linux/Documentation/ABI/testing/sysfs-platform-intel-pmc

What:		/sys/devices/platform/<platform>/etr3
Date:		Apr 2021
KernelVersion:	5.13
Contact:	"Tomas Winkler" <[email protected]>
Description:
		The file exposes "Extended Test Mode Register 3" global
		reset bits. The bits are used during an Intel platform
		manufacturing process to indicate that consequent reset
		of the platform is a "global reset". This type of reset
		is required in order for manufacturing configurations
		to take effect.

		Display global reset setting bits for PMC.

			* bit 31 - global reset is locked
			* bit 20 - global reset is set

		Writing bit 20 value to the etr3 will induce
		a platform "global reset" upon consequent platform reset,
		in case the register is not locked.
		The "global reset bit" should be locked on a production
		system and the file is in read-only mode.