--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/z80_util.c	Sat Jan 15 13:15:21 2022 -0800
@@ -0,0 +1,341 @@
+#include <string.h>
+
+void z80_read_8(z80_context *context)
+{
+	context->cycles += 3 * context->opts->gen.clock_divider;
+	uint8_t *fast = context->fastread[context->scratch1 >> 10];
+	if (fast) {
+		context->scratch1 = fast[context->scratch1 & 0x3FF];
+	} else {
+		context->scratch1 = read_byte(context->scratch1, (void **)context->mem_pointers, &context->opts->gen, context);
+	}
+}
+
+void z80_write_8(z80_context *context)
+{
+	context->cycles += 3 * context->opts->gen.clock_divider;
+	uint8_t *fast = context->fastwrite[context->scratch2 >> 10];
+	if (fast) {
+		fast[context->scratch2 & 0x3FF] = context->scratch1;
+	} else {
+		write_byte(context->scratch2, context->scratch1, (void **)context->mem_pointers, &context->opts->gen, context);
+	}
+}
+
+void z80_io_read8(z80_context *context)
+{
+	uint32_t tmp_mask = context->opts->gen.address_mask;
+	memmap_chunk const *tmp_map = context->opts->gen.memmap;
+	uint32_t tmp_chunks = context->opts->gen.memmap_chunks;
+	
+	context->opts->gen.address_mask = context->io_mask;
+	context->opts->gen.memmap = context->io_map;
+	context->opts->gen.memmap_chunks = context->io_chunks;
+	
+	context->cycles += 4 * context->opts->gen.clock_divider;
+	context->scratch1 = read_byte(context->scratch1, (void **)context->mem_pointers, &context->opts->gen, context);
+	
+	context->opts->gen.address_mask = tmp_mask;
+	context->opts->gen.memmap = tmp_map;
+	context->opts->gen.memmap_chunks = tmp_chunks;
+}
+
+void z80_io_write8(z80_context *context)
+{
+	uint32_t tmp_mask = context->opts->gen.address_mask;
+	memmap_chunk const *tmp_map = context->opts->gen.memmap;
+	uint32_t tmp_chunks = context->opts->gen.memmap_chunks;
+	
+	context->opts->gen.address_mask = context->io_mask;
+	context->opts->gen.memmap = context->io_map;
+	context->opts->gen.memmap_chunks = context->io_chunks;
+	
+	context->cycles += 4 * context->opts->gen.clock_divider;
+	write_byte(context->scratch2, context->scratch1, (void **)context->mem_pointers, &context->opts->gen, context);
+	
+	context->opts->gen.address_mask = tmp_mask;
+	context->opts->gen.memmap = tmp_map;
+	context->opts->gen.memmap_chunks = tmp_chunks;
+}
+
+//quick hack until I get a chance to change which init method these get passed to
+static memmap_chunk const * tmp_io_chunks;
+static uint32_t tmp_num_io_chunks, tmp_io_mask;
+void init_z80_opts(z80_options * options, memmap_chunk const * chunks, uint32_t num_chunks, memmap_chunk const * io_chunks, uint32_t num_io_chunks, uint32_t clock_divider, uint32_t io_address_mask)
+{
+	memset(options, 0, sizeof(*options));
+	options->gen.memmap = chunks;
+	options->gen.memmap_chunks = num_chunks;
+	options->gen.address_mask = 0xFFFF;
+	options->gen.max_address = 0xFFFF;
+	options->gen.clock_divider = clock_divider;
+	tmp_io_chunks = io_chunks;
+	tmp_num_io_chunks = num_io_chunks;
+	tmp_io_mask = io_address_mask;
+}
+
+void z80_options_free(z80_options *opts)
+{
+	free(opts);
+}
+
+z80_context * init_z80_context(z80_options *options)
+{
+	z80_context *context = calloc(1, sizeof(z80_context));
+	context->opts = options;
+	context->io_map = (memmap_chunk *)tmp_io_chunks;
+	context->io_chunks = tmp_num_io_chunks;
+	context->io_mask = tmp_io_mask;
+	context->int_cycle = context->int_end_cycle = context->nmi_cycle = 0xFFFFFFFFU;
+	z80_invalidate_code_range(context, 0, 0xFFFF);
+	return context;
+}
+
+void z80_sync_cycle(z80_context *context, uint32_t target_cycle)
+{
+	if (context->iff1 && context->int_cycle < target_cycle) {
+		if (context->cycles > context->int_end_cycle) {
+			context->int_cycle = 0xFFFFFFFFU;
+		} else {
+			target_cycle = context->int_cycle;
+		}
+	};
+	if (context->nmi_cycle < target_cycle) {
+		target_cycle = context->nmi_cycle;
+	}
+	context->sync_cycle = target_cycle;
+}
+
+void z80_run(z80_context *context, uint32_t target_cycle)
+{
+	if (context->reset || context->busack) {
+		context->cycles = target_cycle;
+	} else if (target_cycle > context->cycles) {
+		if (context->busreq) {
+			//busreq is sampled at the end of an m-cycle
+			//we can approximate that by running for a single m-cycle after a bus request
+			target_cycle = context->cycles + 4 * context->opts->gen.clock_divider;
+		}
+		z80_execute(context, target_cycle);
+		if (context->busreq) {
+			context->busack = 1;
+		}
+	}
+}
+
+void z80_assert_reset(z80_context * context, uint32_t cycle)
+{
+	z80_run(context, cycle);
+	context->reset = 1;
+}
+
+void z80_clear_reset(z80_context * context, uint32_t cycle)
+{
+	z80_run(context, cycle);
+	if (context->reset) {
+		context->imode = 0;
+		context->iff1 = context->iff2 = 0;
+		context->pc = 0;
+		context->reset = 0;
+		if (context->busreq) {
+			//TODO: Figure out appropriate delay
+			context->busack = 1;
+		}
+	}
+}
+
+#define MAX_MCYCLE_LENGTH 6
+void z80_assert_busreq(z80_context * context, uint32_t cycle)
+{
+	z80_run(context, cycle);
+	context->busreq = 1;
+	//this is an imperfect aproximation since most M-cycles take less tstates than the max
+	//and a short 3-tstate m-cycle can take an unbounded number due to wait states
+	if (context->cycles - cycle > MAX_MCYCLE_LENGTH * context->opts->gen.clock_divider) {
+		context->busack = 1;
+	}
+}
+
+void z80_clear_busreq(z80_context * context, uint32_t cycle)
+{
+	z80_run(context, cycle);
+	context->busreq = 0;
+	context->busack = 0;
+	//there appears to be at least a 1 Z80 cycle delay between busreq
+	//being released and resumption of execution
+	context->cycles += context->opts->gen.clock_divider;
+}
+
+void z80_assert_nmi(z80_context *context, uint32_t cycle)
+{
+	context->nmi_cycle = cycle;
+}
+
+uint8_t z80_get_busack(z80_context * context, uint32_t cycle)
+{
+	z80_run(context, cycle);
+	return context->busack;
+}
+
+void z80_invalidate_code_range(z80_context *context, uint32_t startA, uint32_t endA)
+{
+	for(startA &= ~0x3FF; startA < endA; startA += 1024)
+	{
+		uint8_t *start = get_native_pointer(startA, (void**)context->mem_pointers, &context->opts->gen);
+		if (start) {
+			uint8_t *end = get_native_pointer(startA + 1023, (void**)context->mem_pointers, &context->opts->gen);
+			if (!end || end - start != 1023) {
+				start = NULL;
+			}
+		}
+		context->fastread[startA >> 10] = start;
+		start = get_native_write_pointer(startA, (void**)context->mem_pointers, &context->opts->gen);
+		if (start) {
+			uint8_t *end = get_native_write_pointer(startA + 1023, (void**)context->mem_pointers, &context->opts->gen);
+			if (!end || end - start != 1023) {
+				start = NULL;
+			}
+		}
+		context->fastwrite[startA >> 10] = start;
+	}
+}
+
+void z80_adjust_cycles(z80_context * context, uint32_t deduction)
+{
+	context->cycles -= deduction;
+	if (context->int_cycle != 0xFFFFFFFFU) {
+		if (context->int_cycle > deduction) {
+			context->int_cycle -= deduction;
+		} else {
+			context->int_cycle = 0;
+		}
+	}
+	if (context->int_end_cycle != 0xFFFFFFFFU) {
+		if (context->int_end_cycle > deduction) {
+			context->int_end_cycle -= deduction;
+		} else {
+			context->int_end_cycle = 0;
+		}
+	}
+	if (context->nmi_cycle != 0xFFFFFFFFU) {
+		if (context->nmi_cycle > deduction) {
+			context->nmi_cycle -= deduction;
+		} else {
+			context->nmi_cycle = 0;
+		}
+	}
+}
+
+void z80_serialize(z80_context *context, serialize_buffer *buf)
+{
+	save_int8(buf, context->main[1]);//C
+	save_int8(buf, context->main[0]);//B
+	save_int8(buf, context->main[3]);//E
+	save_int8(buf, context->main[2]);//D
+	save_int8(buf, context->main[5]);//L
+	save_int8(buf, context->main[4]);//H
+	save_int8(buf, context->ix);//IXL
+	save_int8(buf, context->ix >> 8);//IXH
+	save_int8(buf, context->iy);//IYL
+	save_int8(buf, context->iy >> 8);//IYH
+	save_int8(buf, context->i);
+	save_int8(buf, (context->rhigh & 0x80) | (context->r & 0x7F));
+	save_int8(buf, context->main[7]);//A
+	uint8_t f = context->last_flag_result & 0xA8
+		| (context->zflag ? 0x40 : 0)
+		| (context->chflags & 8 ? 0x10 : 0)
+		| (context->pvflag ? 4 : 0)
+		| (context->nflag ? 2 : 0)
+		| (context->chflags & 0x80 ? 1 : 0);
+	save_int8(buf, f);
+	save_int8(buf, context->alt[1]);//C
+	save_int8(buf, context->alt[0]);//B
+	save_int8(buf, context->alt[3]);//E
+	save_int8(buf, context->alt[2]);//D
+	save_int8(buf, context->alt[5]);//L
+	save_int8(buf, context->alt[4]);//H
+	save_int8(buf, 0);//non-existant alt ixl
+	save_int8(buf, 0);//non-existant alt ixh
+	save_int8(buf, 0);//non-existant alt iyl
+	save_int8(buf, 0);//non-existant alt iyh
+	save_int8(buf, 0);//non-existant alt i
+	save_int8(buf, 0);//non-existant alt r
+	save_int8(buf, context->alt[7]);//A
+	save_int8(buf, context->alt[6]);//F
+	
+	save_int16(buf, context->pc);
+	save_int16(buf, context->sp);
+	save_int8(buf, context->imode);
+	save_int8(buf, context->iff1);
+	save_int8(buf, context->iff2);
+	uint8_t is_nmi = context->nmi_cycle != 0xFFFFFFFF && (context->nmi_cycle < context->int_cycle || !context->iff1);
+	save_int8(buf,  is_nmi);//int_is_nmi
+	save_int8(buf, context->busack);
+	save_int32(buf, context->cycles);
+	save_int32(buf, is_nmi ? context->nmi_cycle : context->int_cycle);//int_cycle
+	save_int32(buf, 0);//int_enable_cycle
+	save_int32(buf, context->int_cycle);
+	save_int32(buf, context->int_end_cycle);
+	save_int32(buf, context->nmi_cycle);
+}
+
+void z80_deserialize(deserialize_buffer *buf, void *vcontext)
+{
+	z80_context *context = vcontext;
+	context->main[1] = load_int8(buf);//C
+	context->main[0] = load_int8(buf);//B
+	context->main[3] = load_int8(buf);//E
+	context->main[2] = load_int8(buf);//D
+	context->main[5] = load_int8(buf);//L
+	context->main[4] = load_int8(buf);//H
+	context->ix = load_int8(buf);//IXL
+	context->ix |= load_int8(buf) << 8;//IXH
+	context->iy = load_int8(buf);//IYL
+	context->iy |= load_int8(buf) << 8;//IYH
+	context->i = load_int8(buf);
+	context->r = load_int8(buf);
+	context->rhigh = context->r & 0x80;
+	context->main[7] = load_int8(buf);//A
+	context->last_flag_result = load_int8(buf);
+	context->zflag = context->last_flag_result & 0x40;
+	context->chflags = context->last_flag_result & 0x10 ? 8 : 0;
+	context->pvflag = context->last_flag_result & 4;
+	context->nflag = context->last_flag_result & 2;
+	context->chflags |= context->last_flag_result & 1 ? 0x80 : 0;
+	context->alt[1] = load_int8(buf);//C
+	context->alt[0] = load_int8(buf);//B
+	context->alt[3] = load_int8(buf);//E
+	context->alt[2] = load_int8(buf);//D
+	context->alt[5] = load_int8(buf);//L
+	context->alt[4] = load_int8(buf);//H
+	load_int8(buf);//non-existant alt ixl
+	load_int8(buf);//non-existant alt ixh
+	load_int8(buf);//non-existant alt iyl
+	load_int8(buf);//non-existant alt iyh
+	load_int8(buf);//non-existant alt i
+	load_int8(buf);//non-existant alt r
+	context->alt[7] = load_int8(buf);//A
+	context->alt[6] = load_int8(buf);//F
+	
+	context->pc = load_int16(buf);
+	context->sp = load_int16(buf);
+	context->imode = load_int8(buf);
+	context->iff1 = load_int8(buf);
+	context->iff2 = load_int8(buf);
+	load_int8(buf);//int_is_nmi
+	context->busack = load_int8(buf);
+	context->cycles = load_int32(buf);
+	load_int32(buf);//int_cycle
+	load_int32(buf);//int_enable_cycle
+	context->int_cycle = load_int32(buf);
+	context->int_end_cycle = load_int32(buf);
+	context->nmi_cycle = load_int32(buf);
+}
+
+void zinsert_breakpoint(z80_context * context, uint16_t address, uint8_t * bp_handler)
+{
+}
+
+void zremove_breakpoint(z80_context * context, uint16_t address)
+{
+}