Communicate to serial device on x86_64

Hi there.
I am new to seL4 and I am using CAmkES for seL4. Currently, I am trying to communicate (R+W) with the serial device identified as /dev/ttyUSB2. I tried open() as I did in Linux but it seems like the open() call only supports O_RDONLY. Is there a way to do normal read and write like in Linux? What library should i look at? Or do I need to implement it manually?

i was trying something like this:

int fd = open( "/dev/ttyUSB2", O_RDWR | O_NOCTTY | O_SYNC);

and got:

sys_open_impl@sys_io.c:184 Open only supports O_RDONLY, not 0x101102 on /dev/ttyUSB2