ARM VERSION 1.2 - Manual (Page 80)

Assembler Reference
3-2 Copyright © 2000, 2001 ARM Limited. All rights reserved. ARM DUI 0068B
3.1 Command syntax
This section relates only to armasm . The inline assemblers are part of the C and C++
compilers, and have no command syntax of their own.
The armasm command line is case-insensitive, except in filenames, and where specified.
Invoke the ARM assembler using this command:
armasm [-16|-32] [-apcs [none|[/qualifier[/qualifier[...]]]]]
[-bigend|-littleend] [-checkreglist] [-cpu cpu] [-depend dependfile|-m|-md]
[-errors errorfile] [-fpu name] [-g] [-help] [-i dir [,dir]…] [-keep] [-list
[listingfile] [options]] [-maxcache n] [-memaccess attributes] [-nocache]
[-noesc] [-noregs] [-nowarn] [-o filename] [-predefine "directive"] [-split_ldm]
[-unsafe] [-via file] inputfile
where:
-16 instructs the assembler to interpret instructions as Thumb instructions.
This is equivalent to a
CODE16 directive at the head of the source file.
-32 instructs the assembler to interpret instructions as ARM instructions.
This is the default.
-apcs [none|[/qualifier[/qualifier[...]]]]
specifies whether you are using the ARM/Thumb Procedure Call
Standard (ATPCS). It can also specify some attributes of code sections.
See ADS Developer Guide for more information about the ATPCS.
/none specifies that inputfile does not use ATPCS. ATPCS registers
are not set up. Qualifiers are not allowed.
Note
ATPCS qualifiers do not affect the code produced by the assembler. They
are an assertion by the programmer that the code in
inputfile complies
with a particular variant of ATPCS. They cause attributes to be set in the
object file produced by the assembler. The linker uses these attributes to
check compatibility of files, and to select appropriate library variants.
Values for qualifier are:
/interwork specifies that the code in inputfile is suitable for
ARM/Thumb interworking. See ADS Developer
Guide for information on interworking.
/nointerwork specifies that the code in inputfile is not suitable
for ARM/Thumb interworking. This is the default.