diff mbox series

[v8,1/2] dt-bindings: mtd: fixed-partitions: Add alignment properties

Message ID 20240315204521.28613-1-sjg@chromium.org
State New
Headers show
Series [v8,1/2] dt-bindings: mtd: fixed-partitions: Add alignment properties | expand

Commit Message

Simon Glass March 15, 2024, 8:45 p.m. UTC
Add three properties for controlling alignment of partitions, aka
'entries' in fixed-partition.

For now there is no explicit mention of hierarchy, so a 'section' is
just the 'fixed-partitions' node.

These new properties are inputs to the Binman packaging process, but are
also needed if the firmware is repacked, to ensure that alignment
constraints are not violated. Therefore they are provided as part of
the schema.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

(no changes since v7)

Changes in v7:
- Drop patch 'Add binman compatible'
- Put the alignment properties into the fixed-partition binding

Changes in v6:
- Correct schema-validation errors missed due to older dt-schema
  (enum fix and reg addition)

Changes in v5:
- Add value ranges
- Consistently mention alignment must be power-of-2
- Mention that alignment refers to bytes

Changes in v2:
- Fix 'a' typo in commit message

 .../bindings/mtd/partitions/partition.yaml    | 72 +++++++++++++++++++
 1 file changed, 72 insertions(+)

Comments

Rob Herring (Arm) March 15, 2024, 10:39 p.m. UTC | #1
On Sat, 16 Mar 2024 09:45:20 +1300, Simon Glass wrote:
> Add three properties for controlling alignment of partitions, aka
> 'entries' in fixed-partition.
> 
> For now there is no explicit mention of hierarchy, so a 'section' is
> just the 'fixed-partitions' node.
> 
> These new properties are inputs to the Binman packaging process, but are
> also needed if the firmware is repacked, to ensure that alignment
> constraints are not violated. Therefore they are provided as part of
> the schema.
> 
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
> 
> (no changes since v7)
> 
> Changes in v7:
> - Drop patch 'Add binman compatible'
> - Put the alignment properties into the fixed-partition binding
> 
> Changes in v6:
> - Correct schema-validation errors missed due to older dt-schema
>   (enum fix and reg addition)
> 
> Changes in v5:
> - Add value ranges
> - Consistently mention alignment must be power-of-2
> - Mention that alignment refers to bytes
> 
> Changes in v2:
> - Fix 'a' typo in commit message
> 
>  .../bindings/mtd/partitions/partition.yaml    | 72 +++++++++++++++++++
>  1 file changed, 72 insertions(+)
> 

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:

dtschema/dtc warnings/errors:
Documentation/devicetree/bindings/mtd/partitions/partition.example.dtb: /example-0/partitions/partition@100000: failed to match any schema with compatible: ['u-boot']
Documentation/devicetree/bindings/mtd/partitions/partition.example.dtb: /example-0/partitions/partition@200000: failed to match any schema with compatible: ['tfa-bl31']

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20240315204521.28613-1-sjg@chromium.org

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/mtd/partitions/partition.yaml b/Documentation/devicetree/bindings/mtd/partitions/partition.yaml
index 1ebe9e2347ea..3df12df06116 100644
--- a/Documentation/devicetree/bindings/mtd/partitions/partition.yaml
+++ b/Documentation/devicetree/bindings/mtd/partitions/partition.yaml
@@ -57,6 +57,57 @@  properties:
       user space from
     type: boolean
 
+  align:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 0x80000000
+    multipleOf: 2
+    description:
+      This sets the alignment of the entry in bytes.
+
+      The entry offset is adjusted so that the entry starts on an aligned
+      boundary within the containing section or image. For example ‘align =
+      <16>’ means that the entry will start on a 16-byte boundary. This may
+      mean that padding is added before the entry. The padding is part of
+      the containing section but is not included in the entry, meaning that
+      an empty space may be created before the entry starts. Alignment
+      must be a power of 2. If ‘align’ is not provided, no alignment is
+      performed.
+
+  align-size:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 0x80000000
+    multipleOf: 2
+    description:
+      This sets the alignment of the entry size in bytes. It must be a power
+      of 2.
+
+      For example, to ensure that the size of an entry is a multiple of 64
+      bytes, set this to 64. While this does not affect the contents of the
+      entry within binman itself (the padding is performed only when its
+      parent section is assembled), the end result is that the entry ends
+      with the padding bytes, so may grow. If ‘align-size’ is not provided,
+      no alignment is performed.
+
+  align-end:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 0x80000000
+    multipleOf: 2
+    description:
+      This sets the alignment (in bytes) of the end of an entry with respect
+      to the containing section. It must be a power of 2.
+
+      Some entries require that they end on an alignment boundary,
+      regardless of where they start. This does not move the start of the
+      entry, so the contents of the entry will still start at the beginning.
+      But there may be padding at the end. While this does not affect the
+      contents of the entry within binman itself (the padding is performed
+      only when its parent section is assembled), the end result is that the
+      entry ends with the padding bytes, so may grow. If ‘align-end’ is not
+      provided, no alignment is performed.
+
 if:
   not:
     required: [ reg ]
@@ -67,3 +118,24 @@  then:
 
 # This is a generic file other binding inherit from and extend
 additionalProperties: true
+
+examples:
+  - |
+    partitions {
+        compatible = "fixed-partitions";
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        partition@100000 {
+            compatible = "u-boot";
+            reg = <0x100000 0xf00000>;
+            align-size = <0x1000>;
+            align-end = <0x10000>;
+        };
+
+        partition@200000 {
+            compatible = "tfa-bl31";
+            reg = <0x200000 0x100000>;
+            align = <0x4000>;
+        };
+    };