**4. Developing methodology**

The previous sections have been devoted to describing the basic technical characteristics of the platform proposed. This section, however, is devoted to discuss the development methodology of embedded systems based on this platform. The developing methodology of SOCs is divided two main parts: hardware developing and software developing. Although both are interlaced, they are very different. With regard to hardware development, begin identifying the components needed for the specific embedded system will be implemented. These components will be the interface of the SoC with the ports needed by the system.

Once identified, we must make the complete design of SoC (as shown in Figure 1) including all necessary components. As mentioned in section 2, this process will be done with GRLIB library that comes with the development system LEON3 processor. GRLIB includes a large number of components common in embedded systems. One of the advantages of this 8 Will-be-set-by-IN-TECH

modified the description file load during the boot process of the operating system, the file

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

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

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

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

This argument was necessary to provide the kernel to configure the system console through

Finally started, the system with the new kernel and the Debian Linux installation that, after

Importantly, once complete the whole process of installation and configuration, has the tools Debian APT package installation, such as apt-get, which allow you to install many libraries and applications, such as compilers, servers, internet services, daemons, desktop

The previous sections have been devoted to describing the basic technical characteristics of the platform proposed. This section, however, is devoted to discuss the development methodology of embedded systems based on this platform. The developing methodology of SOCs is divided two main parts: hardware developing and software developing. Although both are interlaced, they are very different. With regard to hardware development, begin identifying the components needed for the specific embedded system will be implemented. These components will be the interface of the SoC with the ports needed by the system.

Once identified, we must make the complete design of SoC (as shown in Figure 1) including all necessary components. As mentioned in section 2, this process will be done with GRLIB library that comes with the development system LEON3 processor. GRLIB includes a large number of components common in embedded systems. One of the advantages of this

/etc/inittab, by adding the following line:

configuration file /etc/fstab.

**4. Developing methodology**

task done using the mknod command.

restarts.

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

root file system (the drives) by modifying the boot loader configuration.

loading, presented a console with all the benefits of this operating system.

environments, etc., and even full distribution upgrades quickly and conveniently.

the serial port and to tell the kernel where the root filesystem was:
