1Representing flash partitions in devicetree 2 3Partitions can be represented by sub-nodes of an mtd device. This can be used 4on platforms which have strong conventions about which portions of a flash are 5used for what purposes, but which don't use an on-flash partition table such 6as RedBoot. 7 8The partition table should be a subnode of the mtd node and should be named 9'partitions'. This node should have the following property: 10- compatible : (required) must be "fixed-partitions" 11Partitions are then defined in subnodes of the partitions node. 12 13For backwards compatibility partitions as direct subnodes of the mtd device are 14supported. This use is discouraged. 15NOTE: also for backwards compatibility, direct subnodes that have a compatible 16string are not considered partitions, as they may be used for other bindings. 17 18#address-cells & #size-cells must both be present in the partitions subnode of the 19mtd device. There are two valid values for both: 20<1>: for partitions that require a single 32-bit cell to represent their 21 size/address (aka the value is below 4 GiB) 22<2>: for partitions that require two 32-bit cells to represent their 23 size/address (aka the value is 4 GiB or greater). 24 25Required properties: 26- reg : The partition's offset and size within the mtd bank. 27 28Optional properties: 29- label : The label / name for this partition. If omitted, the label is taken 30 from the node name (excluding the unit address). 31- read-only : This parameter, if present, is a hint to Linux that this 32 partition should only be mounted read-only. This is usually used for flash 33 partitions containing early-boot firmware images or data which should not be 34 clobbered. 35 36Examples: 37 38 39flash@0 { 40 partitions { 41 compatible = "fixed-partitions"; 42 #address-cells = <1>; 43 #size-cells = <1>; 44 45 partition@0 { 46 label = "u-boot"; 47 reg = <0x0000000 0x100000>; 48 read-only; 49 }; 50 51 uimage@100000 { 52 reg = <0x0100000 0x200000>; 53 }; 54 }; 55}; 56 57flash@1 { 58 partitions { 59 compatible = "fixed-partitions"; 60 #address-cells = <1>; 61 #size-cells = <2>; 62 63 /* a 4 GiB partition */ 64 partition@0 { 65 label = "filesystem"; 66 reg = <0x00000000 0x1 0x00000000>; 67 }; 68 }; 69}; 70 71flash@2 { 72 partitions { 73 compatible = "fixed-partitions"; 74 #address-cells = <2>; 75 #size-cells = <2>; 76 77 /* an 8 GiB partition */ 78 partition@0 { 79 label = "filesystem #1"; 80 reg = <0x0 0x00000000 0x2 0x00000000>; 81 }; 82 83 /* a 4 GiB partition */ 84 partition@200000000 { 85 label = "filesystem #2"; 86 reg = <0x2 0x00000000 0x1 0x00000000>; 87 }; 88 }; 89}; 90