Re: [PATCH 4/5] dt-bindings: mtd: describe BCM963XX ImageTag format and usage

[Rob Herring <robh@xxxxxxxxxx>]

On Tue, Aug 28, 2018 at 01:19:43PM +0200, Jonas Gorski wrote:
> Describe how to use the BCM963XX ImageTag format in a mixed flash layout
> environment.
> 
> Signed-off-by: Jonas Gorski <jonas.gorski@xxxxxxxxx>
> ---
>  .../mtd/partitions/brcm,bcm963xx-imagetag.txt      | 78 ++++++++++++++++++++++
>  1 file changed, 78 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mtd/partitions/brcm,bcm963xx-imagetag.txt
> 
> diff --git a/Documentation/devicetree/bindings/mtd/partitions/brcm,bcm963xx-imagetag.txt b/Documentation/devicetree/bindings/mtd/partitions/brcm,bcm963xx-imagetag.txt
> new file mode 100644
> index 000000000000..f4a444d69d9a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/partitions/brcm,bcm963xx-imagetag.txt
> @@ -0,0 +1,78 @@
> +Broadcom BCM963XX ImageTag Partition Container
> +==============================================
> +
> +Some Broadcom BCM63XX SoC based devices contain additional, non discoverable
> +partitions or non standard bootloader partition sizes. For these a mixed layout
> +needs to be used with an explicit firmware partition.
> +
> +The BCM963XX ImageTag is a simple firmware header describing the offsets and
> +sizes of the rootfs and kernel parts contained in the firmware.
> +
> +Required properties:
> +- compatible : must be "brcm,bcm963xx-imagetag"
> +
> +Examples:
> +
> +flash@1e000000 {
> +	compatible = "cfi-flash";
> +	reg = <0x1e000000 0x2000000>;
> +	bank-width = <2>;
> +
> +	partitions {
> +		compatible = "fixed-partitions";
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +
> +		cfe@0 {
> +			reg = <0x0 0x10000>;
> +			read-only;
> +		};
> +
> +		firmware@10000 {
> +			reg = <0x10000 0x7d0000>;
> +			compatible = "brcm,bcm963xx-imagetag";
> +		};
> +
> +		caldata@7e0000 {
> +			reg = <0x7e0000 0x10000>;
> +			read-only;
> +		};
> +
> +		nvram@7f0000 {
> +			reg = <0x7f0000 0x10000>;
> +		};
> +	};
> +};
> +
> +
> +flash@1e000000 {
> +	compatible = "cfi-flash";
> +	reg = <0x1e000000 0x2000000>;
> +	bank-width = <2>;
> +
> +	partitions {
> +		compatible = "fixed-partitions";
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +
> +		/*
> +		 * Some devices use a flash chip with 64k erase blocks, some
> +		 * use one with 128k erase blocks, so the vendor decided to
> +		 * always use 128k as the firmware offset.
> +		 */

That's a interesting piece of info, but not really a reason to have a 
second example.

> +
> +		cfe@0 {
> +			reg = <0x0 0x20000>;
> +			read-only;
> +		};
> +
> +		firmware@20000 {
> +			reg = <0x20000 0x7c0000>;
> +			compatible = "brcm,bcm963xx-imagetag";
> +		};
> +
> +		nvram@7e0000 {
> +			reg = <0x7e0000 0x20000>;
> +		};
> +	};
> +};
> -- 
> 2.13.2
> 


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