Intel XENIX 286 Programmers Guide (86) - Tenox.tc

XENIX Programming adb: Program Debugger
Setting the Maximum Offset
adb normally displays memory and file addresses as the sum of a symbol and an offset.
This helps associate the instructions and data you are viewing with a given function or
variable. When first invoked, adb sets the maximum offset to 255. This means
instructions or data no more than 255 bytes from the start of the function or variable
are given symbolic addresses. Instructions or data beyond this point are given numeric
addresses.
In many programs, the size of a function or variable is actually larger than 255 bytes.
For this reason adb lets you change the maximum offset to accommodate larger
programs. You can change the maximum offset by using the $s command. The
command has the form
n$s
where n is an integer giving the new offset. For example, the command
4095$s
increases the maximum possible offset to 4095. All instructions and data no more than
4095 bytes away are given symbolic addresses.
Note that you can disable all sy mbolic addressing by setting the maximum offset to
zero. All addresses will be given nu meric values instead.
Setting Default Input Format
You can set the default format for numbers used in commands with the $d (decimal), $o
(octal), and $x (hexadecimal) commands. The default format tells adb how to interpret
numbers that do not begin with "O" or "Ox" and how to display numbers when no specific
format is given.
The commands are useful if you wish to work with a combination of decimal, octal, and
hexadecimal numbers. For example, if you use
$x
you may give addresses in hexadecimal without prepending each address with "Ox".
Furthermore, adb displays all numbers in hexadecimal except those specifically
requested to be in some other format.
When you first start adb, the default format is decimal. You may change this at any
time and restore it as necessary using the $d command.
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