1.. _device-tree/ibm,opal/sysparams:
2
3sysparams
4=========
5
6.. code-block:: c
7
8   /* System parameter permission */
9   enum OpalSysparamPerm {
10	OPAL_SYSPARAM_READ  = 0x1,
11	OPAL_SYSPARAM_WRITE = 0x2,
12	OPAL_SYSPARAM_RW    = (OPAL_SYSPARAM_READ | OPAL_SYSPARAM_WRITE),
13   };
14
15
16.. code-block:: dts
17
18   sysparams {
19		compatible = "ibm,opal-sysparams";
20                param-id = <0xf0000001 0xf0000003 0xf0000012 0xf0000016 0xf000001d 0xf0000023 0xf0000024 0xf0000025 0xf0000026 0xf0000027>;
21                param-name = "surveillance", "hmc-management", "cupd-policy", "plat-hmc-managed", "fw-license-policy", "world-wide-port-num", "default-boot-device", "next-boot-device", "console-select", "boot-device-path";
22                param-perm = [03 01 03 03 03 02 03 03 03 03];
23                phandle = <0x10000032>;
24                param-len = <0x4 0x4 0x4 0x4 0x4 0xc 0x1 0x1 0x1 0x30>;
25                linux,phandle = <0x10000032>;
26   };
27
28Device tree node for system parameters accessible through the
29:ref:`opal-sysparams` calls :ref:`OPAL_GET_PARAM` and :ref:`OPAL_SET_PARAM`.
30
31While many systems and platforms will support parameters and configuration via
32either nvram or over IPMI, some platforms may have parameters that need to be
33set a different way.
34
35Some parameters may be set Read Only, so the `param-perm` property indicates
36permissions.
37
38Currently, this is only something that exists on FSP based systems.
39