To write a network driver for the Solaris OS, use the Solaris Generic LAN Driver (GLD) framework.
For new Ethernet drivers, use the GLDv3 framework. See GLDv3 Network Device Driver Framework. The GLDv3 framework is a function calls-based interface.
To maintain older Ethernet, Token Ring, or FDDI drivers, use the GLDv2 framework. See GLDv2 Network Device Driver Framework. The GLDv2 is a kernel module that provides common code for drivers to share.