171 lines
6.2 KiB
Plaintext
171 lines
6.2 KiB
Plaintext
README for GAS
|
||
|
||
A number of things have changed since version 1 and the wonderful
|
||
world of gas looks very different. There's still a lot of irrelevant
|
||
garbage lying around that will be cleaned up in time. Documentation
|
||
is scarce, as are logs of the changes made since the last gas release.
|
||
My apologies, and I'll try to get something useful.
|
||
|
||
Unpacking and Installation - Summary
|
||
====================================
|
||
|
||
See ../binutils/README.
|
||
|
||
To build just the assembler, make the target all-gas.
|
||
|
||
Documentation
|
||
=============
|
||
|
||
The GAS release includes texinfo source for its manual, which can be processed
|
||
into `info' or `dvi' forms.
|
||
|
||
The DVI form is suitable for printing or displaying; the commands for doing
|
||
this vary from system to system. On many systems, `lpr -d' will print a DVI
|
||
file. On others, you may need to run a program such as `dvips' to convert the
|
||
DVI file into a form your system can print.
|
||
|
||
If you wish to build the DVI file, you will need to have TeX installed on your
|
||
system. You can rebuild it by typing:
|
||
|
||
cd gas/doc
|
||
make as.dvi
|
||
|
||
The Info form is viewable with the GNU Emacs `info' subsystem, or the
|
||
stand-alone `info' program, available as part of the GNU Texinfo distribution.
|
||
To build the info files, you will need the `makeinfo' program. Type:
|
||
|
||
cd gas/doc
|
||
make info
|
||
|
||
Specifying names for hosts and targets
|
||
======================================
|
||
|
||
The specifications used for hosts and targets in the `configure'
|
||
script are based on a three-part naming scheme, but some short
|
||
predefined aliases are also supported. The full naming scheme encodes
|
||
three pieces of information in the following pattern:
|
||
|
||
ARCHITECTURE-VENDOR-OS
|
||
|
||
For example, you can use the alias `sun4' as a HOST argument or in a
|
||
`--target=TARGET' option. The equivalent full name is
|
||
`sparc-sun-sunos4'.
|
||
|
||
The `configure' script accompanying GAS does not provide any query
|
||
facility to list all supported host and target names or aliases.
|
||
`configure' calls the Bourne shell script `config.sub' to map
|
||
abbreviations to full names; you can read the script, if you wish, or
|
||
you can use it to test your guesses on abbreviations--for example:
|
||
|
||
% sh config.sub i386v
|
||
i386-unknown-sysv
|
||
% sh config.sub i786v
|
||
Invalid configuration `i786v': machine `i786v' not recognized
|
||
|
||
|
||
`configure' options
|
||
===================
|
||
|
||
Here is a summary of the `configure' options and arguments that are
|
||
most often useful for building GAS. `configure' also has several other
|
||
options not listed here.
|
||
|
||
configure [--help]
|
||
[--prefix=DIR]
|
||
[--srcdir=PATH]
|
||
[--host=HOST]
|
||
[--target=TARGET]
|
||
[--with-OPTION]
|
||
[--enable-OPTION]
|
||
|
||
You may introduce options with a single `-' rather than `--' if you
|
||
prefer; but you may abbreviate option names if you use `--'.
|
||
|
||
`--help'
|
||
Print a summary of the options to `configure', and exit.
|
||
|
||
`-prefix=DIR'
|
||
Configure the source to install programs and files under directory
|
||
`DIR'.
|
||
|
||
`--srcdir=PATH'
|
||
Look for the package's source code in directory DIR. Usually
|
||
`configure' can determine that directory automatically.
|
||
|
||
`--host=HOST'
|
||
Configure GAS to run on the specified HOST. Normally the
|
||
configure script can figure this out automatically.
|
||
|
||
There is no convenient way to generate a list of all available
|
||
hosts.
|
||
|
||
`--target=TARGET'
|
||
Configure GAS for cross-assembling programs for the specified
|
||
TARGET. Without this option, GAS is configured to assemble .o files
|
||
that run on the same machine (HOST) as GAS itself.
|
||
|
||
There is no convenient way to generate a list of all available
|
||
targets.
|
||
|
||
`--enable-OPTION'
|
||
These flags tell the program or library being configured to
|
||
configure itself differently from the default for the specified
|
||
host/target combination. See below for a list of `--enable'
|
||
options recognized in the gas distribution.
|
||
|
||
`configure' accepts other options, for compatibility with configuring
|
||
other GNU tools recursively; but these are the only options that affect
|
||
GAS or its supporting libraries.
|
||
|
||
The `--enable' options recognized by software in the gas distribution are:
|
||
|
||
`--enable-targets=...'
|
||
This causes one or more specified configurations to be added to those for
|
||
which BFD support is compiled. Currently gas cannot use any format other
|
||
than its compiled-in default, so this option is not very useful.
|
||
|
||
`--enable-bfd-assembler'
|
||
This causes the assembler to use the new code being merged into it to use
|
||
BFD data structures internally, and use BFD for writing object files.
|
||
For most targets, this isn't supported yet. For most targets where it has
|
||
been done, it's already the default. So generally you won't need to use
|
||
this option.
|
||
|
||
Compiler Support Hacks
|
||
======================
|
||
|
||
On a few targets, the assembler has been modified to support a feature
|
||
that is potentially useful when assembling compiler output, but which
|
||
may confuse assembly language programmers. If assembler encounters a
|
||
.word pseudo-op of the form symbol1-symbol2 (the difference of two
|
||
symbols), and the difference of those two symbols will not fit in 16
|
||
bits, the assembler will create a branch around a long jump to
|
||
symbol1, and insert this into the output directly before the next
|
||
label: The .word will (instead of containing garbage, or giving an
|
||
error message) contain (the address of the long jump)-symbol2. This
|
||
allows the assembler to assemble jump tables that jump to locations
|
||
very far away into code that works properly. If the next label is
|
||
more than 32K away from the .word, you lose (silently); RMS claims
|
||
this will never happen. If the -K option is given, you will get a
|
||
warning message when this happens.
|
||
|
||
|
||
REPORTING BUGS IN GAS
|
||
=====================
|
||
|
||
Bugs in gas should be reported to:
|
||
|
||
bug-binutils@gnu.org.
|
||
|
||
They may be cross-posted to gcc-bugs@gnu.org if they affect the use of
|
||
gas with gcc. They should not be reported just to gcc-bugs, since not
|
||
all of the maintainers read that list.
|
||
|
||
See ../binutils/README for what we need in a bug report.
|
||
|
||
Copyright (C) 2012-2014 Free Software Foundation, Inc.
|
||
|
||
Copying and distribution of this file, with or without modification,
|
||
are permitted in any medium without royalty provided the copyright
|
||
notice and this notice are preserved.
|