Embedded Software for SoC - Grupo de Mecatrônica EESC/USP

A Flexible Object-Oriented Software Architecture 113
2. PLATFORM AND APPLICATION SPECIFICS
The development of the software architecture and application were to be based
on an initial member of a product family of SWCDs, requiring support of
that particular platform while being open to future extensions.
The resource-constrained, cost-optimized SWCD hardware platform (for
details, see [3]) was resembled by a core module comprising a NEC-type
processor operating at 20 MHz, a variable amount of on-board RAM (up to
2 MB), and a number of optional components, such as a GPS module, a
GSM/GPRS modem, UARTs, a real-time clock (RTC), Flash memory, etc.
This core module was meant to be supplemented by a power supply, additional
interface circuitry, and any of a number of additional components, such
as USB, Ethernet, or Bluetooth interfaces.
As can be concluded from this brief description, the hardware platform was
characterized by a high degree of variability with respect to incorporated
components. This variability is shown in more detail in the feature diagram
of Figure 9-1. Furthermore, rather than assuming just a single specific
component per component type, components could vary as well with respect
to their exact model or even manufacturer.
The basis for software development on this SWCD platform was formed
by eCos, a real-time operating system (RTOS) originally developed by Red
Hat, Inc. eCos is open-source and license-cost-free, contributing to a reduction
in overall costs. It offers both a native and a number of standardized
(though limitedly-implemented) APIs.
Building upon both the hardware’s capabilities and the RTOS, there is a
prototypical application for this kind of platform which is able to make use
of the entire range of (optional and mandatory) components the hardware