| 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: |
| |
| https://sourceware.org/bugzilla/ |
| |
| See ../binutils/README for what we need in a bug report. |
| |
| Copyright (C) 2012-2024 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. |