From: Rafał Miłecki Date: Mon, 25 Jun 2018 22:05:07 +0000 (+0200) Subject: dt-bindings: mtd: document Broadcom's TRX firmware format binding X-Git-Tag: v4.19-rc1~171^2~20 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d1001b060621d2119a81ee00b652a84595b03abe;p=thirdparty%2Fkernel%2Flinux.git dt-bindings: mtd: document Broadcom's TRX firmware format binding 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: Rafał Miłecki Reviewed-by: Rob Herring Signed-off-by: Boris Brezillon --- 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 0000000000000..b677147ca4e10 --- /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@0 { + partitions { + compatible = "brcm,trx"; + }; +};