Why there is no hardware SPI available in u8g2setupc?

[Wosamarak]

When using the plain C initialisation I can't find any hint, how to work with hardware SPI.
u8g2setupc
I can only find sw_spi init functions.

Is there a way, to use hardware SPI with plain C, or do I have to migrate my project to CPP?

[olikraus]

When using the plain C initialisation I can't find any hint, how to work with hardware SPI.

You need to add calls to your uC specific SPI subsytem:
https://github.com/olikraus/u8g2/wiki/Porting-to-new-MCU-platform#hardware-spi-communication

[Wosamarak]

thanks for the explanation