72 lines
1.8 KiB
Text
72 lines
1.8 KiB
Text
|
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>;
|
||
|
|
};
|
||
|
|
};
|