tutorials/stm32/nucleo-f746zg-make-baremetal-builtin-cmsis_driver/README.md
Mongoose includes a driver for CMSIS-Driver, that is, Mongoose built-in TCP/IP stack can run over any (ARM) chip that has a CMSIS Driver for its Ethernet controller, and uses a PHY that also has a CMSIS Driver. You can follow this example to use Mongoose there, the Makefile in this example performs the following list of actions.
Actions:
enable the driver by defining MG_ENABLE_DRIVER_CMSIS=1
select it in your main.c
struct mg_tcpip_if mif = {.driver = &mg_tcpip_driver_cmsis}