/usr/sbin/debootstrap -arch sparc stable /mnt/debinst
http://ftp.es.debian.org/debian
```
This command starts downloading packages from the Internet repository. These software packages are stored in the mass storage unit, to be validated and then installed in the system.

Once the process gets the basic installation of Debian on the drive, then it's necessary to configure certain aspects before its first use. At this point the use of chroot command proved quite useful to facilitate the entire process of design and preparation. This command allows the change of the root environment file system and keep running applications of the new distribution in the path that has been installed, allowing one to continue the setup process without restarting the whole system.

Firstly, the process was necessary to explicitly indicate the operating system to invoke a command line (shell) when booting the system (init process). To achieve this we simply

platform is the possibility of designing a controller or peripheral specific for a particular application, which can be included in the SoC. It is also possible to reuse IP cores available for other systems. In these cases, it will make a design interface with the AMBA bus, which is the

Open Development Platform for Embedded Systems 319

The most important improvement on this platform is under software developing since, the biggest effort in SOCs developing falls on the software and specifically in the interaction with peripherals. Our platform includes a operating system installed that solves the peripheral management through the device drivers. Even if a given driver is not avaliable for a new hardware, using Debian distribution we have tools to makes easy the developing. While with a conventional software developing methodology, some external tools are required: cross compilers, emulators, debug connection tools, etc., once installed the Debian distribution some advantages are achieved versus conventional software development methodologies of

We have achived significant improvements in the software tasks such as installing, compiling and developing, also, in the manage of devices drives or in high level applications. All this due some advantages of the using Debian as base software, it can be summarized as following:

• The Debian repositories has a large set of precompiled software that can be easily installed using the distribution tools. All is done inside of the platform without external tools. • The distribution provides a the development environment and integrated debug tools that

• Several improvements in the process of update firmware/software. The distribution adds

Usually, is not an easy task to install any precompiled software in a SoC. Most medium-high complex software applications depend of other software as shared libraries or external tools. Software distributions give tools to solve applications dependences. Specifically, the main feature of Debian software distribution is the Debian package machinery. This resolves the software dependencies and creates a minimal configuration for each installed software. This minimal configuration allows the putting services on just after install processes and also, can

Using precompiled software avoids the heavy task of compile software. Compile software for embeded systems is a heavy task due some of following reasons: one, is the dependence between applications and shared libraries making the compilation process complex. Usually one application needs an exact version of each required shared library. If there are several applications installed at the same time, the same library could appear several times, but with a different version number. In this situation install, upgrade and maintain the software is a

Other reasons that make the task of compile software for SoCs complex is the use of cross compilers to generate software. Once compiled software, to test it, all necessary files must be transferred and installed: executable files, shared libraries, config files, etc. The steps of compiling and transference are repeated as many times as necessary to achieve the software to be ready. This process is improved when the Debian distribution is installed. It is possible to install all compiler tools in the platform and make the compilation process inside of platform. Also, this task is assisted by Debian tools since, it detects all dependencies between

may be installed inside the platform. Also, without the need of external tools.

tools to update all software installed inside in an automated mode.

be used as example of end software configuration.

main bus that uses the hardware platform.

embedded systems.

tedious task.

modified the description file load during the boot process of the operating system, the file /etc/inittab, by adding the following line:

T0: 234: respawn:/sbin/getty -L ttyS0 38400 vt100

Thus, the getty application launched a shell connected to the serial port every time the system restarts.

Secondly, the network interface and the name servers (DNS) have to be configured in order to introduce a suitable network configuration, adjusting the files /etc/network/interfaces and /etc/resolv.conf . Also it's need to tell where the mount points of the units will be, such as the boot, root and swap file systems. Like in other standard distributions, one just has to edit the configuration file /etc/fstab.

Finally the /dev directory is empty in the new distribution installation and so it was necessary to create the block and character devices in order to let the kernel manage the peripherals, a task done using the mknod command.

Once the installation and configuration of the Debian Linux distribution is complete, it's time to recompile the kernel adapted to the LEON3 microprocessor. In this new compilation the romfs partition is removed and the kernel will take the parameters where to locate the actual root file system (the drives) by modifying the boot loader configuration.

This argument was necessary to provide the kernel to configure the system console through the serial port and to tell the kernel where the root filesystem was:

```