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diff --git a/x/binutils/gas/README b/x/binutils/gas/README new file mode 100644 index 0000000..7905395 --- /dev/null +++ b/x/binutils/gas/README @@ -0,0 +1,241 @@ + 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 sun4 + sparc-sun-sunos411 + % sh config.sub sun3 + m68k-sun-sunos411 + % sh config.sub decstation + mips-dec-ultrix42 + % sh config.sub hp300bsd + m68k-hp-bsd + % 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. + +Supported platforms +=================== + +At this point I believe gas to be ANSI only code for most target cpu's. That +is, there should be relatively few, if any host system dependencies. So +porting (as a cross-assembler) to hosts not yet supported should be fairly +easy. Porting to a new target shouldn't be too tough if it's a variant of one +already supported. + +Native assembling should work on: + + sun3 + sun4 + 386bsd + bsd/386 + delta (m68k-sysv from Motorola) + delta88 (m88k-sysv from Motorola) + GNU/linux + m68k hpux 8.0 (hpux 7.0 may be a problem) + vax bsd, ultrix, vms + hp9000s300 + decstation + irix 4 + irix 5 + miniframe (m68k-sysv from Convergent Technologies) + i386-aix (ps/2) + hppa (hpux 4.3bsd, osf1) + AIX + unixware + sco 3.2v4.2 + sco openserver 5.0 (a.k.a. 3.2v5.0 ) + sparc solaris + ns32k (netbsd, lites) + +I believe that gas as a cross-assembler can currently be targeted for +most of the above hosts, plus + + arm + decstation-bsd (a.out format, to be used in BSD 4.4) + ebmon29k + go32 (DOS on i386, with DJGPP -- old a.out version) + H8/300, H8/500 (Hitachi) + i386-aix (ps/2) + i960-coff + mips ecoff (decstation-ultrix, iris, mips magnum, mips-idt-ecoff) + Mitsubishi d10v and d30v + nindy960 + powerpc EABI + SH (Hitachi) + sco386 + TI tic30 and tic80 + vax bsd or ultrix? + vms + vxworks68k + vxworks960 + z8000 (Zilog) + +MIPS ECOFF support has been added, but GAS will not run a C-style +preprocessor. If you want that, rename your file to have a ".S" suffix, and +run gcc on it. Or run "gcc -xassembler-with-cpp foo.s". + +Support for ELF should work now for sparc, hppa, i386, alpha, m68k, +MIPS, powerpc. + +Support for sequent (ns32k), tahoe, i860 may be suffering from bitrot. + +If you try out gas on some host or target not listed above, please let me know +the results, so I can update the list. + +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. |
