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# SPDX-License-Identifier: (GPL-2.0 OR MIT)
%YAML 1.2
---
$id: http://devicetree.org/schemas/riscv/cpus.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: RISC-V bindings for 'cpus' DT nodes
maintainers:
- Paul Walmsley <paul.walmsley@sifive.com>
- Palmer Dabbelt <palmer@sifive.com>
description: |
This document uses some terminology common to the RISC-V community
that is not widely used, the definitions of which are listed here:
hart: A hardware execution context, which contains all the state
mandated by the RISC-V ISA: a PC and some registers. This
terminology is designed to disambiguate software's view of execution
contexts from any particular microarchitectural implementation
strategy. For example, an Intel laptop containing one socket with
two cores, each of which has two hyperthreads, could be described as
having four harts.
properties:
compatible:
items:
- enum:
- sifive,rocket0
- sifive,e5
- sifive,e51
- sifive,u54-mc
- sifive,u54
- sifive,u5
- const: riscv
description:
Identifies that the hart uses the RISC-V instruction set
and identifies the type of the hart.
mmu-type:
allOf:
- $ref: "/schemas/types.yaml#/definitions/string"
- enum:
- riscv,sv32
- riscv,sv39
- riscv,sv48
description:
Identifies the MMU address translation mode used on this
hart. These values originate from the RISC-V Privileged
Specification document, available from
https://riscv.org/specifications/
riscv,isa:
allOf:
- $ref: "/schemas/types.yaml#/definitions/string"
- enum:
- rv64imac
- rv64imafdc
description:
Identifies the specific RISC-V instruction set architecture
supported by the hart. These are documented in the RISC-V
User-Level ISA document, available from
https://riscv.org/specifications/
While the isa strings in ISA specification are case
insensitive, letters in the riscv,isa string must be all
lowercase to simplify parsing.
timebase-frequency:
type: integer
minimum: 1
description:
Specifies the clock frequency of the system timer in Hz.
This value is common to all harts on a single system image.
interrupt-controller:
type: object
description: Describes the CPU's local interrupt controller
properties:
'#interrupt-cells':
const: 1
compatible:
const: riscv,cpu-intc
interrupt-controller: true
required:
- '#interrupt-cells'
- compatible
- interrupt-controller
required:
- riscv,isa
- timebase-frequency
- interrupt-controller
examples:
- |
// Example 1: SiFive Freedom U540G Development Kit
cpus {
#address-cells = <1>;
#size-cells = <0>;
timebase-frequency = <1000000>;
cpu@0 {
clock-frequency = <0>;
compatible = "sifive,rocket0", "riscv";
device_type = "cpu";
i-cache-block-size = <64>;
i-cache-sets = <128>;
i-cache-size = <16384>;
reg = <0>;
riscv,isa = "rv64imac";
cpu_intc0: interrupt-controller {
#interrupt-cells = <1>;
compatible = "riscv,cpu-intc";
interrupt-controller;
};
};
cpu@1 {
clock-frequency = <0>;
compatible = "sifive,rocket0", "riscv";
d-cache-block-size = <64>;
d-cache-sets = <64>;
d-cache-size = <32768>;
d-tlb-sets = <1>;
d-tlb-size = <32>;
device_type = "cpu";
i-cache-block-size = <64>;
i-cache-sets = <64>;
i-cache-size = <32768>;
i-tlb-sets = <1>;
i-tlb-size = <32>;
mmu-type = "riscv,sv39";
reg = <1>;
riscv,isa = "rv64imafdc";
tlb-split;
cpu_intc1: interrupt-controller {
#interrupt-cells = <1>;
compatible = "riscv,cpu-intc";
interrupt-controller;
};
};
};
- |
// Example 2: Spike ISA Simulator with 1 Hart
cpus {
#address-cells = <1>;
#size-cells = <0>;
cpu@0 {
device_type = "cpu";
reg = <0>;
compatible = "riscv";
riscv,isa = "rv64imafdc";
mmu-type = "riscv,sv48";
interrupt-controller {
#interrupt-cells = <1>;
interrupt-controller;
compatible = "riscv,cpu-intc";
};
};
};
...
|
