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

as: Assembler XENIX Programming
Instructions and data definitions with initial values must not be used after a .bss
directive, but symbols may be defined and dot moved by assignment.
If no explicit segment directive is given in a program, code is copied to the text
segment.
Common Directive
.comm name [, expression
The .comm directive makes name globally known to all files of the program. If name
also appears in an assignment or as a label in a file, then the .comm directive has the
same effect as the .globl directive. In this case, any expression given is ignored. If
name does not have an explicit definition, then .comm directs the XENIX linker to
automatically allocate expression bytes for name in the bss segment of the program.
These bytes appear before any bytes specifically allocated within the bss segment.
Insert Directive
.insrt "filename"
The .insrt directive directs the assembler to suspend processing of the current file until
all statements in the given file have been read. filename must be enclosed within
double quotation marks. If the file cannot be opened or does not exist, the assembler
displays the message
Cannot open insert file
Otherwise, it reads the contents of the file. The file may contain other .insrt
directives; up to ten levels of directives may be nested in this way.
The .insrt directive is useful for including a standard set of comments or symbol
assignments at the beginning of a program, e.g., the definitions for system calls found in
the file /usr/include/sys.s. The directive is also useful for breaking up a large source
program into easily manageable pieces.
ASCII Directives
.ascii /string/
.asciz /string/
The .ascii and .asciz directives translate string into an equivalent sequence of ASCII
byte values and copy these bytes to allocated storage in the current segment. The
.asciz directive also appends a null byte to the end of the sequence.
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