[PATCH] schemas: Add a schema for memory map

[Simon Glass]

+linux-acpi at vger.kernel.org
+lk

Since there was a related discussion here:
https://patches.linaro.org/project/linux-acpi/patch/20230426034001.16-1-cuiyunhui@bytedance.com/

On Fri, 11 Aug 2023 at 15:57, Simon Glass <sjg at chromium.org> wrote:
>
> The Devicespec specification skips over handling of a logical view of
> the memory map, pointing users to the UEFI specification.
>
> It is common to split firmware into 'Platform Init', which does the
> initial hardware setup and a "Payload" which selects the OS to be booted.
> Thus an handover interface is required between these two pieces.
>
> Where UEFI boot-time services are not available, but UEFI firmware is
> present on either side of this interface, information about memory usage
> and attributes must be presented to the "Payload" in some form.
>
> This aims to provide an initial schema for this mapping.
>
> Note that this is separate from the existing /memory and /reserved-memory
> nodes, since it is mostly concerned with what the memory is used for. It
> may cover only a small fraction of available memory, although it could be
> used to signal which area of memory has ECC.
>
> For now, no attempt is made to create an exhaustive binding, but this can
> be completed once this has passed initial review.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
>  dtschema/schemas/memory-map.yaml | 51 ++++++++++++++++++++++++++++++++
>  1 file changed, 51 insertions(+)
>  create mode 100644 dtschema/schemas/memory-map.yaml
>
> diff --git a/dtschema/schemas/memory-map.yaml b/dtschema/schemas/memory-map.yaml
> new file mode 100644
> index 0000000..97e531e
> --- /dev/null
> +++ b/dtschema/schemas/memory-map.yaml
> @@ -0,0 +1,51 @@
> +# SPDX-License-Identifier: BSD-2-Clause
> +# Copyright 2023 Google LLC
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/memory-map.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: /memory-map nodes
> +description: |
> +  Common properties always required in /memory-map nodes. These nodes are
> +  intended to resolve the nonchalant clause 3.4.1 ("/memory node and UEFI")
> +  in the Devicetree Specification.
> +
> +maintainers:
> +  - Simon Glass <sjg at chromium.org>
> +
> +properties:
> +  $nodename:
> +    const: '/'
> +  usage:
> +    $ref: /schemas/types.yaml#/definitions/string
> +    description: |
> +      Describes the usage of the memory region, e.g.:
> +
> +        "acpi-reclaim", "acpi-nvs", "bootcode", "bootdata", "bootdata",
> +        "runtime-code", "runtime-data"
> +  attr:
> +    $ref: /schemas/types.yaml#/definitions/string-array
> +    description: |
> +      Attributes possessed by this memory region:
> +
> +        "single-bit-ecc" - supports single-bit ECC
> +        "multi-bit-ecc" - supports multiple-bit ECC
> +        "no-ecc" - non-ECC memory
> +
> +patternProperties:
> +  "^([a-z][a-z0-9\\-]+@[0-9a-f]+)?$":
> +    type: object
> +    additionalProperties: false
> +
> +    properties:
> +      reg:
> +        minItems: 1
> +        maxItems: 1024
> +
> +    required:
> +      - reg
> +
> +additionalProperties: true
> +
> +...
> --
> 2.41.0.694.ge786442a9b-goog
>