"sysroot" included only dynamic library(*.so), I can not find any static library(*.a).
$ cd project_dir/bitbake_build/tmp/sysroots/ $ find | grep librt copy the static library to the exporting sysroot.
1) make export-sdk 2) wrlinux-5.0.1.*-sdk.sh 3) cd <export path> 4) find | grep librt ==> "sysroot" did not include librt.a(static library). ./x86_64-wrlinuxsdk-linux/lib/librt-2.15.so ./x86_64-wrlinuxsdk-linux/lib/librt.so.1 ./fsl_t4xxx-wrs-linux/usr/lib/librt.so ./fsl_t4xxx-wrs-linux/lib/librt-2.15.so ./fsl_t4xxx-wrs-linux/lib/librt.so.1 ./fsl_t4xxx-wrs-linux/lib/.debug/librt-2.15.so ./fsl_t4xxx-wrs-linux/lib/.debug/librt.so.1