[PATCH 2/2] dt-bindings: nvmem: u-boot,env: describe "data-size" property

From: Rafał Miłecki
Date: Wed Dec 13 2023 - 10:47:51 EST


From: Rafał Miłecki <rafal@xxxxxxxxxx>

Describe what "data-size" means in U-Boot env context and why it may be
needed. It's a generic property but giving it some extra meaning in
U-Boot context may be helpful.

Cc: Christian Marangi <ansuelsmth@xxxxxxxxx>
Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
---
.../devicetree/bindings/nvmem/u-boot,env.yaml | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
index 9c36afc7084b..0006f022d0af 100644
--- a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
+++ b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
@@ -44,6 +44,15 @@ properties:
reg:
maxItems: 1

+ data-size:
+ description:
+ U-Boot environment data size is set and hardcoded during compilation using
+ CONFIG_ENV_SIZE. Knowing it is critical for CRC32 checksum calculation.
+
+ This property allows specifying it in case it differs from NVMEM device
+ size. It may happen if device partitioning was designed with different
+ concepts in mind (like block alignment or future-proof size).
+
bootcmd:
type: object
description: Command to use for automatic booting
@@ -76,6 +85,7 @@ examples:
env: partition@40000 {
compatible = "u-boot,env";
reg = <0x40000 0x10000>;
+ data-size = <0x4000>;

mac: ethaddr {
#nvmem-cell-cells = <1>;
--
2.35.3