From a178b68d342c3d67a2171f692eb9be09380c6fac Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Mon, 13 Apr 1998 19:43:21 +0000 Subject: Mistake --- doc/started_ada/intro.t.bak | 122 -------------------------------------------- 1 file changed, 122 deletions(-) delete mode 100644 doc/started_ada/intro.t.bak diff --git a/doc/started_ada/intro.t.bak b/doc/started_ada/intro.t.bak deleted file mode 100644 index 2dceabb5b2..0000000000 --- a/doc/started_ada/intro.t.bak +++ /dev/null @@ -1,122 +0,0 @@ -@c -@c COPYRIGHT (c) 1988-1998. -@c On-Line Applications Research Corporation (OAR). -@c All rights reserved. -@c -@c $Id$ -@c - -@chapter Introduction - -The purpose of this document is to guide you through the process of -installing a GNU cross development environment to use with RTEMS. - -If you are already familiar with the concepts behind a cross compiler and -have a background in Unix these instructions should provide the bare -essentials for performing a setup of the following items: - -@itemize @bullet -@item GNU C/C++ Cross Compilation Tools for RTEMS on your host system -@item RTEMS OS for the target host -@item GDB Debugger -@end itemize - -The remainder of this chapter provides background information on real-time -embedded systems and cross development. If you are not familiar with either -of these areas, please read them. This will help familiarize you with the -types of systems RTEMS is designed to be used in and the cross development -process used when developing RTEMS applications. - -@section Real-Time Embedded Systems - -Real-time embedded systems are found in practically every facet of our -everyday lives. Today's systems range from the common telephone, automobile -control systems, and kitchen appliances to complex air traffic control -systems, military weapon systems, an d production line control including -robotics and automation. However, in the current climate of rapidly changing -technology, it is difficult to reach a consensus on the definition of a -real-time embedded system. Hardware costs are continuing to rapidly de cline -while at the same time the hardware is increasing in power and functionality. -As a result, embedded systems that were not considered viable two years ago -are suddenly a cost effective solution. In this domain, it is not uncommon -for a single hardware configuration to employ a variety of architectures and -technologies. Therefore, we shall define an embedded system as any computer -system that is built into a larger system consisting of multiple technologies -such as digital and analog electronics, mec hanical devices, and sensors. - -Even as hardware platforms become more powerful, most embedded systems are -critically dependent on the real-time software embedded in the systems -themselves. Regardless of how efficiently the hardware operates, the -performance of the embedded real-time s oftware determines the success of the -system. As the complexity of the embedded hardware platform grows, so does -the size and complexity of the embedded software. Software systems must -routinely perform activities which were only dreamed of a short time ago. -These large, complex, real-time embedded applications now commonly contain -one million lines of code or more. - -Real-time embedded systems have a complex set of characteristics that -distinguish them from other software applications. Real-time embedded -systems are driven by and must respond to real world events while adhering to -rigorous requirements imposed by the environment with which they interact. -The correctness of the system depends not only on the results of -computations, but also on the time at which the results are produced. The -most important and complex characteristic of real-time application systems is -that they must receive and respond to a set of external stimuli within rigid -and critical time constraints. - -A single real-time application can be composed of both soft and hard -real-time components. A typical example of a hard real-time system is a -nuclear reactor control system that must not only detect failures, but must -also respond quickly enough to prevent a meltdown. This application also has -soft real-time requirements because it may involve a man-machine interface. -Providing an interactive input to the control system is not as critical as -setting off an alarm to indicate a failure condition. However, th e -interactive system component must respond within an acceptable time limit to -allow the operator to interact efficiently with the control system. - -@section Cross Development - -Today almost all real-time embedded software systems are developed in a -@b{cross development} environment using cross development tools. In the cross -development environment, software development activities are typically -performed on one computer system, the @b{host} system, while the result of the -development effort (produced by the cross tools) is a software system that -executes on the @b{target} platform. The requirements for the target platform are -usually incompatible and quite often in direct conflict with the requirements -for the host. Moreover, the target hardware is often custom designed for a -particular project. This means that the cross development toolset must allow -the developer to customize the tools to address target specific run-time -issues. The toolset must have provisions for board dependent initialization -code, device drivers, and error handling code. - -The host computer is optimized to support the code development cycle with -support for code editors, compilers, and linkers requiring large disk drives, -user development windows, and multiple developer connections. Thus the host -computer is typically a traditional UNIX workstation such as are available -from SUN or Silicon Graphics, or a PC running either a version of MS-Windows -or UNIX. The host system may also be required to execute office productivity -applications to allow the software developer to write documentation, make -presentations, or track the project's progress using a project management -tool. This necessitates that the host computer be general purpose with -resources such as a thirty-two or sixty-four bit processor, large amounts of -RAM, a monitor, mouse, keyboard, hard and floppy disk drives, CD-ROM drive, -and a graphics card. It is likely that the system will be multimedia capable -and have some networking capability. - -Conversely, the target platform generally has limited traditional computer -resources. The hardware is designed for the particular functionality and -requirements of the embedded system and optimized to perform those tasks -effectively. Instead of hard driverss and keyboards, it is composed of -sensors, relays, and stepper motors. The per-unit cost of the target platform -is typically a critical concern. No hardware component is included without -being cost justified. As a result, the processor of the target system is -often from a different processor family than that of the host system and -usually has lower performance. In addition to the processor families -targeted only for use in embedded systems, there are versions of nearly every -general-purpose process or specifically tailored for real-time embedded -systems. For example, many of the processors targeting the embedded market -do not include hardware floating point units, but do include peripherals such -as timers, serial controllers, or network interfaces. - - - -- cgit v1.2.3