nordic,owned-memory

Vendor: Nordic Semiconductor

Description

Nordic Owned Memory

Memory region with permission attributes. Each enabled region of this kind
will be recorded in the UICR of the compiled domain. Memory ownership and
access is then configured for the domain at boot time, based on the UICR.

Example:

  reserved-memory {
      memory@2fc00000 {
          compatible = "nordic,owned-memory";
          reg = <0x2fc00000 0x1000>;
          status = "okay";
          nordic,access = <NRF_OWNER_ID_APPLICATION NRF_PERM_R>,
                          <NRF_OWNER_ID_RADIOCORE NRF_PERM_W>;
      };
  };

A single local domain can request a memory region to be reserved on behalf of
multiple access owners. A single memory region shall be reserved by at most
one domain, by setting status "okay" on the associated node. For example, if
the region defined above is enabled by Application on behalf of Radiocore,
then the Radiocore's devicetree must set status "disabled" on that node.

Each of the different owners may have a different set of permissions granted,
as also shown above.

Note: one domain can also reserve memory for another domain and not itself.
Whichever domain has status "okay" set on the node does not need to be listed
as one of the access owners.

Properties

Properties not inherited from the base binding file.

Name

Type

Details

nordic,access

array

 
Array of (owner-id, permission-flags) pairs, where:

- Owner ID represents the domain that will have access to this memory.
  Valid values can be found in dts/common/nordic/<soc>.dtsi,
  where they are defined as NRF_OWNER_ID_*

- Permissions are encoded as a 32-bit bitfield, using the flags found in
  include/zephyr/dt-bindings/reserved-memory/nordic-owned-memory.h,
  where they are defined as NRF_PERM_*

  The same file defines all possible permission flag combinations.
  For example, one can use:
    <NRF_OWNER_ID_APPLICATION NRF_PERM_RWX>

  as a shorthand for:
    <NRF_OWNER_ID_APPLICATION (NRF_PERM_R | NRF_PERM_W | NRF_PERM_X)>

zephyr,memory-region

string

 
Signify that this node should result in a dedicated linker script
memory region in the final executable. The region address and size
is taken from the <reg> property, while the name is the value of
this property.

zephyr,memory-region-flags

string

 
Set attributes such as read-only or executable for the linker script
memory region. The string set here will be specified in parentheses
after the area name in the linker script.

zephyr,memory-attr

int

 
Attribute or set of attributes (bitmask) for the memory region. See
'include/zephyr/dt-bindings/memory-attr/memory-attr.h' for a
comprehensive list with description of possible values.