Cocotb take care of the core of cosimulation library. But for our design test some bus-test library are required. They are managed separately.
Here is a list of cocotb modules libraries
cocotb_usb
For testing USB 1.1 version.
cocotbext-wishbone
Read/write simulation master on wishbone bus
cocotbext-uart
For uart testing
cocotbext-spi
For SPI
cocotbext-fifointerface
To test some fifo interfaces