linuxdebug/Documentation/devicetree/bindings/mtd/partitions/brcm,bcm947xx-cfe-partition...

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YAML

# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
%YAML 1.2
---
$id: http://devicetree.org/schemas/mtd/partitions/brcm,bcm947xx-cfe-partitions.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Broadcom BCM47xx Partitions
description: |
Broadcom is one of hardware manufacturers providing SoCs (BCM47xx) used in
home routers. Their BCM947xx boards using CFE bootloader have several
partitions without any on-flash partition table. On some devices their sizes
and/or meanings can also vary so fixed partitioning can't be used.
Discovering partitions on these devices is possible thanks to having a special
header and/or magic signature at the beginning of each of them. They are also
block aligned which is important for determinig a size.
Most of partitions use ASCII text based magic for determining a type. More
complex partitions (like TRX with its HDR0 magic) may include extra header
containing some details, including a length.
A list of supported partitions includes:
1) Bootloader with Broadcom's CFE (Common Firmware Environment)
2) NVRAM with configuration/calibration data
3) Device manufacturer's data with some default values (e.g. SSIDs)
4) TRX firmware container which can hold up to 4 subpartitions
5) Backup TRX firmware used after failed upgrade
As mentioned earlier, role of some partitions may depend on extra
configuration. For example both: main firmware and backup firmware use the
same TRX format with the same header. To distinguish currently used firmware a
CFE's environment variable "bootpartition" is used.
maintainers:
- Rafał Miłecki <rafal@milecki.pl>
properties:
compatible:
const: brcm,bcm947xx-cfe-partitions
additionalProperties: false
examples:
- |
partitions {
compatible = "brcm,bcm947xx-cfe-partitions";
};