Root directory "//" refers to "/vendor/hisi/hi3861/hi3861".
We use header files from musl ("//platform/os/Huawei_LiteOS/components/lib/libc/musl/include").

Some posix apis are already defined in different places:
errno is defined in             //build/libs/libc_base.o
malloc and free are defined in  //build/libs/libc_base.o
pthread_mutex_* are defined in  //build/libs/hi3861/release/no_mesh/liblitekernel_flash.a
semaphore is defined in         //build/libs/hi3861/release/no_mesh/liblitekernel_flash.a
usleep is defined in            //build/libs/hi3861/release/no_mesh/liblitekernel_flash.a
clock_* are defined in          //build/libs/liblitekernel_base.o
printf is defined in            //build/libs/liblitekernel_base.o
fcntl and socket apis are defined in //build/libs/liblwip.a