Embedded Software for SoC - Grupo de Mecatrônica EESC/USP

Chapter 15
HARDWARE/SOFTWARE PARTITIONING OF
OPERATING SYSTEMS
The Hardware/Software RTOS Generation
Framework for SoC
Vincent J. Mooney III
School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA,
USA
Abstract. We present a few specific hardware/software partitions for real-time operating systems
and a framework able to automatically generate a large variety of such partitioned RTOSes.
Starting from the traditional view of an operating system, we explore novel ways to partition
the OS functionality between hardware and software. We show how such partitioning can result
in large performance gains in specific cases involving multiprocessor System-on-a-Chip scenarios.
Key words: hardware/software partitioning, operating systems
1. INTRODUCTION
Traditionally, an Operating System (OS) implements in software basic system
functions such as task/process management and I/O. Furthermore, a Real-Time
Operating Systems (RTOS) traditionally implements in software functionality
to manage tasks in a predictable, real-time manner. However, with
System-on-a-Chip (SoC) architectures similar to Figure 15-1 becoming more
and more common, OS and RTOS functionality need not be imple-mented
solely in software. Thus, partitioning the interface between hard-ware and
software for an OS is a new idea that can have a significant impact.
We present the hardware/software RTOS generation framework for
System-on-a-Chip (SoC). We claim that current SoC designs tend to ignore
the RTOS until late in the SoC design phase. In contrast, we propose
RTOS/SoC codesign where both the multiprocessor SoC architecture and a
custom RTOS (with part potentially in hardware) are designed together.
In short, this paper introduces a hardware/software RTOS generation
framework for customized design of an RTOS within specific predefined
RTOS services and capabilities available in software and/or hardware
(depending on the service or capability).
187
A Jerraya et al. (eds.), Embedded Software for SOC, 187–206, 2003.
© 2003 Kluwer Academic Publishers. Printed in the Netherlands.