1 #ifndef M68K__HEADER 2 #define M68K__HEADER 3 4 #ifdef __cplusplus 5 extern "C" { 6 #endif 7 8 /* ======================================================================== */ 9 /* ========================= LICENSING & COPYRIGHT ======================== */ 10 /* ======================================================================== */ 11 /* 12 * MUSASHI 13 * Version 3.32 14 * 15 * A portable Motorola M680x0 processor emulation engine. 16 * Copyright Karl Stenerud. All rights reserved. 17 * 18 * This code may be freely used for non-commercial purposes as long as this 19 * copyright notice remains unaltered in the source code and any binary files 20 * containing this code in compiled form. 21 * 22 * All other licensing terms must be negotiated with the author 23 * (Karl Stenerud). 24 * 25 * The latest version of this code can be obtained at: 26 * http://kstenerud.cjb.net 27 */ 28 29 30 31 /* ============================ GENERAL DEFINES =========================== */ 32 33 /* ======================================================================== */ 34 35 /* There are 7 levels of interrupt to the 68K. 36 * A transition from < 7 to 7 will cause a non-maskable interrupt (NMI). 37 */ 38 #define M68K_IRQ_NONE 0 39 #define M68K_IRQ_1 1 40 #define M68K_IRQ_2 2 41 #define M68K_IRQ_3 3 42 #define M68K_IRQ_4 4 43 #define M68K_IRQ_5 5 44 #define M68K_IRQ_6 6 45 #define M68K_IRQ_7 7 46 47 48 /* Special interrupt acknowledge values. 49 * Use these as special returns from the interrupt acknowledge callback 50 * (specified later in this header). 51 */ 52 53 /* Causes an interrupt autovector (0x18 + interrupt level) to be taken. 54 * This happens in a real 68K if VPA or AVEC is asserted during an interrupt 55 * acknowledge cycle instead of DTACK. 56 */ 57 #define M68K_INT_ACK_AUTOVECTOR 0xffffffff 58 59 /* Causes the spurious interrupt vector (0x18) to be taken 60 * This happens in a real 68K if BERR is asserted during the interrupt 61 * acknowledge cycle (i.e. no devices responded to the acknowledge). 62 */ 63 #define M68K_INT_ACK_SPURIOUS 0xfffffffe 64 65 66 /* CPU types for use in m68k_set_cpu_type() */ 67 enum 68 { 69 M68K_CPU_TYPE_INVALID, 70 M68K_CPU_TYPE_68000, 71 M68K_CPU_TYPE_68008, 72 M68K_CPU_TYPE_68010, 73 M68K_CPU_TYPE_68EC020, 74 M68K_CPU_TYPE_68020, 75 M68K_CPU_TYPE_68030, /* Supported by disassembler ONLY */ 76 M68K_CPU_TYPE_68040 /* Supported by disassembler ONLY */ 77 }; 78 79 /* Registers used by m68k_get_reg() and m68k_set_reg() */ 80 enum _m68k_register_t 81 { 82 /* Real registers */ 83 M68K_REG_D0, /* Data registers */ 84 M68K_REG_D1, 85 M68K_REG_D2, 86 M68K_REG_D3, 87 M68K_REG_D4, 88 M68K_REG_D5, 89 M68K_REG_D6, 90 M68K_REG_D7, 91 M68K_REG_A0, /* Address registers */ 92 M68K_REG_A1, 93 M68K_REG_A2, 94 M68K_REG_A3, 95 M68K_REG_A4, 96 M68K_REG_A5, 97 M68K_REG_A6, 98 M68K_REG_A7, 99 M68K_REG_PC, /* Program Counter */ 100 M68K_REG_SR, /* Status Register */ 101 M68K_REG_SP, /* The current Stack Pointer (located in A7) */ 102 M68K_REG_USP, /* User Stack Pointer */ 103 M68K_REG_ISP, /* Interrupt Stack Pointer */ 104 M68K_REG_MSP, /* Master Stack Pointer */ 105 M68K_REG_SFC, /* Source Function Code */ 106 M68K_REG_DFC, /* Destination Function Code */ 107 M68K_REG_VBR, /* Vector Base Register */ 108 M68K_REG_CACR, /* Cache Control Register */ 109 M68K_REG_CAAR, /* Cache Address Register */ 110 111 /* Assumed registers */ 112 /* These are cheat registers which emulate the 1-longword prefetch 113 * present in the 68000 and 68010. 114 */ 115 M68K_REG_PREF_ADDR, /* Last prefetch address */ 116 M68K_REG_PREF_DATA, /* Last prefetch data */ 117 118 /* Convenience registers */ 119 M68K_REG_PPC, /* Previous value in the program counter */ 120 M68K_REG_IR, /* Instruction register */ 121 M68K_REG_CPU_TYPE /* Type of CPU being run */ 122 }; 123 typedef enum _m68k_register_t m68k_register_t; 124 125 126 127 /* ======================================================================== */ 128 /* ====================== FUNCTIONS CALLED BY THE CPU ===================== */ 129 /* ======================================================================== */ 130 131 /* You will have to implement these functions */ 132 133 /* read/write functions called by the CPU to access memory. 134 * while values used are 32 bits, only the appropriate number 135 * of bits are relevant (i.e. in write_memory_8, only the lower 8 bits 136 * of value should be written to memory). 137 * 138 * NOTE: I have separated the immediate and PC-relative memory fetches 139 * from the other memory fetches because some systems require 140 * differentiation between PROGRAM and DATA fetches (usually 141 * for security setups such as encryption). 142 * This separation can either be achieved by setting 143 * M68K_SEPARATE_READS in m68kconf.h and defining 144 * the read functions, or by setting M68K_EMULATE_FC and 145 * making a function code callback function. 146 * Using the callback offers better emulation coverage 147 * because you can also monitor whether the CPU is in SYSTEM or 148 * USER mode, but it is also slower. 149 */ 150 151 /* Read from anywhere */ 152 unsigned int m68k_read_memory_8(unsigned int address); 153 unsigned int m68k_read_memory_16(unsigned int address); 154 unsigned int m68k_read_memory_32(unsigned int address); 155 156 /* Read data immediately following the PC */ 157 unsigned int m68k_read_immediate_16(unsigned int address); 158 unsigned int m68k_read_immediate_32(unsigned int address); 159 160 /* Read data relative to the PC */ 161 unsigned int m68k_read_pcrelative_8(unsigned int address); 162 unsigned int m68k_read_pcrelative_16(unsigned int address); 163 unsigned int m68k_read_pcrelative_32(unsigned int address); 164 165 /* Memory access for the disassembler */ 166 unsigned int m68k_read_disassembler_8 (unsigned int address); 167 unsigned int m68k_read_disassembler_16 (unsigned int address); 168 unsigned int m68k_read_disassembler_32 (unsigned int address); 169 170 /* Write to anywhere */ 171 void m68k_write_memory_8(unsigned int address, unsigned int value); 172 void m68k_write_memory_16(unsigned int address, unsigned int value); 173 void m68k_write_memory_32(unsigned int address, unsigned int value); 174 175 /* Special call to simulate undocumented 68k behavior when move.l with a 176 * predecrement destination mode is executed. 177 * To simulate real 68k behavior, first write the high word to 178 * [address+2], and then write the low word to [address]. 179 * 180 * Enable this functionality with M68K_SIMULATE_PD_WRITES in m68kconf.h. 181 */ 182 void m68k_write_memory_32_pd(unsigned int address, unsigned int value); 183 184 185 186 /* ======================================================================== */ 187 /* ============================== CALLBACKS =============================== */ 188 /* ======================================================================== */ 189 190 /* These functions allow you to set callbacks to the host when specific events 191 * occur. Note that you must enable the corresponding value in m68kconf.h 192 * in order for these to do anything useful. 193 * Note: I have defined default callbacks which are used if you have enabled 194 * the corresponding #define in m68kconf.h but either haven't assigned a 195 * callback or have assigned a callback of NULL. 196 */ 197 198 /* Set the callback for an interrupt acknowledge. 199 * You must enable M68K_EMULATE_INT_ACK in m68kconf.h. 200 * The CPU will call the callback with the interrupt level being acknowledged. 201 * The host program must return either a vector from 0x02-0xff, or one of the 202 * special interrupt acknowledge values specified earlier in this header. 203 * If this is not implemented, the CPU will always assume an autovectored 204 * interrupt, and will automatically clear the interrupt request when it 205 * services the interrupt. 206 * Default behavior: return M68K_INT_ACK_AUTOVECTOR. 207 */ 208 void m68k_set_int_ack_callback(int (*callback)(int int_level)); 209 210 211 /* Set the callback for a breakpoint acknowledge (68010+). 212 * You must enable M68K_EMULATE_BKPT_ACK in m68kconf.h. 213 * The CPU will call the callback with whatever was in the data field of the 214 * BKPT instruction for 68020+, or 0 for 68010. 215 * Default behavior: do nothing. 216 */ 217 void m68k_set_bkpt_ack_callback(void (*callback)(unsigned int data)); 218 219 220 /* Set the callback for the RESET instruction. 221 * You must enable M68K_EMULATE_RESET in m68kconf.h. 222 * The CPU calls this callback every time it encounters a RESET instruction. 223 * Default behavior: do nothing. 224 */ 225 void m68k_set_reset_instr_callback(void (*callback)(void)); 226 227 228 /* Set the callback for the CMPI.L #v, Dn instruction. 229 * You must enable M68K_CMPILD_HAS_CALLBACK in m68kconf.h. 230 * The CPU calls this callback every time it encounters a CMPI.L #v, Dn instruction. 231 * Default behavior: do nothing. 232 */ 233 void m68k_set_cmpild_instr_callback(void (*callback)(unsigned int val, int reg)); 234 235 236 /* Set the callback for the RTE instruction. 237 * You must enable M68K_RTE_HAS_CALLBACK in m68kconf.h. 238 * The CPU calls this callback every time it encounters a RTE instruction. 239 * Default behavior: do nothing. 240 */ 241 void m68k_set_rte_instr_callback(void (*callback)(void)); 242 243 /* Set the callback for the TAS instruction. 244 * You must enable M68K_TAS_HAS_CALLBACK in m68kconf.h. 245 * The CPU calls this callback every time it encounters a TAS instruction. 246 * Default behavior: return 1, allow writeback. 247 */ 248 void m68k_set_tas_instr_callback(int (*callback)(void)); 249 250 251 252 /* Set the callback for informing of a large PC change. 253 * You must enable M68K_MONITOR_PC in m68kconf.h. 254 * The CPU calls this callback with the new PC value every time the PC changes 255 * by a large value (currently set for changes by longwords). 256 * Default behavior: do nothing. 257 */ 258 void m68k_set_pc_changed_callback(void (*callback)(unsigned int new_pc)); 259 260 261 /* Set the callback for CPU function code changes. 262 * You must enable M68K_EMULATE_FC in m68kconf.h. 263 * The CPU calls this callback with the function code before every memory 264 * access to set the CPU's function code according to what kind of memory 265 * access it is (supervisor/user, program/data and such). 266 * Default behavior: do nothing. 267 */ 268 void m68k_set_fc_callback(void (*callback)(unsigned int new_fc)); 269 270 271 /* Set a callback for the instruction cycle of the CPU. 272 * You must enable M68K_INSTRUCTION_HOOK in m68kconf.h. 273 * The CPU calls this callback just before fetching the opcode in the 274 * instruction cycle. 275 * Default behavior: do nothing. 276 */ 277 void m68k_set_instr_hook_callback(void (*callback)(unsigned int pc)); 278 279 280 281 /* ======================================================================== */ 282 /* ====================== FUNCTIONS TO ACCESS THE CPU ===================== */ 283 /* ======================================================================== */ 284 285 /* Use this function to set the CPU type you want to emulate. 286 * Currently supported types are: M68K_CPU_TYPE_68000, M68K_CPU_TYPE_68008, 287 * M68K_CPU_TYPE_68010, M68K_CPU_TYPE_EC020, and M68K_CPU_TYPE_68020. 288 */ 289 void m68k_set_cpu_type(unsigned int cpu_type); 290 291 /* Do whatever initialisations the core requires. Should be called 292 * at least once at init time. 293 */ 294 void m68k_init(void); 295 296 /* Pulse the RESET pin on the CPU. 297 * You *MUST* reset the CPU at least once to initialize the emulation 298 * Note: If you didn't call m68k_set_cpu_type() before resetting 299 * the CPU for the first time, the CPU will be set to 300 * M68K_CPU_TYPE_68000. 301 */ 302 void m68k_pulse_reset(void); 303 304 /* execute num_cycles worth of instructions. returns number of cycles used */ 305 int m68k_execute(int num_cycles); 306 int m68k_executeMD(int num_cycles); /* slight modification for Megadrive */ 307 void m68k_megadrive_sr_checkint_mode(int onoff); /* enable check cycles before servicing interrupts in m68ki_set_sr() */ 308 309 /* These functions let you read/write/modify the number of cycles left to run 310 * while m68k_execute() is running. 311 * These are useful if the 68k accesses a memory-mapped port on another device 312 * that requires immediate processing by another CPU. 313 */ 314 int m68k_cycles_run(void); /* Number of cycles run so far */ 315 int m68k_cycles_remaining(void); /* Number of cycles left */ 316 void m68k_cycles_remaining_set(int cycles); /* for megadrive, similar to modify_timeslice() but without changing initial cycles */ 317 void m68k_modify_timeslice(int cycles); /* Modify cycles left */ 318 void m68k_end_timeslice(void); /* End timeslice now */ 319 void m68k_burn_until_irq(int enabled); /* Sleep until INT (speedhacks) */ 320 321 /* Set the IPL0-IPL2 pins on the CPU (IRQ). 322 * A transition from < 7 to 7 will cause a non-maskable interrupt (NMI). 323 * Setting IRQ to 0 will clear an interrupt request. 324 */ 325 void m68k_set_irq(unsigned int int_level); 326 void m68k_set_irq_delay(unsigned int int_level); 327 328 /* Set the virtual irq lines, where the highest level 329 * active line is automatically selected. If you use this function, 330 * do not use m68k_set_irq. 331 */ 332 void m68k_set_virq(unsigned int level, unsigned int active); 333 unsigned int m68k_get_virq(unsigned int level); 334 335 /* For Megadrive -dink */ 336 int m68k_check_shouldinterrupt(void); 337 338 /* Halt the CPU as if you pulsed the HALT pin. */ 339 void m68k_pulse_halt(void); 340 341 342 /* Context switching to allow multiple CPUs */ 343 344 /* Get the size of the cpu context in bytes */ 345 unsigned int m68k_context_size(void); 346 347 /* Get the size of the cpu context without the pointer-block, for savestates */ 348 unsigned int m68k_context_size_no_pointers(void); 349 350 /* Get a cpu context */ 351 unsigned int m68k_get_context(void* dst); 352 353 /* set the current cpu context */ 354 void m68k_set_context(void* dst); 355 356 /* Register the CPU state information */ 357 void m68k_state_register(const char *type, int index); 358 359 360 /* Peek at the internals of a CPU context. This can either be a context 361 * retrieved using m68k_get_context() or the currently running context. 362 * If context is NULL, the currently running CPU context will be used. 363 */ 364 unsigned int m68k_get_reg(void* context, m68k_register_t reg); 365 366 /* Poke values into the internals of the currently running CPU context */ 367 void m68k_set_reg(m68k_register_t reg, unsigned int value); 368 369 /* Check if an instruction is valid for the specified CPU type */ 370 unsigned int m68k_is_valid_instruction(unsigned int instruction, unsigned int cpu_type); 371 372 /* Disassemble 1 instruction using the epecified CPU type at pc. Stores 373 * disassembly in str_buff and returns the size of the instruction in bytes. 374 */ 375 unsigned int m68k_disassemble(char* str_buff, unsigned int pc, unsigned int cpu_type); 376 377 /* Same as above but accepts raw opcode data directly rather than fetching 378 * via the read/write interfaces. 379 */ 380 unsigned int m68k_disassemble_raw(char* str_buff, unsigned int pc, const unsigned char* opdata, const unsigned char* argdata, unsigned int cpu_type); 381 382 383 /* ======================================================================== */ 384 /* ============================= CONFIGURATION ============================ */ 385 /* ======================================================================== */ 386 387 /* Import the configuration for this build */ 388 #include "m68kconf.h" 389 390 391 /* ======================================================================== */ 392 /* ============================== END OF FILE ============================= */ 393 /* ======================================================================== */ 394 395 #ifdef __cplusplus 396 } 397 #endif 398 399 #endif /* M68K__HEADER */ 400