xref: /linux/Documentation/ABI/testing/sysfs-secvar (revision bd5d9c743d38f67d64ea1b512a461f6b5a5f6bec)
1*bd5d9c74SNayna JainWhat:		/sys/firmware/secvar
2*bd5d9c74SNayna JainDate:		August 2019
3*bd5d9c74SNayna JainContact:	Nayna Jain <nayna@linux.ibm.com>
4*bd5d9c74SNayna JainDescription:	This directory is created if the POWER firmware supports OS
5*bd5d9c74SNayna Jain		secureboot, thereby secure variables. It exposes interface
6*bd5d9c74SNayna Jain		for reading/writing the secure variables
7*bd5d9c74SNayna Jain
8*bd5d9c74SNayna JainWhat:		/sys/firmware/secvar/vars
9*bd5d9c74SNayna JainDate:		August 2019
10*bd5d9c74SNayna JainContact:	Nayna Jain <nayna@linux.ibm.com>
11*bd5d9c74SNayna JainDescription:	This directory lists all the secure variables that are supported
12*bd5d9c74SNayna Jain		by the firmware.
13*bd5d9c74SNayna Jain
14*bd5d9c74SNayna JainWhat:		/sys/firmware/secvar/format
15*bd5d9c74SNayna JainDate:		August 2019
16*bd5d9c74SNayna JainContact:	Nayna Jain <nayna@linux.ibm.com>
17*bd5d9c74SNayna JainDescription:	A string indicating which backend is in use by the firmware.
18*bd5d9c74SNayna Jain		This determines the format of the variable and the accepted
19*bd5d9c74SNayna Jain		format of variable updates.
20*bd5d9c74SNayna Jain
21*bd5d9c74SNayna JainWhat:		/sys/firmware/secvar/vars/<variable name>
22*bd5d9c74SNayna JainDate:		August 2019
23*bd5d9c74SNayna JainContact:	Nayna Jain <nayna@linux.ibm.com>
24*bd5d9c74SNayna JainDescription:	Each secure variable is represented as a directory named as
25*bd5d9c74SNayna Jain		<variable_name>. The variable name is unique and is in ASCII
26*bd5d9c74SNayna Jain		representation. The data and size can be determined by reading
27*bd5d9c74SNayna Jain		their respective attribute files.
28*bd5d9c74SNayna Jain
29*bd5d9c74SNayna JainWhat:		/sys/firmware/secvar/vars/<variable_name>/size
30*bd5d9c74SNayna JainDate:		August 2019
31*bd5d9c74SNayna JainContact:	Nayna Jain <nayna@linux.ibm.com>
32*bd5d9c74SNayna JainDescription:	An integer representation of the size of the content of the
33*bd5d9c74SNayna Jain		variable. In other words, it represents the size of the data.
34*bd5d9c74SNayna Jain
35*bd5d9c74SNayna JainWhat:		/sys/firmware/secvar/vars/<variable_name>/data
36*bd5d9c74SNayna JainDate:		August 2019
37*bd5d9c74SNayna JainContact:	Nayna Jain h<nayna@linux.ibm.com>
38*bd5d9c74SNayna JainDescription:	A read-only file containing the value of the variable. The size
39*bd5d9c74SNayna Jain		of the file represents the maximum size of the variable data.
40*bd5d9c74SNayna Jain
41*bd5d9c74SNayna JainWhat:		/sys/firmware/secvar/vars/<variable_name>/update
42*bd5d9c74SNayna JainDate:		August 2019
43*bd5d9c74SNayna JainContact:	Nayna Jain <nayna@linux.ibm.com>
44*bd5d9c74SNayna JainDescription:	A write-only file that is used to submit the new value for the
45*bd5d9c74SNayna Jain		variable. The size of the file represents the maximum size of
46*bd5d9c74SNayna Jain		the variable data that can be written.
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