2 // m68kinterface.c: Code interface to the UAE 68000 core and support code
5 // (C) 2011 Underground Software
7 // JLH = James Hammons <jlhamm@acm.org>
10 // --- ---------- -------------------------------------------------------------
11 // JLH 10/28/2011 Created this file ;-)
14 #include "m68kinterface.h"
15 //#include <pthread.h>
21 // Exception Vectors handled by emulation
22 #define EXCEPTION_BUS_ERROR 2 /* This one is not emulated! */
23 #define EXCEPTION_ADDRESS_ERROR 3 /* This one is partially emulated (doesn't stack a proper frame yet) */
24 #define EXCEPTION_ILLEGAL_INSTRUCTION 4
25 #define EXCEPTION_ZERO_DIVIDE 5
26 #define EXCEPTION_CHK 6
27 #define EXCEPTION_TRAPV 7
28 #define EXCEPTION_PRIVILEGE_VIOLATION 8
29 #define EXCEPTION_TRACE 9
30 #define EXCEPTION_1010 10
31 #define EXCEPTION_1111 11
32 #define EXCEPTION_FORMAT_ERROR 14
33 #define EXCEPTION_UNINITIALIZED_INTERRUPT 15
34 #define EXCEPTION_SPURIOUS_INTERRUPT 24
35 #define EXCEPTION_INTERRUPT_AUTOVECTOR 24
36 #define EXCEPTION_TRAP_BASE 32
38 // These are found in obj/cpustbl.c (generated by gencpu)
40 //extern const struct cputbl op_smalltbl_0_ff[]; /* 68040 */
41 //extern const struct cputbl op_smalltbl_1_ff[]; /* 68020 + 68881 */
42 //extern const struct cputbl op_smalltbl_2_ff[]; /* 68020 */
43 //extern const struct cputbl op_smalltbl_3_ff[]; /* 68010 */
44 extern const struct cputbl op_smalltbl_4_ff[]; /* 68000 */
45 extern const struct cputbl op_smalltbl_5_ff[]; /* 68000 slow but compatible. */
47 // Externs, supplied by the user...
48 //extern int irq_ack_handler(int);
50 // Function prototypes...
51 STATIC_INLINE void m68ki_check_interrupts(void);
52 void m68ki_exception_interrupt(uint32_t intLevel);
53 STATIC_INLINE uint32_t m68ki_init_exception(void);
54 STATIC_INLINE void m68ki_stack_frame_3word(uint32_t pc, uint32_t sr);
55 unsigned long IllegalOpcode(uint32_t opcode);
56 void BuildCPUFunctionTable(void);
57 void m68k_set_irq2(unsigned int intLevel);
59 // Local "Global" vars
60 static int32_t initialCycles;
61 cpuop_func * cpuFunctionTable[65536];
63 // By virtue of the fact that m68k_set_irq() can be called asychronously by
64 // another thread, we need something along the lines of this:
65 static int checkForIRQToHandle = 0;
66 //static pthread_mutex_t executionLock = PTHREAD_MUTEX_INITIALIZER;
67 static int IRQLevelToHandle = 0;
70 #define ADD_CYCLES(A) m68ki_remaining_cycles += (A)
71 #define USE_CYCLES(A) m68ki_remaining_cycles -= (A)
72 #define SET_CYCLES(A) m68ki_remaining_cycles = A
73 #define GET_CYCLES() m68ki_remaining_cycles
74 #define USE_ALL_CYCLES() m68ki_remaining_cycles = 0
76 #define CPU_INT_LEVEL m68ki_cpu.int_level /* ASG: changed from CPU_INTS_PENDING */
77 #define CPU_INT_CYCLES m68ki_cpu.int_cycles /* ASG */
78 #define CPU_STOPPED m68ki_cpu.stopped
79 #define CPU_PREF_ADDR m68ki_cpu.pref_addr
80 #define CPU_PREF_DATA m68ki_cpu.pref_data
81 #define CPU_ADDRESS_MASK m68ki_cpu.address_mask
82 #define CPU_SR_MASK m68ki_cpu.sr_mask
88 void Dasm(uint32_t offset, uint32_t qt)
91 // back up a few instructions...
93 static char buffer[2048];//, mem[64];
94 int pc = offset, oldpc;
100 for(int j=0; j<64; j++)
101 mem[j^0x01] = jaguar_byte_read(pc + j);
103 pc += Dasm68000((char *)mem, buffer, 0);
104 WriteLog("%08X: %s\n", oldpc, buffer);//*/
106 pc += m68k_disassemble(buffer, pc, 0);//M68K_CPU_TYPE_68000);
107 // WriteLog("%08X: %s\n", oldpc, buffer);//*/
108 printf("%08X: %s\n", oldpc, buffer);//*/
115 void DumpRegisters(void)
121 printf("%s%i: %08X ", (i < 8 ? "D" : "A"), i & 0x7, regs.regs[i]);
130 void M68KDebugHalt(void)
132 regs.spcflags |= SPCFLAG_DEBUGGER;
136 void M68KDebugResume(void)
138 regs.spcflags &= ~SPCFLAG_DEBUGGER;
142 void m68k_set_cpu_type(unsigned int type)
147 // Pulse the RESET line on the CPU
148 void m68k_pulse_reset(void)
150 static uint32_t emulation_initialized = 0;
152 // The first call to this function initializes the opcode handler jump table
153 if (!emulation_initialized)
156 m68ki_build_opcode_table();
157 m68k_set_int_ack_callback(NULL);
158 m68k_set_bkpt_ack_callback(NULL);
159 m68k_set_reset_instr_callback(NULL);
160 m68k_set_pc_changed_callback(NULL);
161 m68k_set_fc_callback(NULL);
162 m68k_set_instr_hook_callback(NULL);
164 // Build opcode handler table here...
167 BuildCPUFunctionTable();
169 emulation_initialized = 1;
172 // if (CPU_TYPE == 0) /* KW 990319 */
173 // m68k_set_cpu_type(M68K_CPU_TYPE_68000);
176 /* Clear all stop levels and eat up all remaining cycles */
180 /* Turn off tracing */
181 FLAG_T1 = FLAG_T0 = 0;
183 /* Interrupt mask to level 7 */
184 FLAG_INT_MASK = 0x0700;
187 /* Go to supervisor mode */
188 m68ki_set_sm_flag(SFLAG_SET | MFLAG_CLEAR);
190 /* Invalidate the prefetch queue */
191 #if M68K_EMULATE_PREFETCH
192 /* Set to arbitrary number since our first fetch is from 0 */
193 CPU_PREF_ADDR = 0x1000;
194 #endif /* M68K_EMULATE_PREFETCH */
196 /* Read the initial stack pointer and program counter */
198 REG_SP = m68ki_read_imm_32();
199 REG_PC = m68ki_read_imm_32();
204 regs.remainingCycles = 0;
207 regs.s = 1; // Supervisor mode ON
209 // Read initial SP and PC
210 m68k_areg(regs, 7) = m68k_read_memory_32(0);
211 m68k_setpc(m68k_read_memory_32(4));
212 refill_prefetch(m68k_getpc(), 0);
217 int m68k_execute(int num_cycles)
221 regs.remainingCycles = 0; // int32_t
222 regs.interruptCycles = 0; // uint32_t
228 /* Set our pool of clock cycles available */
229 SET_CYCLES(num_cycles);
230 m68ki_initial_cycles = num_cycles;
232 /* ASG: update cycles */
233 USE_CYCLES(CPU_INT_CYCLES);
236 /* Return point if we had an address error */
237 m68ki_set_address_error_trap(); /* auto-disable (see m68kcpu.h) */
239 regs.remainingCycles = num_cycles;
240 /*int32_t*/ initialCycles = num_cycles;
242 regs.remainingCycles -= regs.interruptCycles;
243 regs.interruptCycles = 0;
246 /* Main loop. Keep going until we run out of clock cycles */
249 // This is so our debugging code can break in on a dime.
250 // Otherwise, this is just extra slow down :-P
251 if (regs.spcflags & SPCFLAG_DEBUGGER)
253 // Not sure this is correct... :-P
254 num_cycles = initialCycles - regs.remainingCycles;
255 regs.remainingCycles = 0; // int32_t
256 regs.interruptCycles = 0; // uint32_t
261 /* Set tracing accodring to T1. (T0 is done inside instruction) */
262 m68ki_trace_t1(); /* auto-disable (see m68kcpu.h) */
264 /* Set the address space for reads */
265 m68ki_use_data_space(); /* auto-disable (see m68kcpu.h) */
267 /* Call external hook to peek at CPU */
268 m68ki_instr_hook(); /* auto-disable (see m68kcpu.h) */
270 /* Record previous program counter */
273 /* Read an instruction and call its handler */
274 REG_IR = m68ki_read_imm_16();
275 m68ki_instruction_jump_table[REG_IR]();
276 USE_CYCLES(CYC_INSTRUCTION[REG_IR]);
278 /* Trace m68k_exception, if necessary */
279 m68ki_exception_if_trace(); /* auto-disable (see m68kcpu.h) */
281 //Testing Hover Strike...
284 static int hitCount = 0;
285 static int inRoutine = 0;
288 //if (regs.pc == 0x80340A)
289 if (regs.pc == 0x803416)
294 printf("%i: $80340A start. A0=%08X, A1=%08X ", hitCount, regs.regs[8], regs.regs[9]);
296 else if (regs.pc == 0x803422)
299 printf("(%i instructions)\n", instSeen);
305 // AvP testing... (problem was: 32 bit addresses on 24 bit address cpu--FIXED)
309 if (regs.pc == 0x94BA)
315 if (regs.pc == 0x94C6)
318 // if (regs.regs[10] == 0xFFFFFFFF && go)
321 // printf("A2=-1, PC=%08X\n", regs.pc);
323 // Dasm(regs.pc, 130);
327 //94BA: 2468 0000 MOVEA.L (A0,$0000) == $0002328A, A2
328 //94BE: 200A MOVE.L A2, D0
329 //94C0: 6A02 BPL.B $94C4
330 //94C2: 2452 MOVEA.L (A2), A2 ; <--- HERE
331 //94C4: 4283 CLR.L D3
333 // pthread_mutex_lock(&executionLock);
334 if (checkForIRQToHandle)
336 checkForIRQToHandle = 0;
337 m68k_set_irq2(IRQLevelToHandle);
340 #ifdef M68K_HOOK_FUNCTION
341 M68KInstructionHook();
343 uint32_t opcode = get_iword(0);
344 //if ((opcode & 0xFFF8) == 0x31C0)
346 // printf("MOVE.W D%i, EA\n", opcode & 0x07);
348 int32_t cycles = (int32_t)(*cpuFunctionTable[opcode])(opcode);
349 regs.remainingCycles -= cycles;
350 // pthread_mutex_unlock(&executionLock);
352 //printf("Executed opcode $%04X (%i cycles)...\n", opcode, cycles);
355 while (regs.remainingCycles > 0);
358 /* set previous PC to current PC for the next entry into the loop */
361 /* ASG: update cycles */
362 USE_CYCLES(CPU_INT_CYCLES);
365 /* return how many clocks we used */
366 return m68ki_initial_cycles - GET_CYCLES();
368 regs.remainingCycles -= regs.interruptCycles;
369 regs.interruptCycles = 0;
371 // Return # of clock cycles used
372 return initialCycles - regs.remainingCycles;
377 void m68k_set_irq(unsigned int intLevel)
379 // We need to check for stopped state as well...
382 m68k_set_irq2(intLevel);
386 // Since this can be called asynchronously, we need to fix it so that it
387 // doesn't fuck up the main execution loop.
388 IRQLevelToHandle = intLevel;
389 checkForIRQToHandle = 1;
393 /* ASG: rewrote so that the int_level is a mask of the IPL0/IPL1/IPL2 bits */
394 void m68k_set_irq2(unsigned int intLevel)
396 // pthread_mutex_lock(&executionLock);
397 // printf("m68k_set_irq: Could not get the lock!!!\n");
399 int oldLevel = regs.intLevel;
400 regs.intLevel = intLevel;
402 // A transition from < 7 to 7 always interrupts (NMI)
403 // Note: Level 7 can also level trigger like a normal IRQ
404 if (oldLevel != 0x07 && regs.intLevel == 0x07)
405 m68ki_exception_interrupt(7); // Edge triggered level 7 (NMI)
407 m68ki_check_interrupts(); // Level triggered (IRQ)
409 // pthread_mutex_unlock(&executionLock);
413 // Check for interrupts
414 STATIC_INLINE void m68ki_check_interrupts(void)
417 if(CPU_INT_LEVEL > FLAG_INT_MASK)
418 m68ki_exception_interrupt(CPU_INT_LEVEL>>8);
420 if (regs.intLevel > regs.intmask)
421 m68ki_exception_interrupt(regs.intLevel);
426 // Service an interrupt request and start exception processing
427 void m68ki_exception_interrupt(uint32_t intLevel)
434 /* Turn off the stopped state */
435 CPU_STOPPED &= ~STOP_LEVEL_STOP;
437 /* If we are halted, don't do anything */
441 /* Acknowledge the interrupt */
442 vector = m68ki_int_ack(int_level);
444 /* Get the interrupt vector */
445 if(vector == M68K_INT_ACK_AUTOVECTOR)
446 /* Use the autovectors. This is the most commonly used implementation */
447 vector = EXCEPTION_INTERRUPT_AUTOVECTOR+int_level;
448 else if(vector == M68K_INT_ACK_SPURIOUS)
449 /* Called if no devices respond to the interrupt acknowledge */
450 vector = EXCEPTION_SPURIOUS_INTERRUPT;
451 else if(vector > 255)
453 M68K_DO_LOG_EMU((M68K_LOG_FILEHANDLE "%s at %08x: Interrupt acknowledge returned invalid vector $%x\n",
454 m68ki_cpu_names[CPU_TYPE], ADDRESS_68K(REG_PC), vector));
458 /* Start exception processing */
459 sr = m68ki_init_exception();
461 /* Set the interrupt mask to the level of the one being serviced */
462 FLAG_INT_MASK = int_level<<8;
465 new_pc = m68ki_read_data_32((vector<<2) + REG_VBR);
467 /* If vector is uninitialized, call the uninitialized interrupt vector */
469 new_pc = m68ki_read_data_32((EXCEPTION_UNINITIALIZED_INTERRUPT<<2) + REG_VBR);
471 /* Generate a stack frame */
472 m68ki_stack_frame_0000(REG_PC, sr, vector);
474 if(FLAG_M && CPU_TYPE_IS_EC020_PLUS(CPU_TYPE))
476 /* Create throwaway frame */
477 m68ki_set_sm_flag(FLAG_S); /* clear M */
478 sr |= 0x2000; /* Same as SR in master stack frame except S is forced high */
479 m68ki_stack_frame_0001(REG_PC, sr, vector);
484 /* Defer cycle counting until later */
485 CPU_INT_CYCLES += CYC_EXCEPTION[vector];
487 #if !M68K_EMULATE_INT_ACK
488 /* Automatically clear IRQ if we are not using an acknowledge scheme */
490 #endif /* M68K_EMULATE_INT_ACK */
492 // Turn off the stopped state (N.B.: normal 68K behavior!)
495 //JLH: need to add halt state?
496 // prolly, for debugging/alpine mode... :-/
497 // but then again, this should be handled already by the main execution loop :-P
498 // If we are halted, don't do anything
502 // Acknowledge the interrupt (NOTE: This is a user supplied function!)
503 uint32_t vector = irq_ack_handler(intLevel);
505 // Get the interrupt vector
506 if (vector == M68K_INT_ACK_AUTOVECTOR)
507 // Use the autovectors. This is the most commonly used implementation
508 vector = EXCEPTION_INTERRUPT_AUTOVECTOR + intLevel;
509 else if (vector == M68K_INT_ACK_SPURIOUS)
510 // Called if no devices respond to the interrupt acknowledge
511 vector = EXCEPTION_SPURIOUS_INTERRUPT;
512 else if (vector > 255)
514 // M68K_DO_LOG_EMU((M68K_LOG_FILEHANDLE "%s at %08x: Interrupt acknowledge returned invalid vector $%x\n",
515 // m68ki_cpu_names[CPU_TYPE], ADDRESS_68K(REG_PC), vector));
519 // Start exception processing
520 uint32_t sr = m68ki_init_exception();
522 // Set the interrupt mask to the level of the one being serviced
523 regs.intmask = intLevel;
526 extern int startM68KTracing;
527 if (startM68KTracing)
529 printf("IRQ: old PC=%06X, ", regs.pc);
534 uint32_t newPC = m68k_read_memory_32(vector << 2);
537 if (startM68KTracing)
539 printf("new PC=%06X, vector=%u, ", newPC, vector);
543 // If vector is uninitialized, call the uninitialized interrupt vector
545 newPC = m68k_read_memory_32(EXCEPTION_UNINITIALIZED_INTERRUPT << 2);
547 // Generate a stack frame
548 m68ki_stack_frame_3word(regs.pc, sr);
552 if (startM68KTracing)
554 printf("(PC=%06X)\n", regs.pc);
558 // Defer cycle counting until later
559 regs.interruptCycles += 56; // NOT ACCURATE-- !!! FIX !!!
560 // CPU_INT_CYCLES += CYC_EXCEPTION[vector];
565 // Initiate exception processing
566 STATIC_INLINE uint32_t m68ki_init_exception(void)
569 /* Save the old status register */
570 uint sr = m68ki_get_sr();
572 /* Turn off trace flag, clear pending traces */
573 FLAG_T1 = FLAG_T0 = 0;
575 /* Enter supervisor mode */
576 m68ki_set_s_flag(SFLAG_SET);
581 uint32_t sr = regs.sr; // Save old status register
582 regs.s = 1; // Set supervisor mode
589 // 3 word stack frame (68000 only)
590 STATIC_INLINE void m68ki_stack_frame_3word(uint32_t pc, uint32_t sr)
597 m68k_areg(regs, 7) -= 4;
598 m68k_write_memory_32(m68k_areg(regs, 7), pc);
600 m68k_areg(regs, 7) -= 2;
601 m68k_write_memory_16(m68k_areg(regs, 7), sr);
606 unsigned int m68k_get_reg(void * context, m68k_register_t reg)
608 if (reg <= M68K_REG_A7)
609 return regs.regs[reg];
610 else if (reg == M68K_REG_PC)
612 else if (reg == M68K_REG_SR)
617 else if (reg == M68K_REG_SP)
618 return regs.regs[15];
624 void m68k_set_reg(m68k_register_t reg, unsigned int value)
626 if (reg <= M68K_REG_A7)
627 regs.regs[reg] = value;
628 else if (reg == M68K_REG_PC)
630 else if (reg == M68K_REG_SR)
635 else if (reg == M68K_REG_SP)
636 regs.regs[15] = value;
641 // Check if the instruction is a valid one
643 unsigned int m68k_is_valid_instruction(unsigned int instruction, unsigned int cpu_type)
645 instruction &= 0xFFFF;
647 if (cpuFunctionTable[instruction] == IllegalOpcode)
654 // Dummy functions, for now, until we prove the concept here. :-)
656 // Temp, while we're using the Musashi disassembler...
658 unsigned int m68k_disassemble(char * str_buff, unsigned int pc, unsigned int cpu_type)
664 int m68k_cycles_run(void) {} /* Number of cycles run so far */
665 int m68k_cycles_remaining(void) {} /* Number of cycles left */
666 //void m68k_modify_timeslice(int cycles) {} /* Modify cycles left */
667 //void m68k_end_timeslice(void) {} /* End timeslice now */
670 void m68k_modify_timeslice(int cycles)
672 regs.remainingCycles = cycles;
676 void m68k_end_timeslice(void)
679 m68ki_initial_cycles = GET_CYCLES();
682 initialCycles = regs.remainingCycles;
683 regs.remainingCycles = 0;
688 unsigned long IllegalOpcode(uint32_t opcode)
691 uint32_t pc = m68k_getpc ();
693 if ((opcode & 0xF000) == 0xF000)
695 Exception(0x0B, 0, M68000_EXC_SRC_CPU); // LineF exception...
698 else if ((opcode & 0xF000) == 0xA000)
700 Exception(0x0A, 0, M68000_EXC_SRC_CPU); // LineA exception...
705 write_log ("Illegal instruction: %04x at %08lx\n", opcode, (long)pc);
708 Exception(0x04, 0, M68000_EXC_SRC_CPU); // Illegal opcode exception...
713 void BuildCPUFunctionTable(void)
716 unsigned long opcode;
718 // We're only using the "fast" 68000 emulation here, not the "compatible"
719 // ("fast" doesn't throw exceptions, so we're using "compatible" now :-P)
721 const struct cputbl * tbl = (currprefs.cpu_compatible
722 ? op_smalltbl_5_ff : op_smalltbl_4_ff);
724 //let's try "compatible" and see what happens here...
725 // const struct cputbl * tbl = op_smalltbl_4_ff;
726 const struct cputbl * tbl = op_smalltbl_5_ff;
729 // Log_Printf(LOG_DEBUG, "Building CPU function table (%d %d %d).\n",
730 // currprefs.cpu_level, currprefs.cpu_compatible, currprefs.address_space_24);
732 // Set all instructions to Illegal...
733 for(opcode=0; opcode<65536; opcode++)
734 cpuFunctionTable[opcode] = IllegalOpcode;
736 // Move functions from compact table into our full function table...
737 for(i=0; tbl[i].handler!=NULL; i++)
738 cpuFunctionTable[tbl[i].opcode] = tbl[i].handler;
740 //JLH: According to readcpu.c, handler is set to -1 and never changes.
741 // Actually, it does read this crap in readcpu.c, do_merges() does it... :-P
742 // Again, seems like a build time thing could be done here...
744 for(opcode=0; opcode<65536; opcode++)
746 // if (table68k[opcode].mnemo == i_ILLG || table68k[opcode].clev > currprefs.cpu_level)
747 if (table68k[opcode].mnemo == i_ILLG || table68k[opcode].clev > 0)
750 if (table68k[opcode].handler != -1)
752 //printf("Relocate: $%04X->$%04X\n", table68k[opcode].handler, opcode);
753 cpuop_func * f = cpuFunctionTable[table68k[opcode].handler];
755 if (f == IllegalOpcode)
758 cpuFunctionTable[opcode] = f;