1 # SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
4 $id: http://devicetree.org/schemas/reserved-memory/reserved-memory.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
7 title: /reserved-memory Child Node Common Device Tree Bindings
10 - devicetree-spec@vger.kernel.org
13 Reserved memory is specified as a node under the /reserved-memory node. The
14 operating system shall exclude reserved memory from normal usage one can
15 create child nodes describing particular reserved (excluded from normal use)
16 memory regions. Such memory regions are usually designed for the special
17 usage by various device drivers.
19 Each child of the reserved-memory node specifies one or more regions
20 of reserved memory. Each child node may either use a 'reg' property to
21 specify a specific range of reserved memory, or a 'size' property with
22 optional constraints to request a dynamically allocated block of
25 Following the generic-names recommended practice, node names should
26 reflect the purpose of the node (ie. "framebuffer" or "dma-pool").
27 Unit address (@<address>) should be appended to the name if the node
28 is a static allocation.
34 $ref: /schemas/types.yaml#/definitions/uint32-array
38 Length based on parent's \#size-cells. Size in bytes of memory to
42 $ref: /schemas/types.yaml#/definitions/uint32-array
46 Length based on parent's \#size-cells. Address boundary for
47 alignment of allocation.
50 $ref: /schemas/types.yaml#/definitions/uint32-array
52 Address and Length pairs. Specifies regions of memory that are
53 acceptable to allocate from.
58 Indicates the operating system must not create a virtual mapping
59 of the region as part of its standard mapping of system memory,
60 nor permit speculative access to it under any circumstances other
61 than under the control of the device driver using the region.
66 The operating system can use the memory in this region with the
67 limitation that the device driver(s) owning the region need to be
68 able to reclaim it back. Typically that means that the operating
69 system can use that region to store volatile or cached data that
70 can be otherwise regenerated or migrated elsewhere.
98 additionalProperties: true