利用linux来和R5，M4做ipc通信，更改官方的例程rpmsg_char_simple.c之后如何编译，编译一直没法通过
/usr/lib/gcc/aarch64-linux/9.2.1/../../../../aarch64-linux/bin/ld: /tmp/ccygnyZN.o: in function `rpmsg_char_ping': rpmsg_char_simple.c:(.text+0x150): undefined reference to `rpmsg_char_open' /usr/lib/gcc/aarch64-linux/9.2.1/../../../../aarch64-linux/bin/ld: rpmsg_char_simple.c:(.text+0x308): undefined reference to `rpmsg_char_close' /usr/lib/gcc/aarch64-linux/9.2.1/../../../../aarch64-linux/bin/ld: /tmp/ccygnyZN.o: in function `main': rpmsg_char_simple.c:(.text+0x4b0): undefined reference to `rpmsg_char_init' /usr/lib/gcc/aarch64-linux/9.2.1/../../../../aarch64-linux/bin/ld: rpmsg_char_simple.c:(.text+0x4f4): undefined reference to `rpmsg_char_exit' collect2: error: ld returned 1 exit status
这是报错
