1*4882a593SmuzhiyunWhat: /sys/firmware/secvar 2*4882a593SmuzhiyunDate: August 2019 3*4882a593SmuzhiyunContact: Nayna Jain <nayna@linux.ibm.com> 4*4882a593SmuzhiyunDescription: This directory is created if the POWER firmware supports OS 5*4882a593Smuzhiyun secureboot, thereby secure variables. It exposes interface 6*4882a593Smuzhiyun for reading/writing the secure variables 7*4882a593Smuzhiyun 8*4882a593SmuzhiyunWhat: /sys/firmware/secvar/vars 9*4882a593SmuzhiyunDate: August 2019 10*4882a593SmuzhiyunContact: Nayna Jain <nayna@linux.ibm.com> 11*4882a593SmuzhiyunDescription: This directory lists all the secure variables that are supported 12*4882a593Smuzhiyun by the firmware. 13*4882a593Smuzhiyun 14*4882a593SmuzhiyunWhat: /sys/firmware/secvar/format 15*4882a593SmuzhiyunDate: August 2019 16*4882a593SmuzhiyunContact: Nayna Jain <nayna@linux.ibm.com> 17*4882a593SmuzhiyunDescription: A string indicating which backend is in use by the firmware. 18*4882a593Smuzhiyun This determines the format of the variable and the accepted 19*4882a593Smuzhiyun format of variable updates. 20*4882a593Smuzhiyun 21*4882a593SmuzhiyunWhat: /sys/firmware/secvar/vars/<variable name> 22*4882a593SmuzhiyunDate: August 2019 23*4882a593SmuzhiyunContact: Nayna Jain <nayna@linux.ibm.com> 24*4882a593SmuzhiyunDescription: Each secure variable is represented as a directory named as 25*4882a593Smuzhiyun <variable_name>. The variable name is unique and is in ASCII 26*4882a593Smuzhiyun representation. The data and size can be determined by reading 27*4882a593Smuzhiyun their respective attribute files. 28*4882a593Smuzhiyun 29*4882a593SmuzhiyunWhat: /sys/firmware/secvar/vars/<variable_name>/size 30*4882a593SmuzhiyunDate: August 2019 31*4882a593SmuzhiyunContact: Nayna Jain <nayna@linux.ibm.com> 32*4882a593SmuzhiyunDescription: An integer representation of the size of the content of the 33*4882a593Smuzhiyun variable. In other words, it represents the size of the data. 34*4882a593Smuzhiyun 35*4882a593SmuzhiyunWhat: /sys/firmware/secvar/vars/<variable_name>/data 36*4882a593SmuzhiyunDate: August 2019 37*4882a593SmuzhiyunContact: Nayna Jain h<nayna@linux.ibm.com> 38*4882a593SmuzhiyunDescription: A read-only file containing the value of the variable. The size 39*4882a593Smuzhiyun of the file represents the maximum size of the variable data. 40*4882a593Smuzhiyun 41*4882a593SmuzhiyunWhat: /sys/firmware/secvar/vars/<variable_name>/update 42*4882a593SmuzhiyunDate: August 2019 43*4882a593SmuzhiyunContact: Nayna Jain <nayna@linux.ibm.com> 44*4882a593SmuzhiyunDescription: A write-only file that is used to submit the new value for the 45*4882a593Smuzhiyun variable. The size of the file represents the maximum size of 46*4882a593Smuzhiyun the variable data that can be written. 47