Nintendo GameCube / Wii / Wii U Get Real-Time Clock Driver With Linux 5.17

The RTC subsystem changes have been submitted for the in-development Linux 5.17 kernel ahead of its merge window winding down this weekend.

For those hobbyists interested in running Linux on Nintendo video game consoles, Linux 5.17 is set to introduce the "gamecube" RTC driver that provides real-time clock support for not only the Nintendo GameCube but also the Wii and Wii U hardware.

The GameCube / Wii / Wii U all leverage a MX23L4005 chip with a clock and 64 bytes of SRAM storage. The new Linux driver provides support for using that chip as the real-time clock device with read/set support.

This RTC support isn't as exciting as other Nintendo hardware features to work their way to the Linux kernel but another step forward for those wishing to tinker with Linux on their hardware.

The RTC CMOS code also has a century handling fix that is a bit noteworthy and of relevance to more Linux users. If setting the year past 2069, it would return to the wrong century -- e.g. setting the RTC year to 2070 would return 1970 due to a mathematics / logic mistake in calculating the century.

See the RTC pull request for more details.