Documentation/devicetree/bindings/mtd/partition.txt

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