reserved-memory device tree nodes

OPAL exposes reserved memory through a top-level reserved-memory node, containing subnodes that represent each reserved memory region.

This follows the Linux specification for the /reserved-memory node, described in the kernel source tree, in:

Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt

The top-level /reserved-memory node contains:

#size-cells = <2>
#address-cells = <2>

Addresses and sizes are all 64-bits.

ranges

the empty ranges node indicates no translation of physical addresses in the subnodes.

The sub-nodes under the /reserved-memory node contain:

reg = <address size>

the address and size of the reserved memory region. The address and size values are two cells each, as signified by the top-level #{address,size}-cells

ibm,prd-label = "string"

a string token for use by the prd system. Specific ranges may be used by prd - those will be referenced by this label.