0001 What: /sys/firmware/secvar
0002 Date: August 2019
0003 Contact: Nayna Jain <nayna@linux.ibm.com>
0004 Description: This directory is created if the POWER firmware supports OS
0005 secureboot, thereby secure variables. It exposes interface
0006 for reading/writing the secure variables
0007
0008 What: /sys/firmware/secvar/vars
0009 Date: August 2019
0010 Contact: Nayna Jain <nayna@linux.ibm.com>
0011 Description: This directory lists all the secure variables that are supported
0012 by the firmware.
0013
0014 What: /sys/firmware/secvar/format
0015 Date: August 2019
0016 Contact: Nayna Jain <nayna@linux.ibm.com>
0017 Description: A string indicating which backend is in use by the firmware.
0018 This determines the format of the variable and the accepted
0019 format of variable updates.
0020
0021 What: /sys/firmware/secvar/vars/<variable name>
0022 Date: August 2019
0023 Contact: Nayna Jain <nayna@linux.ibm.com>
0024 Description: Each secure variable is represented as a directory named as
0025 <variable_name>. The variable name is unique and is in ASCII
0026 representation. The data and size can be determined by reading
0027 their respective attribute files.
0028
0029 What: /sys/firmware/secvar/vars/<variable_name>/size
0030 Date: August 2019
0031 Contact: Nayna Jain <nayna@linux.ibm.com>
0032 Description: An integer representation of the size of the content of the
0033 variable. In other words, it represents the size of the data.
0034
0035 What: /sys/firmware/secvar/vars/<variable_name>/data
0036 Date: August 2019
0037 Contact: Nayna Jain h<nayna@linux.ibm.com>
0038 Description: A read-only file containing the value of the variable. The size
0039 of the file represents the maximum size of the variable data.
0040
0041 What: /sys/firmware/secvar/vars/<variable_name>/update
0042 Date: August 2019
0043 Contact: Nayna Jain <nayna@linux.ibm.com>
0044 Description: A write-only file that is used to submit the new value for the
0045 variable. The size of the file represents the maximum size of
0046 the variable data that can be written.
