How can i build libmetal for a barametal soc?

[kikuyuchanj]

I want to build libmetal and openamp for a barametal system, which is not Xillinx. But when I build cmake with newlib toolchain, I meet this problem:
-- Found Threads: TRUE
CMake Error at /usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:137 (message):
Could NOT find LibRt (missing: LIBRT_LIBRARIES)
Call Stack (most recent call first):
/usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:378 (_FPHSA_FAILURE_MESSAGE)
cmake/modules/FindLibRt.cmake:36 (find_package_handle_standard_args)
cmake/depends.cmake:24 (find_package)
CMakeLists.txt:24 (include)

[arnopo]

your issue seems linked to your environment.
The issue is reported here, indicating that you are building the libraries for a Linux target, not a baremetal target