u-boot,env.yaml

  1# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
  2%YAML 1.2
  3---
  4$id: http://devicetree.org/schemas/nvmem/layouts/u-boot,env.yaml#
  5$schema: http://devicetree.org/meta-schemas/core.yaml#
  6
  7title: U-Boot environment variables layout
  8
  9description: |
 10  U-Boot uses environment variables to store device parameters and
 11  configuration. They may be used for booting process, setup or keeping end user
 12  info.
 13
 14  Data is stored using U-Boot specific formats (variant specific header and NUL
 15  separated key-value pairs).
 16
 17  Environment data can be stored on various storage entities, e.g.:
 18  1. Raw flash partition
 19  2. UBI volume
 20
 21  This binding allows marking storage device (as containing env data) and
 22  specifying used format.
 23
 24  Variables can be defined as NVMEM device subnodes.
 25
 26maintainers:
 27  - Rafał Miłecki <rafal@milecki.pl>
 28
 29properties:
 30  compatible:
 31    oneOf:
 32      - description: A standalone env data block
 33        const: u-boot,env
 34      - description: Two redundant blocks with active one flagged
 35        const: u-boot,env-redundant-bool
 36      - description: Two redundant blocks with active having higher counter
 37        const: u-boot,env-redundant-count
 38      - description: Broadcom's variant with custom header
 39        const: brcm,env
 40
 41  reg:
 42    description: Partition offset and size for env on top of MTD
 43    maxItems: 1
 44
 45  bootcmd:
 46    type: object
 47    description: Command to use for automatic booting
 48
 49  env-size:
 50    description:
 51      Size in bytes of the environment data used by U-Boot for CRC
 52      calculation. If omitted, the full NVMEM region size is used.
 53    $ref: /schemas/types.yaml#/definitions/uint32
 54
 55  ethaddr:
 56    type: object
 57    description: Ethernet interfaces base MAC address.
 58    additionalProperties: false
 59
 60    properties:
 61      "#nvmem-cell-cells":
 62        description: The first argument is a MAC address offset.
 63        const: 1
 64
 65allOf:
 66  - if:
 67      properties:
 68        $nodename:
 69          not:
 70            contains:
 71              pattern: "^partition@[0-9a-f]+$"
 72    then:
 73      properties:
 74        reg: false
 75
 76additionalProperties: false
 77
 78examples:
 79  - |
 80    partitions {
 81        compatible = "fixed-partitions";
 82        #address-cells = <1>;
 83        #size-cells = <1>;
 84
 85        partition@0 {
 86            reg = <0x0 0x40000>;
 87            label = "u-boot";
 88            read-only;
 89        };
 90
 91        env: partition@40000 {
 92            compatible = "u-boot,env";
 93            reg = <0x40000 0x10000>;
 94
 95            mac: ethaddr {
 96                #nvmem-cell-cells = <1>;
 97            };
 98        };
 99    };
100  - |
101    partitions {
102        compatible = "fixed-partitions";
103        #address-cells = <1>;
104        #size-cells = <1>;
105
106        partition@0 {
107            reg = <0x0 0x100000>;
108            compatible = "brcm,u-boot";
109            label = "u-boot";
110
111            partition-u-boot-env {
112                compatible = "brcm,env";
113                env-size = <0x20000>;
114
115                ethaddr {
116                };
117            };
118        };
119    };
120  - |
121    partition@0 {
122        reg = <0x0 0x100000>;
123        label = "ubi";
124        compatible = "linux,ubi";
125
126        volumes {
127            ubi-volume-u-boot-env {
128                volname = "env";
129
130                nvmem-layout {
131                    compatible = "u-boot,env";
132
133                    ethaddr {
134                        #nvmem-cell-cells = <1>;
135                    };
136                };
137            };
138        };
139    };