NAME
GNU as--the portable GNU assembler.

SYNOPSIS
as [-D] [-f] [-k] [-L] [-o objfile] [-R] [-v] [-w] [-- | files...]

m680x0-only options:
[-l] [-mc68000|-mc68010|-mc68020

DESCRIPTION
GNU as is really a family of assemblers. If you use (or have used)
the GNU assembler on one architecture, you should find a fairly
similar environment when you use it on another architecture. Each
version has much in common with the others, including object file
formats, most assembler directives (often called pseudo-ops) and
assembler syntax.

For information on the syntax and pseudo-ops used by GNU as, see
‘as’ entry in info (or the manual Using as: The GNU Assembler).

as is primarily intended to assemble the output of the GNU C
compiler gcc for use by the linker ld. Nevertheless, we’ve tried
to make as assemble correctly everything that the native assembler
would. This doesn’t mean as always uses the same syntax as another
assembler for the same architecture; for example, we know of
several incompatible versions of 680x0 assembly language syntax.

Each time you run as it assembles exactly one source program. The
source program is made up of one or more files. (The standard
input is also a file.)

If as is given no file names it attempts to read one input file
from the as standard input, which is normally your terminal. You
may have to type ctl-D to tell as there is no more program to
assemble. Use ‘--’ if you need to explicitly name the standard
input file in your command line.

as may write warnings and error messages to the standard error file
(usually your terminal). This should not happen when as is run
automatically by a compiler. Warnings report an assumption made so
that as could keep assembling a flawed program; errors report a
grave problem that stops the assembly.

OPTIONS
-D This option is accepted only for script compatibility with
calls to other assemblers; it has no effect on as.

-f "fast"--skip preprocessing (assume source is compiler
output).

-k Issue warnings when difference tables altered for long
displacements.

-L Keep (in symbol table) local symbols, starting with ‘L’

-o objfile
Name the object-file output from as

-R Fold data section into text section

-v Announce as version

-W Suppress warning messages

-- | files...
Source files to assemble, or standard input (--)

-l (When configured for Motorola 68000).
Shorten references to undefined symbols, to one word instead
of two.

-mc68000|-mc68010|-mc68020
(When configured for Motorola 68000).
Specify what processor in the 68000 family is the target
(default 68000).

Options may be in any order, and may be before, after, or between
file names. The order of file names is significant.

‘--’ (two hyphens) by itself names the standard input file
explicitly, as one of the files for as to assemble.

Except for ‘--’ any command line argument that begins with a hyphen
(‘-’) is an option. Each option changes the behavior of as. No
option changes the way another option works. An option is a ‘-’
followed by one or more letters; the case of the letter is
important. All options are optional.

The ‘-o’ option expects exactly one file name to follow. The file
name may either immediately follow the option’s letter (compatible
with older assemblers) or it may be the next command argument (GNU
standard).

These two command lines are equivalent:
as -o my-object-file.o mumble.s
as -omy-object-file.o mumble.s

SEE ALSO
gcc(1), ld(1);
Using as: The GNU Assembler

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