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

adb: Program Debugger XENIX Programming
Leaving adb
You can stop adb and return to the system shell by using the $q or $Q commands. You
can also stop the debugger by typing CONTROL-D.
You cannot stop adb by pressing the INTERRUPT or QUIT keys. These keys are caught
by adb and cause it to to wait for a new command.
Displaying Instructions and Data
adb provides several commands for displaying the instructions and data of a given
program and the data of a given data file. The commands have the form
address [, count 1 =
format
address [, count 1 ? format
address [, count 1 I format
where address is a value or expression giving the location of the instruction or data
item, count is an expression giving the number of items to be displayed, and format is an
expression defining how to display the items. The equal sign (=), question mark (?), and
slash (/) tell adb from what source to take the item to be displayed.
The following sections explain how to form addresses, how to choose formats, and how
to use the display commands.
Forming Addresses
In adb, every address has the form
[segment :1 offset
where segment is an expression giving the address of a specific segment of memory, and
offset is an expression giving an offset from the beginning of the specified segment to
the desired item. Segments and offsets are formed by combining numbers, sym bols,
variables, and operators. The following are some valid addresses:
0:1
Ox0bce:772
segment: is optional. If not given, the most recently typed segment is used.
Forming Expressions
Expressions may contain decimal, octal, and hexadecimal integers, sym bols, adb
variables, register names, and a variety of arithmetic and logical operators.
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