xref: /openbmc/qemu/target/avr/cpu.h (revision 2f44bea9)
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 CPUAVRState CPUAVRState;
112 
113 struct CPUAVRState {
114     uint32_t pc_w; /* 0x003fffff up to 22 bits */
115 
116     uint32_t sregC; /* 0x00000001 1 bit */
117     uint32_t sregZ; /* 0x00000001 1 bit */
118     uint32_t sregN; /* 0x00000001 1 bit */
119     uint32_t sregV; /* 0x00000001 1 bit */
120     uint32_t sregS; /* 0x00000001 1 bit */
121     uint32_t sregH; /* 0x00000001 1 bit */
122     uint32_t sregT; /* 0x00000001 1 bit */
123     uint32_t sregI; /* 0x00000001 1 bit */
124 
125     uint32_t rampD; /* 0x00ff0000 8 bits */
126     uint32_t rampX; /* 0x00ff0000 8 bits */
127     uint32_t rampY; /* 0x00ff0000 8 bits */
128     uint32_t rampZ; /* 0x00ff0000 8 bits */
129     uint32_t eind; /* 0x00ff0000 8 bits */
130 
131     uint32_t r[NUMBER_OF_CPU_REGISTERS]; /* 8 bits each */
132     uint32_t sp; /* 16 bits */
133 
134     uint32_t skip; /* if set skip instruction */
135 
136     uint64_t intsrc; /* interrupt sources */
137     bool fullacc; /* CPU/MEM if true MEM only otherwise */
138 
139     uint64_t features;
140 };
141 
142 /**
143  *  AVRCPU:
144  *  @env: #CPUAVRState
145  *
146  *  A AVR CPU.
147  */
148 typedef struct AVRCPU {
149     /*< private >*/
150     CPUState parent_obj;
151     /*< public >*/
152 
153     CPUNegativeOffsetState neg;
154     CPUAVRState env;
155 } AVRCPU;
156 
157 extern const struct VMStateDescription vms_avr_cpu;
158 
159 void avr_cpu_do_interrupt(CPUState *cpu);
160 bool avr_cpu_exec_interrupt(CPUState *cpu, int int_req);
161 hwaddr avr_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
162 int avr_cpu_gdb_read_register(CPUState *cpu, GByteArray *buf, int reg);
163 int avr_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
164 int avr_print_insn(bfd_vma addr, disassemble_info *info);
165 vaddr avr_cpu_gdb_adjust_breakpoint(CPUState *cpu, vaddr addr);
166 
167 static inline int avr_feature(CPUAVRState *env, AVRFeature feature)
168 {
169     return (env->features & (1U << feature)) != 0;
170 }
171 
172 static inline void set_avr_feature(CPUAVRState *env, int feature)
173 {
174     env->features |= (1U << feature);
175 }
176 
177 #define cpu_list avr_cpu_list
178 #define cpu_mmu_index avr_cpu_mmu_index
179 
180 static inline int avr_cpu_mmu_index(CPUAVRState *env, bool ifetch)
181 {
182     return ifetch ? MMU_CODE_IDX : MMU_DATA_IDX;
183 }
184 
185 void avr_cpu_tcg_init(void);
186 
187 void avr_cpu_list(void);
188 int cpu_avr_exec(CPUState *cpu);
189 int avr_cpu_memory_rw_debug(CPUState *cs, vaddr address, uint8_t *buf,
190                             int len, bool is_write);
191 
192 enum {
193     TB_FLAGS_FULL_ACCESS = 1,
194     TB_FLAGS_SKIP = 2,
195 };
196 
197 static inline void cpu_get_tb_cpu_state(CPUAVRState *env, target_ulong *pc,
198                                         target_ulong *cs_base, uint32_t *pflags)
199 {
200     uint32_t flags = 0;
201 
202     *pc = env->pc_w * 2;
203     *cs_base = 0;
204 
205     if (env->fullacc) {
206         flags |= TB_FLAGS_FULL_ACCESS;
207     }
208     if (env->skip) {
209         flags |= TB_FLAGS_SKIP;
210     }
211 
212     *pflags = flags;
213 }
214 
215 static inline int cpu_interrupts_enabled(CPUAVRState *env)
216 {
217     return env->sregI != 0;
218 }
219 
220 static inline uint8_t cpu_get_sreg(CPUAVRState *env)
221 {
222     uint8_t sreg;
223     sreg = (env->sregC) << 0
224          | (env->sregZ) << 1
225          | (env->sregN) << 2
226          | (env->sregV) << 3
227          | (env->sregS) << 4
228          | (env->sregH) << 5
229          | (env->sregT) << 6
230          | (env->sregI) << 7;
231     return sreg;
232 }
233 
234 static inline void cpu_set_sreg(CPUAVRState *env, uint8_t sreg)
235 {
236     env->sregC = (sreg >> 0) & 0x01;
237     env->sregZ = (sreg >> 1) & 0x01;
238     env->sregN = (sreg >> 2) & 0x01;
239     env->sregV = (sreg >> 3) & 0x01;
240     env->sregS = (sreg >> 4) & 0x01;
241     env->sregH = (sreg >> 5) & 0x01;
242     env->sregT = (sreg >> 6) & 0x01;
243     env->sregI = (sreg >> 7) & 0x01;
244 }
245 
246 bool avr_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
247                       MMUAccessType access_type, int mmu_idx,
248                       bool probe, uintptr_t retaddr);
249 
250 typedef CPUAVRState CPUArchState;
251 typedef AVRCPU ArchCPU;
252 
253 #include "exec/cpu-all.h"
254 
255 #endif /* !defined (QEMU_AVR_CPU_H) */
256