Programming Embedded Systems in C and C++

30

Chapter 4

In this chapter:

• When in ROM…

• Remote Debuggers

• Emulators

• Simulators and Other

Tools

4

Downloading and

Debugging

4.

I can remember the exact instant when I realized that a

large part of my life from then on was going to be spent

in finding mistakes in my own programs.

—Maurice Wilkes, Head of the Computer

Laboratory of the University of Cambridge, 1949

Once you have an executable binary image stored as a file on the host computer,

you will need a way to download that image to the embedded system and exe-

cute it. The executable binary image is usually loaded into a memory device on

the target board and executed from there. And if you have the right tools at your

disposal, it will be possible to set breakpoints in the program or to observe its exe-

cution in less intrusive ways. This chapter describes various techniques for down-

loading, executing, and debugging embedded software.

When in ROM…

One of the most obvious ways to download your embedded software is to load

the binary image into a read-only memory device and insert that chip into a socket

on the target board. Obviously, the contents of a truly read-only memory device

could not be overwritten. However, as you’ll see in Chapter 6, Memory, embed-

ded systems commonly employ special read-only memory devices that can be pro-

grammed (or reprogrammed) with the help of a special piece of equipment called

a device programmer. A device ...