Whenever I try to use API, I'm blocked by this error log

Hello, I'm developing ARM target board. My develop environment is composed by yocto linux, and I'm using AWS RDS. I applied Mariadb to my target board, and when I try to access DB directly by shell, It is working well,

But whenever I try to access DB by C API, the problem is occured.

Here is error log

------------------------------------>>>>>>>>>>>>>>>>>>>>>>>>>
700101  1:47:39 InnoDB: The InnoDB memory heap is disabled
700101  1:47:39 InnoDB: Mutexes and rw_locks use InnoDB's own implementation
700101  1:47:39 InnoDB: Compressed tables use zlib 1.2.8
700101  1:47:39 InnoDB: Using Linux native AIO
700101  1:47:39 InnoDB: Initializing buffer pool, size = 128.0M
700101  1:47:39 InnoDB: Completed initialization of buffer pool
700101  1:47:39  InnoDB: Operating system error number 2 in a file operation.
InnoDB: The error means the system cannot find the path specified.
InnoDB: If you are installing InnoDB, remember that you must create
InnoDB: directories yourself, InnoDB does not create them.
InnoDB: File name /var/mysql/ibdata1
InnoDB: File operation call: 'create'.
InnoDB: Cannot continue operation.
<<<<<<<<<<<<<<<<<<<<<<-------------------------------------------

I tried to change innodb file path, DB storage engine to MyISAM by modifying my.cnf But, it's not working. Nothing has changed. A few days has been passed, I'm still stuck in same page.

could you do me a faver?

thanks