1# SPDX-License-Identifier: (GPL-2.0 OR MIT)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/riscv/cpus.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: RISC-V CPUs
8
9maintainers:
10  - Paul Walmsley <paul.walmsley@sifive.com>
11  - Palmer Dabbelt <palmer@sifive.com>
12  - Conor Dooley <conor@kernel.org>
13
14description: |
15  This document uses some terminology common to the RISC-V community
16  that is not widely used, the definitions of which are listed here:
17
18  hart: A hardware execution context, which contains all the state
19  mandated by the RISC-V ISA: a PC and some registers.  This
20  terminology is designed to disambiguate software's view of execution
21  contexts from any particular microarchitectural implementation
22  strategy.  For example, an Intel laptop containing one socket with
23  two cores, each of which has two hyperthreads, could be described as
24  having four harts.
25
26properties:
27  compatible:
28    oneOf:
29      - items:
30          - enum:
31              - andestech,ax45mp
32              - canaan,k210
33              - sifive,bullet0
34              - sifive,e5
35              - sifive,e7
36              - sifive,e71
37              - sifive,rocket0
38              - sifive,u5
39              - sifive,u54
40              - sifive,u7
41              - sifive,u74
42              - sifive,u74-mc
43              - thead,c906
44              - thead,c910
45          - const: riscv
46      - items:
47          - enum:
48              - sifive,e51
49              - sifive,u54-mc
50          - const: sifive,rocket0
51          - const: riscv
52      - const: riscv    # Simulator only
53    description:
54      Identifies that the hart uses the RISC-V instruction set
55      and identifies the type of the hart.
56
57  mmu-type:
58    description:
59      Identifies the MMU address translation mode used on this
60      hart.  These values originate from the RISC-V Privileged
61      Specification document, available from
62      https://riscv.org/specifications/
63    $ref: "/schemas/types.yaml#/definitions/string"
64    enum:
65      - riscv,sv32
66      - riscv,sv39
67      - riscv,sv48
68      - riscv,none
69
70  riscv,cbom-block-size:
71    $ref: /schemas/types.yaml#/definitions/uint32
72    description:
73      The blocksize in bytes for the Zicbom cache operations.
74
75  riscv,isa:
76    description:
77      Identifies the specific RISC-V instruction set architecture
78      supported by the hart.  These are documented in the RISC-V
79      User-Level ISA document, available from
80      https://riscv.org/specifications/
81
82      While the isa strings in ISA specification are case
83      insensitive, letters in the riscv,isa string must be all
84      lowercase to simplify parsing.
85    $ref: "/schemas/types.yaml#/definitions/string"
86    pattern: ^rv(?:64|32)imaf?d?q?c?b?v?k?h?(?:_[hsxz](?:[a-z])+)*$
87
88  # RISC-V requires 'timebase-frequency' in /cpus, so disallow it here
89  timebase-frequency: false
90
91  interrupt-controller:
92    type: object
93    description: Describes the CPU's local interrupt controller
94
95    properties:
96      '#interrupt-cells':
97        const: 1
98
99      compatible:
100        const: riscv,cpu-intc
101
102      interrupt-controller: true
103
104    required:
105      - '#interrupt-cells'
106      - compatible
107      - interrupt-controller
108
109  cpu-idle-states:
110    $ref: '/schemas/types.yaml#/definitions/phandle-array'
111    items:
112      maxItems: 1
113    description: |
114      List of phandles to idle state nodes supported
115      by this hart (see ./idle-states.yaml).
116
117required:
118  - riscv,isa
119  - interrupt-controller
120
121additionalProperties: true
122
123examples:
124  - |
125    // Example 1: SiFive Freedom U540G Development Kit
126    cpus {
127        #address-cells = <1>;
128        #size-cells = <0>;
129        timebase-frequency = <1000000>;
130        cpu@0 {
131                clock-frequency = <0>;
132                compatible = "sifive,rocket0", "riscv";
133                device_type = "cpu";
134                i-cache-block-size = <64>;
135                i-cache-sets = <128>;
136                i-cache-size = <16384>;
137                reg = <0>;
138                riscv,isa = "rv64imac";
139                cpu_intc0: interrupt-controller {
140                        #interrupt-cells = <1>;
141                        compatible = "riscv,cpu-intc";
142                        interrupt-controller;
143                };
144        };
145        cpu@1 {
146                clock-frequency = <0>;
147                compatible = "sifive,rocket0", "riscv";
148                d-cache-block-size = <64>;
149                d-cache-sets = <64>;
150                d-cache-size = <32768>;
151                d-tlb-sets = <1>;
152                d-tlb-size = <32>;
153                device_type = "cpu";
154                i-cache-block-size = <64>;
155                i-cache-sets = <64>;
156                i-cache-size = <32768>;
157                i-tlb-sets = <1>;
158                i-tlb-size = <32>;
159                mmu-type = "riscv,sv39";
160                reg = <1>;
161                riscv,isa = "rv64imafdc";
162                tlb-split;
163                cpu_intc1: interrupt-controller {
164                        #interrupt-cells = <1>;
165                        compatible = "riscv,cpu-intc";
166                        interrupt-controller;
167                };
168        };
169    };
170
171  - |
172    // Example 2: Spike ISA Simulator with 1 Hart
173    cpus {
174        #address-cells = <1>;
175        #size-cells = <0>;
176        cpu@0 {
177                device_type = "cpu";
178                reg = <0>;
179                compatible = "riscv";
180                riscv,isa = "rv64imafdc";
181                mmu-type = "riscv,sv48";
182                interrupt-controller {
183                        #interrupt-cells = <1>;
184                        interrupt-controller;
185                        compatible = "riscv,cpu-intc";
186                };
187        };
188    };
189...
190