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Diffstat (limited to 'Documentation/ABI/testing/sysfs-secvar')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-secvar | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-secvar b/Documentation/ABI/testing/sysfs-secvar new file mode 100644 index 000000000..c52a5fd15 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-secvar @@ -0,0 +1,65 @@ +What: /sys/firmware/secvar +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +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 <nayna@linux.ibm.com> +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 <nayna@linux.ibm.com> +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. + + On powernv/OPAL, this value is provided by the OPAL firmware + and is expected to be "ibm,edk2-compat-v1". + + On pseries/PLPKS, this is generated by the kernel based on the + version number in the SB_VERSION variable in the keystore. The + version numbering in the SB_VERSION variable starts from 1. The + format string takes the form "ibm,plpks-sb-v<version>" in the + case of dynamic key management mode. If the SB_VERSION variable + does not exist (or there is an error while reading it), it takes + the form "ibm,plpks-sb-v0", indicating that the key management + mode is static. + +What: /sys/firmware/secvar/vars/<variable name> +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: Each secure variable is represented as a directory named as + <variable_name>. The variable name is unique and is in ASCII + representation. The data and size can be determined by reading + their respective attribute files. + + Only secvars relevant to the key management mode are exposed. + Only in the dynamic key management mode should the user have + access (read and write) to the secure boot secvars db, dbx, + grubdb, grubdbx, and sbat. These secvars are not consumed in the + static key management mode. PK, trustedcadb and moduledb are the + secvars common to both static and dynamic key management modes. + +What: /sys/firmware/secvar/vars/<variable_name>/size +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +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/<variable_name>/data +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +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/<variable_name>/update +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +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. |