- 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
