The STM32F7 on-chip RTC can be used to maintain date and time in Linux from battery or back-up power, even in absence of main power. This is a critical requirement for many embedded applications.

The STM32F7 Discovery board does not provide a battery for the on-chip RTC. Refer to Using On-Chip RTC in Linux on Emcraft STM32F7 SOM for a detailed application note explaining how to use the on-chip RTC in Linux.