xref: /openbmc/qemu/target/avr/cpu.h (revision b1be65f6)
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 AVR_CPU_TYPE_SUFFIX "-" TYPE_AVR_CPU
32 #define AVR_CPU_TYPE_NAME(name) (name AVR_CPU_TYPE_SUFFIX)
33 #define CPU_RESOLVING_TYPE TYPE_AVR_CPU
34 
35 #define TCG_GUEST_DEFAULT_MO 0
36 
37 /*
38  * AVR has two memory spaces, data & code.
39  * e.g. both have 0 address
40  * ST/LD instructions access data space
41  * LPM/SPM and instruction fetching access code memory space
42  */
43 #define MMU_CODE_IDX 0
44 #define MMU_DATA_IDX 1
45 
46 #define EXCP_RESET 1
47 #define EXCP_INT(n) (EXCP_RESET + (n) + 1)
48 
49 /* Number of CPU registers */
50 #define NUMBER_OF_CPU_REGISTERS 32
51 /* Number of IO registers accessible by ld/st/in/out */
52 #define NUMBER_OF_IO_REGISTERS 64
53 
54 /*
55  * Offsets of AVR memory regions in host memory space.
56  *
57  * This is needed because the AVR has separate code and data address
58  * spaces that both have start from zero but have to go somewhere in
59  * host memory.
60  *
61  * It's also useful to know where some things are, like the IO registers.
62  */
63 /* Flash program memory */
64 #define OFFSET_CODE 0x00000000
65 /* CPU registers, IO registers, and SRAM */
66 #define OFFSET_DATA 0x00800000
67 /* CPU registers specifically, these are mapped at the start of data */
68 #define OFFSET_CPU_REGISTERS OFFSET_DATA
69 /*
70  * IO registers, including status register, stack pointer, and memory
71  * mapped peripherals, mapped just after CPU registers
72  */
73 #define OFFSET_IO_REGISTERS (OFFSET_DATA + NUMBER_OF_CPU_REGISTERS)
74 
75 typedef enum AVRFeature {
76     AVR_FEATURE_SRAM,
77 
78     AVR_FEATURE_1_BYTE_PC,
79     AVR_FEATURE_2_BYTE_PC,
80     AVR_FEATURE_3_BYTE_PC,
81 
82     AVR_FEATURE_1_BYTE_SP,
83     AVR_FEATURE_2_BYTE_SP,
84 
85     AVR_FEATURE_BREAK,
86     AVR_FEATURE_DES,
87     AVR_FEATURE_RMW, /* Read Modify Write - XCH LAC LAS LAT */
88 
89     AVR_FEATURE_EIJMP_EICALL,
90     AVR_FEATURE_IJMP_ICALL,
91     AVR_FEATURE_JMP_CALL,
92 
93     AVR_FEATURE_ADIW_SBIW,
94 
95     AVR_FEATURE_SPM,
96     AVR_FEATURE_SPMX,
97 
98     AVR_FEATURE_ELPMX,
99     AVR_FEATURE_ELPM,
100     AVR_FEATURE_LPMX,
101     AVR_FEATURE_LPM,
102 
103     AVR_FEATURE_MOVW,
104     AVR_FEATURE_MUL,
105     AVR_FEATURE_RAMPD,
106     AVR_FEATURE_RAMPX,
107     AVR_FEATURE_RAMPY,
108     AVR_FEATURE_RAMPZ,
109 } AVRFeature;
110 
111 typedef struct CPUArchState {
112     uint32_t pc_w; /* 0x003fffff up to 22 bits */
113 
114     uint32_t sregC; /* 0x00000001 1 bit */
115     uint32_t sregZ; /* 0x00000001 1 bit */
116     uint32_t sregN; /* 0x00000001 1 bit */
117     uint32_t sregV; /* 0x00000001 1 bit */
118     uint32_t sregS; /* 0x00000001 1 bit */
119     uint32_t sregH; /* 0x00000001 1 bit */
120     uint32_t sregT; /* 0x00000001 1 bit */
121     uint32_t sregI; /* 0x00000001 1 bit */
122 
123     uint32_t rampD; /* 0x00ff0000 8 bits */
124     uint32_t rampX; /* 0x00ff0000 8 bits */
125     uint32_t rampY; /* 0x00ff0000 8 bits */
126     uint32_t rampZ; /* 0x00ff0000 8 bits */
127     uint32_t eind; /* 0x00ff0000 8 bits */
128 
129     uint32_t r[NUMBER_OF_CPU_REGISTERS]; /* 8 bits each */
130     uint32_t sp; /* 16 bits */
131 
132     uint32_t skip; /* if set skip instruction */
133 
134     uint64_t intsrc; /* interrupt sources */
135     bool fullacc; /* CPU/MEM if true MEM only otherwise */
136 
137     uint64_t features;
138 } CPUAVRState;
139 
140 /**
141  *  AVRCPU:
142  *  @env: #CPUAVRState
143  *
144  *  A AVR CPU.
145  */
146 struct ArchCPU {
147     /*< private >*/
148     CPUState parent_obj;
149     /*< public >*/
150 
151     CPUAVRState env;
152 };
153 
154 extern const struct VMStateDescription vms_avr_cpu;
155 
156 void avr_cpu_do_interrupt(CPUState *cpu);
157 bool avr_cpu_exec_interrupt(CPUState *cpu, int int_req);
158 hwaddr avr_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
159 int avr_cpu_gdb_read_register(CPUState *cpu, GByteArray *buf, int reg);
160 int avr_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
161 int avr_print_insn(bfd_vma addr, disassemble_info *info);
162 vaddr avr_cpu_gdb_adjust_breakpoint(CPUState *cpu, vaddr addr);
163 
164 static inline int avr_feature(CPUAVRState *env, AVRFeature feature)
165 {
166     return (env->features & (1U << feature)) != 0;
167 }
168 
169 static inline void set_avr_feature(CPUAVRState *env, int feature)
170 {
171     env->features |= (1U << feature);
172 }
173 
174 #define cpu_list avr_cpu_list
175 #define cpu_mmu_index avr_cpu_mmu_index
176 
177 static inline int avr_cpu_mmu_index(CPUAVRState *env, bool ifetch)
178 {
179     return ifetch ? MMU_CODE_IDX : MMU_DATA_IDX;
180 }
181 
182 void avr_cpu_tcg_init(void);
183 
184 void avr_cpu_list(void);
185 int cpu_avr_exec(CPUState *cpu);
186 
187 enum {
188     TB_FLAGS_FULL_ACCESS = 1,
189     TB_FLAGS_SKIP = 2,
190 };
191 
192 static inline void cpu_get_tb_cpu_state(CPUAVRState *env, vaddr *pc,
193                                         uint64_t *cs_base, uint32_t *pflags)
194 {
195     uint32_t flags = 0;
196 
197     *pc = env->pc_w * 2;
198     *cs_base = 0;
199 
200     if (env->fullacc) {
201         flags |= TB_FLAGS_FULL_ACCESS;
202     }
203     if (env->skip) {
204         flags |= TB_FLAGS_SKIP;
205     }
206 
207     *pflags = flags;
208 }
209 
210 static inline int cpu_interrupts_enabled(CPUAVRState *env)
211 {
212     return env->sregI != 0;
213 }
214 
215 static inline uint8_t cpu_get_sreg(CPUAVRState *env)
216 {
217     return (env->sregC) << 0
218          | (env->sregZ) << 1
219          | (env->sregN) << 2
220          | (env->sregV) << 3
221          | (env->sregS) << 4
222          | (env->sregH) << 5
223          | (env->sregT) << 6
224          | (env->sregI) << 7;
225 }
226 
227 static inline void cpu_set_sreg(CPUAVRState *env, uint8_t sreg)
228 {
229     env->sregC = (sreg >> 0) & 0x01;
230     env->sregZ = (sreg >> 1) & 0x01;
231     env->sregN = (sreg >> 2) & 0x01;
232     env->sregV = (sreg >> 3) & 0x01;
233     env->sregS = (sreg >> 4) & 0x01;
234     env->sregH = (sreg >> 5) & 0x01;
235     env->sregT = (sreg >> 6) & 0x01;
236     env->sregI = (sreg >> 7) & 0x01;
237 }
238 
239 bool avr_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
240                       MMUAccessType access_type, int mmu_idx,
241                       bool probe, uintptr_t retaddr);
242 
243 #include "exec/cpu-all.h"
244 
245 #endif /* QEMU_AVR_CPU_H */
246