6.4.12. Representing flash partitions in devicetree

In addition to the upstream binding, barebox supports parsing OF partitions for EEPROMs and for SD/MMC as well. SD/MMC OF partitions in barebox are allowed to co-exist with GPT/MBR partitions as long as they don’t overlap.

This is different from the Linux behavior where OF partitions have precedence over GPT/MBR. For this reason, barebox also accepts the compatible barebox,fixed-partitions, which is handled inside barebox identically to fixed-partitions, but is ignored by Linux.

Additionally, barebox supports an extra optional property:

• partuuid: The global partition UUID for this partition. For GPT partitions, the partuuid is the 16-byte GPT Partition UUID (e.g. de6f4f5c-c055-4374-09f7-8c6821dfb60e). For MBR partitions, the partuuid is the 4-byte disk identifier followed by a dash and the partition number (starting with 1, e.g. c9178f9d-01).

  The partuuid is case-insensitive.

Additionally, barebox also supports partitioning the eMMC boot partitions if the partition table node is named appropriately:

• partitions : user partition

• boot0-partitions : boot0 partition

• boot1-partitions : boot1 partition

boot0-partitions and boot1-partitions are deprecated. Use partitions-boot1 and partitions-boot2 instead which is supported under Linux as well.

In addition to the upstream fixed-partitions compatible binding, barebox also supports a barebox,fixed-partitions binding.

Examples:

/ {
      partitions {
              compatible = "fixed-partitions";
              #address-cells = <1>;
              #size-cells = <1>;

              state_part: state {
                      partuuid = "16367da7-c518-499f-9aad-e1f366692365";
              };
      };
};

emmc@1 {
      boot0-partitions {
              compatible = "fixed-partitions";
              #address-cells = <1>;
              #size-cells = <1>;

              barebox@0 {
                      label = "barebox";
                      reg = <0x0 0x300000>;
              };
      };
};

sd {
      partitions {
              compatible = "barebox,fixed-partitions";
              #address-cells = <1>;
              #size-cells = <1>;

              barebox-env@1000 {
                      label = "barebox-environment";
                      reg = <0x1000 0x20000>;
              };
      };
};