[PATCH V2 1/2] dt-bindings: mtd: document Broadcom's TRX firmware format binding

[boris.brezillon@xxxxxxxxxxx (Boris Brezillon)]

On Tue, 26 Jun 2018 00:05:07 +0200
Rafa? Mi?ecki <zajec5 at gmail.com> wrote:

> From: Rafa? Mi?ecki <rafal at milecki.pl>
> 
> Broadcom based home router devices use TRX firmware format. It's a
> container that can hold few partitions. If operating system is expected
> to access them it has to understand that format and parse flash data
> accordingly.
> 
> Signed-off-by: Rafa? Mi?ecki <rafal at milecki.pl>

Applied both patches.

Thanks,

Boris

> ---
> V2: Drop unneeded "brcm,trx-v1" and "brcm,trx-v2" bindings.
> ---
>  .../bindings/mtd/partitions/brcm,trx.txt           | 37 ++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt
> 
> diff --git a/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt b/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt
> new file mode 100644
> index 000000000000..b677147ca4e1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt
> @@ -0,0 +1,37 @@
> +Broadcom TRX Container Partition
> +================================
> +
> +TRX is Broadcom's official firmware format for the BCM947xx boards. It's used by
> +most of the vendors building devices based on Broadcom's BCM47xx SoCs and is
> +supported by the CFE bootloader.
> +
> +Design of the TRX format is very minimalistic. Its header contains
> +identification fields, CRC32 checksum and the locations of embedded partitions.
> +Its purpose is to store a few partitions in a format that can be distributed as
> +a standalone file and written in a flash memory.
> +
> +Container can hold up to 4 partitions. The first partition has to contain a
> +device executable binary (e.g. a kernel) as it's what the CFE bootloader starts
> +executing. Other partitions can be used for operating system purposes. This is
> +useful for systems that keep kernel and rootfs separated.
> +
> +TRX doesn't enforce any strict partition boundaries or size limits. All
> +partitions have to be less than the 4GiB max size limit.
> +
> +There are two existing/known TRX variants:
> +1) v1 which contains 3 partitions
> +2) v2 which contains 4 partitions
> +
> +There aren't separated compatible bindings for them as version can be trivialy
> +detected by a software parsing TRX header.
> +
> +Required properties:
> +- compatible : (required) must be "brcm,trx"
> +
> +Example:
> +
> +flash at 0 {
> +	partitions {
> +		compatible = "brcm,trx";
> +	};
> +};