diff options
| author | Rafał Miłecki <rafal@milecki.pl> | 2022-02-28 14:12:50 +0100 |
|---|---|---|
| committer | Rob Herring <robh@kernel.org> | 2022-03-23 18:10:00 -0500 |
| commit | 5db1c2dbc04c161d9e6b3f93457452e2ee904bde (patch) | |
| tree | 1e1fb92d12595435ba9a14d25e12ef1810b880eb | |
| parent | 3d8fa7a22dcd54ccfdcea6ed0d9badbdb8594274 (diff) | |
dt-bindings: nvmem: add U-Boot environment variables binding
U-Boot uses environment variables for storing device setup data. It
usually needs to be accessed by a bootloader, kernel and often
user-space.
This binding allows describing environment data located in a raw flash
partition. It's treated as NVMEM device and can be reused later for
other storage devices.
Using DT should be cleaner than hardcoding & duplicating such info in
multiple places. Bootloader & kernel can share DTS and user-space can
try reading it too or just have correct data exposed by a kernel.
A custom "compatible" string allows system to automatically load
relevant NVMEM driver but phandle can be also used for reading raw
location.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220228131250.16943-1-zajec5@gmail.com
| -rw-r--r-- | Documentation/devicetree/bindings/nvmem/u-boot,env.yaml | 62 | ||||
| -rw-r--r-- | MAINTAINERS | 5 |
2 files changed, 67 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml new file mode 100644 index 000000000000..e70b2a60cb9a --- /dev/null +++ b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml @@ -0,0 +1,62 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/nvmem/u-boot,env.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: U-Boot environment variables + +description: | + U-Boot uses environment variables to store device parameters and + configuration. They may be used for booting process, setup or keeping end user + info. + + Data is stored using U-Boot specific formats (variant specific header and NUL + separated key-value pairs). + + Environment data can be stored on various storage entities, e.g.: + 1. Raw flash partition + 2. UBI volume + + This binding allows marking storage device (as containing env data) and + specifying used format. + + Right now only flash partition case is covered but it may be extended to e.g. + UBI volumes in the future. + +maintainers: + - Rafał Miłecki <rafal@milecki.pl> + +properties: + compatible: + oneOf: + - description: A standalone env data block + const: u-boot,env + - description: Two redundant blocks with active one flagged + const: u-boot,env-redundant-bool + - description: Two redundant blocks with active having higher counter + const: u-boot,env-redundant-count + + reg: + maxItems: 1 + +additionalProperties: false + +examples: + - | + partitions { + compatible = "fixed-partitions"; + #address-cells = <1>; + #size-cells = <1>; + + partition@0 { + reg = <0x0 0x40000>; + label = "u-boot"; + read-only; + }; + + env: partition@40000 { + compatible = "u-boot,env"; + reg = <0x40000 0x10000>; + }; + }; diff --git a/MAINTAINERS b/MAINTAINERS index fa7eb84277a3..562571223095 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -19665,6 +19665,11 @@ W: http://linuxtv.org T: git git://linuxtv.org/media_tree.git F: drivers/media/pci/tw686x/ +U-BOOT ENVIRONMENT VARIABLES +M: Rafał Miłecki <rafal@milecki.pl> +S: Maintained +F: Documentation/devicetree/bindings/nvmem/u-boot,env.yaml + UACCE ACCELERATOR FRAMEWORK M: Zhangfei Gao <zhangfei.gao@linaro.org> M: Zhou Wang <wangzhou1@hisilicon.com> |