@@ -13,6 +13,10 @@ description: |
This documents describes the devicetree bindings for a mmc-host controller
child node describing a mmc-card / an eMMC.
+ It's possible to define a fixed partition table for an eMMC for the user
+ partition and one of the 2 boot partition (boot0/boot1) if supported by the
+ eMMC.
+
properties:
compatible:
const: mmc-card
@@ -26,6 +30,48 @@ properties:
Use this to indicate that the mmc-card has a broken hpi
implementation, and that hpi should not be used.
+ "#address-cells": true
+
+ "#size-cells": true
+
+patternProperties:
+ "^partitions(-boot[01])?$":
+ type: object
+
+ properties:
+ "#address-cells": true
+
+ "#size-cells": true
+
+ patternProperties:
+ "@[0-9a-f]+$":
+ type: object
+
+ properties:
+ reg:
+ description: partition's offset and size within the flash (in sector
+ block, 512byte)
+ maxItems: 1
+
+
+ label:
+ description: The label / name for this partition.
+
+ read-only:
+ description: This parameter, if present, is a hint 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.
+ type: boolean
+
+ required:
+ - reg
+ - label
+
+ additionalProperties: false
+
+ additionalProperties: false
+
required:
- compatible
- reg
@@ -42,6 +88,35 @@ examples:
compatible = "mmc-card";
reg = <0>;
broken-hpi;
+
+ #address-cells = <0>;
+ #size-cells = <0>;
+
+ partitions {
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ partition@0 {
+ label = "kernel"; /* Kernel */
+ reg = <0x0 0x10000>; /* 32 MB */
+ };
+
+ partition@3400 {
+ label = "rootfs";
+ reg = <0x3400 0x200000>; /* 1GB */
+ };
+ };
+
+ partitions-boot0 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ partition@0 {
+ label = "bl";
+ reg = <0x0 0x10000>; /* 32MB */
+ read-only;
+ };
+ };
};
};
Document support for defining a partition table in the mmc-card node. This is needed if the eMMC doesn't have a partition table written and the bootloader of the device load data by using absolute offset of the block device. This is common on embedded device that have eMMC installed to save space and have non removable block devices. eMMC provide a generic disk for user data and if supported also provide one or two additional disk (boot0 and boot1) for special usage of boot operation where normally is stored the bootloader or boot info. Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> --- .../devicetree/bindings/mmc/mmc-card.yaml | 75 +++++++++++++++++++ 1 file changed, 75 insertions(+)