150477SpeterWhat: /sys/firmware/secvar 21598SrgrimesDate: August 2019 3156813SruContact: Nayna Jain <nayna@linux.ibm.com> 4156813SruDescription: This directory is created if the POWER firmware supports OS 558284Speter secureboot, thereby secure variables. It exposes interface 6156813Sru for reading/writing the secure variables 7116865Speter 8129269ScognetWhat: /sys/firmware/secvar/vars 91598SrgrimesDate: August 2019 10143145SgrogContact: Nayna Jain <nayna@linux.ibm.com> 11180627SmaximDescription: This directory lists all the secure variables that are supported 12180627Smaxim by the firmware. 13171245Sbz 14180627SmaximWhat: /sys/firmware/secvar/format 15180627SmaximDate: August 2019 16180428SobrienContact: Nayna Jain <nayna@linux.ibm.com> 17180627SmaximDescription: A string indicating which backend is in use by the firmware. 18180428Sobrien This determines the format of the variable and the accepted 19180428Sobrien format of variable updates. 20180428Sobrien 21143145Sgrog On powernv/OPAL, this value is provided by the OPAL firmware 22124610Sru and is expected to be "ibm,edk2-compat-v1". 23143145Sgrog 2461744Sobrien On pseries/PLPKS, this is generated by the kernel based on the 2561744Sobrien version number in the SB_VERSION variable in the keystore, and 2661744Sobrien has the form "ibm,plpks-sb-v<version>", or 2761744Sobrien "ibm,plpks-sb-unknown" if there is no SB_VERSION variable. 2827356Sjkh 2927356SjkhWhat: /sys/firmware/secvar/vars/<variable name> 30171245SbzDate: August 2019 31179174SobrienContact: Nayna Jain <nayna@linux.ibm.com> 32179174SobrienDescription: Each secure variable is represented as a directory named as 33179174Sobrien <variable_name>. The variable name is unique and is in ASCII 34143145Sgrog representation. The data and size can be determined by reading 35179174Sobrien their respective attribute files. 36179174Sobrien 37179174SobrienWhat: /sys/firmware/secvar/vars/<variable_name>/size 38143145SgrogDate: August 2019 39179174SobrienContact: Nayna Jain <nayna@linux.ibm.com> 40179174SobrienDescription: An integer representation of the size of the content of the 41179174Sobrien variable. In other words, it represents the size of the data. 42171245Sbz 43179174SobrienWhat: /sys/firmware/secvar/vars/<variable_name>/data 44143145SgrogDate: August 2019 45179174SobrienContact: Nayna Jain <nayna@linux.ibm.com> 46143145SgrogDescription: A read-only file containing the value of the variable. The size 47181432Sphilip of the file represents the maximum size of the variable data. 48181432Sphilip 49181756SphilipWhat: /sys/firmware/secvar/vars/<variable_name>/update 50181756SphilipDate: August 2019 51181756SphilipContact: Nayna Jain <nayna@linux.ibm.com> 52181756SphilipDescription: A write-only file that is used to submit the new value for the 53181432Sphilip variable. The size of the file represents the maximum size of 54181432Sphilip the variable data that can be written. 55181432Sphilip 56181432SphilipWhat: /sys/firmware/secvar/config 57181432SphilipDate: February 2023 581598SrgrimesContact: Nayna Jain <nayna@linux.ibm.com> 59Description: This optional directory contains read-only config attributes as 60 defined by the secure variable implementation. All data is in 61 ASCII format. The directory is only created if the backing 62 implementation provides variables to populate it, which at 63 present is only PLPKS on the pseries platform. 64 65What: /sys/firmware/secvar/config/version 66Date: February 2023 67Contact: Nayna Jain <nayna@linux.ibm.com> 68Description: Config version as reported by the hypervisor in ASCII decimal 69 format. 70 71 Currently only provided by PLPKS on the pseries platform. 72 73What: /sys/firmware/secvar/config/max_object_size 74Date: February 2023 75Contact: 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 be 80 written to an update file as writes can contain more than 81 object data, you should use the size of the update file for 82 that purpose. 83 84 Currently only provided by PLPKS on the pseries platform. 85 86What: /sys/firmware/secvar/config/total_size 87Date: February 2023 88Contact: Nayna Jain <nayna@linux.ibm.com> 89Description: Total size of the PLPKS in bytes, represented in ASCII decimal 90 format. 91 92 Currently only provided by PLPKS on the pseries platform. 93 94What: /sys/firmware/secvar/config/used_space 95Date: February 2023 96Contact: Nayna Jain <nayna@linux.ibm.com> 97Description: Current space consumed by the key store, in bytes, represented 98 in ASCII decimal format. 99 100 Currently only provided by PLPKS on the pseries platform. 101 102What: /sys/firmware/secvar/config/supported_policies 103Date: February 2023 104Contact: 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 the 107 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_algorithms 112Date: February 2023 113Contact: Nayna Jain <nayna@linux.ibm.com> 114Description: Bitmask of flags indicating which algorithms the hypervisor 115 supports for signed update of objects, represented as a 16 byte 116 hexadecimal ASCII string. Consult the hypervisor documentation 117 for what these flags mean. 118 119 Currently only provided by PLPKS on the pseries platform. 120