HCL Talk:GX6605S
The author of GX6605S said that c-sky has provided binutils in https://github.com/c-sky/binutils-gdb and gcc-7 in https://github.com/c-sky/gcc, and he provides the location of dts file https://github.com/c-sky/buildroot/blob/master/board/nationalchip/gx66xx/gx6605s.dts