Download repo and within binutils-gdb:

mkdir cross-build
cd cross-build
../configure --enable-plugins --target=ppc-amigaos --prefix=/usr/local/amiga
make 

h2. AmigaOS4 native builds

There are tow development branches targing native builds for AmigaOS4 based on the released binutils version 2.40

h3. Using newlib

The @nativeOS4-build-newlib@ branch is for the native AmigaOS4 version using *newlib* as c library, download the repo, checkout the branch, cd in, and:

mkdir native-build
cd native-build
CFLAGS="-mcrt=newlib -Wno-sign-compare" LDFLAGS="-lunix" ../configure --disable-gdb --disable-plugins --disable-sim --host=ppc-amigaos --target=ppc-amigaos --prefix=<absolut-path-to>/dist
make -j 4
make install

h3. Using clib4 

The @nativeOS4-build-clib4@ branch is for the native AmigaOS4 version using latest beta10 (with sigsuspend) *clib4* as c library, download the repo, checkout the branch, cd in and:

mkdir native-build
cd native-build
CFLAGS="-mcrt=clib4 -Wno-sign-compare -gstabs -lpthread -athread=native" CXXFLAGS="-mcrt=clib4 -Wno-sign-compare -gstabs -lpthread -athread=native" ../configure --disable-plugins --disable-sim --host=ppc-amigaos --target=ppc-amigaos --prefix=<absolut-path-to>/dist
make -j 4
make install

h4. Building *GDB*

If gdb shall be build use the following 

mkdir native-build
cd native-build
CFLAGS="-mcrt=clib4 -Wno-sign-compare -gstabs -lpthread -athread=native -DENABLE_HAVE_AMIGA_BASED_FILE_SYSTEM" CXXFLAGS="-mcrt=clib4 -Wno-sign-compare -gstabs -lpthread -athread=native -DENABLE_HAVE_AMIGA_BASED_FILE_SYSTEM" ../configure --disable-plugins --disable-sim --without-auto-load-safe-path --host=ppc-amigaos --target=ppc-amigaos --prefix=<absolut-path-to>/dist
make -j 4
make install

That even genartes all other tools like ld, ar, etc. It is not recommanded to use them, they might behave strangly.