how to port stdc++ ?

[Andrushka]

I'm trying to port by self libstdc++.
Please say me what is necessary steps compleat to build libstdc++.a ?

I'm explored next:
1. Download stdc++ from GNU archives.
2. Modify config.sub (add drops target)
3. Modify configure add 
    *-*-drops*)
    os_include_dir="os/generic"
    ;;
4. run ./configure --target=drops --host=i486-pc-linux
5. run make make all-target-libiberty all-target-libstdc++-v3

Please!  Write in steps what are you doing to succesful build
libstdc++ for L4Env!!!
What changes and additions you made to raw libstdc++ sources?
Maybe there are any guide ?
Thanks.