Where are hwlibs for Cyclone V SoC HPS EMAC?

Looks like only the Register space for the EMAC is defined in the HWLIBs. I do not see any API documentation. You can find this information under Address Space -> Component: EMAC Module - ALT_EMAC.

Intel (Altera) does mention the following:

WARNING: The C register and register group struct declarations are provided for convenience and illustrative purposes. They should, however, be used with caution as the C language standard provides no guarantees about the alignment or atomicity of device memory accesses. The recommended practice for writing hardware drivers is to use the SoCAL access macros and alt_read_word() and alt_write_word() functions.

Looks like we have to write our own drivers for the EMAC using the register space provided and the alt_write_word() and alt_read_word() functions.

If you look into the following location you will find the emac header file:

/intelFPGA/18.1/embedded/ip/altera/hps/altera_hps/hwlib/include/soc_cv_av/socal