Cross-assembling for AIX/PowerPC64

[Jonas Maebe <jonas.maebe@elis.ugent.be>]

Hi,

I have configured binutils 2.24 using the following configure command 
(on OS X 10.9):

   ../configure --target=powerpc-ibm-aix53 --with-sysroot --disable-werror

The resulting assembler can assemble for AIX/PowerPC (32 bit) fine. 
However, when I try to assemble for AIX/PowerPC64 with this command:

   powerpc-ibm-aix53-as -a64 -u -o 
../../rtl/units/powerpc64-aix/ctypes.o 
../../rtl/units/powerpc64-aix/ctypes.s -mpwr5

Then I get the following error:

   Assembler messages:
   Fatal error: selected target format 'aixcoff64-rs6000' unknown

Looking at "powerpc-ibm-aix53-objdump -i", these are the supported 
object file formats:

***
aixcoff-rs6000
  (header big endian, data big endian)
   powerpc:common
   rs6000:6000
aix5coff64-rs6000
  (header big endian, data big endian)
   powerpc:common
   rs6000:6000
srec
  (header endianness unknown, data endianness unknown)
   powerpc:common
   rs6000:6000
symbolsrec
  (header endianness unknown, data endianness unknown)
   powerpc:common
   rs6000:6000
verilog
  (header endianness unknown, data endianness unknown)
   powerpc:common
   rs6000:6000
tekhex
  (header endianness unknown, data endianness unknown)
   powerpc:common
   rs6000:6000
binary
  (header endianness unknown, data endianness unknown)
   powerpc:common
   rs6000:6000
ihex
  (header endianness unknown, data endianness unknown)
   powerpc:common
   rs6000:6000

                aixcoff-rs6000 aix5coff64-rs6000 srec symbolsrec verilog 
tekhex
powerpc:common aixcoff-rs6000 aix5coff64-rs6000 srec symbolsrec verilog 
tekhex
    rs6000:6000 aixcoff-rs6000 aix5coff64-rs6000 srec symbolsrec verilog 
tekhex

                binary ihex
powerpc:common binary ihex
    rs6000:6000 binary ihex
***

How can I either add support for aixcoff64-rs6000, or make "-a64" select 
aix5coff64-rs6000 as opposed to aixcoff64-rs6000? Additionally, while 
I'm almost sure that there must be a command line option for "as" to 
explicitly specify the output file format (like there is for ld), I 
couldn't find it in its help (although that wouldn't be a final 
solution, because then our compiler would have to auto-detect whether 
it's using GNU as or native AIX as to determine which command line 
options to pass).

Thanks,


Jonas

PS: the command I use to assemble for AIX/PowerPC (32 bit) is the same 
as the one for 64 bit, except without the "-a64" (explicitly adding 
"-a32" also works in that case).