[PATCH 3/3] dt-bindings: mtd: binman-partitions: Add alignment properties

[Simon Glass <sjg@chromium.org>]

Add three properties for controlling alignment of partitions, aka
'entries' in binman.

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

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

 .../mtd/partitions/binman-partition.yaml      | 39 +++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/partitions/binman-partition.yaml b/Documentation/devicetree/bindings/mtd/partitions/binman-partition.yaml
index 6ee832cb4c4c..9cd424447e76 100644
--- a/Documentation/devicetree/bindings/mtd/partitions/binman-partition.yaml
+++ b/Documentation/devicetree/bindings/mtd/partitions/binman-partition.yaml
@@ -27,6 +27,42 @@ properties:
         - u-boot       # u-boot.bin from U-Boot projec6t
         - atf-bl31     # bl31.bin or bl31.elf from TF-A project
 
+  align:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      This sets the alignment of the entry. 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 should be a power of 2. If ‘align’ is not
+      provided, no alignment is performed.
+
+  align-size:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      This sets the alignment of the entry size. 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
+    description:
+      This sets the alignment of the end of an entry with respect to the
+      containing section. 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.
+
 additionalProperties: false
 
 examples:
@@ -39,10 +75,13 @@ examples:
         partition-u-boot@100000 {
             label = "u-boot";
             reg = <0x100000 0xf00000>;
+            align-size = <0x1000>;
+            align-end = <0x10000>;
         };
 
         partition-atf-bl31t@200000 {
             label = "atf-bl31";
             reg = <0x200000 0x100000>;
+            align = <0x4000>;
         };
     };
-- 
2.42.0.515.g380fc7ccd1-goog


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