| Representing flash partitions in devicetree |
| |
| Partitions can be represented by sub-nodes of an mtd device. This can be used |
| on platforms which have strong conventions about which portions of a flash are |
| used for what purposes, but which don't use an on-flash partition table such |
| as RedBoot. |
| NOTE: if the sub-node has a compatible string, then it is not a partition. |
| |
| #address-cells & #size-cells must both be present in the mtd device. There are |
| two valid values for both: |
| <1>: for partitions that require a single 32-bit cell to represent their |
| size/address (aka the value is below 4 GiB) |
| <2>: for partitions that require two 32-bit cells to represent their |
| size/address (aka the value is 4 GiB or greater). |
| |
| Required properties: |
| - reg : The partition's offset and size within the mtd bank. |
| |
| Optional properties: |
| - label : The label / name for this partition. If omitted, the label is taken |
| from the node name (excluding the unit address). |
| - read-only : This parameter, if present, is a hint to Linux that this |
| partition should only be mounted read-only. This is usually used for flash |
| partitions containing early-boot firmware images or data which should not be |
| clobbered. |
| |
| Examples: |
| |
| |
| flash@0 { |
| #address-cells = <1>; |
| #size-cells = <1>; |
| |
| partition@0 { |
| label = "u-boot"; |
| reg = <0x0000000 0x100000>; |
| read-only; |
| }; |
| |
| uimage@100000 { |
| reg = <0x0100000 0x200000>; |
| }; |
| }; |
| |
| flash@1 { |
| #address-cells = <1>; |
| #size-cells = <2>; |
| |
| /* a 4 GiB partition */ |
| partition@0 { |
| label = "filesystem"; |
| reg = <0x00000000 0x1 0x00000000>; |
| }; |
| }; |
| |
| flash@2 { |
| #address-cells = <2>; |
| #size-cells = <2>; |
| |
| /* an 8 GiB partition */ |
| partition@0 { |
| label = "filesystem #1"; |
| reg = <0x0 0x00000000 0x2 0x00000000>; |
| }; |
| |
| /* a 4 GiB partition */ |
| partition@200000000 { |
| label = "filesystem #2"; |
| reg = <0x2 0x00000000 0x1 0x00000000>; |
| }; |
| }; |