xref: /qemu/target/avr/cpu.h (revision 9c2ff9cdc9b33472333e9431cbf4417f5f228883)
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 #include "exec/cpu-interrupt.h"
27 #include "system/memory.h"
28 
29 #ifdef CONFIG_USER_ONLY
30 #error "AVR 8-bit does not support user mode"
31 #endif
32 
33 #define CPU_RESOLVING_TYPE TYPE_AVR_CPU
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 
50 /* CPU registers mapped into i/o ports 0x38-0x3f. */
51 #define REG_38_RAMPD  0
52 #define REG_38_RAMPX  1
53 #define REG_38_RAMPY  2
54 #define REG_38_RAMPZ  3
55 #define REG_38_EIDN   4
56 #define REG_38_SPL    5
57 #define REG_38_SPH    6
58 #define REG_38_SREG   7
59 
60 /*
61  * Offsets of AVR memory regions in host memory space.
62  *
63  * This is needed because the AVR has separate code and data address
64  * spaces that both have start from zero but have to go somewhere in
65  * host memory.
66  *
67  * It's also useful to know where some things are, like the IO registers.
68  */
69 /* Flash program memory */
70 #define OFFSET_CODE 0x00000000
71 /* CPU registers, IO registers, and SRAM */
72 #define OFFSET_DATA 0x00800000
73 /*
74  * IO registers, including status register, stack pointer, and memory
75  * mapped peripherals, mapped just after CPU registers
76  */
77 #define OFFSET_IO_REGISTERS (OFFSET_DATA + NUMBER_OF_CPU_REGISTERS)
78 
79 typedef enum AVRFeature {
80     AVR_FEATURE_SRAM,
81 
82     AVR_FEATURE_1_BYTE_PC,
83     AVR_FEATURE_2_BYTE_PC,
84     AVR_FEATURE_3_BYTE_PC,
85 
86     AVR_FEATURE_1_BYTE_SP,
87     AVR_FEATURE_2_BYTE_SP,
88 
89     AVR_FEATURE_BREAK,
90     AVR_FEATURE_DES,
91     AVR_FEATURE_RMW, /* Read Modify Write - XCH LAC LAS LAT */
92 
93     AVR_FEATURE_EIJMP_EICALL,
94     AVR_FEATURE_IJMP_ICALL,
95     AVR_FEATURE_JMP_CALL,
96 
97     AVR_FEATURE_ADIW_SBIW,
98 
99     AVR_FEATURE_SPM,
100     AVR_FEATURE_SPMX,
101 
102     AVR_FEATURE_ELPMX,
103     AVR_FEATURE_ELPM,
104     AVR_FEATURE_LPMX,
105     AVR_FEATURE_LPM,
106 
107     AVR_FEATURE_MOVW,
108     AVR_FEATURE_MUL,
109     AVR_FEATURE_RAMPD,
110     AVR_FEATURE_RAMPX,
111     AVR_FEATURE_RAMPY,
112     AVR_FEATURE_RAMPZ,
113 } AVRFeature;
114 
115 typedef struct CPUArchState {
116     uint32_t pc_w; /* 0x003fffff up to 22 bits */
117 
118     uint32_t sregC; /* 0x00000001 1 bit */
119     uint32_t sregZ; /* 0x00000001 1 bit */
120     uint32_t sregN; /* 0x00000001 1 bit */
121     uint32_t sregV; /* 0x00000001 1 bit */
122     uint32_t sregS; /* 0x00000001 1 bit */
123     uint32_t sregH; /* 0x00000001 1 bit */
124     uint32_t sregT; /* 0x00000001 1 bit */
125     uint32_t sregI; /* 0x00000001 1 bit */
126 
127     uint32_t rampD; /* 0x00ff0000 8 bits */
128     uint32_t rampX; /* 0x00ff0000 8 bits */
129     uint32_t rampY; /* 0x00ff0000 8 bits */
130     uint32_t rampZ; /* 0x00ff0000 8 bits */
131     uint32_t eind; /* 0x00ff0000 8 bits */
132 
133     uint32_t r[NUMBER_OF_CPU_REGISTERS]; /* 8 bits each */
134     uint32_t sp; /* 16 bits */
135 
136     uint32_t skip; /* if set skip instruction */
137 
138     uint64_t intsrc; /* interrupt sources */
139     bool fullacc; /* CPU/MEM if true MEM only otherwise */
140 
141     uint64_t features;
142 } CPUAVRState;
143 
144 /**
145  *  AVRCPU:
146  *  @env: #CPUAVRState
147  *
148  *  A AVR CPU.
149  */
150 struct ArchCPU {
151     CPUState parent_obj;
152 
153     CPUAVRState env;
154 
155     MemoryRegion cpu_reg1;
156     MemoryRegion cpu_reg2;
157 
158     /* Initial value of stack pointer */
159     uint32_t init_sp;
160 };
161 
162 /**
163  *  AVRCPUClass:
164  *  @parent_realize: The parent class' realize handler.
165  *  @parent_phases: The parent class' reset phase handlers.
166  *
167  *  A AVR CPU model.
168  */
169 struct AVRCPUClass {
170     CPUClass parent_class;
171 
172     DeviceRealize parent_realize;
173     ResettablePhases parent_phases;
174 };
175 
176 extern const struct VMStateDescription vms_avr_cpu;
177 
178 void avr_cpu_do_interrupt(CPUState *cpu);
179 bool avr_cpu_exec_interrupt(CPUState *cpu, int int_req);
180 hwaddr avr_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
181 int avr_cpu_gdb_read_register(CPUState *cpu, GByteArray *buf, int reg);
182 int avr_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
183 int avr_print_insn(bfd_vma addr, disassemble_info *info);
184 vaddr avr_cpu_gdb_adjust_breakpoint(CPUState *cpu, vaddr addr);
185 
186 static inline int avr_feature(CPUAVRState *env, AVRFeature feature)
187 {
188     return (env->features & (1U << feature)) != 0;
189 }
190 
191 static inline void set_avr_feature(CPUAVRState *env, int feature)
192 {
193     env->features |= (1U << feature);
194 }
195 
196 void avr_cpu_tcg_init(void);
197 void avr_cpu_translate_code(CPUState *cs, TranslationBlock *tb,
198                             int *max_insns, vaddr pc, void *host_pc);
199 
200 int cpu_avr_exec(CPUState *cpu);
201 
202 enum {
203     TB_FLAGS_FULL_ACCESS = 1,
204     TB_FLAGS_SKIP = 2,
205 };
206 
207 static inline void cpu_get_tb_cpu_state(CPUAVRState *env, vaddr *pc,
208                                         uint64_t *cs_base, uint32_t *pflags)
209 {
210     uint32_t flags = 0;
211 
212     *pc = env->pc_w * 2;
213     *cs_base = 0;
214 
215     if (env->fullacc) {
216         flags |= TB_FLAGS_FULL_ACCESS;
217     }
218     if (env->skip) {
219         flags |= TB_FLAGS_SKIP;
220     }
221 
222     *pflags = flags;
223 }
224 
225 static inline int cpu_interrupts_enabled(CPUAVRState *env)
226 {
227     return env->sregI != 0;
228 }
229 
230 static inline uint8_t cpu_get_sreg(CPUAVRState *env)
231 {
232     return (env->sregC) << 0
233          | (env->sregZ) << 1
234          | (env->sregN) << 2
235          | (env->sregV) << 3
236          | (env->sregS) << 4
237          | (env->sregH) << 5
238          | (env->sregT) << 6
239          | (env->sregI) << 7;
240 }
241 
242 static inline void cpu_set_sreg(CPUAVRState *env, uint8_t sreg)
243 {
244     env->sregC = (sreg >> 0) & 0x01;
245     env->sregZ = (sreg >> 1) & 0x01;
246     env->sregN = (sreg >> 2) & 0x01;
247     env->sregV = (sreg >> 3) & 0x01;
248     env->sregS = (sreg >> 4) & 0x01;
249     env->sregH = (sreg >> 5) & 0x01;
250     env->sregT = (sreg >> 6) & 0x01;
251     env->sregI = (sreg >> 7) & 0x01;
252 }
253 
254 bool avr_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
255                       MMUAccessType access_type, int mmu_idx,
256                       bool probe, uintptr_t retaddr);
257 
258 extern const MemoryRegionOps avr_cpu_reg1;
259 extern const MemoryRegionOps avr_cpu_reg2;
260 
261 #include "exec/cpu-all.h"
262 
263 #endif /* QEMU_AVR_CPU_H */
264