xref: /openbmc/qemu/target/avr/cpu.h (revision 48663349)
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 /*
34  * AVR has two memory spaces, data & code.
35  * e.g. both have 0 address
36  * ST/LD instructions access data space
37  * LPM/SPM and instruction fetching access code memory space
38  */
39 #define MMU_CODE_IDX 0
40 #define MMU_DATA_IDX 1
41 
42 #define EXCP_RESET 1
43 #define EXCP_INT(n) (EXCP_RESET + (n) + 1)
44 
45 /* Number of CPU registers */
46 #define NUMBER_OF_CPU_REGISTERS 32
47 /* Number of IO registers accessible by ld/st/in/out */
48 #define NUMBER_OF_IO_REGISTERS 64
49 
50 /*
51  * Offsets of AVR memory regions in host memory space.
52  *
53  * This is needed because the AVR has separate code and data address
54  * spaces that both have start from zero but have to go somewhere in
55  * host memory.
56  *
57  * It's also useful to know where some things are, like the IO registers.
58  */
59 /* Flash program memory */
60 #define OFFSET_CODE 0x00000000
61 /* CPU registers, IO registers, and SRAM */
62 #define OFFSET_DATA 0x00800000
63 /* CPU registers specifically, these are mapped at the start of data */
64 #define OFFSET_CPU_REGISTERS OFFSET_DATA
65 /*
66  * IO registers, including status register, stack pointer, and memory
67  * mapped peripherals, mapped just after CPU registers
68  */
69 #define OFFSET_IO_REGISTERS (OFFSET_DATA + NUMBER_OF_CPU_REGISTERS)
70 
71 typedef enum AVRFeature {
72     AVR_FEATURE_SRAM,
73 
74     AVR_FEATURE_1_BYTE_PC,
75     AVR_FEATURE_2_BYTE_PC,
76     AVR_FEATURE_3_BYTE_PC,
77 
78     AVR_FEATURE_1_BYTE_SP,
79     AVR_FEATURE_2_BYTE_SP,
80 
81     AVR_FEATURE_BREAK,
82     AVR_FEATURE_DES,
83     AVR_FEATURE_RMW, /* Read Modify Write - XCH LAC LAS LAT */
84 
85     AVR_FEATURE_EIJMP_EICALL,
86     AVR_FEATURE_IJMP_ICALL,
87     AVR_FEATURE_JMP_CALL,
88 
89     AVR_FEATURE_ADIW_SBIW,
90 
91     AVR_FEATURE_SPM,
92     AVR_FEATURE_SPMX,
93 
94     AVR_FEATURE_ELPMX,
95     AVR_FEATURE_ELPM,
96     AVR_FEATURE_LPMX,
97     AVR_FEATURE_LPM,
98 
99     AVR_FEATURE_MOVW,
100     AVR_FEATURE_MUL,
101     AVR_FEATURE_RAMPD,
102     AVR_FEATURE_RAMPX,
103     AVR_FEATURE_RAMPY,
104     AVR_FEATURE_RAMPZ,
105 } AVRFeature;
106 
107 typedef struct CPUArchState {
108     uint32_t pc_w; /* 0x003fffff up to 22 bits */
109 
110     uint32_t sregC; /* 0x00000001 1 bit */
111     uint32_t sregZ; /* 0x00000001 1 bit */
112     uint32_t sregN; /* 0x00000001 1 bit */
113     uint32_t sregV; /* 0x00000001 1 bit */
114     uint32_t sregS; /* 0x00000001 1 bit */
115     uint32_t sregH; /* 0x00000001 1 bit */
116     uint32_t sregT; /* 0x00000001 1 bit */
117     uint32_t sregI; /* 0x00000001 1 bit */
118 
119     uint32_t rampD; /* 0x00ff0000 8 bits */
120     uint32_t rampX; /* 0x00ff0000 8 bits */
121     uint32_t rampY; /* 0x00ff0000 8 bits */
122     uint32_t rampZ; /* 0x00ff0000 8 bits */
123     uint32_t eind; /* 0x00ff0000 8 bits */
124 
125     uint32_t r[NUMBER_OF_CPU_REGISTERS]; /* 8 bits each */
126     uint32_t sp; /* 16 bits */
127 
128     uint32_t skip; /* if set skip instruction */
129 
130     uint64_t intsrc; /* interrupt sources */
131     bool fullacc; /* CPU/MEM if true MEM only otherwise */
132 
133     uint64_t features;
134 } CPUAVRState;
135 
136 /**
137  *  AVRCPU:
138  *  @env: #CPUAVRState
139  *
140  *  A AVR CPU.
141  */
142 struct ArchCPU {
143     CPUState parent_obj;
144 
145     CPUAVRState env;
146 
147     /* Initial value of stack pointer */
148     uint32_t init_sp;
149 };
150 
151 /**
152  *  AVRCPUClass:
153  *  @parent_realize: The parent class' realize handler.
154  *  @parent_phases: The parent class' reset phase handlers.
155  *
156  *  A AVR CPU model.
157  */
158 struct AVRCPUClass {
159     CPUClass parent_class;
160 
161     DeviceRealize parent_realize;
162     ResettablePhases parent_phases;
163 };
164 
165 extern const struct VMStateDescription vms_avr_cpu;
166 
167 void avr_cpu_do_interrupt(CPUState *cpu);
168 bool avr_cpu_exec_interrupt(CPUState *cpu, int int_req);
169 hwaddr avr_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
170 int avr_cpu_gdb_read_register(CPUState *cpu, GByteArray *buf, int reg);
171 int avr_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
172 int avr_print_insn(bfd_vma addr, disassemble_info *info);
173 vaddr avr_cpu_gdb_adjust_breakpoint(CPUState *cpu, vaddr addr);
174 
175 static inline int avr_feature(CPUAVRState *env, AVRFeature feature)
176 {
177     return (env->features & (1U << feature)) != 0;
178 }
179 
180 static inline void set_avr_feature(CPUAVRState *env, int feature)
181 {
182     env->features |= (1U << feature);
183 }
184 
185 void avr_cpu_tcg_init(void);
186 
187 int cpu_avr_exec(CPUState *cpu);
188 
189 enum {
190     TB_FLAGS_FULL_ACCESS = 1,
191     TB_FLAGS_SKIP = 2,
192 };
193 
194 static inline void cpu_get_tb_cpu_state(CPUAVRState *env, vaddr *pc,
195                                         uint64_t *cs_base, uint32_t *pflags)
196 {
197     uint32_t flags = 0;
198 
199     *pc = env->pc_w * 2;
200     *cs_base = 0;
201 
202     if (env->fullacc) {
203         flags |= TB_FLAGS_FULL_ACCESS;
204     }
205     if (env->skip) {
206         flags |= TB_FLAGS_SKIP;
207     }
208 
209     *pflags = flags;
210 }
211 
212 static inline int cpu_interrupts_enabled(CPUAVRState *env)
213 {
214     return env->sregI != 0;
215 }
216 
217 static inline uint8_t cpu_get_sreg(CPUAVRState *env)
218 {
219     return (env->sregC) << 0
220          | (env->sregZ) << 1
221          | (env->sregN) << 2
222          | (env->sregV) << 3
223          | (env->sregS) << 4
224          | (env->sregH) << 5
225          | (env->sregT) << 6
226          | (env->sregI) << 7;
227 }
228 
229 static inline void cpu_set_sreg(CPUAVRState *env, uint8_t sreg)
230 {
231     env->sregC = (sreg >> 0) & 0x01;
232     env->sregZ = (sreg >> 1) & 0x01;
233     env->sregN = (sreg >> 2) & 0x01;
234     env->sregV = (sreg >> 3) & 0x01;
235     env->sregS = (sreg >> 4) & 0x01;
236     env->sregH = (sreg >> 5) & 0x01;
237     env->sregT = (sreg >> 6) & 0x01;
238     env->sregI = (sreg >> 7) & 0x01;
239 }
240 
241 bool avr_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
242                       MMUAccessType access_type, int mmu_idx,
243                       bool probe, uintptr_t retaddr);
244 
245 #include "exec/cpu-all.h"
246 
247 #endif /* QEMU_AVR_CPU_H */
248