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1What: /sys/firmware/secvar2Date: August 20193Contact: Nayna Jain <nayna@linux.ibm.com>4Description: This directory is created if the POWER firmware supports OS5 secureboot, thereby secure variables. It exposes interface6 for reading/writing the secure variables7 8What: /sys/firmware/secvar/vars9Date: August 201910Contact: Nayna Jain <nayna@linux.ibm.com>11Description: This directory lists all the secure variables that are supported12 by the firmware.13 14What: /sys/firmware/secvar/format15Date: August 201916Contact: Nayna Jain <nayna@linux.ibm.com>17Description: A string indicating which backend is in use by the firmware.18 This determines the format of the variable and the accepted19 format of variable updates.20 21 On powernv/OPAL, this value is provided by the OPAL firmware22 and is expected to be "ibm,edk2-compat-v1".23 24 On pseries/PLPKS, this is generated by the kernel based on the25 version number in the SB_VERSION variable in the keystore, and26 has the form "ibm,plpks-sb-v<version>", or27 "ibm,plpks-sb-unknown" if there is no SB_VERSION variable.28 29What: /sys/firmware/secvar/vars/<variable name>30Date: August 201931Contact: Nayna Jain <nayna@linux.ibm.com>32Description: Each secure variable is represented as a directory named as33 <variable_name>. The variable name is unique and is in ASCII34 representation. The data and size can be determined by reading35 their respective attribute files.36 37What: /sys/firmware/secvar/vars/<variable_name>/size38Date: August 201939Contact: Nayna Jain <nayna@linux.ibm.com>40Description: An integer representation of the size of the content of the41 variable. In other words, it represents the size of the data.42 43What: /sys/firmware/secvar/vars/<variable_name>/data44Date: August 201945Contact: Nayna Jain <nayna@linux.ibm.com>46Description: A read-only file containing the value of the variable. The size47 of the file represents the maximum size of the variable data.48 49What: /sys/firmware/secvar/vars/<variable_name>/update50Date: August 201951Contact: Nayna Jain <nayna@linux.ibm.com>52Description: A write-only file that is used to submit the new value for the53 variable. The size of the file represents the maximum size of54 the variable data that can be written.55 56What: /sys/firmware/secvar/config57Date: February 202358Contact: Nayna Jain <nayna@linux.ibm.com>59Description: This optional directory contains read-only config attributes as60 defined by the secure variable implementation. All data is in61 ASCII format. The directory is only created if the backing62 implementation provides variables to populate it, which at63 present is only PLPKS on the pseries platform.64 65What: /sys/firmware/secvar/config/version66Date: February 202367Contact: Nayna Jain <nayna@linux.ibm.com>68Description: Config version as reported by the hypervisor in ASCII decimal69 format.70 71 Currently only provided by PLPKS on the pseries platform.72 73What: /sys/firmware/secvar/config/max_object_size74Date: February 202375Contact: Nayna Jain <nayna@linux.ibm.com>76Description: Maximum allowed size of objects in the keystore in bytes,77 represented in ASCII decimal format.78 79 This is not necessarily the same as the max size that can be80 written to an update file as writes can contain more than81 object data, you should use the size of the update file for82 that purpose.83 84 Currently only provided by PLPKS on the pseries platform.85 86What: /sys/firmware/secvar/config/total_size87Date: February 202388Contact: Nayna Jain <nayna@linux.ibm.com>89Description: Total size of the PLPKS in bytes, represented in ASCII decimal90 format.91 92 Currently only provided by PLPKS on the pseries platform.93 94What: /sys/firmware/secvar/config/used_space95Date: February 202396Contact: Nayna Jain <nayna@linux.ibm.com>97Description: Current space consumed by the key store, in bytes, represented98 in ASCII decimal format.99 100 Currently only provided by PLPKS on the pseries platform.101 102What: /sys/firmware/secvar/config/supported_policies103Date: February 2023104Contact: Nayna Jain <nayna@linux.ibm.com>105Description: Bitmask of supported policy flags by the hypervisor,106 represented as an 8 byte hexadecimal ASCII string. Consult the107 hypervisor documentation for what these flags are.108 109 Currently only provided by PLPKS on the pseries platform.110 111What: /sys/firmware/secvar/config/signed_update_algorithms112Date: February 2023113Contact: Nayna Jain <nayna@linux.ibm.com>114Description: Bitmask of flags indicating which algorithms the hypervisor115 supports for signed update of objects, represented as a 16 byte116 hexadecimal ASCII string. Consult the hypervisor documentation117 for what these flags mean.118 119 Currently only provided by PLPKS on the pseries platform.120