1# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause 2%YAML 1.2 3--- 4$id: http://devicetree.org/schemas/mtd/partitions/partition.yaml# 5$schema: http://devicetree.org/meta-schemas/core.yaml# 6 7title: Partition 8 9description: | 10 This binding describes a single flash partition. Each partition must have its 11 relative offset and size specified. Depending on partition function extra 12 properties can be used. 13 14 A partition may be dynamically allocated by a specific parser at runtime. 15 In this specific case, a specific suffix is required to the node name. 16 Everything after 'partition-' will be used as the partition name to compare 17 with the one dynamically allocated by the specific parser. 18 If the partition contains invalid char a label can be provided that will 19 be used instead of the node name to make the comparison. 20 This is used to assign an OF node to the dynamiccally allocated partition 21 so that subsystem like NVMEM can provide an OF node and declare NVMEM cells. 22 The OF node will be assigned only if the partition label declared match the 23 one assigned by the parser at runtime. 24 25maintainers: 26 - Rafał Miłecki <rafal@milecki.pl> 27 28properties: 29 reg: 30 description: partition's offset and size within the flash 31 maxItems: 1 32 33 label: 34 description: The label / name for this partition. If omitted, the label 35 is taken from the node name (excluding the unit address). 36 37 read-only: 38 description: This parameter, if present, is a hint that this partition 39 should only be mounted read-only. This is usually used for flash 40 partitions containing early-boot firmware images or data which should 41 not be clobbered. 42 type: boolean 43 44 lock: 45 description: Do not unlock the partition at initialization time (not 46 supported on all devices) 47 type: boolean 48 49 slc-mode: 50 description: This parameter, if present, allows one to emulate SLC mode 51 on a partition attached to an MLC NAND thus making this partition 52 immune to paired-pages corruptions 53 type: boolean 54 55 linux,rootfs: 56 description: Marks partition that contains root filesystem to mount and boot 57 user space from 58 type: boolean 59 60 align: 61 $ref: /schemas/types.yaml#/definitions/uint32 62 minimum: 2 63 maximum: 0x80000000 64 multipleOf: 2 65 description: 66 This sets the alignment of the entry in bytes. 67 68 The entry offset is adjusted so that the entry starts on an aligned 69 boundary within the containing section or image. For example ‘align = 70 <16>’ means that the entry will start on a 16-byte boundary. This may 71 mean that padding is added before the entry. The padding is part of 72 the containing section but is not included in the entry, meaning that 73 an empty space may be created before the entry starts. Alignment 74 must be a power of 2. If ‘align’ is not provided, no alignment is 75 performed. 76 77 align-size: 78 $ref: /schemas/types.yaml#/definitions/uint32 79 minimum: 2 80 maximum: 0x80000000 81 multipleOf: 2 82 description: 83 This sets the alignment of the entry size in bytes. It must be a power 84 of 2. 85 86 For example, to ensure that the size of an entry is a multiple of 64 87 bytes, set this to 64. While this does not affect the content of the 88 entry itself (the padding is performed only when its parent section is 89 assembled), the end result is that the entry ends with the padding 90 bytes, so may grow. If ‘align-size’ is not provided, no alignment is 91 performed. 92 93 align-end: 94 $ref: /schemas/types.yaml#/definitions/uint32 95 minimum: 2 96 maximum: 0x80000000 97 multipleOf: 2 98 description: 99 This sets the alignment (in bytes) of the end of an entry with respect 100 to the containing section. It must be a power of 2. 101 102 Some entries require that they end on an alignment boundary, 103 regardless of where they start. This does not move the start of the 104 entry, so the content of the entry will still start at the beginning. 105 But there may be padding at the end. While this does not affect the 106 content of the entry itself (the padding is performed only when its 107 parent section is assembled), the end result is that the entry ends 108 with the padding bytes, so may grow. If ‘align-end’ is not provided, 109 no alignment is performed. 110 111if: 112 not: 113 required: [ reg ] 114then: 115 properties: 116 $nodename: 117 pattern: '^partition-.*$' 118 119# This is a generic file other binding inherit from and extend 120additionalProperties: true 121 122examples: 123 - | 124 partitions { 125 compatible = "fixed-partitions"; 126 #address-cells = <1>; 127 #size-cells = <1>; 128 129 partition@100000 { 130 compatible = "u-boot"; 131 reg = <0x100000 0xf00000>; 132 align-size = <0x1000>; 133 align-end = <0x10000>; 134 }; 135 136 partition@200000 { 137 compatible = "tfa-bl31"; 138 reg = <0x200000 0x100000>; 139 align = <0x4000>; 140 }; 141 }; 142