xref: /openbmc/qemu/target/avr/cpu.h (revision d349d5ab)
1 /*
2  * QEMU AVR CPU
3  *
4  * Copyright (c) 2016-2020 Michael Rolnik
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see
18  * <http://www.gnu.org/licenses/lgpl-2.1.html>
19  */
20 
21 #ifndef QEMU_AVR_CPU_H
22 #define QEMU_AVR_CPU_H
23 
24 #include "cpu-qom.h"
25 #include "exec/cpu-defs.h"
26 
27 #ifdef CONFIG_USER_ONLY
28 #error "AVR 8-bit does not support user mode"
29 #endif
30 
31 #define CPU_RESOLVING_TYPE TYPE_AVR_CPU
32 
33 #define TCG_GUEST_DEFAULT_MO 0
34 
35 /*
36  * AVR has two memory spaces, data & code.
37  * e.g. both have 0 address
38  * ST/LD instructions access data space
39  * LPM/SPM and instruction fetching access code memory space
40  */
41 #define MMU_CODE_IDX 0
42 #define MMU_DATA_IDX 1
43 
44 #define EXCP_RESET 1
45 #define EXCP_INT(n) (EXCP_RESET + (n) + 1)
46 
47 /* Number of CPU registers */
48 #define NUMBER_OF_CPU_REGISTERS 32
49 /* Number of IO registers accessible by ld/st/in/out */
50 #define NUMBER_OF_IO_REGISTERS 64
51 
52 /*
53  * Offsets of AVR memory regions in host memory space.
54  *
55  * This is needed because the AVR has separate code and data address
56  * spaces that both have start from zero but have to go somewhere in
57  * host memory.
58  *
59  * It's also useful to know where some things are, like the IO registers.
60  */
61 /* Flash program memory */
62 #define OFFSET_CODE 0x00000000
63 /* CPU registers, IO registers, and SRAM */
64 #define OFFSET_DATA 0x00800000
65 /* CPU registers specifically, these are mapped at the start of data */
66 #define OFFSET_CPU_REGISTERS OFFSET_DATA
67 /*
68  * IO registers, including status register, stack pointer, and memory
69  * mapped peripherals, mapped just after CPU registers
70  */
71 #define OFFSET_IO_REGISTERS (OFFSET_DATA + NUMBER_OF_CPU_REGISTERS)
72 
73 typedef enum AVRFeature {
74     AVR_FEATURE_SRAM,
75 
76     AVR_FEATURE_1_BYTE_PC,
77     AVR_FEATURE_2_BYTE_PC,
78     AVR_FEATURE_3_BYTE_PC,
79 
80     AVR_FEATURE_1_BYTE_SP,
81     AVR_FEATURE_2_BYTE_SP,
82 
83     AVR_FEATURE_BREAK,
84     AVR_FEATURE_DES,
85     AVR_FEATURE_RMW, /* Read Modify Write - XCH LAC LAS LAT */
86 
87     AVR_FEATURE_EIJMP_EICALL,
88     AVR_FEATURE_IJMP_ICALL,
89     AVR_FEATURE_JMP_CALL,
90 
91     AVR_FEATURE_ADIW_SBIW,
92 
93     AVR_FEATURE_SPM,
94     AVR_FEATURE_SPMX,
95 
96     AVR_FEATURE_ELPMX,
97     AVR_FEATURE_ELPM,
98     AVR_FEATURE_LPMX,
99     AVR_FEATURE_LPM,
100 
101     AVR_FEATURE_MOVW,
102     AVR_FEATURE_MUL,
103     AVR_FEATURE_RAMPD,
104     AVR_FEATURE_RAMPX,
105     AVR_FEATURE_RAMPY,
106     AVR_FEATURE_RAMPZ,
107 } AVRFeature;
108 
109 typedef struct CPUArchState {
110     uint32_t pc_w; /* 0x003fffff up to 22 bits */
111 
112     uint32_t sregC; /* 0x00000001 1 bit */
113     uint32_t sregZ; /* 0x00000001 1 bit */
114     uint32_t sregN; /* 0x00000001 1 bit */
115     uint32_t sregV; /* 0x00000001 1 bit */
116     uint32_t sregS; /* 0x00000001 1 bit */
117     uint32_t sregH; /* 0x00000001 1 bit */
118     uint32_t sregT; /* 0x00000001 1 bit */
119     uint32_t sregI; /* 0x00000001 1 bit */
120 
121     uint32_t rampD; /* 0x00ff0000 8 bits */
122     uint32_t rampX; /* 0x00ff0000 8 bits */
123     uint32_t rampY; /* 0x00ff0000 8 bits */
124     uint32_t rampZ; /* 0x00ff0000 8 bits */
125     uint32_t eind; /* 0x00ff0000 8 bits */
126 
127     uint32_t r[NUMBER_OF_CPU_REGISTERS]; /* 8 bits each */
128     uint32_t sp; /* 16 bits */
129 
130     uint32_t skip; /* if set skip instruction */
131 
132     uint64_t intsrc; /* interrupt sources */
133     bool fullacc; /* CPU/MEM if true MEM only otherwise */
134 
135     uint64_t features;
136 } CPUAVRState;
137 
138 /**
139  *  AVRCPU:
140  *  @env: #CPUAVRState
141  *
142  *  A AVR CPU.
143  */
144 struct ArchCPU {
145     CPUState parent_obj;
146 
147     CPUAVRState env;
148 
149     /* Initial value of stack pointer */
150     uint32_t init_sp;
151 };
152 
153 /**
154  *  AVRCPUClass:
155  *  @parent_realize: The parent class' realize handler.
156  *  @parent_phases: The parent class' reset phase handlers.
157  *
158  *  A AVR CPU model.
159  */
160 struct AVRCPUClass {
161     CPUClass parent_class;
162 
163     DeviceRealize parent_realize;
164     ResettablePhases parent_phases;
165 };
166 
167 extern const struct VMStateDescription vms_avr_cpu;
168 
169 void avr_cpu_do_interrupt(CPUState *cpu);
170 bool avr_cpu_exec_interrupt(CPUState *cpu, int int_req);
171 hwaddr avr_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
172 int avr_cpu_gdb_read_register(CPUState *cpu, GByteArray *buf, int reg);
173 int avr_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
174 int avr_print_insn(bfd_vma addr, disassemble_info *info);
175 vaddr avr_cpu_gdb_adjust_breakpoint(CPUState *cpu, vaddr addr);
176 
177 static inline int avr_feature(CPUAVRState *env, AVRFeature feature)
178 {
179     return (env->features & (1U << feature)) != 0;
180 }
181 
182 static inline void set_avr_feature(CPUAVRState *env, int feature)
183 {
184     env->features |= (1U << feature);
185 }
186 
187 #define cpu_list avr_cpu_list
188 #define cpu_mmu_index avr_cpu_mmu_index
189 
190 static inline int avr_cpu_mmu_index(CPUAVRState *env, bool ifetch)
191 {
192     return ifetch ? MMU_CODE_IDX : MMU_DATA_IDX;
193 }
194 
195 void avr_cpu_tcg_init(void);
196 
197 void avr_cpu_list(void);
198 int cpu_avr_exec(CPUState *cpu);
199 
200 enum {
201     TB_FLAGS_FULL_ACCESS = 1,
202     TB_FLAGS_SKIP = 2,
203 };
204 
205 static inline void cpu_get_tb_cpu_state(CPUAVRState *env, vaddr *pc,
206                                         uint64_t *cs_base, uint32_t *pflags)
207 {
208     uint32_t flags = 0;
209 
210     *pc = env->pc_w * 2;
211     *cs_base = 0;
212 
213     if (env->fullacc) {
214         flags |= TB_FLAGS_FULL_ACCESS;
215     }
216     if (env->skip) {
217         flags |= TB_FLAGS_SKIP;
218     }
219 
220     *pflags = flags;
221 }
222 
223 static inline int cpu_interrupts_enabled(CPUAVRState *env)
224 {
225     return env->sregI != 0;
226 }
227 
228 static inline uint8_t cpu_get_sreg(CPUAVRState *env)
229 {
230     return (env->sregC) << 0
231          | (env->sregZ) << 1
232          | (env->sregN) << 2
233          | (env->sregV) << 3
234          | (env->sregS) << 4
235          | (env->sregH) << 5
236          | (env->sregT) << 6
237          | (env->sregI) << 7;
238 }
239 
240 static inline void cpu_set_sreg(CPUAVRState *env, uint8_t sreg)
241 {
242     env->sregC = (sreg >> 0) & 0x01;
243     env->sregZ = (sreg >> 1) & 0x01;
244     env->sregN = (sreg >> 2) & 0x01;
245     env->sregV = (sreg >> 3) & 0x01;
246     env->sregS = (sreg >> 4) & 0x01;
247     env->sregH = (sreg >> 5) & 0x01;
248     env->sregT = (sreg >> 6) & 0x01;
249     env->sregI = (sreg >> 7) & 0x01;
250 }
251 
252 bool avr_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
253                       MMUAccessType access_type, int mmu_idx,
254                       bool probe, uintptr_t retaddr);
255 
256 #include "exec/cpu-all.h"
257 
258 #endif /* QEMU_AVR_CPU_H */
259