adding a new target (m68k-gnu)

adding a new target (m68k-gnu)

[Aymeric Vincent]

  Hi,

Could you please add a new m68k-gnu target to the binutils? It's
basically an elf target, like i386-gnu (without mach3 stuff) or
m68k-linux.

I give you a very small README I wrote to explain the changes that
have to be done, but there is (at least) *one* thing which is wrong
with it:

I would like to have REGISTER_PREFIX_OPTIONAL set for this target, but
didn't figure out where it had to be put... I just put it in tc-m68k.h
(as described below), but it's of course a stupid solution, which did
the trick for what I had to do...

Thanks a lot, let me know if you need any more information,
Aymeric

--- snip ---

 You have to change the following files in order to support the m68k-gnu
target:

 - binutils-2.8.1/bfd/config.bfd

Add the following lines to the big case statement:

  m68*-*-gnu*)
    targ_defvec=bfd_elf32_m68k_vec
#    targ_selvecs=m68kmach3_vec
    targ_cflags=-DSTAT_FOR_EXEC
    ;;

 - binutils-2.8.1/gas/config/tc-m68k.h

Add this line at the beginning of the file (that's really ugly)

#define REGISTER_PREFIX_OPTIONAL 1

(you can preferably pass a flag to make if you want
.. or use an option of gas everytime you use it...)

 - binutils-2.8.1/gas/configure.in

Add this line to the huge case statement

      m68k-*-gnu*)          fmt=elf ;;

 - binutils-2.8.1/ld/configure.tgt

Add this line to the case statement

m68*-*-gnu*)            targ_emul=m68kelf ;;

--- snip ---

-- 
I am a poet:
 Linux
 Sucks

Re: adding a new target (m68k-gnu)

[Ian Lance Taylor]

   Date: Tue, 27 Oct 1998 15:12:03 +0100
   From: Aymeric Vincent <Aymeric.Vincent@emi.u-bordeaux.fr>

   Could you please add a new m68k-gnu target to the binutils? It's
   basically an elf target, like i386-gnu (without mach3 stuff) or
   m68k-linux.

I patched bfd/config.bfd, gas/configure.in, and ld/configure.tgt for
m68k-gnu.  Sorry about the long delay.

   I would like to have REGISTER_PREFIX_OPTIONAL set for this target, but
   didn't figure out where it had to be put... I just put it in tc-m68k.h
   (as described below), but it's of course a stupid solution, which did
   the trick for what I had to do...

I don't understand why you want to make this change.  This is normally
the wrong thing to do for an m68k ELF target.  The macro only exists
for target with a lot of legacy m68k code which does not use register
prefixes, but presumably that is not the case for m68k-gnu.  The flag
should not normally be set when compiling C code, unless the compiler
has been modified to use leading underscores on symbol names;
otherwise, the flag can cause gas to misassemble C code which uses
function or global variables with names that happen to be the same as
m68k register names.

Ian

Re: adding a new target (m68k-gnu)

[Aymeric Vincent]

>>  I would like to have REGISTER_PREFIX_OPTIONAL set for this target, but

>I don't understand why you want to make this change.  This is normally
>the wrong thing to do for an m68k ELF target.  The macro only exists
>for target with a lot of legacy m68k code which does not use register
>prefixes, but presumably that is not the case for m68k-gnu.

 Well, there is already some assembly typed but it's true that there
aren't plenty of it. Thank you very much for the support, I'll just
add percent-signs (I guess that's the right prefix) to my code... :)
BTW, it's better to have it that way since the people behind the HURD
seem to want it as compatible with Linux as possible...

Thanks again,
Aymeric