7E2B46103FF84F83A1E6A12D66B740F00CF6

Download Linux Kernel 3.5.4 / 3.6.0

2012-09-30T22:37:00.000-10:00

I am sharing my kernel builds for Linux 3.5.4 and 3.6.0. Hope it works for everyone.

To Compile ndiswrapper 1.58rc1 for Linux 3.5.4

2012-09-30T13:24:00.000-10:00

ndiswrapper allows Linux users to use Windows drivers for PCI/USB network adapters on Linux. If you own a network device for which Linux support is still absent or premature, then you need to compile ndiswrapper yourself and install Windows driver for your network device. Fortunately, today's Linux supports most network devices out-of-box, so most distributions don't bother to include ndiswrapper. However, I am compiling ndiswrapper believing that Windows NDIS drivers would outperform native Linux drivers.

To my surprise, building the latest version of ndiswrapper (1.58rc1) did not require any patch. After compiling Linux 3.5.4, I downloaded the ndiswrapper source from the sourceforge site. I chose the testing version because I thought it would work better with Linux 3.5.x. I unpacked the source.

tar xzvf ndiswrapper-1.58rc1.tar.gz
cd ndiswrapper-1.58rc1

I typed the following commands to compile and install ndiswrapper.

KVERS=3.5.4 make uninstall
KVERS=3.5.4 make
KVERS=3.5.4 make install

Then, I generated modules.* files again.

depmod -e -m -F /boot/System.map-3.5.4 3.5.4

The following files were installed by ndiswrapper.

/lib/modules/3.5.4/misc/ndiswrapper.ko
/sbin/loadndisdriver
/usr/sbin/ndiswrapper
/usr/sbin/ndiswrapper-buginfo
/usr/share/man/man8/loadndisdriver.8
/usr/share/man/man8/ndiswrapper.8

Happiness the Movie 2007

2012-09-30T01:33:00.000-10:00

Happiness is a Korean movie that makes you think seriously about the true meaning of happiness in life. It tells a story of two terminal patients who met at a remote nursing home and fell in love with each other. However, the guy leaves the girl for a careless, material life in the city. In the end, he comes back to the girl only to find her dying and regrets having left her. The movie tries to teach us that true happiness is about being close to someone you care about no matter how sick or poor he/she is.

My All-Purpose Init Script for initrd / initramfs Boot Images

2012-09-29T22:18:00.000-10:00

Here I post my init script. It is used in my initrd/initramfs boot images for the following purposes.

Boot from a live CD / DVD
Boot from a read-only filesystem image, compressed in SquashFS
Copy the filesystem image to a RAM disk and run Linux entirely on memory
Boot Linux from a USB flash drive
Boot Linux from a local disk partition
Run a rescue shell without booting Linux

I have yet to implement network booting. Right now it is good enough for my current needs. It takes the following boot parameters.

root=

Specifies the root partition to boot Linux from. For example, /dev/sda2.
label=

Specifies the label of the device to boot from. For example, label=DEBIAN.
uuid=

Specifies the UUID of the device to boot from. For example, uuid=dcfd6a0a-2a0f-4b3d-8a1a-5e7d642ebfbd
boot=

Can be cdrom, loop, ram, usb or ata.
vmode=

Specifies the screen resolution of the framebuffer video. For example, vmode=640x480
single

Boot into the single-user mode.
nox

Boot into the console mode in runlevel 2

#!/bin/dash

# Define a function to parse kernel command line options.
get_opt() {
  echo $@ | cut -d "=" -f 2
}

# Define a function to load drivers.
loadmod() {
  for i in $@ ; do
    for j in $(grep $i /tmp/pcimodules.txt); do
      modprobe $j
    done
  done
}

# Define a function to guess the partition type.
gpart() {
  for i in $(blkid | grep $1); do
    case $i in
      *\=*)
        eval $i
        ;;
      *)
        true
        ;;
    esac
  done
}

# Define a function for mounting the root partition.
mountr() {
  if [ $uuid ]; then
    if [ $# = 2 ]; then
      mount -r -U $uuid $2
    elif [ $# = 1 ]; then
      mount -r -U $uuid $1
    else mount -r -U $uuid /mnt
    fi
  elif [ $label ]; then
    if [ $# = 2 ]; then
      mount -r -L $label $2
    elif [ $# = 1 ]; then
      mount -r -L $label $1
    else mount -r -L $label /mnt
    fi
  else
    gpart $1
    case $TYPE in
      ext*)
        e2fsck -p $1
        [ $# = 2 ] && mount $1 $2 || mount $1 /mnt
        ;;
      jfs)
        jfs_fsck $1
        if [ $# = 2 ]; then
          mount -t jfs -o ro,iocharset=utf8 $1 $2
        else mount -t jfs -o ro,iocharset=utf8 $1 /mnt
        fi
        ;;
      vfat)
        if [ $# = 2 ]; then
          mount -t vfat -o ro,gid=100,dmask=2,fmask=113 $1 $2
        else mount -t vfat -o ro,gid=100,dmask=2,fmask=113 $1 /mnt
        fi
        ;;
      *)
        [ $# = 2 ] && mount -r $1 $2 || mount -r $1 /mnt
        ;;
    esac
  fi
}

# Create a union filesystem
union() {
  mount -t tmpfs none /opt/tmp
  modinfo unionfs > /dev/null 2>&1 &&
  mount -t unionfs -o dirs=/opt/tmp=rw:/opt=ro none /mnt ||
  ( mkdir /opt/tmp/.change
    modprobe fuse
    unionfs-fuse -o allow_other,use_ino,suid,dev,nonempty,kernel_cache \
     -o cow,chroot=/opt,max_files=32768 /tmp/.change=RW:/=RO /mnt )
}

# Mount proc and sysfs.
mount -t proc none /proc
mount -t sysfs none /sys

# Find the available PCI hardware
mount -t tmpfs none /tmp
pcimodules > /tmp/pcimodules.txt

# Populate /dev (Needs kernel >= 2.6.32)
mount -t devtmpfs none /dev
mkdir -m 755 /dev/pts
mount -t devpts -o gid=5,mode=620 none /dev/pts

# Set default values
boot=ata
root=/dev/sda6

# Find the root=, label=, uuid= and boot= values on kernel command line.
for i in $(cat /proc/cmdline); do
  case $i in
    root\=*)
        root=$(get_opt $i)
        case $root in
          /dev/cdr* | /dev/dvd* | /dev/sr* | /dev/scd*)
            boot=cdrom
            ;;
          0x200)
            root=/dev/fd0
            ;;
        esac
        ;;
    label\=* | uuid\=* | boot\=* | vmode\=* )
        eval $i
        ;;
    single)
        RUNLEVEL=single
        ;;
    nox)
        RUNLEVEL=2
        ;;
  esac
done

# Activate framebuffer display devices.
if [ $vmode ]; then
  if [ $boot = cdrom ]; then
    modprobe uvesafb scroll=ywrap mode_option=$vmode-16
  else for i in $(grep fb /tmp/pcimodules.txt); do
    case $i in
      atyfb)
        modprobe $i mode=$vmode-16
        ;;
      nvidiafb | rivafb)
        modprobe nvidiafb mode_option=$vmode bpp=16 hwcur=1
        ;;
      radeonfb | savagefb)
        modprobe $i mode_option=$vmode-16
        ;;
      sisfb)
        modprobe $i mode=$vmodex16 mem=12288 font=SUN12x22
        ;;
      viafb | vt8623fb)
        modprobe viafb viafb_mode=$vmode viafb_bpp=16
        ;;
      *)
        modprobe $i
        ;;
    esac
  done
    if grep -q i915 /tmp/pcimodules.txt; then true
    else [ -c /dev/fb0 ] || modprobe uvesafb scroll=ywrap mode_option=$vmode-16
    fi
  fi
fi

case $boot in
    cdrom)
        # Boot Linux from a live CD.
        loadmod ata_ ahci pdc_adma ^.hci-hcd
        modprobe usb-storage &&
        modprobe sr_mod &&
        sleep 7
        modprobe isofs
        mount -t iso9660 /dev/sr0 /media
        [ -d /media/isolinux -o -d /media/boot/isolinux ] || 
          mount -t iso9660 /dev/sr1 /media
        if [ -f /media/*.[Ss][Qq]* ]; then
          SQF=$(ls -t /media/*.[Ss][Qq]* | head -n 1)
          if [ $root = /dev/ram ]; then 
               echo "Please wait until the RAM disk is ready."
               dd if=$SQF of=/dev/ram1 bs=2048 &&
               mount -t squashfs /dev/ram1 /opt
          else modprobe loop
               mount -t squashfs -o loop $SQF /opt
          fi
        else
          mount --move /media /opt
        fi
        union
        ;;
    loop)
        # Boot Linux from an image file.
        loadmod ata_ ahci pdc_adma ^.hci-hcd
        modprobe usb-storage &&
        modprobe sd_mod &&
        sleep 7
        mountr $root /media
        modprobe loop
        if [ -f /media/*.[Ss][Qq]* ]; then
          SQF=$(ls -t /media/*.[Ss][Qq]* | head -n 1)
          mount -t squashfs -o loop $SQF /opt
        elif [ -f /media/*.[Ii][Ss][Oo] ]; then
          ISO=$(ls -t /media/*.[Ii][Ss][Oo] | head -n 1)
          modprobe isofs
          mount -t iso9660 -o loop $ISO /opt
        fi
        union
        ;;
    ram)
        # Boot Linux from ramdisk.
        loadmod ata_ ahci pdc_adma ^.hci-hcd
        modprobe usb-storage &&
        modprobe sd_mod &&
        sleep 7
        mountr $root /media
        echo "Please wait until the RAM disk is ready."
        if [ -f /media/*.[Ss][Qq]* ]; then
          SQF=$(ls -t /media/*.[Ss][Qq]* | head -n 1)
          dd if=$SQF of=/dev/ram1 &&
          mount -t squashfs /dev/ram1 /opt
        elif [ -f /media/*.[Ii][Ss][Oo] ]; then
          ISO=$(ls -t /media/*.[Ii][Ss][Oo] | head -n 1)
          dd if=$ISO of=/dev/ram1 bs=2048 &&
          modprobe isofs
          mount -t iso9660 /dev/ram1 /opt
        fi
        union
        ;;
    usb*)
        # Boot Linux from a USB drive.
        loadmod ^.hci-hcd
        modprobe usb-storage &&
        modprobe sd_mod &&
        sleep 7
        mountr $root
        ;;
    ata*)
        loadmod ata_ ahci pdc_adma &&
        modprobe sd_mod &&
        mountr $root
        ;;
esac

# Make sure that init exists and is executable.
if [ -x /mnt/sbin/init ]; then
  mount --move /dev /mnt/dev
  mount --move /proc /mnt/proc
  mount --move /sys /mnt/sys
  umount /tmp

# Start init from the root filesystem.
  cd /mnt
  [ -f /media/updates.zip ] && unzip -o /media/updates.zip
  case $boot in
    cdrom)
      [ $root = /dev/ram ] && umount /media
      [ $RUNLEVEL ] || RUNLEVEL=3
      ;;
    loop | ram)
      umount /media
      [ $RUNLEVEL ] || RUNLEVEL=3
      ;;
    *)
      [ $RUNLEVEL ] || RUNLEVEL=5
      ;;
  esac
  [ -d initrd ] && pivot_root . initrd
  exec chroot . /sbin/init $RUNLEVEL
fi

# Start a shell as a last resort.
echo "Error booting from the root filesystem. Starting a shell."
exec /bin/dash

The following are examples of boot parameters that can be used with my init script.

Boot Linux from the local hard drive partition /dev/sda8
```
boot=ata root=/dev/sda8
```
Boot Linux from the latest squashfs file (*.sq*) on /dev/sda1
```
boot=loop root=/dev/sda1
```
Boot Linux from the CD-ROM with 1024x768 video resolution
```
boot=cdrom vmode=1024x768
```
Copy the squashfs image from CD-ROM into memory and run Linux on memory
```
boot=cdrom root=/dev/ram ramdisk_size=573440 vmode=800x600
```
Boot Linux from the second partition of a USB drive
```
boot=usb root=/dev/sda2
```

Using UnionfsFuse on Debian/Ubuntu Linux

2012-09-26T22:29:00.000-10:00

Unionfs-fuse is a user-space implementation of unionfs that makes it possible to run Linux over a read-only medium, such as CD-ROM. Unionfs-fuse is a convenient alternative to kernel implementations (unionfs, aufs and overlayfs), so users don't have to patch the kernel in order to try unionfs. There are many possible uses of unionfs:

Create a live CD
Run Linux from a read-only filesystem image, such as a squashfs file
Freeze an existing Linux system and save all changes in the memory

Unionfs achieves all this by merging a read-only filesystem and a writeable filesystem into a single virtual filesystem and mount it at a certain mount point. Let's try and apply unionfs-fuse to the third situation above. Basically, we need to create an initramfs file containing unionfs-fuse and a custom init script. The basic procedure is like this:

Load kernel drivers necessary to access the underlying storage device
Mount the read-only filesystem image at /opt
Mount tmpfs at /opt/tmp and create a directory /opt/tmp/.change
Use unionfs-fuse to merge the two and mount it at /mnt
Use chroot and start /sbin/init to boot the new unionfs filesystem

To carry about the above steps, an init script might look like this:

#!/bin/dash
# Use the small but functional dash to process this script

# Mount /proc, /sys, /dev and /dev/pts just in case
mount -t proc none /proc
mount -t sysfs none /sys
mount -t devtmpfs none /dev
mkdir -m 755 /dev/pts
mount -t devpts -o gid=5,mode=620 none /dev/pts

# Write commands here to load modules necessary to access a hard drive
modprobe pata_via
modprobe sd_mod

# Mount the Linux filesystem read-only at /opt
mount -r /dev/sda6 /opt

# Mount tmpfs at /opt/tmp
mount -t tmpfs none /opt/tmp
mkdir /opt/tmp/.change

# Create a unionfs mount at /mnt
modprobe fuse
unionfs-fuse -o allow_other,use_ino,suid,dev,nonempty,kernel_cache \
   -o cow,chroot=/opt,max_files=32768 /tmp/.change=RW:/=RO /mnt

# Make sure that init exists and is executable
if [ -x /mnt/sbin/init ]; then
  mount --move /dev /mnt/dev
  mount --move /proc /mnt/proc
  mount --move /sys /mnt/sys

# Start init from the root filesystem with runlevel 5.
  exec chroot /mnt /sbin/init 5
fi

The computer will boot into a virtual unionfs, consisting of writable tmpfs on top of read-only root filesystem. Make sure to modify /etc/rc.local so that it contains the following snippet of code.

for i in `ps ax | grep unionfs | grep -v grep | awk '{print $1}'`; do
  echo $i > /var/run/sendsigs.omit.d/unionfs.$i;
done

This prevents Linux from killing unionfs-fuse during shutdown so the system will properly shut down.

Manually Creating initrd / initramfs to Boot Linux

To Build Transmission-Daemon for Windows

2012-09-26T13:22:00.000-10:00

Transmission is a free bittorrent application available on Linux. It is a pretty neat tool compared to other bittorrent software. It is possible to compile and use Transmission on Windows, thanks to Cygwin. First, install Cygwin using the Cygwin installer(setup.exe). I set the Root directory to C:\Cygwin and chose to install the following packages in addition to base packages.

bison
gettext-devel
libtool
make
binutils
gcc4-g++
patch
pkg-config

Compile zlib.

./configure --prefix=/usr --static
make
cp -iv zconf.h zlib.h /usr/include
cp -iv libz.a /usr/lib

Build OpenSSL.

./Configure -DHAVE_STRUCT_TIMESPEC -lz -lpthread threads zlib --prefix=/usr cygwin
make
make install

Build CURL.

./configure --prefix=/usr --disable-shared --with-ssl --with-ca-bundle=ca-bundle.crt
make
make install

Compile libevent.

./configure --prefix=/usr --disable-shared
make 
make install

Lastly, build transmission.

./configure --prefix=/usr --disable-shared --enable-static --disable-nls --without-gtk CPPFLAGS=-DHAVE_STRUCT_TIMESPEC
make
make install

If you get snprintf error with libutp, insert the following line into utp.cpp:

extern int snprintf(char *, size_t, const char *, ...);

To Compile UnionFS-fuse 0.26 on Debian Linux

2012-09-22T23:26:00.000-10:00

I am trying to switch to unionfs-fuse for my live CD, but so far I haven't much success yet. Debian's unionfs-fuse package in Sid is outdated (version 0.24), so I compiled version 0.26. I had to install libfuse-dev in order to be able to build UnionFS-fuse. I probably needed cmake too, but I didn't choose to install cmake.

cmake
gcc
libfuse-dev
make

I edited Makefile to change PREFIX.

PREFIX=/usr
BINDIR=/bin
SBINDIR=/sbin

I just typed make to begin compilation.

make
make install

The following files are installed.

/usr/bin/unionfs
/usr/sbin/mount.unionfs
/usr/share/man/man8/unionfs-fuse.8

To make it compatible with Debian and derivatives, I renamed unionfs.

mv /usr/bin/unionfs /usr/bin/unionfs-fuse

Reign of Assassins 劍雨 2010

2012-09-21T14:45:00.000-10:00

Reign of Assassins (劍雨) is a Chinese wuxia (武俠) film starring Michelle Yeoh. In my opinion, it's a pretty enjoyable movie. The following clip has both English and Vietnamese subtitles.

Download Aria2 1.15.2

2012-09-20T11:32:00.000-10:00

Here you can download my Windows builds of aria2. This is the result of my previous post on how to build aria2 for Windows.

aria2c.exe version 1.15.2 for 32-bit Windows

I didn't expect my Windows build to depend on libstdc++-6.dll. I think that's because I used Cygwin's mingw64 compiler. It still works, though.

Aria2c Usage

aria2c --file-allocation=prealloc ftp://192.168.1.64/pardus.iso

If aria2 aborts a download due to a connection error, you can resume the download any time using aria2c like this:

aria2c -c ftp://192.168.1.64/pardus.iso

To download files from URL's written in a file urls.txt to a folder Downloads, run aria2 as follows. The urls.txt should contain one download per line with URL's seperated by a tab:

aria2c -i urls.txt -d Downloads

Daily Report

Temporary Post Used For Theme Detection (60e1939a-2979-48b7-9892-1855b83f8069 - 3bfe001a-32de-4114-a6b4-4005b770f6d7)

Apple Losing the Patent War Against Samsung In UK

To Install the Same Set of Packages as Another Debian Machine

Share your Linux desktop with x11vnc

Administrator To Monitor Someone's Desktop with X11VNC

x11vnc with SSL

Setting Up XDM on Debian/Ubuntu Linux

/etc/X11/xdm/Xaccess

/etc/X11/xdm/Xresources

/etc/X11/xdm/Xresources

/etc/X11/xdm/Xsetup

/etc/X11/xdm/xdm-config

/etc/X11/xdm/xdm-options

Resetting XDM

To Create SSL Certificates for Personal / Intranet Use

Read Also:

Linux: Transmitting a Bunch of Files using socat

Using the SCTP protocol

Using the SSL connection

How to Extract Boot Images from Acronis Bootable CD

Aria2 shell script and batch file

isolinux.cfg for a live CD

Linux: Building X.org Kdrive Server Xfbdev on Debian Wheezy

Installing X Protocol Headers

Compiling Xfbdev

Installed Files

To Use Xfbdev

Download my X.org build 1.13.0

Also Read:

My Live CD based on Debian Linux Sid

Specifying the locale at boot time

Using GraphicsMagick to Set the Background

Setting the Locale on Linux

Generating locale-archive Again

Enabling All Possible Locales

Running Applications In Different Locales

Disk Cloning / Imaging over Network with SSH, Netcat, DD and XZ

Disk Cloning using dd, xz, netcat and ssh

Disk Imaging using dd, xz, netcat and ssh

Alternative Simple Commands for Disk Cloning / Imaging

Also Read:

Bittorrent Info Hash Values for Windows 8 ISO

Download Linux Kernel 3.5.4 / 3.6.0

To Compile ndiswrapper 1.58rc1 for Linux 3.5.4

Also read:

Happiness the Movie 2007

My All-Purpose Init Script for initrd / initramfs Boot Images

Also read:

Using UnionfsFuse on Debian/Ubuntu Linux

Related Posts

To Build Transmission-Daemon for Windows

To Compile UnionFS-fuse 0.26 on Debian Linux

Reign of Assassins 劍雨 2010

Download Aria2 1.15.2

Aria2c Usage