Embedded Linux From Scratch in 90 minutes

Goals
- Linux kernel configuring and compiling;
- Root file system creation;
- Busybox compiling and installation;
- Device file creation;
- System initialization scripts: virtual file system, networking;
- Setup of a simple HTTP interface to the system.

1. Download fast processor emulator using a portable dynamic translator.

wget http://download.savannah.gnu.org/releases/qemu/qemu-0.12.2.tar.gz
tar zxvf qemu-0.12.2.tar.gz
cd qemu-0.12.2.tar.gz

Then you configure QEMU and build it (usually no options are needed):

./configure

install zlib if you need (apt-get install zlib1g-dev)

make

Then type as root user:

make install

2. Getting the Kernel sources:

wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.25.4.tar.gz

Start with a minimalistic kernel configuration

make allnoconfig

Adding settings specific to the embedded system
install ncurses if you need (apt-get install libncurses5-dev)

make menuconfig

Compiling:

make

You will get
arch/x86/boot/bzImage


3. Getting Busybox source

wget http://www.busybox.net/downloads/busybox-1.15.3.tar.gz

Configuring BusyBox

make menuconfig

choosing to build a statically, natively compiled executable.

Compiling busybox

make

Pre-installing busybox (in the _install/ subdirectory):

make install

4. Creating a root filesystem
Creating an empty file with a 1000K size:
dd if=/dev/zero of=rootfs.img bs=1k count=1000

Formating this file for the ext2 filesystem:
mkfs.ext2 -i 1024 -F rootfs.img

5. Populating the root filesystem
logged as root:
Creating a mount point:
mkdir /mnt/tmproot

Mounting the root filesystem image:
mount -o loop rootfs.img /mnt/tmproot

Copying the busybox file structure into the mounted image:
rsync -a busybox/_install/ /mnt/tmproot/
(or cp -ax busybox/_install/ /mnt/tmproot/)
chown -R root:rooot /mnt/tmproot/

Flushing the changes into the mounted filesystem image:
sync

6. Booting the Virtual System
Using the QEMU emulator as a bootloader
qemu -m 32 -hda rootfs.img -kernel linux-2.6.25.4/arch/x86/boot/bzImage -append "root=/dev/hda" -redir tcp:5555::80

click "Applications -> Internet -> Terminal Server Client"then fill in the Computer with "127.0.0.1:5900",and select VNC in the protocol, if VNC grayed, install vncviewer

apt-get install vncviewer

Network Traffic Generation Tool for Linux

Mausezahn is a free fast traffic generator written in C which allows you to send nearly every possible and impossible packet. It is mainly used to test VoIP or multicast networks but also for security audits to check whether your systems are hardened enough for specific attacks.

http://www.perihel.at/sec/mz/index.html

How to "Android"

Environment

Eclipse
Android SDK

add Android SDK to Eclipse - Quick Start

How to start
Lessons

How to build cheap cloud storage

How to Assemble a Storage

How to read data from XML file to Crystal Report in C#

private void Form1_Load_1(object sender, EventArgs e)
{
string xmlFilename = "C:\\Project\\XMLCrystalReport\\books.xml";

DataSet newDataSet = new DataSet();
// read the XML document into the DataSet.
newDataSet.ReadXml(xmlFilename);

ReportDocument customerReport = new ReportDocument();
customerReport.Load(@"C:\Project\XMLCrystalReport\collection.rpt");
customerReport.SetDataSource(newDataSet);
crystalReportViewer1.ReportSource = customerReport;
}

Performance Monitoring

Install performance monitoring tools.

yum install sysstat

Network Performace

sar -n DEV 10 1000

CPUs Performance

mpstat 2 -P ALL

Overview Hardware

lspci

How to backup MySQL databases

1. create /backup directory
2. create startbackup.sh script file:

rm -f /backup/mysql*
### System Setup ###
BACKUP=/backup
NOW=$(date +"%d-%m-%Y")

### MySQL Setup ###
MUSER="mysqluser"
MPASS="password"
MHOST="localhost"
MYSQL="$(which mysql)"
MYSQLDUMP="$(which mysqldump)"
GZIP="$(which gzip)"


### Start MySQL Backup ###
# Get all databases name
DBS="$($MYSQL -u $MUSER -h $MHOST -p$MPASS -Bse 'show databases')"
for db in $DBS
do
FILE=$BACKUP/mysql-$db.$NOW-$(date +"%T").gz
$MYSQLDUMP -u $MUSER -h $MHOST -p$MPASS $db | $GZIP -9 > $FILE
done