Hardware Reference
In-Depth Information
5 Linking modules (including those taken from the user's library) in order to
produce a complete executable program.
6 Testing, debugging, and documenting the final program prior to evaluation
and/or acceptance testing by the end-user (see Chapter 4).
In practice, the development process is largely iterative and there may also
be some considerable overlap between phases. In order to ensure that the tar-
get specification is met within the constraints of time and budget, an ongoing
appraisal is necessary in order to maximize resources in the areas for which
there is much need.
Software tools
The following items of utility software (software tools) are normally required
in the development process:
•
an ASCII text editor (e.g. Microsoft's M);
•
a macro assembler (e.g. Microsoft's MASM);
•
a linker (e.g. Microsoft's LINK).
In
addition,
three
further
software
tools
may
be
found
to
be
invaluable.
These are:
•
a cross-referencing utility (e.g. Microsoft's CREF);
•
a library manager (e.g. Microsoft's LIB);
•
a utility which can help automate the program development cycle (e.g.
Microsoft's MAKE).
Note that, in order to assist the programmer and to help automate the produc-
tion of executable code, an
Integrated Development Environment
(IDE) is often
used. This acts as a 'shell' which launches the various software tools, passing
any required parameters without requiring the user to be aware of the necessary
command syntax. However, for the benefit of the newcomer to assembly lan-
guage programming, we shall briefly explain the function of each of the basic
tools and their role in the production of assembly language programs.
Editors
Editors allow users to create and manipulate text files. Such files can be thought
of as a sequence of keystrokes saved to disk. An assembly language
source
code
file is simply a text file written using assembly language mnemonics and
containing appropriate
assembler directives.
The
Microsoft Editor
(M) is invoked using a command line of the form:
M <options><file list>
The options include that of allowing the user to load a previously saved con-
figuration file (TOOLS.INI). This file contains settings which will be used to
initialize the editor and thus the user may easily customize the software to
his/her own particular requirements. The file list is simply a list of files that will
be loaded into the editor. The first file in the list will be the first to be edited.
Then, when the user selects the exit option (F8), the next file in the list, ready
for editing, is loaded.
