view z80_to_x86.c @ 235:d9bf8e61c33c

Get Z80 core working for simple programs
author Mike Pavone <pavone@retrodev.com>
date Thu, 25 Apr 2013 21:01:11 -0700
parents 4d4559b04c59
children 19fb3523a9e5
line wrap: on
line source

#include "z80inst.h"
#include "z80_to_x86.h"
#include "gen_x86.h"
#include "mem.h"
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>

#define MODE_UNUSED (MODE_IMMED-1)

#define ZCYCLES RBP
#define SCRATCH1 R13
#define SCRATCH2 R14
#define CONTEXT RSI

//TODO: Find out the actual value for this
#define MAX_NATIVE_SIZE 128

void z80_read_byte();
void z80_read_word();
void z80_write_byte();
void z80_write_word_highfirst();
void z80_write_word_lowfirst();
void z80_save_context();
void z80_native_addr();

uint8_t z80_size(z80inst * inst)
{
	uint8_t reg = (inst->reg & 0x1F);
	if (reg != Z80_UNUSED && reg != Z80_USE_IMMED) {
		return reg < Z80_BC ? SZ_B : SZ_W;
	}
	//TODO: Handle any necessary special cases
	return SZ_B;
}

uint8_t * zcycles(uint8_t * dst, uint32_t num_cycles)
{
	return add_ir(dst, num_cycles, ZCYCLES, SZ_D);
}

uint8_t * translate_z80_reg(z80inst * inst, x86_ea * ea, uint8_t * dst, x86_z80_options * opts)
{
	if (inst->reg == Z80_USE_IMMED) {
		ea->mode = MODE_IMMED;
		ea->disp = inst->immed;
	} else if ((inst->reg & 0x1F) == Z80_UNUSED) {
		ea->mode = MODE_UNUSED;
	} else {
		ea->mode = MODE_REG_DIRECT;
		if (inst->reg == Z80_IYH) {
			ea->base = opts->regs[Z80_IYL];
			dst = ror_ir(dst, 8, opts->regs[Z80_IY], SZ_W);
		} else {
			ea->base = opts->regs[inst->reg];
		}
	}
	return dst;
}

uint8_t * z80_save_reg(uint8_t * dst, z80inst * inst, x86_z80_options * opts)
{
	if (inst->reg == Z80_IYH) {
		dst = ror_ir(dst, 8, opts->regs[Z80_IY], SZ_W);
	}
	return dst;
}

uint8_t * translate_z80_ea(z80inst * inst, x86_ea * ea, uint8_t * dst, x86_z80_options * opts, uint8_t read, uint8_t modify)
{
	uint8_t size, reg, areg;
	ea->mode = MODE_REG_DIRECT;
	areg = read ? SCRATCH1 : SCRATCH2;
	switch(inst->addr_mode & 0x1F)
	{
	case Z80_REG:
		if (inst->ea_reg == Z80_IYH) {
			ea->base = opts->regs[Z80_IYL];
			dst = ror_ir(dst, 8, opts->regs[Z80_IY], SZ_W);
		} else {
			ea->base = opts->regs[inst->ea_reg];
		}
		break;
	case Z80_REG_INDIRECT:
		dst = mov_rr(dst, opts->regs[inst->ea_reg], areg, SZ_W);
		size = z80_size(inst);
		if (read) {
			if (modify) {
				dst = push_r(dst, SCRATCH1);
			}
			if (size == SZ_B) {
				dst = call(dst, (uint8_t *)z80_read_byte);
			} else {
				dst = call(dst, (uint8_t *)z80_read_word);
			}
			if (modify) {
				dst = pop_r(dst, SCRATCH2);
			}
		}
		ea->base = SCRATCH1;
		break;
	case Z80_IMMED:
		ea->mode = MODE_IMMED;
		ea->disp = inst->immed;
		break;
	case Z80_IMMED_INDIRECT:
		dst = mov_ir(dst, inst->immed, areg, SZ_W);
		size = z80_size(inst);
		if (read) {
			if (modify) {
				dst = push_r(dst, SCRATCH1);
			}
			if (size == SZ_B) {
				dst = call(dst, (uint8_t *)z80_read_byte);
			} else {
				dst = call(dst, (uint8_t *)z80_read_word);
			}
			if (modify) {
				dst = pop_r(dst, SCRATCH2);
			}
		}
		ea->base = SCRATCH1;
		break;
	case Z80_IX_DISPLACE:
	case Z80_IY_DISPLACE:
		reg = opts->regs[inst->addr_mode == Z80_IX_DISPLACE ? Z80_IX : Z80_IY];
		dst = mov_rr(dst, reg, areg, SZ_W);
		dst = add_ir(dst, inst->immed, areg, SZ_W);
		size = z80_size(inst);
		if (read) {
			if (modify) {
				dst = push_r(dst, SCRATCH1);
			}
			if (size == SZ_B) {
				dst = call(dst, (uint8_t *)z80_read_byte);
			} else {
				dst = call(dst, (uint8_t *)z80_read_word);
			}
			if (modify) {
				dst = pop_r(dst, SCRATCH2);
			}
		}
		break;
	case Z80_UNUSED:
		ea->mode = MODE_UNUSED;
		break;
	default:
		fprintf(stderr, "Unrecognized Z80 addressing mode %d\n", inst->addr_mode);
		exit(1);
	}
	return dst;
}

uint8_t * z80_save_ea(uint8_t * dst, z80inst * inst, x86_z80_options * opts)
{
	if (inst->addr_mode == Z80_REG && inst->ea_reg == Z80_IYH) {
		dst = ror_ir(dst, 8, opts->regs[Z80_IY], SZ_W);
	}
	return dst;
}

uint8_t * z80_save_result(uint8_t * dst, z80inst * inst)
{
	if (z80_size(inst) == SZ_B) {
		dst = call(dst, (uint8_t *)z80_write_byte);
	} else {
		dst = call(dst, (uint8_t *)z80_write_word_lowfirst);
	}
	return dst;
}

enum {
	DONT_READ=0,
	READ
};

enum {
	DONT_MODIFY=0,
	MODIFY
};

uint8_t zf_off(uint8_t flag)
{
	return offsetof(z80_context, flags) + flag;
}

void z80_print_regs_exit(z80_context * context)
{
	printf("A: %X\nB: %X\nC: %X\nD: %X\nE: %X\nHL: %X\nIX: %X\nIY: %X\nSP: %X\n", 
		context->regs[Z80_A], context->regs[Z80_B], context->regs[Z80_C],
		context->regs[Z80_D], context->regs[Z80_E], 
		(context->regs[Z80_H] << 8) | context->regs[Z80_L], 
		(context->regs[Z80_IXH] << 8) | context->regs[Z80_IXL], 
		(context->regs[Z80_IYH] << 8) | context->regs[Z80_IYL], 
		context->sp);
	exit(0);
}

uint8_t * translate_z80inst(z80inst * inst, uint8_t * dst, z80_context * context, uint16_t address)
{
	uint32_t cycles;
	x86_ea src_op, dst_op;
	uint8_t size;
	x86_z80_options *opts = context->options;
	switch(inst->op)
	{
	case Z80_LD:
		size = z80_size(inst);
		switch (inst->addr_mode & 0x1F)
		{
		case Z80_REG:
		case Z80_REG_INDIRECT:
 			cycles = size == SZ_B ? 4 : 6;
			if (inst->ea_reg == Z80_IX || inst->ea_reg == Z80_IY) {
				cycles += 4;
			}
			break;
		case Z80_IMMED:
			cycles = size == SZ_B ? 7 : 10;
			break;
		case Z80_IMMED_INDIRECT:
			cycles = 10;
			break;
		case Z80_IX_DISPLACE:
		case Z80_IY_DISPLACE:
			cycles = 12;
			break;
		}
		if ((inst->reg >= Z80_IXL && inst->reg <= Z80_IYH) || inst->reg == Z80_IX || inst->reg == Z80_IY) {
			cycles += 4;
		}
		dst = zcycles(dst, cycles);
		if (inst->addr_mode & Z80_DIR) {
			dst = translate_z80_reg(inst, &src_op, dst, opts);
			dst = translate_z80_ea(inst, &dst_op, dst, opts, DONT_READ, MODIFY);
		} else {
			dst = translate_z80_ea(inst, &src_op, dst, opts, READ, DONT_MODIFY);
			dst = translate_z80_reg(inst, &dst_op, dst, opts);
		}
		if (src_op.mode == MODE_REG_DIRECT) {
			dst = mov_rr(dst, src_op.base, dst_op.base, size);
		} else {
			dst = mov_ir(dst, src_op.disp, dst_op.base, size);
		}
		dst = z80_save_reg(dst, inst, opts);
		dst = z80_save_ea(dst, inst, opts);
		if (inst->addr_mode & Z80_DIR) {
			dst = z80_save_result(dst, inst);
		}
		break;
	case Z80_PUSH:
		dst = zcycles(dst, (inst->reg == Z80_IX || inst->reg == Z80_IY) ? 9 : 5);
		dst = sub_ir(dst, 2, opts->regs[Z80_SP], SZ_W);
		if (inst->reg == Z80_AF) {
			dst = mov_rdisp8r(dst, CONTEXT, zf_off(ZF_S), SCRATCH2, SZ_B);
			dst = shl_ir(dst, 1, SCRATCH2, SZ_B);
			dst = or_rdisp8r(dst, CONTEXT, zf_off(ZF_Z), SCRATCH2, SZ_B);
			dst = shl_ir(dst, 2, SCRATCH2, SZ_B);
			dst = or_rdisp8r(dst, CONTEXT, zf_off(ZF_H), SCRATCH2, SZ_B);
			dst = shl_ir(dst, 2, SCRATCH2, SZ_B);
			dst = or_rdisp8r(dst, CONTEXT, zf_off(ZF_PV), SCRATCH2, SZ_B);
			dst = shl_ir(dst, 1, SCRATCH2, SZ_B);
			dst = or_rdisp8r(dst, CONTEXT, zf_off(ZF_N), SCRATCH2, SZ_B);
			dst = shl_ir(dst, 1, SCRATCH2, SZ_B);
			dst = or_rdisp8r(dst, CONTEXT, zf_off(ZF_C), SCRATCH2, SZ_B);
			dst = shl_ir(dst, 8, SCRATCH2, SZ_W);
			dst = mov_rr(dst, opts->regs[Z80_A], SCRATCH2, SZ_B);
		} else {
			dst = translate_z80_reg(inst, &src_op, dst, opts);
			dst = mov_rr(dst, src_op.base, SCRATCH2, SZ_W);
		}
		dst = mov_rr(dst, opts->regs[Z80_SP], SCRATCH1, SZ_W);
		dst = call(dst, (uint8_t *)z80_write_word_highfirst);
		//no call to save_z80_reg needed since there's no chance we'll use the only
		//the upper half of a register pair
		break;
	case Z80_POP:
		dst = zcycles(dst, (inst->reg == Z80_IX || inst->reg == Z80_IY) ? 8 : 4);
		dst = mov_rr(dst, opts->regs[Z80_SP], SCRATCH1, SZ_W);
		dst = call(dst, (uint8_t *)z80_read_word);
		dst = add_ir(dst, 2, opts->regs[Z80_SP], SZ_W);
		if (inst->reg == Z80_AF) {
			dst = mov_rr(dst, SCRATCH1, opts->regs[Z80_A], SZ_B);
			dst = bt_ir(dst, 8, SCRATCH1, SZ_W);
			dst = setcc_rdisp8(dst, CC_C, CONTEXT, zf_off(ZF_C));
			dst = bt_ir(dst, 9, SCRATCH1, SZ_W);
			dst = setcc_rdisp8(dst, CC_C, CONTEXT, zf_off(ZF_N));
			dst = bt_ir(dst, 10, SCRATCH1, SZ_W);
			dst = setcc_rdisp8(dst, CC_C, CONTEXT, zf_off(ZF_PV));
			dst = bt_ir(dst, 12, SCRATCH1, SZ_W);
			dst = setcc_rdisp8(dst, CC_C, CONTEXT, zf_off(ZF_H));
			dst = bt_ir(dst, 14, SCRATCH1, SZ_W);
			dst = setcc_rdisp8(dst, CC_C, CONTEXT, zf_off(ZF_Z));
			dst = bt_ir(dst, 15, SCRATCH1, SZ_W);
			dst = setcc_rdisp8(dst, CC_C, CONTEXT, zf_off(ZF_S));
		} else {
			dst = translate_z80_reg(inst, &src_op, dst, opts);
			dst = mov_rr(dst, SCRATCH1, src_op.base, SZ_W);
		}
		//no call to save_z80_reg needed since there's no chance we'll use the only
		//the upper half of a register pair
		break;
	/*case Z80_EX:
	case Z80_EXX:
	case Z80_LDI:
	case Z80_LDIR:
	case Z80_LDD:
	case Z80_LDDR:
	case Z80_CPI:
	case Z80_CPIR:
	case Z80_CPD:
	case Z80_CPDR:
		break;*/
	case Z80_ADD:
		cycles = 4;
		if (inst->addr_mode == Z80_IX_DISPLACE || inst->addr_mode == Z80_IY_DISPLACE) {
			cycles += 12;
		} else if(inst->addr_mode == Z80_IMMED) {
			cycles += 3;
		} else if(z80_size(inst) == SZ_W) {
			cycles += 4;
		}
		dst = zcycles(dst, cycles);
		dst = translate_z80_reg(inst, &dst_op, dst, opts);
		dst = translate_z80_ea(inst, &src_op, dst, opts, READ, DONT_MODIFY);
		if (src_op.mode == MODE_REG_DIRECT) {
			dst = add_rr(dst, src_op.base, dst_op.base, z80_size(inst));
		} else {
			dst = add_ir(dst, src_op.disp, dst_op.base, z80_size(inst));
		}
		dst = setcc_rdisp8(dst, CC_C, CONTEXT, zf_off(ZF_C));
		dst = mov_irdisp8(dst, 0, CONTEXT, zf_off(ZF_N), SZ_B);
		//TODO: Implement half-carry flag
		if (z80_size(inst) == SZ_B) {
			dst = setcc_rdisp8(dst, CC_O, CONTEXT, zf_off(ZF_PV));
			dst = setcc_rdisp8(dst, CC_Z, CONTEXT, zf_off(ZF_Z));
			dst = setcc_rdisp8(dst, CC_S, CONTEXT, zf_off(ZF_S));
		}
		dst = z80_save_reg(dst, inst, opts);
		dst = z80_save_ea(dst, inst, opts);
		break;
	/*case Z80_ADC:
		break;*/
	case Z80_SUB:
		cycles = 4;
		if (inst->addr_mode == Z80_IX_DISPLACE || inst->addr_mode == Z80_IY_DISPLACE) {
			cycles += 12;
		} else if(inst->addr_mode == Z80_IMMED) {
			cycles += 3;
		}
		dst = zcycles(dst, cycles);
		dst = translate_z80_reg(inst, &dst_op, dst, opts);
		dst = translate_z80_ea(inst, &src_op, dst, opts, READ, DONT_MODIFY);
		if (src_op.mode == MODE_REG_DIRECT) {
			dst = sub_rr(dst, src_op.base, dst_op.base, z80_size(inst));
		} else {
			dst = sub_ir(dst, src_op.disp, dst_op.base, z80_size(inst));
		}
		dst = setcc_rdisp8(dst, CC_C, CONTEXT, zf_off(ZF_C));
		dst = mov_irdisp8(dst, 1, CONTEXT, zf_off(ZF_N), SZ_B);
		dst = setcc_rdisp8(dst, CC_O, CONTEXT, zf_off(ZF_PV));
		//TODO: Implement half-carry flag
		dst = setcc_rdisp8(dst, CC_Z, CONTEXT, zf_off(ZF_Z));
		dst = setcc_rdisp8(dst, CC_S, CONTEXT, zf_off(ZF_S));
		dst = z80_save_reg(dst, inst, opts);
		dst = z80_save_ea(dst, inst, opts);
		break;
	/*case Z80_SBC:
	case Z80_AND:
	case Z80_OR:
	case Z80_XOR:
	case Z80_CP:*/
	case Z80_INC:
		cycles = 4;
		if (inst->reg == Z80_IX || inst->reg == Z80_IY) {
			cycles += 6;
		} else if(z80_size(inst) == SZ_W) {
			cycles += 2;
		} else if(inst->reg == Z80_IXH || inst->reg == Z80_IXL || inst->reg == Z80_IYH || inst->reg == Z80_IYL || inst->addr_mode == Z80_IX_DISPLACE || inst->addr_mode == Z80_IY_DISPLACE) {
			cycles += 4;
		}
		dst = translate_z80_reg(inst, &dst_op, dst, opts);
		if (dst_op.mode == MODE_UNUSED) {
			dst = translate_z80_ea(inst, &dst_op, dst, opts, READ, MODIFY);
		}
		dst = add_ir(dst, 1, dst_op.base, z80_size(inst));
		if (z80_size(inst) == SZ_B) {
			dst = mov_irdisp8(dst, 0, CONTEXT, zf_off(ZF_N), SZ_B);
			//TODO: Implement half-carry flag
			dst = setcc_rdisp8(dst, CC_O, CONTEXT, zf_off(ZF_PV));
			dst = setcc_rdisp8(dst, CC_Z, CONTEXT, zf_off(ZF_Z));
			dst = setcc_rdisp8(dst, CC_S, CONTEXT, zf_off(ZF_S));
		}
		dst = z80_save_reg(dst, inst, opts);
		dst = z80_save_ea(dst, inst, opts);
		break;
	/*case Z80_DEC:
		break;
	case Z80_DAA:
	case Z80_CPL:
	case Z80_NEG:
	case Z80_CCF:
	case Z80_SCF:*/
	case Z80_NOP:
		if (inst->immed == 42) {
			dst = call(dst, (uint8_t *)z80_save_context);
			dst = mov_rr(dst, CONTEXT, RDI, SZ_Q);
			dst = jmp(dst, (uint8_t *)z80_print_regs_exit);
		} else {
			dst = zcycles(dst, 4 * inst->immed);
		}
		break;
	/*case Z80_HALT:
	case Z80_DI:
	case Z80_EI:
	case Z80_IM:
	case Z80_RLC:
	case Z80_RL:
	case Z80_RRC:
	case Z80_RR:
	case Z80_SLA:
	case Z80_SRA:
	case Z80_SLL:
	case Z80_SRL:
	case Z80_RLD:
	case Z80_RRD:
	case Z80_BIT:
	case Z80_SET:
	case Z80_RES:
	case Z80_JP:
	case Z80_JPCC:
	case Z80_JR:*/
	case Z80_JRCC: {
		dst = zcycles(dst, 7);//T States: 4,3
		uint8_t cond = CC_Z;
		switch (inst->reg)
		{
		case Z80_CC_NZ:
			cond = CC_NZ;
		case Z80_CC_Z:
			dst = cmp_irdisp8(dst, 0, CONTEXT, zf_off(ZF_Z), SZ_B);
			break;
		case Z80_CC_NC:
			cond = CC_NZ;
		case Z80_CC_C:
			dst = cmp_irdisp8(dst, 0, CONTEXT, zf_off(ZF_C), SZ_B);
			break;
		}
		uint8_t *no_jump_off = dst+1;
		dst = jcc(dst, cond, dst+2);
		dst = zcycles(dst, 5);//T States: 5
		uint16_t dest_addr = address + inst->immed + 2;
		if (dest_addr < 0x4000) {
			uint8_t * call_dst = z80_get_native_address(context, dest_addr);
			if (!call_dst) {
				opts->deferred = defer_address(opts->deferred, dest_addr, dst + 1);
				//fake address to force large displacement
				call_dst = dst + 256;
			}
			dst = jmp(dst, call_dst);
		} else {
			dst = mov_ir(dst, dest_addr, SCRATCH1, SZ_W);
			dst = call(dst, (uint8_t *)z80_native_addr);
			dst = jmp_r(dst, SCRATCH1);
		}
		*no_jump_off = dst - (no_jump_off+1);
		break;
	}
	//case Z80_DJNZ:*/
	case Z80_CALL: {
		dst = zcycles(dst, 11);//T States: 4,3,4
		dst = sub_ir(dst, 2, opts->regs[Z80_SP], SZ_W);
		dst = mov_ir(dst, address + 3, SCRATCH2, SZ_W);
		dst = mov_rr(dst, opts->regs[Z80_SP], SCRATCH1, SZ_W);
		dst = call(dst, (uint8_t *)z80_write_word_highfirst);//T States: 3, 3
		if (inst->immed < 0x4000) {
			uint8_t * call_dst = z80_get_native_address(context, inst->immed);
			if (!call_dst) {
				opts->deferred = defer_address(opts->deferred, inst->immed, dst + 1);
				//fake address to force large displacement
				call_dst = dst + 256;
			}
			dst = jmp(dst, call_dst);
		} else {
			dst = mov_ir(dst, inst->immed, SCRATCH1, SZ_W);
			dst = call(dst, (uint8_t *)z80_native_addr);
			dst = jmp_r(dst, SCRATCH1);
		}
		break;
	}
	//case Z80_CALLCC:
	case Z80_RET:
		dst = zcycles(dst, 4);//T States: 4
		dst = mov_rr(dst, opts->regs[Z80_SP], SCRATCH1, SZ_W);
		dst = call(dst, (uint8_t *)z80_read_word);//T STates: 3, 3
		dst = add_ir(dst, 2, opts->regs[Z80_SP], SZ_W);
		dst = call(dst, (uint8_t *)z80_native_addr);
		dst = jmp_r(dst, SCRATCH1);
		break;
	/*case Z80_RETCC:
	case Z80_RETI:
	case Z80_RETN:
	case Z80_RST:
	case Z80_IN:
	case Z80_INI:
	case Z80_INIR:
	case Z80_IND:
	case Z80_INDR:
	case Z80_OUT:
	case Z80_OUTI:
	case Z80_OTIR:
	case Z80_OUTD:
	case Z80_OTDR:*/
	default: {
		char disbuf[80];
		z80_disasm(inst, disbuf);
		fprintf(stderr, "unimplemented instruction: %s\n", disbuf);
		exit(1);
	}
	}
	return dst;
}

uint8_t * z80_get_native_address(z80_context * context, uint32_t address)
{
	native_map_slot *map;
	if (address < 0x4000) {
		address &= 0x1FFF;
		map = context->static_code_map;
	} else if (address >= 0x8000) {
		address &= 0x7FFF;
		map = context->banked_code_map + context->bank_reg;
	} else {
		return NULL;
	}
	if (!map->base || !map->offsets || map->offsets[address] == INVALID_OFFSET) {
		return NULL;
	}
	return map->base + map->offsets[address];
}

//TODO: Record z80 instruction size and code size for addresses to support modification of translated code
void z80_map_native_address(z80_context * context, uint32_t address, uint8_t * native_address)
{
	native_map_slot *map;
	if (address < 0x4000) {
		address &= 0x1FFF;
		map = context->static_code_map;
	} else if (address >= 0x8000) {
		address &= 0x7FFF;
		map = context->banked_code_map + context->bank_reg;
		if (!map->offsets) {
			map->offsets = malloc(sizeof(int32_t) * 0x8000);
			memset(map->offsets, 0xFF, sizeof(int32_t) * 0x8000);
		}
	} else {
		return;
	}
	if (!map->base) {
		map->base = native_address;
	}
	map->offsets[address] = native_address - map->base;
}

uint8_t * z80_get_native_address_trans(z80_context * context, uint32_t address)
{
	uint8_t * addr = z80_get_native_address(context, address);
	if (!addr) {
		translate_z80_stream(context, address);
		addr = z80_get_native_address(context, address);
	}
	return addr;
}

void translate_z80_stream(z80_context * context, uint32_t address)
{
	char disbuf[80];
	if (z80_get_native_address(context, address)) {
		return;
	}
	x86_z80_options * opts = context->options;
	uint8_t * encoded = NULL, *next;
	if (address < 0x4000) {
		encoded = context->mem_pointers[0] + (address & 0x1FFF);
	} else if(address >= 0x8000 && context->mem_pointers[1]) {
		encoded = context->mem_pointers[1] + (address & 0x7FFF);
	}
	while (encoded != NULL)
	{
		z80inst inst;
		printf("translating Z80 code at address %X\n", address);
		do {
			if (opts->code_end-opts->cur_code < MAX_NATIVE_SIZE) {
				if (opts->code_end-opts->cur_code < 5) {
					puts("out of code memory, not enough space for jmp to next chunk");
					exit(1);
				}
				size_t size = 1024*1024;
				opts->cur_code = alloc_code(&size);
				opts->code_end = opts->cur_code + size;
				jmp(opts->cur_code, opts->cur_code);
			}
			if (address > 0x4000 & address < 0x8000) {
				opts->cur_code = xor_rr(opts->cur_code, RDI, RDI, SZ_D);
				opts->cur_code = call(opts->cur_code, (uint8_t *)exit);
				break;
			}
			uint8_t * existing = z80_get_native_address(context, address);
			if (existing) {
				opts->cur_code = jmp(opts->cur_code, existing);
				break;
			}
			next = z80_decode(encoded, &inst);
			z80_disasm(&inst, disbuf);
			if (inst.op == Z80_NOP) {
				printf("%X\t%s(%d)\n", address, disbuf, inst.immed);
			} else {
				printf("%X\t%s\n", address, disbuf);
			}
			z80_map_native_address(context, address, opts->cur_code);
			opts->cur_code = translate_z80inst(&inst, opts->cur_code, context, address);
			address += next-encoded;
			encoded = next;
		} while (!(inst.op == Z80_RET || inst.op == Z80_RETI || inst.op == Z80_RETN || (inst.op = Z80_NOP && inst.immed == 42)));
		process_deferred(&opts->deferred, context, (native_addr_func)z80_get_native_address);
		if (opts->deferred) {
			address = opts->deferred->address;
			printf("defferred address: %X\n", address);
			if (address < 0x4000) {
				encoded = context->mem_pointers[0] + (address & 0x1FFF);
			} else if (address > 0x8000 && context->mem_pointers[1]) {
				encoded = context->mem_pointers[1] + (address  & 0x7FFF);
			} else {
				printf("attempt to translate non-memory address: %X\n", address);
				exit(1);
			}
		} else {
			encoded = NULL;
		}
	}
}

void init_x86_z80_opts(x86_z80_options * options)
{
	options->flags = 0;
	options->regs[Z80_B] = BH;
	options->regs[Z80_C] = RBX;
	options->regs[Z80_D] = CH;
	options->regs[Z80_E] = RCX;
	options->regs[Z80_H] = AH;
	options->regs[Z80_L] = RAX;
	options->regs[Z80_IXH] = DH;
	options->regs[Z80_IXL] = RDX;
	options->regs[Z80_IYH] = -1;
	options->regs[Z80_IYL] = -1;
	options->regs[Z80_I] = -1;
	options->regs[Z80_R] = -1;
	options->regs[Z80_A] = R10;
	options->regs[Z80_BC] = RBX;
	options->regs[Z80_DE] = RCX;
	options->regs[Z80_HL] = RAX;
	options->regs[Z80_SP] = R9;
	options->regs[Z80_AF] = -1;
	options->regs[Z80_IX] = RDX;
	options->regs[Z80_IY] = R8;
	size_t size = 1024 * 1024;
	options->cur_code = alloc_code(&size);
	options->code_end = options->cur_code + size;
	options->deferred = NULL;
}

void init_z80_context(z80_context * context, x86_z80_options * options)
{
	memset(context, 0, sizeof(*context));
	context->static_code_map = malloc(sizeof(context->static_code_map));
	context->static_code_map->offsets = malloc(sizeof(int32_t) * 0x2000);
	memset(context->static_code_map->offsets, 0xFF, sizeof(int32_t) * 0x2000);
	context->banked_code_map = malloc(sizeof(native_map_slot) * (1 << 9));
	context->options = options;
}

void z80_reset(z80_context * context)
{
	context->native_pc = z80_get_native_address_trans(context, 0);
}