How to add a new target in BFD?

[Yu Mao]

Hi,

I met a problem, When I do "cross-compile binutils" for setup 
cross-compilation env for building Mozilla for arca, a
new risc CPU, in a Red hat 7.2 environment.

1> Download binutils and apply the binutils-cross-libpath.path
2> Copied target libs to /ARCA/arca1/lib and /ARCA/arca1/usr/lib
3> Go to binutils path,
vi config.sub and move to 352 line, add followed lines
         arca1)
                 basic_machine=arca1-arca
                 os=-linux
                 ;;

4> Then run command
    env CROSS_LIB_PATH="/ARCA/arca1/lib:/ARCA/arca1/usr/lib"
./configure --target=arca1 --prefix=/ARCA

configure failed with error message

"*** BFD does not support target arca1-arca-linux-gnu.
*** Look in bfd/config.bfd for supported targets.
Configure in /cross_compile/binutils-2.13.90.0.4/build_tmp/opcodes
failed, exiting."

How can I add a new target in BFD? Or is there any workaround?

Any suggestion will be appreciated,

Yu Mao