1 /* ======================================================================== */ 2 /* ========================= LICENSING & COPYRIGHT ======================== */ 3 /* ======================================================================== */ 4 /* 5 * MUSASHI 6 * Version 3.4 7 * 8 * A portable Motorola M680x0 processor emulation engine. 9 * Copyright 1998-2001 Karl Stenerud. All rights reserved. 10 * 11 * Permission is hereby granted, free of charge, to any person obtaining a copy 12 * of this software and associated documentation files (the "Software"), to deal 13 * in the Software without restriction, including without limitation the rights 14 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 15 * copies of the Software, and to permit persons to whom the Software is 16 * furnished to do so, subject to the following conditions: 17 * 18 * The above copyright notice and this permission notice shall be included in 19 * all copies or substantial portions of the Software. 20 21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 22 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 24 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 25 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 26 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 27 * THE SOFTWARE. 28 */ 29 30 #ifndef M68K_HEADER 31 #define M68K_HEADER 32 33 #include <stdint.h> 34 35 36 /* ======================================================================== */ 37 /* ============================= CONFIGURATION ============================ */ 38 /* ======================================================================== */ 39 40 /* Import the configuration for this build */ 41 #include "m68kconf.h" 42 43 44 /* ======================================================================== */ 45 /* ============================ GENERAL DEFINES =========================== */ 46 47 /* ======================================================================== */ 48 49 /* There are 7 levels of interrupt to the 68K. 50 * A transition from < 7 to 7 will cause a non-maskable interrupt (NMI). 51 */ 52 #define M68K_IRQ_NONE 0 53 #define M68K_IRQ_1 1 54 #define M68K_IRQ_2 2 55 #define M68K_IRQ_3 3 56 #define M68K_IRQ_4 4 57 #define M68K_IRQ_5 5 58 #define M68K_IRQ_6 6 59 #define M68K_IRQ_7 7 60 61 62 /* Special interrupt acknowledge values. 63 * Use these as special returns from the interrupt acknowledge callback 64 * (specified later in this header). 65 */ 66 67 /* Causes an interrupt autovector (0x18 + interrupt level) to be taken. 68 * This happens in a real 68K if VPA or AVEC is asserted during an interrupt 69 * acknowledge cycle instead of DTACK. 70 */ 71 #define M68K_INT_ACK_AUTOVECTOR 0xffffffff 72 73 /* Causes the spurious interrupt vector (0x18) to be taken 74 * This happens in a real 68K if BERR is asserted during the interrupt 75 * acknowledge cycle (i.e. no devices responded to the acknowledge). 76 */ 77 #define M68K_INT_ACK_SPURIOUS 0xfffffffe 78 79 80 /* CPU types for use in m68k_set_cpu_type() */ 81 enum 82 { 83 M68K_CPU_TYPE_INVALID, 84 M68K_CPU_TYPE_68000, 85 M68K_CPU_TYPE_68010, 86 M68K_CPU_TYPE_68EC020, 87 M68K_CPU_TYPE_68020, 88 M68K_CPU_TYPE_68030, /* Supported by disassembler ONLY */ 89 M68K_CPU_TYPE_68040, /* Supported by disassembler ONLY */ 90 M68K_CPU_TYPE_DBVZ 91 }; 92 93 /* Registers used by m68k_get_reg() and m68k_set_reg() */ 94 typedef enum 95 { 96 /* Real registers */ 97 M68K_REG_D0, /* Data registers */ 98 M68K_REG_D1, 99 M68K_REG_D2, 100 M68K_REG_D3, 101 M68K_REG_D4, 102 M68K_REG_D5, 103 M68K_REG_D6, 104 M68K_REG_D7, 105 M68K_REG_A0, /* Address registers */ 106 M68K_REG_A1, 107 M68K_REG_A2, 108 M68K_REG_A3, 109 M68K_REG_A4, 110 M68K_REG_A5, 111 M68K_REG_A6, 112 M68K_REG_A7, 113 M68K_REG_PC, /* Program Counter */ 114 M68K_REG_SR, /* Status Register */ 115 M68K_REG_SP, /* The current Stack Pointer (located in A7) */ 116 M68K_REG_USP, /* User Stack Pointer */ 117 M68K_REG_ISP, /* Interrupt Stack Pointer */ 118 M68K_REG_MSP, /* Master Stack Pointer */ 119 M68K_REG_SFC, /* Source Function Code */ 120 M68K_REG_DFC, /* Destination Function Code */ 121 M68K_REG_VBR, /* Vector Base Register */ 122 M68K_REG_CACR, /* Cache Control Register */ 123 M68K_REG_CAAR, /* Cache Address Register */ 124 125 /* Assumed registers */ 126 /* These are cheat registers which emulate the 1-longword prefetch 127 * present in the 68000 and 68010. 128 */ 129 M68K_REG_PREF_ADDR, /* Last prefetch address */ 130 M68K_REG_PREF_DATA, /* Last prefetch data */ 131 132 /* Convenience registers */ 133 M68K_REG_PPC, /* Previous value in the program counter */ 134 M68K_REG_IR, /* Instruction register */ 135 M68K_REG_CPU_TYPE /* Type of CPU being run */ 136 } m68k_register_t; 137 138 /* ======================================================================== */ 139 /* ====================== FUNCTIONS CALLED BY THE CPU ===================== */ 140 /* ======================================================================== */ 141 142 /* You will have to implement these functions */ 143 144 /* read/write functions called by the CPU to access memory. 145 * while values used are 32 bits, only the appropriate number 146 * of bits are relevant (i.e. in write_memory_8, only the lower 8 bits 147 * of value should be written to memory). 148 * 149 * NOTE: I have separated the immediate and PC-relative memory fetches 150 * from the other memory fetches because some systems require 151 * differentiation between PROGRAM and DATA fetches (usually 152 * for security setups such as encryption). 153 * This separation can either be achieved by setting 154 * M68K_SEPARATE_READS in m68kconf.h and defining 155 * the read functions, or by setting M68K_EMULATE_FC and 156 * making a function code callback function. 157 * Using the callback offers better emulation coverage 158 * because you can also monitor whether the CPU is in SYSTEM or 159 * USER mode, but it is also slower. 160 */ 161 162 /* Read from anywhere */ 163 uint8_t m68k_read_memory_8(uint32_t address); 164 uint16_t m68k_read_memory_16(uint32_t address); 165 uint32_t m68k_read_memory_32(uint32_t address); 166 167 /* Read data immediately following the PC */ 168 uint16_t m68k_read_immediate_16(uint32_t address); 169 uint32_t m68k_read_immediate_32(uint32_t address); 170 171 /* Read data relative to the PC */ 172 uint8_t m68k_read_pcrelative_8(uint32_t address); 173 uint16_t m68k_read_pcrelative_16(uint32_t address); 174 uint32_t m68k_read_pcrelative_32(uint32_t address); 175 176 /* Memory access for the disassembler */ 177 uint8_t m68k_read_disassembler_8(uint32_t address); 178 uint16_t m68k_read_disassembler_16(uint32_t address); 179 uint32_t m68k_read_disassembler_32(uint32_t address); 180 181 /* Write to anywhere */ 182 void m68k_write_memory_8(uint32_t address, uint8_t value); 183 void m68k_write_memory_16(uint32_t address, uint16_t value); 184 void m68k_write_memory_32(uint32_t address, uint32_t value); 185 186 /* Special call to simulate undocumented 68k behavior when move.l with a 187 * predecrement destination mode is executed. 188 * To simulate real 68k behavior, first write the high word to 189 * [address+2], and then write the low word to [address]. 190 * 191 * Enable this functionality with M68K_SIMULATE_PD_WRITES in m68kconf.h. 192 */ 193 void m68k_write_memory_32_pd(uint32_t address, uint32_t value); 194 195 196 197 /* ======================================================================== */ 198 /* ============================== CALLBACKS =============================== */ 199 /* ======================================================================== */ 200 201 /* These functions allow you to set callbacks to the host when specific events 202 * occur. Note that you must enable the corresponding value in m68kconf.h 203 * in order for these to do anything useful. 204 * Note: I have defined default callbacks which are used if you have enabled 205 * the corresponding #define in m68kconf.h but either haven't assigned a 206 * callback or have assigned a callback of NULL. 207 */ 208 209 /* Set the callback for an interrupt acknowledge. 210 * You must enable M68K_EMULATE_INT_ACK in m68kconf.h. 211 * The CPU will call the callback with the interrupt level being acknowledged. 212 * The host program must return either a vector from 0x02-0xff, or one of the 213 * special interrupt acknowledge values specified earlier in this header. 214 * If this is not implemented, the CPU will always assume an autovectored 215 * interrupt, and will automatically clear the interrupt request when it 216 * services the interrupt. 217 * Default behavior: return M68K_INT_ACK_AUTOVECTOR. 218 */ 219 void m68k_set_int_ack_callback(int32_t (*callback)(int32_t int_level)); 220 221 222 /* Set the callback for a breakpoint acknowledge (68010+). 223 * You must enable M68K_EMULATE_BKPT_ACK in m68kconf.h. 224 * The CPU will call the callback with whatever was in the data field of the 225 * BKPT instruction for 68020+, or 0 for 68010. 226 * Default behavior: do nothing. 227 */ 228 void m68k_set_bkpt_ack_callback(void (*callback)(uint32_t data)); 229 230 231 /* Set the callback for the RESET instruction. 232 * You must enable M68K_EMULATE_RESET in m68kconf.h. 233 * The CPU calls this callback every time it encounters a RESET instruction. 234 * Default behavior: do nothing. 235 */ 236 void m68k_set_reset_instr_callback(void (*callback)(void)); 237 238 239 /* Set the callback for informing of a large PC change. 240 * You must enable M68K_MONITOR_PC in m68kconf.h. 241 * The CPU calls this callback with the new PC value every time the PC changes 242 * by a large value (currently set for changes by longwords). 243 * Default behavior: do nothing. 244 */ 245 void m68k_set_pc_changed_callback(void (*callback)(uint32_t new_pc)); 246 247 248 /* Set the callback for CPU function code changes. 249 * You must enable M68K_EMULATE_FC in m68kconf.h. 250 * The CPU calls this callback with the function code before every memory 251 * access to set the CPU's function code according to what kind of memory 252 * access it is (supervisor/user, program/data and such). 253 * Default behavior: do nothing. 254 */ 255 void m68k_set_fc_callback(void (*callback)(uint32_t new_fc)); 256 257 258 /* Set a callback for the instruction cycle of the CPU. 259 * You must enable M68K_INSTRUCTION_HOOK in m68kconf.h. 260 * The CPU calls this callback just before fetching the opcode in the 261 * instruction cycle. 262 * Default behavior: do nothing. 263 */ 264 void m68k_set_instr_hook_callback(void (*callback)(void)); 265 266 267 268 /* ======================================================================== */ 269 /* ====================== FUNCTIONS TO ACCESS THE CPU ===================== */ 270 /* ======================================================================== */ 271 272 /* Use this function to set the CPU type you want to emulate. 273 * Currently supported types are: M68K_CPU_TYPE_68000, M68K_CPU_TYPE_68010, 274 * M68K_CPU_TYPE_EC020, and M68K_CPU_TYPE_68020. 275 */ 276 void m68k_set_cpu_type(uint32_t cpu_type); 277 278 /* Do whatever initialisations the core requires. Should be called 279 * at least once at init time. 280 */ 281 void m68k_init(void); 282 283 /* Pulse the RESET pin on the CPU. 284 * You *MUST* reset the CPU at least once to initialize the emulation 285 * Note: If you didn't call m68k_set_cpu_type() before resetting 286 * the CPU for the first time, the CPU will be set to 287 * M68K_CPU_TYPE_68000. 288 */ 289 void m68k_pulse_reset(void); 290 291 /* execute num_cycles worth of instructions. returns number of cycles used */ 292 int32_t m68k_execute(int32_t num_cycles); 293 294 /* These functions let you read/write/modify the number of cycles left to run 295 * while m68k_execute() is running. 296 * These are useful if the 68k accesses a memory-mapped port on another device 297 * that requires immediate processing by another CPU. 298 */ 299 int32_t m68k_cycles_run(void); /* Number of cycles run so far */ 300 int32_t m68k_cycles_remaining(void); /* Number of cycles left */ 301 void m68k_modify_timeslice(int32_t cycles); /* Modify cycles left */ 302 void m68k_end_timeslice(void); /* End timeslice now */ 303 304 /* Set the IPL0-IPL2 pins on the CPU (IRQ). 305 * A transition from < 7 to 7 will cause a non-maskable interrupt (NMI). 306 * Setting IRQ to 0 will clear an interrupt request. 307 */ 308 void m68k_set_irq(uint32_t int_level); 309 310 311 /* Halt the CPU as if you pulsed the HALT pin. */ 312 void m68k_pulse_halt(void); 313 314 315 /* Context switching to allow multiple CPUs */ 316 317 /* Get the size of the cpu context in bytes */ 318 uint32_t m68k_context_size(void); 319 320 /* Get a cpu context */ 321 uint32_t m68k_get_context(void* dst); 322 323 /* set the current cpu context */ 324 void m68k_set_context(void* dst); 325 326 /* Register the CPU state information */ 327 void m68k_state_register(const char *type); 328 329 330 /* Peek at the internals of a CPU context. This can either be a context 331 * retrieved using m68k_get_context() or the currently running context. 332 * If context is NULL, the currently running CPU context will be used. 333 */ 334 uint32_t m68k_get_reg(void* context, m68k_register_t reg); 335 336 /* Poke values into the internals of the currently running CPU context */ 337 void m68k_set_reg(m68k_register_t reg, uint32_t value); 338 339 /* Check if an instruction is valid for the specified CPU type */ 340 uint32_t m68k_is_valid_instruction(uint32_t instruction, uint32_t cpu_type); 341 342 /* Disassemble 1 instruction using the specified CPU type at pc. Stores 343 * disassembly in str_buff and returns the size of the instruction in bytes. 344 */ 345 uint32_t m68k_disassemble(char* str_buff, uint32_t pc, uint32_t cpu_type); 346 347 348 /* ======================================================================== */ 349 /* ============================== END OF FILE ============================= */ 350 /* ======================================================================== */ 351 352 #endif /* M68K_HEADER */ 353