sh-rtems-as






AS − the portable GNU assembler.

as [−a[cdhlns][=file]] [−D] [−−defsym sym=val]
 [−f] [−−gstabs] [−−gdwarf2] [−−help] [−I dir]
 [−J] [−K] [−L]
 [−−listing−lhs−width=NUM] [−−listing−lhs−width2=NUM]
 [−−listing−rhs−width=NUM] [−−listing−cont−lines=NUM]
 [−−keep−locals] [−o objfile] [−R] [−−statistics] [−v]
 [−version] [−−version] [−W] [−−warn] [−−fatal−warnings]
 [−w] [−x] [−Z] [−−target−help] [target‐options]
 [−−files ...]

     Target Alpha options:
   [−mcpu]
   [−mdebug −no−mdebug]
   [−relax] [−g] [−Gsize]
   [−F] [−32addr]

     Target ARC options:
   [−marc[5⎪6⎪7⎪8]]
   [−EB−EL]

     Target ARM options:
   [−mcpu=processor[+extension...]]
   [−march=architecture[+extension...]]
   [−mfpu=floating‐point‐fromat]
   [−mthumb]
   [−EB−EL]
   [−mapcs−32−mapcs−26−mapcs−float−mapcs−reentrant]
   [−mthumb−interwork] [−moabi] [−k]

     Target CRIS options:
   [−−underscore −−no−underscore]
   [−−pic] [−N]
   [−−emulation=criself −−emulation=crisaout]

     Target D10V options:
   [−O]

     Target D30V options:
   [−O−n−N]

     Target i386 options:
   [−−32−−64]

     Target i960 options:
   [−ACA−ACA_A−ACB−ACC−AKA−AKB−AKC−AMC]
   [−b] [−no−relax]

     Target M32R options:
   [−−m32rx−−[no−]warn−explicit−parallel−conflicts−−W[n]p]









                             ‐2‐


     Target M680X0 options:
   [−l] [−m68000−m68010−m68020⎪...]

     Target M68HC11 options:
   [−m68hc11−m68hc12]
   [−−force−long−branchs] [−−short−branchs]
   [−−strict−direct−mode] [−−print−insn−syntax]
   [−−print−opcodes] [−−generate−example]

     Target MCORE options:
   [−jsri2bsr] [−sifilter] [−relax]
   [−mcpu=[210⎪340]]

     Target MIPS options:
   [−nocpp] [−EL] [−EB] [−n] [−O[optimization level]]
   [−g[debug level]] [−G num] [−KPIC] [−call_shared]
   [−non_shared] [−xgot] [−−membedded−pic]
   [−mabi=ABI] [−32] [−n32] [−64] [−mfp32] [−mgp32]
   [−march=CPU] [−mtune=CPU] [−mips1] [−mips2]
   [−mips3] [−mips4] [−mips5] [−mips32] [−mips64]
   [−construct−floats] [−no−construct−floats]
   [−trap] [−no−break] [−break] [−no−trap]
   [−mfix7000] [−mno−fix7000]
   [−mips16] [−no−mips16]
   [−mips3d] [−no−mips3d]
   [−mdmx] [−no−mdmx]
   [−mdebug] [−no−mdebug]

     Target MMIX options:
   [−−fixed−special−register−names] [−−globalize−symbols]
   [−−gnu−syntax] [−−relax] [−−no−predefined−symbols]
   [−−no−expand] [−−no−merge−gregs] [−x]
   [−−linker−allocated−gregs]

     Target PDP11 options:
   [−mpic−mno−pic] [−mall] [−mno−extensions]
   [−mextension−mno−extension]
   [−mcpu] [−mmachine]

     Target picoJava options:
   [−mb−me]

     Target PowerPC options:
   [−mpwrx−mpwr2−mpwr−m601−mppc−mppc32−m603−m604−m403−m405−mppc64−m620−mppc64bridge−mbooke−mbooke32−mbooke64]
   [−mcom−many−maltivec] [−memb]
   [−mregnames−mno−regnames]
   [−mrelocatable−mrelocatable−lib]
   [−mlittle−mlittle−endian−mbig−mbig−endian]
   [−msolaris−mno−solaris]

     Target SPARC options:
   [−Av6−Av7−Av8−Asparclet−Asparclite









                             ‐3‐


    −Av8plus−Av8plusa−Av9−Av9a]
   [−xarch=v8plus−xarch=v8plusa] [−bump]
   [−32−64]

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.

     as is primarily intended to assemble the output of the
GNU C compiler  for use by the linker .  Nevertheless, we’ve
tried to make as assemble correctly everything that other
assemblers for the same machine would assemble.  Any
exceptions are documented explicitly.  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.)

     You give as a command line that has zero or more input
file names.  The input files are read (from left file name
to right).  A command line argument (in any position) that
has no special meaning is taken to be an input file name.

     If you give as 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.

     If the source is empty, as produces a small, empty
object file.

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

     If you are invoking as via the GNU C compiler (version
2), you can use the −Wa option to pass arguments through to
the assembler.  The assembler arguments must be separated
from each other (and the −Wa) by commas.  For example:

             gcc ‐c ‐g ‐O ‐Wa,‐alh,‐L file.c










                             ‐4‐


     This passes two options to the assembler: −alh (emit a
listing to standard output with high‐level and assembly
source) and −L (retain local symbols in the symbol table).

     Usually you do not need to use this −Wa mechanism,
since many compiler command‐line options are automatically
passed to the assembler by the compiler.  (You can call the
GNU compiler driver with the −v option to see precisely what
options it passes to each compilation pass, including the
assembler.)



−a[cdhlmns]
    Turn on listings, in any of a variety of ways:

    −ac omit false conditionals

    −ad omit debugging directives

    −ah include high‐level source

    −al include assembly

    −am include macro expansions

    −an omit forms processing

    −as include symbols

    =file
        set the name of the listing file

        You may combine these options; for example, use −aln
        for assembly listing without forms processing.  The
        =file option, if used, must be the last one.  By
        itself, −a defaults to −ahls.

−D  Ignored.  This option is accepted for script
    compatibility with calls to other assemblers.

−−defsym sym=value
    Define the symbol sym to be value before assembling the
    input file.  value must be an integer constant.  As in
    C, a leading 0x indicates a hexadecimal value, and a
    leading 0 indicates an octal value.

−f  ‘‘fast’’−−−skip whitespace and comment preprocessing
    (assume source is compiler output).

−−gstabs
    Generate stabs debugging information for each assembler
    line.  This may help debugging assembler code, if the
    debugger can handle it.









                             ‐5‐


−−gdwarf2
    Generate DWARF2 debugging information for each assembler
    line.  This may help debugging assembler code, if the
    debugger can handle it.  Note − this option is only
    supported by some targets, not all of them.

−−help
    Print a summary of the command line options and exit.

−−target−help
    Print a summary of all target specific options and exit.

−I dir
    Add directory dir to the search list for ".include"
    directives.

−J  Don’t warn about signed overflow.

−K  This option is accepted but has no effect on the TARGET
    family.

−L

−−keep−locals
    Keep (in the symbol table) local symbols.  On
    traditional a.out systems these start with L, but
    different systems have different local label prefixes.

−−listing−lhs−width=number
    Set the maximum width, in words, of the output data
    column for an assembler listing to number.

−−listing−lhs−width2=number
    Set the maximum width, in words, of the output data
    column for continuation lines in an assembler listing to
    number.

−−listing−rhs−width=number
    Set the maximum width of an input source line, as
    displayed in a listing, to number bytes.

−−listing−cont−lines=number
    Set the maximum number of lines printed in a listing for
    a single line of input to number + 1.

−o objfile
    Name the object‐file output from as objfile.

−R  Fold the data section into the text section.

−−statistics
    Print the maximum space (in bytes) and total time (in
    seconds) used by assembly.










                             ‐6‐


−−strip−local−absolute
    Remove local absolute symbols from the outgoing symbol
    table.

−v

−version
    Print the as version.

−−version
    Print the as version and exit.

−W

−−no−warn
    Suppress warning messages.

−−fatal−warnings
    Treat warnings as errors.

−−warn
    Don’t suppress warning messages or treat them as errors.

−w  Ignored.

−x  Ignored.

−Z  Generate an object file even after errors.

−− ⎪ files ...
    Standard input, or source files to assemble.

     The following options are available when as is
configured for an ARC processor.

−marc[5⎪6⎪7⎪8]
    This option selects the core processor variant.

−EB ⎪ −EL
    Select either big‐endian (−EB) or little‐endian (−EL)
    output.

     The following options are available when as is
configured for the ARM processor family.

−mcpu=processor[+extension...]
    Specify which ARM processor variant is the target.

−march=architecture[+extension...]
    Specify which ARM architecture variant is used by the
    target.

−mfpu=floating‐point‐format
    Select which Floating Point architecture is the target.









                             ‐7‐


−mthumb
    Enable Thumb only instruction decoding.

−mapcs−32 ⎪ −mapcs−26 ⎪ −mapcs−float ⎪ −mapcs−reentrant ⎪
    −moabi
    Select which procedure calling convention is in use.

−EB ⎪ −EL
    Select either big‐endian (−EB) or little‐endian (−EL)
    output.

−mthumb−interwork
    Specify that the code has been generated with
    interworking between Thumb and ARM code in mind.

−k  Specify that PIC code has been generated.

     See the info pages for documentation of the CRIS‐
specific options.

     The following options are available when as is
configured for a D10V processor.

−O  Optimize output by parallelizing instructions.

     The following options are available when as is
configured for a D30V processor.

−O  Optimize output by parallelizing instructions.

−n  Warn when nops are generated.

−N  Warn when a nop after a 32−bit multiply instruction is
    generated.

     The following options are available when as is
configured for the Intel 80960 processor.

−ACA ⎪ −ACA_A ⎪ −ACB ⎪ −ACC ⎪ −AKA ⎪ −AKB ⎪ −AKC ⎪ −AMC
    Specify which variant of the 960 architecture is the
    target.

−b  Add code to collect statistics about branches taken.

−no−relax
    Do not alter compare‐and‐branch instructions for long
    displacements; error if necessary.

     The following options are available when as is
configured for the Mitsubishi M32R series.

−−m32rx
    Specify which processor in the M32R family is the
    target.  The default is normally the M32R, but this









                             ‐8‐


    option changes it to the M32RX.

−−warn−explicit−parallel−conflicts or −−Wp
    Produce warning messages when questionable parallel
    constructs are encountered.

−−no−warn−explicit−parallel−conflicts or −−Wnp
    Do not produce warning messages when questionable
    parallel constructs are encountered.

     The following options are available when as is
configured for the Motorola 68000 series.

−l  Shorten references to undefined symbols, to one word
    instead of two.

−m68000 ⎪ −m68008 ⎪ −m68010 ⎪ −m68020 ⎪ −m68030

⎪ −m68040 ⎪ −m68060 ⎪ −m68302 ⎪ −m68331 ⎪ −m68332

⎪ −m68333 ⎪ −m68340 ⎪ −mcpu32 ⎪ −m5200
    Specify what processor in the 68000 family is the
    target.  The default is normally the 68020, but this can
    be changed at configuration time.

−m68881 ⎪ −m68882 ⎪ −mno−68881 ⎪ −mno−68882
    The target machine does (or does not) have a floating‐
    point coprocessor.  The default is to assume a
    coprocessor for 68020, 68030, and cpu32.  Although the
    basic 68000 is not compatible with the 68881, a
    combination of the two can be specified, since it’s
    possible to do emulation of the coprocessor instructions
    with the main processor.

−m68851 ⎪ −mno−68851
    The target machine does (or does not) have a memory‐
    management unit coprocessor.  The default is to assume
    an MMU for 68020 and up.

     For details about the PDP−11 machine dependent features
options, see @ref{PDP−11−Options}.

−mpic ⎪ −mno−pic
    Generate position‐independent (or position−dependent)
    code.  The default is −mpic.

−mall

−mall−extensions
    Enable all instruction set extensions.  This is the
    default.

−mno−extensions
    Disable all instruction set extensions.









                             ‐9‐


−mextension ⎪ −mno−extension
    Enable (or disable) a particular instruction set
    extension.

−mcpu
    Enable the instruction set extensions supported by a
    particular CPU, and disable all other extensions.

−mmachine
    Enable the instruction set extensions supported by a
    particular machine model, and disable all other
    extensions.

     The following options are available when as is
configured for a picoJava processor.

−mb Generate ‘‘big endian’’ format output.

−ml Generate ‘‘little endian’’ format output.

     The following options are available when as is
configured for the Motorola 68HC11 or 68HC12 series.

−m68hc11 ⎪ −m68hc12
    Specify what processor is the target.  The default is
    defined by the configuration option when building the
    assembler.

−−force−long−branchs
    Relative branches are turned into absolute ones. This
    concerns conditional branches, unconditional branches
    and branches to a sub routine.

−S ⎪ −−short−branchs
    Do not turn relative branchs into absolute ones when the
    offset is out of range.

−−strict−direct−mode
    Do not turn the direct addressing mode into extended
    addressing mode when the instruction does not support
    direct addressing mode.

−−print−insn−syntax
    Print the syntax of instruction in case of error.

−−print−opcodes
    print the list of instructions with syntax and then
    exit.

−−generate−example
    print an example of instruction for each possible
    instruction and then exit.  This option is only useful
    for testing as.










                            ‐10‐


     The following options are available when as is
configured for the SPARC architecture:

−Av6 ⎪ −Av7 ⎪ −Av8 ⎪ −Asparclet ⎪ −Asparclite

−Av8plus ⎪ −Av8plusa ⎪ −Av9 ⎪ −Av9a
    Explicitly select a variant of the SPARC architecture.

    −Av8plus and −Av8plusa select a 32 bit environment.
    −Av9 and −Av9a select a 64 bit environment.

    −Av8plusa and −Av9a enable the SPARC V9 instruction set
    with UltraSPARC extensions.

−xarch=v8plus ⎪ −xarch=v8plusa
    For compatibility with the Solaris v9 assembler.  These
    options are equivalent to −Av8plus and −Av8plusa,
    respectively.

−bump
    Warn when the assembler switches to another
    architecture.

     The following options are available when as is
configured for a MIPS processor.

−G num
    This option sets the largest size of an object that can
    be referenced implicitly with the "gp" register.  It is
    only accepted for targets that use ECOFF format, such as
    a DECstation running Ultrix.  The default value is 8.

−EB Generate ‘‘big endian’’ format output.

−EL Generate ‘‘little endian’’ format output.

−mips1

−mips2

−mips3

−mips4

−mips5

−mips32

−mips64
    Generate code for a particular MIPS Instruction Set
    Architecture level.  −mips1 is an alias for
    −march=r3000, −mips2 is an alias for −march=r6000,
    −mips3 is an alias for −march=r4000 and −mips4 is an
    alias for −march=r8000.  −mips5, −mips32, and −mips64









                            ‐11‐


    correspond to generic MIPS V, MIPS32, and MIPS64 ISA
    processors, respectively.

−march=CPU
    Generate code for a particular MIPS cpu.

−mtune=cpu
    Schedule and tune for a particular MIPS cpu.

−mfix7000

−mno−fix7000
    Cause nops to be inserted if the read of the destination
    register of an mfhi or mflo instruction occurs in the
    following two instructions.

−mdebug

−no−mdebug
    Cause stabs‐style debugging output to go into an ECOFF‐
    style .mdebug section instead of the standard ELF .stabs
    sections.

−mgp32

−mfp32
    The register sizes are normally inferred from the ISA
    and ABI, but these flags force a certain group of
    registers to be treated as 32 bits wide at all times.
    −mgp32 controls the size of general‐purpose registers
    and −mfp32 controls the size of floating‐point
    registers.

−mips16

−no−mips16
    Generate code for the MIPS 16 processor.  This is
    equivalent to putting ".set mips16" at the start of the
    assembly file.  −no−mips16 turns off this option.

−mips3d

−no−mips3d
    Generate code for the MIPS−3D Application Specific
    Extension.  This tells the assembler to accept MIPS−3D
    instructions.  −no−mips3d turns off this option.

−mdmx

−no−mdmx
    Generate code for the MDMX Application Specific
    Extension.  This tells the assembler to accept MDMX
    instructions.  −no−mdmx turns off this option.










                            ‐12‐


−−construct−floats

−−no−construct−floats
    The −−no−construct−floats option disables the
    construction of double width floating point constants by
    loading the two halves of the value into the two single
    width floating point registers that make up the double
    width register.  By default −−construct−floats is
    selected, allowing construction of these floating point
    constants.

−−emulation=name
    This option causes as to emulate as configured for some
    other target, in all respects, including output format
    (choosing between ELF and ECOFF only), handling of
    pseudo‐opcodes which may generate debugging information
    or store symbol table information, and default
    endianness.  The available configuration names are:
    mipsecoff, mipself, mipslecoff, mipsbecoff, mipslelf,
    mipsbelf.  The first two do not alter the default
    endianness from that of the primary target for which the
    assembler was configured; the others change the default
    to little− or big‐endian as indicated by the b or l in
    the name.  Using −EB or −EL will override the endianness
    selection in any case.

    This option is currently supported only when the primary
    target as is configured for is a MIPS ELF or ECOFF
    target.  Furthermore, the primary target or others
    specified with −−enable−targets=... at configuration
    time must include support for the other format, if both
    are to be available.  For example, the Irix 5
    configuration includes support for both.

    Eventually, this option will support more
    configurations, with more fine‐grained control over the
    assembler’s behavior, and will be supported for more
    processors.

−nocpp
    as ignores this option.  It is accepted for
    compatibility with the native tools.

−−trap

−−no−trap

−−break

−−no−break
    Control how to deal with multiplication overflow and
    division by zero.  −−trap or −−no−break (which are
    synonyms) take a trap exception (and only work for
    Instruction Set Architecture level 2 and higher);









                            ‐13‐


    −−break or −−no−trap (also synonyms, and the default)
    take a break exception.

−n  When this option is used, as will issue a warning every
    time it generates a nop instruction from a macro.

     The following options are available when as is
configured for an MCore processor.

−jsri2bsr

−nojsri2bsr
    Enable or disable the JSRI to BSR transformation.  By
    default this is enabled.  The command line option
    −nojsri2bsr can be used to disable it.

−sifilter

−nosifilter
    Enable or disable the silicon filter behaviour.  By
    default this is disabled.  The default can be overridden
    by the −sifilter command line option.

−relax
    Alter jump instructions for long displacements.

−mcpu=[210⎪340]
    Select the cpu type on the target hardware.  This
    controls which instructions can be assembled.

−EB Assemble for a big endian target.

−EL Assemble for a little endian target.

     See the info pages for documentation of the MMIX‐
specific options.

gcc(1), ld(1), and the Info entries for binutils and ld.

Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000,
2001, 2002 Free Software Foundation, Inc.

     Permission is granted to copy, distribute and/or modify
this document under the terms of the GNU Free Documentation
License, Version 1.1 or any later version published by the
Free Software Foundation; with no Invariant Sections, with
no Front‐Cover Texts, and with no Back‐Cover Texts.  A copy
of the license is included in the section entitled "GNU Free
Documentation License".