It Looks Like AMD Zen 5 SoCs Will Support ACPI PHAT

A few months ago I wrote about AMD Linux engineers working on ACPI PHAT support for the Linux kernel. This week new patches around Linux ACPI PHAT handling have been posted with further confirmation of this functionality coming to "future" AMD SoCs.

ACPI PHAT is for the Platform Health Assessment Table and is a means of exposing additional platform health-related telemetry. This isn't any nasty remote "telemetry" like some may fear but as outlined in the ACPI spec is an extensible set of platform information that can be useful to the software running within the constraints of the OS. For example, ACPI PHAT can be used to communicate the cause of the most recent system reset or boot when hitting unexpected behavior.

AMD's prior ACPI PHAT Linux patches were rather generic in nature while this week's latest patches explicitly lay out:

"Future AMD SOCs will support the ACPI Platform Health Assessment Table (PHAT) to export an extensible set of platform health related telemetry through Firmware Version and Firmware Health Data Records."

Given the timing and that AMD Linux engineers are typically focused on N and N+1 generations but not typically multiple generations ahead like we sometimes see with Intel Linux hardware enablement, this means PHAT is almost surely to be supported for next year's Zen 5 SoCs.

The latest AMD work on ACPI PHAT is a patch adding "parse_phat" as a new tool to live within the Linux kernel source tree for parsing the PHAT table and exporting the Reset Reason Health Records. There's a suggestion so far that this functionality could potentially live in the acpidump utility or elsewhere, so we'll see if/how it ends up evolving. In any event, AMD is working on ACPI PHAT Linux support for what appears to be on path for next-generation Zen 5 SoCs.