Get Jaguar video interrupt working

68kinst.h

@@ -329,7 +329,8 @@ typedef enum {
 	VECTOR_TRAP_12,
 	VECTOR_TRAP_13,
 	VECTOR_TRAP_14,
-	VECTOR_TRAP_15
+	VECTOR_TRAP_15,
+	VECTOR_USER0 = 64
 } m68k_vector;
 
 typedef int (*format_label_fun)(char * dst, uint32_t address, void * data);

blastem.c

@@ -171,7 +171,7 @@ void adjust_int_cycle(m68k_context * context, vdp_context * v_context)
 		}
 	}
 	if (context->int_cycle > context->current_cycle && context->int_pending == INT_PENDING_SR_CHANGE) {
-		context->int_pending = 0;
+		context->int_pending = INT_PENDING_NONE;
 	}
 	/*if (context->int_cycle != old_int_cycle) {
 		printf("int cycle changed to: %d, level: %d @ %d(%d), frame: %d, vcounter: %d, hslot: %d, mask: %d, hint_counter: %d\n", context->int_cycle, context->int_num, v_context->cycles, context->current_cycle, v_context->frame, v_context->vcounter, v_context->hslot, context->status & 0x7, v_context->hint_counter);

jag_video.c

@@ -187,6 +187,27 @@ enum {
 	OBJ_STOP
 };
 
+uint32_t jag_cycles_to_halfline(jag_video *context, uint32_t target)
+{
+	uint32_t cycles = context->regs[VID_HPERIOD] - (context->regs[VID_HCOUNT & 0x3FF]);
+	uint32_t num_lines;
+	if (context->regs[VID_VCOUNT] < target) {
+		num_lines = target - 1 - context->regs[VID_VCOUNT];
+	} else {
+		num_lines = target + context->regs[VID_VPERIOD] - context->regs[VID_VCOUNT];
+	}
+	cycles += num_lines * context->regs[VID_HPERIOD];
+	return cycles;
+}
+
+uint32_t jag_next_vid_interrupt(jag_video *context)
+{
+	if (context->regs[VID_VINT] > context->regs[VID_VPERIOD]) {
+		return 0xFFFFFFF;
+	}
+	return context->cycles + jag_cycles_to_halfline(context, context->regs[VID_VINT]);
+}
+
 void op_run(jag_video *context)
 {
 	while (context->op.cycles < context->cycles)
@@ -547,6 +568,9 @@ void jag_video_run(jag_video *context, uint32_t target_cycle)
 					context->regs[VID_VCOUNT] = 0;
 				} else {
 					context->regs[VID_VCOUNT]++;
+					if (context->regs[VID_VCOUNT] == context->regs[VID_VINT]) {
+						context->cpu_int_pending |= BIT_CPU_VID_INT_ENABLED;
+					}
 				}
 			} else {
 				context->regs[VID_HCOUNT]++;

jag_video.h

@@ -96,6 +96,7 @@ typedef struct {
 	uint8_t          pclock_div;
 	uint8_t          pclock_counter;
 	uint8_t          mode;
+	uint8_t          cpu_int_pending;
 	
 	object_processor op;
 	
@@ -105,5 +106,6 @@ typedef struct {
 jag_video *jag_video_init(void);
 void jag_video_run(jag_video *context, uint32_t target_cycle);
 void jag_video_reg_write(jag_video *context, uint32_t address, uint16_t value);
+uint32_t jag_next_vid_interrupt(jag_video *context);
 
 #endif //JAG_VIDEO_H_

jaguar.c

@@ -3,6 +3,7 @@
 #include <stddef.h>
 #include <stdlib.h>
 #include "m68k_core.h"
+#include "68kinst.h"
 #include "jaguar.h"
 #include "util.h"
 #include "debug.h"
@@ -58,6 +59,38 @@ void handle_mouse_moved(int mouse, uint16_t x, uint16_t y, int16_t deltax, int16
 {
 }
 
+void jag_update_m68k_int(jaguar_context *system)
+{
+	m68k_context *m68k = system->m68k;
+	if (m68k->sync_cycle - m68k->current_cycle > system->max_cycles) {
+		m68k->sync_cycle = m68k->current_cycle + system->max_cycles;
+	}
+	//TODO: Support other interrupt sources
+	if (!system->cpu_int_control || (m68k->status & 0x7)) {
+		m68k->int_cycle = CYCLE_NEVER;
+	} else if(system->cpu_int_control & system->video->cpu_int_pending) {
+		m68k->int_cycle = m68k->current_cycle;
+		//supposedly all interrupts on the jaguar are "level 0" autovector interrupts
+		//which I assume means they're abusing the "spurious interrupt" vector
+		m68k->int_num = VECTOR_USER0 - VECTOR_SPURIOUS_INTERRUPT;
+	} else {
+		m68k->int_cycle = jag_next_vid_interrupt(system->video);
+		m68k->int_num = VECTOR_USER0 - VECTOR_SPURIOUS_INTERRUPT;
+	}
+	
+	if (m68k->int_cycle > m68k->current_cycle && m68k->int_pending == INT_PENDING_SR_CHANGE) {
+		m68k->int_pending = INT_PENDING_NONE;
+	}
+	
+	m68k->target_cycle = m68k->int_cycle < m68k->sync_cycle ? m68k->int_cycle : m68k->sync_cycle;
+	if (m68k->should_return) {
+		m68k->target_cycle = m68k->current_cycle;
+	} else if (m68k->target_cycle < m68k->current_cycle) {
+		//Changes to SR can result in an interrupt cycle that's in the past
+		//This can cause issues with the implementation of STOP though
+		m68k->target_cycle = m68k->current_cycle;
+	}
+}
 
 void rom0_write_16(uint32_t address, jaguar_context *system, uint16_t value)
 {
@@ -111,8 +144,19 @@ void rom0_write_16(uint32_t address, jaguar_context *system, uint16_t value)
 				case 2:
 					system->memcon2 = value;
 					break;
+				case 0xE0:
+					printf("INT1 write: %X\n", value);
+					system->cpu_int_control = value & 0x1F;
+					system->video->cpu_int_pending &= ~(value >> 8);
+					//TODO: apply mask to int pending fields on other components once they are implemented
+					break;
+				case 0xE2:
+					//no real handling of bus conflicts presently, so this doesn't really need to do anything yet
+					printf("INT2 write: %X\n", value);
+					break;
 				default:
 					jag_video_reg_write(system->video, address, value);
+					jag_update_m68k_int(system);
 					break;
 				}
 			} else if (address < 0x100800) {
@@ -144,7 +188,15 @@ void rom0_write_16(uint32_t address, jaguar_context *system, uint16_t value)
 				fprintf(stderr, "Unhandled write to GPU registers %X: %X\n", address, value);
 				if (address == 0x102116 && (value & 1)) {
 					FILE *f = fopen("gpu.bin", "wb");
-					fwrite(system->gpu_local, 1, sizeof(system->gpu_local), f);
+					uint8_t buf[4];
+					for (int i = 0; i < GPU_RAM_BYTES/sizeof(uint32_t); i++)
+					{
+						buf[0] = system->gpu_local[i] >> 24;
+						buf[1] = system->gpu_local[i] >> 16;
+						buf[2] = system->gpu_local[i] >> 8;
+						buf[3] = system->gpu_local[i];
+						fwrite(buf, 1, sizeof(buf), f);
+					}
 					fclose(f);
 				}
 			} else {
@@ -154,7 +206,7 @@ void rom0_write_16(uint32_t address, jaguar_context *system, uint16_t value)
 	} else if (address < 0x11A100) {
 		if (address < 0x110000) {
 			//GPU Local RAM
-			uint32_t offset = address >> 2 & (GPU_RAM_BYTES / sizeof(uint32_t) - 1);
+				uint32_t offset = address >> 2 & (GPU_RAM_BYTES / sizeof(uint32_t) - 1);
 			uint32_t value32 = value;
 			if (address & 2) {
 				system->gpu_local[offset] &= 0xFFFF0000;
@@ -201,7 +253,16 @@ uint16_t rom0_read_16(uint32_t address, jaguar_context *system)
 		if (address < 0x101000) {
 			if (address < 0x100400) {
 				//Video mode / Memory control registers
-				fprintf(stderr, "Unhandled read from video mode/memory control registers - %X\n", address);
+				switch (address & 0x3FE)
+				{
+				case 0xE0:
+					puts("INT1 read");
+					//TODO: Bitwise or with cpu_int_pending fields from other components once implemented
+					return system->video->cpu_int_pending;
+					break;
+				default:
+					fprintf(stderr, "Unhandled read from video mode/memory control registers - %X\n", address);
+				}
 			} else if (address < 0x100800) {
 				//CLUT
 				address = address >> 1 & 255;
@@ -377,10 +438,17 @@ m68k_context * sync_components(m68k_context * context, uint32_t address)
 {
 	jaguar_context *system = context->system;
 	jag_video_run(system->video, context->current_cycle);
+	jag_update_m68k_int(system);
 	if (context->current_cycle > 0x10000000) {
 		context->current_cycle -= 0x10000000;
 		system->video->cycles -= 0x10000000;
 	}
+	if (context->int_ack) {
+		context->int_ack = 0;
+		//hack until 68K core more properly supports non-autovector interrupts
+		context->status |= 1;
+	}
+	jag_update_m68k_int(system);
 	return context;
 }
 
@@ -431,6 +499,8 @@ jaguar_context *init_jaguar(uint16_t *bios, uint32_t bios_size, uint16_t *cart,
 	system->bios_size = bios_size;
 	system->cart = cart;
 	system->cart_size = cart_size;
+	//TODO: Figure out a better default for this and make it configurable
+	system->max_cycles = 3000;
 
 	memmap_chunk *jag_m68k_map = calloc(8, sizeof(memmap_chunk));
 	for (uint32_t start = 0, index=0; index < 8; index++, start += 0x200000)
@@ -450,6 +520,7 @@ jaguar_context *init_jaguar(uint16_t *bios, uint32_t bios_size, uint16_t *cart,
 	m68k_options *opts = malloc(sizeof(m68k_options));
 	init_m68k_opts(opts, jag_m68k_map, 8, 2);
 	system->m68k = init_68k_context(opts, handle_m68k_reset);
+	system->m68k->sync_cycle = system->max_cycles;
 	system->m68k->system = system;
 	system->video = jag_video_init();
 	system->video->system = system;

jaguar.h

@@ -17,6 +17,8 @@ typedef struct {
 	uint32_t     memcon1;
 	uint32_t     memcon2;
 	uint32_t     rom_cycles;
+	uint32_t     max_cycles;
+	uint16_t     cpu_int_control;
 	uint16_t     write_latch;
 	uint8_t      write_pending;
 	
@@ -27,6 +29,8 @@ typedef struct {
 	uint8_t      memcon_written;
 } jaguar_context;
 
+#define BIT_CPU_VID_INT_ENABLED 0x01
+
 uint64_t jag_read_phrase(jaguar_context *system, uint32_t address, uint32_t *cycles);
 uint32_t jag_write_phrase(jaguar_context *system, uint32_t address, uint64_t value);
 

m68k_core.h

@@ -18,7 +18,8 @@ struct m68kinst;
 
 #define M68K_OPT_BROKEN_READ_MODIFY 1
 
-#define INT_PENDING_SR_CHANGE 8
+#define INT_PENDING_SR_CHANGE 254
+#define INT_PENDING_NONE 255
 
 typedef void (*start_fun)(uint8_t * addr, void * context);
 

m68k_core_x86.c

@@ -2762,7 +2762,7 @@ void init_m68k_opts(m68k_options * opts, memmap_chunk * memmap, uint32_t num_chu
 	code->stack_off = tmp_stack_off;
 	*do_int = code->cur - (do_int+1);
 	//implement 1 instruction latency
-	cmp_irdisp(code, 0, opts->gen.context_reg, offsetof(m68k_context, int_pending), SZ_B);
+	cmp_irdisp(code, INT_PENDING_NONE, opts->gen.context_reg, offsetof(m68k_context, int_pending), SZ_B);
 	do_int = code->cur + 1;
 	jcc(code, CC_NZ, do_int);
 	//store current interrupt number so it doesn't change before we start processing the vector
@@ -2824,6 +2824,8 @@ void init_m68k_opts(m68k_options * opts, memmap_chunk * memmap, uint32_t num_chu
 	//update status register
 	and_irdisp(code, 0xF8, opts->gen.context_reg, offsetof(m68k_context, status), SZ_B);
 	mov_rdispr(code, opts->gen.context_reg, offsetof(m68k_context, int_num), opts->gen.scratch1, SZ_B);
+	//need to separate int priority and interrupt vector, but for now mask out large interrupt numbers
+	and_ir(code, 0x7, opts->gen.scratch1, SZ_B);
 	or_ir(code, 0x20, opts->gen.scratch1, SZ_B);
 	or_rrdisp(code, opts->gen.scratch1, opts->gen.context_reg, offsetof(m68k_context, status), SZ_B);
 
@@ -2843,7 +2845,7 @@ void init_m68k_opts(m68k_options * opts, memmap_chunk * memmap, uint32_t num_chu
 	shl_ir(code, 2, opts->gen.scratch1, SZ_D);
 	add_ir(code, 0x60, opts->gen.scratch1, SZ_D);
 	//clear out pending flag
-	mov_irdisp(code, 0, opts->gen.context_reg, offsetof(m68k_context, int_pending), SZ_B);
+	mov_irdisp(code, INT_PENDING_NONE, opts->gen.context_reg, offsetof(m68k_context, int_pending), SZ_B);
 	//read vector
 	call(code, opts->read_32);
 	call(code, opts->native_addr_and_sync);