Open-sourced back in 2019 was the OpenPOWER Microwatt as an open-source, soft processor core of Power ISA 3.0 and intended for use on FPGA boards and then there was seemingly short-lived work to fabricate a Microwatt chip and Microwatt also found its way for use within a BMC implementation . Linux 5.14 added support for this soft CPU core while the upcoming Linux 6.15 cycle is set to introduce SMP support for Microwatt.

Queued up within the Linux PowerPC development tree ahead of the upcoming Linux 6.15 merge window is symmetric multi-processing (SMP) support for the OpenPOWER Microwatt.

This adds support for Microwatt systems with more than one CPU core and the default DeviceTree is now adapted for a two-core Microwatt.

This Microwatt SMP support is queued up within powerpc/linux.git's "next" branch ahead of the Linux 6.15 merge window opening in late March.

This is the first I've heard of Microwatt in some time with the likes of Libre-SOC having failed. Nice to see there still is some activity around this OpenPOWER soft core.