What: /sys/firmware/secvar Date: August 2019 Contact: Nayna Jain Description: This directory is created if the POWER firmware supports OS secureboot, thereby secure variables. It exposes interface for reading/writing the secure variables What: /sys/firmware/secvar/vars Date: August 2019 Contact: Nayna Jain Description: This directory lists all the secure variables that are supported by the firmware. What: /sys/firmware/secvar/format Date: August 2019 Contact: Nayna Jain Description: A string indicating which backend is in use by the firmware. This determines the format of the variable and the accepted format of variable updates. What: /sys/firmware/secvar/vars/ Date: August 2019 Contact: Nayna Jain Description: Each secure variable is represented as a directory named as . The variable name is unique and is in ASCII representation. The data and size can be determined by reading their respective attribute files. What: /sys/firmware/secvar/vars//size Date: August 2019 Contact: Nayna Jain Description: An integer representation of the size of the content of the variable. In other words, it represents the size of the data. What: /sys/firmware/secvar/vars//data Date: August 2019 Contact: Nayna Jain h Description: A read-only file containing the value of the variable. The size of the file represents the maximum size of the variable data. What: /sys/firmware/secvar/vars//update Date: August 2019 Contact: Nayna Jain Description: A write-only file that is used to submit the new value for the variable. The size of the file represents the maximum size of the variable data that can be written.