Mercurial > repos > blastem
view genesis.c @ 1893:7b62e6805e6a
Only look at low 24-bits of reset vector in ROM type detection heuristic
author | Michael Pavone <pavone@retrodev.com> |
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date | Thu, 05 Dec 2019 09:33:30 -0800 |
parents | 377f110e4cea |
children | 5433252329fb |
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/* Copyright 2013-2016 Michael Pavone This file is part of BlastEm. BlastEm is free software distributed under the terms of the GNU General Public License version 3 or greater. See COPYING for full license text. */ #include "genesis.h" #include "blastem.h" #include "nor.h" #include <stdlib.h> #include <ctype.h> #include <time.h> #include <string.h> #include "render.h" #include "gst.h" #include "util.h" #include "debug.h" #include "gdb_remote.h" #include "saves.h" #include "bindings.h" #include "jcart.h" #define MCLKS_NTSC 53693175 #define MCLKS_PAL 53203395 uint32_t MCLKS_PER_68K; #define MCLKS_PER_YM 7 #define MCLKS_PER_Z80 15 #define MCLKS_PER_PSG (MCLKS_PER_Z80*16) #define Z80_INT_PULSE_MCLKS 2573 //measured value is ~171.5 Z80 clocks #define DEFAULT_SYNC_INTERVAL MCLKS_LINE #define DEFAULT_LOWPASS_CUTOFF 3390 //TODO: Figure out the exact value for this #define LINES_NTSC 262 #define LINES_PAL 313 #ifdef IS_LIB #define MAX_SOUND_CYCLES (MCLKS_PER_YM*NUM_OPERATORS*6) #else #define MAX_SOUND_CYCLES 100000 #endif #ifdef NEW_CORE #define Z80_CYCLE cycles #define Z80_OPTS opts #define z80_handle_code_write(...) #else #define Z80_CYCLE current_cycle #define Z80_OPTS options #endif void genesis_serialize(genesis_context *gen, serialize_buffer *buf, uint32_t m68k_pc) { start_section(buf, SECTION_68000); m68k_serialize(gen->m68k, m68k_pc, buf); end_section(buf); start_section(buf, SECTION_Z80); z80_serialize(gen->z80, buf); end_section(buf); start_section(buf, SECTION_VDP); vdp_serialize(gen->vdp, buf); end_section(buf); start_section(buf, SECTION_YM2612); ym_serialize(gen->ym, buf); end_section(buf); start_section(buf, SECTION_PSG); psg_serialize(gen->psg, buf); end_section(buf); start_section(buf, SECTION_GEN_BUS_ARBITER); save_int8(buf, gen->z80->reset); save_int8(buf, gen->z80->busreq); save_int16(buf, gen->z80_bank_reg); end_section(buf); start_section(buf, SECTION_SEGA_IO_1); io_serialize(gen->io.ports, buf); end_section(buf); start_section(buf, SECTION_SEGA_IO_2); io_serialize(gen->io.ports + 1, buf); end_section(buf); start_section(buf, SECTION_SEGA_IO_EXT); io_serialize(gen->io.ports + 2, buf); end_section(buf); start_section(buf, SECTION_MAIN_RAM); save_int8(buf, RAM_WORDS * 2 / 1024); save_buffer16(buf, gen->work_ram, RAM_WORDS); end_section(buf); start_section(buf, SECTION_SOUND_RAM); save_int8(buf, Z80_RAM_BYTES / 1024); save_buffer8(buf, gen->zram, Z80_RAM_BYTES); end_section(buf); cart_serialize(&gen->header, buf); } static uint8_t *serialize(system_header *sys, size_t *size_out) { genesis_context *gen = (genesis_context *)sys; uint32_t address; if (gen->m68k->resume_pc) { gen->m68k->target_cycle = gen->m68k->current_cycle; gen->header.save_state = SERIALIZE_SLOT+1; resume_68k(gen->m68k); if (size_out) { *size_out = gen->serialize_size; } return gen->serialize_tmp; } else { serialize_buffer state; init_serialize(&state); uint32_t address = read_word(4, (void **)gen->m68k->mem_pointers, &gen->m68k->options->gen, gen->m68k) << 16; address |= read_word(6, (void **)gen->m68k->mem_pointers, &gen->m68k->options->gen, gen->m68k); genesis_serialize(gen, &state, address); if (size_out) { *size_out = state.size; } return state.data; } } static void ram_deserialize(deserialize_buffer *buf, void *vgen) { genesis_context *gen = vgen; uint32_t ram_size = load_int8(buf) * 1024 / 2; if (ram_size > RAM_WORDS) { fatal_error("State has a RAM size of %d bytes", ram_size * 2); } load_buffer16(buf, gen->work_ram, ram_size); m68k_invalidate_code_range(gen->m68k, 0xE00000, 0x1000000); } static void zram_deserialize(deserialize_buffer *buf, void *vgen) { genesis_context *gen = vgen; uint32_t ram_size = load_int8(buf) * 1024; if (ram_size > Z80_RAM_BYTES) { fatal_error("State has a Z80 RAM size of %d bytes", ram_size); } load_buffer8(buf, gen->zram, ram_size); z80_invalidate_code_range(gen->z80, 0, 0x4000); } static void update_z80_bank_pointer(genesis_context *gen) { if (gen->z80_bank_reg < 0x140) { gen->z80->mem_pointers[1] = get_native_pointer(gen->z80_bank_reg << 15, (void **)gen->m68k->mem_pointers, &gen->m68k->options->gen); } else { gen->z80->mem_pointers[1] = NULL; } z80_invalidate_code_range(gen->z80, 0x8000, 0xFFFF); } static void bus_arbiter_deserialize(deserialize_buffer *buf, void *vgen) { genesis_context *gen = vgen; gen->z80->reset = load_int8(buf); gen->z80->busreq = load_int8(buf); gen->z80_bank_reg = load_int16(buf) & 0x1FF; } static void adjust_int_cycle(m68k_context * context, vdp_context * v_context); void genesis_deserialize(deserialize_buffer *buf, genesis_context *gen) { register_section_handler(buf, (section_handler){.fun = m68k_deserialize, .data = gen->m68k}, SECTION_68000); register_section_handler(buf, (section_handler){.fun = z80_deserialize, .data = gen->z80}, SECTION_Z80); register_section_handler(buf, (section_handler){.fun = vdp_deserialize, .data = gen->vdp}, SECTION_VDP); register_section_handler(buf, (section_handler){.fun = ym_deserialize, .data = gen->ym}, SECTION_YM2612); register_section_handler(buf, (section_handler){.fun = psg_deserialize, .data = gen->psg}, SECTION_PSG); register_section_handler(buf, (section_handler){.fun = bus_arbiter_deserialize, .data = gen}, SECTION_GEN_BUS_ARBITER); register_section_handler(buf, (section_handler){.fun = io_deserialize, .data = gen->io.ports}, SECTION_SEGA_IO_1); register_section_handler(buf, (section_handler){.fun = io_deserialize, .data = gen->io.ports + 1}, SECTION_SEGA_IO_2); register_section_handler(buf, (section_handler){.fun = io_deserialize, .data = gen->io.ports + 2}, SECTION_SEGA_IO_EXT); register_section_handler(buf, (section_handler){.fun = ram_deserialize, .data = gen}, SECTION_MAIN_RAM); register_section_handler(buf, (section_handler){.fun = zram_deserialize, .data = gen}, SECTION_SOUND_RAM); register_section_handler(buf, (section_handler){.fun = cart_deserialize, .data = gen}, SECTION_MAPPER); while (buf->cur_pos < buf->size) { load_section(buf); } update_z80_bank_pointer(gen); adjust_int_cycle(gen->m68k, gen->vdp); free(buf->handlers); buf->handlers = NULL; } #include "m68k_internal.h" //needed for get_native_address_trans, should be eliminated once handling of PC is cleaned up static void deserialize(system_header *sys, uint8_t *data, size_t size) { genesis_context *gen = (genesis_context *)sys; deserialize_buffer buffer; init_deserialize(&buffer, data, size); genesis_deserialize(&buffer, gen); //HACK: Fix this once PC/IR is represented in a better way in 68K core gen->m68k->resume_pc = get_native_address_trans(gen->m68k, gen->m68k->last_prefetch_address); } uint16_t read_dma_value(uint32_t address) { genesis_context *genesis = (genesis_context *)current_system; //TODO: Figure out what happens when you try to DMA from weird adresses like IO or banked Z80 area if ((address >= 0xA00000 && address < 0xB00000) || (address >= 0xC00000 && address <= 0xE00000)) { return 0; } //addresses here are word addresses (i.e. bit 0 corresponds to A1), so no need to do multiply by 2 return read_word(address * 2, (void **)genesis->m68k->mem_pointers, &genesis->m68k->options->gen, genesis->m68k); } static uint16_t get_open_bus_value(system_header *system) { genesis_context *genesis = (genesis_context *)system; return read_dma_value(genesis->m68k->last_prefetch_address/2); } static void adjust_int_cycle(m68k_context * context, vdp_context * v_context) { //static int old_int_cycle = CYCLE_NEVER; genesis_context *gen = context->system; if (context->sync_cycle - context->current_cycle > gen->max_cycles) { context->sync_cycle = context->current_cycle + gen->max_cycles; } context->int_cycle = CYCLE_NEVER; if ((context->status & 0x7) < 6) { uint32_t next_vint = vdp_next_vint(v_context); if (next_vint != CYCLE_NEVER) { context->int_cycle = next_vint; context->int_num = 6; } if ((context->status & 0x7) < 4) { uint32_t next_hint = vdp_next_hint(v_context); if (next_hint != CYCLE_NEVER) { next_hint = next_hint < context->current_cycle ? context->current_cycle : next_hint; if (next_hint < context->int_cycle) { context->int_cycle = next_hint; context->int_num = 4; } } } } if (context->int_cycle > context->current_cycle && context->int_pending == INT_PENDING_SR_CHANGE) { 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); old_int_cycle = context->int_cycle; }*/ if (context->status & M68K_STATUS_TRACE || context->trace_pending) { context->target_cycle = context->current_cycle; return; } context->target_cycle = context->int_cycle < context->sync_cycle ? context->int_cycle : context->sync_cycle; if (context->should_return) { context->target_cycle = context->current_cycle; } else if (context->target_cycle < context->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 context->target_cycle = context->current_cycle; } if (context->target_cycle == context->int_cycle) { //Currently delays from Z80 access and refresh are applied only when we sync //this can cause extra latency when it comes to interrupts //to prevent this code forces some extra synchronization in the period immediately before an interrupt if ((context->target_cycle - context->current_cycle) > gen->int_latency_prev1) { context->target_cycle = context->sync_cycle = context->int_cycle - gen->int_latency_prev1; } else if ((context->target_cycle - context->current_cycle) > gen->int_latency_prev2) { context->target_cycle = context->sync_cycle = context->int_cycle - gen->int_latency_prev2; } else { context->target_cycle = context->sync_cycle = context->current_cycle; } } /*printf("Cyc: %d, Trgt: %d, Int Cyc: %d, Int: %d, Mask: %X, V: %d, H: %d, HICount: %d, HReg: %d, Line: %d\n", context->current_cycle, context->target_cycle, context->int_cycle, context->int_num, (context->status & 0x7), v_context->regs[REG_MODE_2] & 0x20, v_context->regs[REG_MODE_1] & 0x10, v_context->hint_counter, v_context->regs[REG_HINT], v_context->cycles / MCLKS_LINE);*/ } //#define DO_DEBUG_PRINT #ifdef DO_DEBUG_PRINT #define dprintf printf #define dputs puts #else #define dprintf #define dputs #endif static void z80_next_int_pulse(z80_context * z_context) { genesis_context * gen = z_context->system; #ifdef NEW_CORE z_context->int_cycle = vdp_next_vint_z80(gen->vdp); z_context->int_end_cycle = z_context->int_cycle + Z80_INT_PULSE_MCLKS; z_context->int_value = 0xFF; z80_sync_cycle(z_context, z_context->sync_cycle); #else z_context->int_pulse_start = vdp_next_vint_z80(gen->vdp); z_context->int_pulse_end = z_context->int_pulse_start + Z80_INT_PULSE_MCLKS; z_context->im2_vector = 0xFF; #endif } static void sync_z80(z80_context * z_context, uint32_t mclks) { #ifndef NO_Z80 if (z80_enabled) { #ifdef NEW_CORE if (z_context->int_cycle == 0xFFFFFFFFU) { z80_next_int_pulse(z_context); } #endif z80_run(z_context, mclks); } else #endif { z_context->Z80_CYCLE = mclks; } } static void sync_sound(genesis_context * gen, uint32_t target) { //printf("YM | Cycle: %d, bpos: %d, PSG | Cycle: %d, bpos: %d\n", gen->ym->current_cycle, gen->ym->buffer_pos, gen->psg->cycles, gen->psg->buffer_pos * 2); while (target > gen->psg->cycles && target - gen->psg->cycles > MAX_SOUND_CYCLES) { uint32_t cur_target = gen->psg->cycles + MAX_SOUND_CYCLES; //printf("Running PSG to cycle %d\n", cur_target); psg_run(gen->psg, cur_target); //printf("Running YM-2612 to cycle %d\n", cur_target); ym_run(gen->ym, cur_target); } psg_run(gen->psg, target); ym_run(gen->ym, target); //printf("Target: %d, YM bufferpos: %d, PSG bufferpos: %d\n", target, gen->ym->buffer_pos, gen->psg->buffer_pos * 2); } //TODO: move this inside the system context static uint32_t last_frame_num; //My refresh emulation isn't currently good enough and causes more problems than it solves #define REFRESH_EMULATION #ifdef REFRESH_EMULATION #define REFRESH_INTERVAL 128 #define REFRESH_DELAY 2 uint32_t last_sync_cycle; uint32_t refresh_counter; #endif #include <limits.h> #define ADJUST_BUFFER (8*MCLKS_LINE*313) #define MAX_NO_ADJUST (UINT_MAX-ADJUST_BUFFER) m68k_context * sync_components(m68k_context * context, uint32_t address) { genesis_context * gen = context->system; vdp_context * v_context = gen->vdp; z80_context * z_context = gen->z80; #ifdef REFRESH_EMULATION //lame estimation of refresh cycle delay refresh_counter += context->current_cycle - last_sync_cycle; if (!gen->bus_busy) { context->current_cycle += REFRESH_DELAY * MCLKS_PER_68K * (refresh_counter / (MCLKS_PER_68K * REFRESH_INTERVAL)); } refresh_counter = refresh_counter % (MCLKS_PER_68K * REFRESH_INTERVAL); #endif uint32_t mclks = context->current_cycle; sync_z80(z_context, mclks); sync_sound(gen, mclks); vdp_run_context(v_context, mclks); if (mclks >= gen->reset_cycle) { gen->reset_requested = 1; context->should_return = 1; gen->reset_cycle = CYCLE_NEVER; } if (v_context->frame != last_frame_num) { //printf("reached frame end %d | MCLK Cycles: %d, Target: %d, VDP cycles: %d, vcounter: %d, hslot: %d\n", last_frame_num, mclks, gen->frame_end, v_context->cycles, v_context->vcounter, v_context->hslot); last_frame_num = v_context->frame; if(exit_after){ --exit_after; if (!exit_after) { exit(0); } } if (context->current_cycle > MAX_NO_ADJUST) { uint32_t deduction = mclks - ADJUST_BUFFER; vdp_adjust_cycles(v_context, deduction); io_adjust_cycles(gen->io.ports, context->current_cycle, deduction); io_adjust_cycles(gen->io.ports+1, context->current_cycle, deduction); io_adjust_cycles(gen->io.ports+2, context->current_cycle, deduction); if (gen->mapper_type == MAPPER_JCART) { jcart_adjust_cycles(gen, deduction); } context->current_cycle -= deduction; z80_adjust_cycles(z_context, deduction); gen->ym->current_cycle -= deduction; gen->psg->cycles -= deduction; if (gen->ym->write_cycle != CYCLE_NEVER) { gen->ym->write_cycle = gen->ym->write_cycle >= deduction ? gen->ym->write_cycle - deduction : 0; } if (gen->reset_cycle != CYCLE_NEVER) { gen->reset_cycle -= deduction; } } } gen->frame_end = vdp_cycles_to_frame_end(v_context); context->sync_cycle = gen->frame_end; //printf("Set sync cycle to: %d @ %d, vcounter: %d, hslot: %d\n", context->sync_cycle, context->current_cycle, v_context->vcounter, v_context->hslot); if (context->int_ack) { //printf("acknowledging %d @ %d:%d, vcounter: %d, hslot: %d\n", context->int_ack, context->current_cycle, v_context->cycles, v_context->vcounter, v_context->hslot); vdp_int_ack(v_context); context->int_ack = 0; } if (!address && (gen->header.enter_debugger || gen->header.save_state)) { context->sync_cycle = context->current_cycle + 1; } adjust_int_cycle(context, v_context); if (gen->reset_cycle < context->target_cycle) { context->target_cycle = gen->reset_cycle; } if (address) { if (gen->header.enter_debugger) { gen->header.enter_debugger = 0; debugger(context, address); } #ifdef NEW_CORE if (gen->header.save_state) { #else if (gen->header.save_state && (z_context->pc || !z_context->native_pc || z_context->reset || !z_context->busreq)) { #endif uint8_t slot = gen->header.save_state - 1; gen->header.save_state = 0; #ifndef NEW_CORE if (z_context->native_pc && !z_context->reset) { //advance Z80 core to the start of an instruction while (!z_context->pc) { sync_z80(z_context, z_context->current_cycle + MCLKS_PER_Z80); } } #endif char *save_path = slot == SERIALIZE_SLOT ? NULL : get_slot_name(&gen->header, slot, use_native_states ? "state" : "gst"); if (use_native_states || slot == SERIALIZE_SLOT) { serialize_buffer state; init_serialize(&state); genesis_serialize(gen, &state, address); if (slot == SERIALIZE_SLOT) { gen->serialize_tmp = state.data; gen->serialize_size = state.size; context->sync_cycle = context->current_cycle; context->should_return = 1; } else { save_to_file(&state, save_path); free(state.data); } } else { save_gst(gen, save_path, address); } if (slot != SERIALIZE_SLOT) { debug_message("Saved state to %s\n", save_path); } free(save_path); } else if(gen->header.save_state) { context->sync_cycle = context->current_cycle + 1; } } #ifdef REFRESH_EMULATION last_sync_cycle = context->current_cycle; #endif return context; } static m68k_context * vdp_port_write(uint32_t vdp_port, m68k_context * context, uint16_t value) { if (vdp_port & 0x2700E0) { fatal_error("machine freeze due to write to address %X\n", 0xC00000 | vdp_port); } vdp_port &= 0x1F; //printf("vdp_port write: %X, value: %X, cycle: %d\n", vdp_port, value, context->current_cycle); #ifdef REFRESH_EMULATION //do refresh check here so we can avoid adding a penalty for a refresh that happens during a VDP access refresh_counter += context->current_cycle - 4*MCLKS_PER_68K - last_sync_cycle; context->current_cycle += REFRESH_DELAY * MCLKS_PER_68K * (refresh_counter / (MCLKS_PER_68K * REFRESH_INTERVAL)); refresh_counter = refresh_counter % (MCLKS_PER_68K * REFRESH_INTERVAL); last_sync_cycle = context->current_cycle; #endif sync_components(context, 0); genesis_context * gen = context->system; vdp_context *v_context = gen->vdp; uint32_t before_cycle = v_context->cycles; if (vdp_port < 0x10) { int blocked; if (vdp_port < 4) { while (vdp_data_port_write(v_context, value) < 0) { while(v_context->flags & FLAG_DMA_RUN) { vdp_run_dma_done(v_context, gen->frame_end); if (v_context->cycles >= gen->frame_end) { uint32_t cycle_diff = v_context->cycles - context->current_cycle; uint32_t m68k_cycle_diff = (cycle_diff / MCLKS_PER_68K) * MCLKS_PER_68K; if (m68k_cycle_diff < cycle_diff) { m68k_cycle_diff += MCLKS_PER_68K; } context->current_cycle += m68k_cycle_diff; gen->bus_busy = 1; sync_components(context, 0); gen->bus_busy = 0; } } //context->current_cycle = v_context->cycles; } } else if(vdp_port < 8) { vdp_run_context_full(v_context, context->current_cycle); before_cycle = v_context->cycles; blocked = vdp_control_port_write(v_context, value); if (blocked) { while (blocked) { while(v_context->flags & FLAG_DMA_RUN) { vdp_run_dma_done(v_context, gen->frame_end); if (v_context->cycles >= gen->frame_end) { uint32_t cycle_diff = v_context->cycles - context->current_cycle; uint32_t m68k_cycle_diff = (cycle_diff / MCLKS_PER_68K) * MCLKS_PER_68K; if (m68k_cycle_diff < cycle_diff) { m68k_cycle_diff += MCLKS_PER_68K; } context->current_cycle += m68k_cycle_diff; gen->bus_busy = 1; sync_components(context, 0); gen->bus_busy = 0; } } if (blocked < 0) { blocked = vdp_control_port_write(v_context, value); } else { blocked = 0; } } } else { context->sync_cycle = gen->frame_end = vdp_cycles_to_frame_end(v_context); //printf("Set sync cycle to: %d @ %d, vcounter: %d, hslot: %d\n", context->sync_cycle, context->current_cycle, v_context->vcounter, v_context->hslot); adjust_int_cycle(context, v_context); } } else { fatal_error("Illegal write to HV Counter port %X\n", vdp_port); } if (v_context->cycles != before_cycle) { //printf("68K paused for %d (%d) cycles at cycle %d (%d) for write\n", v_context->cycles - context->current_cycle, v_context->cycles - before_cycle, context->current_cycle, before_cycle); uint32_t cycle_diff = v_context->cycles - context->current_cycle; uint32_t m68k_cycle_diff = (cycle_diff / MCLKS_PER_68K) * MCLKS_PER_68K; if (m68k_cycle_diff < cycle_diff) { m68k_cycle_diff += MCLKS_PER_68K; } context->current_cycle += m68k_cycle_diff; //Lock the Z80 out of the bus until the VDP access is complete gen->bus_busy = 1; sync_z80(gen->z80, v_context->cycles); gen->bus_busy = 0; } } else if (vdp_port < 0x18) { psg_write(gen->psg, value); } else { vdp_test_port_write(gen->vdp, value); } #ifdef REFRESH_EMULATION last_sync_cycle -= 4; //refresh may have happened while we were waiting on the VDP, //so advance refresh_counter but don't add any delays if (vdp_port >= 4 && vdp_port < 8 && v_context->cycles != before_cycle) { refresh_counter = 0; } else { refresh_counter += (context->current_cycle - last_sync_cycle); refresh_counter = refresh_counter % (MCLKS_PER_68K * REFRESH_INTERVAL); } last_sync_cycle = context->current_cycle; #endif return context; } static m68k_context * vdp_port_write_b(uint32_t vdp_port, m68k_context * context, uint8_t value) { return vdp_port_write(vdp_port, context, vdp_port < 0x10 ? value | value << 8 : ((vdp_port & 1) ? value : 0)); } static void * z80_vdp_port_write(uint32_t vdp_port, void * vcontext, uint8_t value) { z80_context * context = vcontext; genesis_context * gen = context->system; vdp_port &= 0xFF; if (vdp_port & 0xE0) { fatal_error("machine freeze due to write to Z80 address %X\n", 0x7F00 | vdp_port); } if (vdp_port < 0x10) { //These probably won't currently interact well with the 68K accessing the VDP if (vdp_port < 4) { vdp_run_context(gen->vdp, context->Z80_CYCLE); vdp_data_port_write(gen->vdp, value << 8 | value); } else if (vdp_port < 8) { vdp_run_context_full(gen->vdp, context->Z80_CYCLE); vdp_control_port_write(gen->vdp, value << 8 | value); } else { fatal_error("Illegal write to HV Counter port %X\n", vdp_port); } } else if (vdp_port < 0x18) { sync_sound(gen, context->Z80_CYCLE); psg_write(gen->psg, value); } else { vdp_test_port_write(gen->vdp, value); } return context; } static uint16_t vdp_port_read(uint32_t vdp_port, m68k_context * context) { if (vdp_port & 0x2700E0) { fatal_error("machine freeze due to read from address %X\n", 0xC00000 | vdp_port); } vdp_port &= 0x1F; uint16_t value; #ifdef REFRESH_EMULATION //do refresh check here so we can avoid adding a penalty for a refresh that happens during a VDP access refresh_counter += context->current_cycle - 4*MCLKS_PER_68K - last_sync_cycle; context->current_cycle += REFRESH_DELAY * MCLKS_PER_68K * (refresh_counter / (MCLKS_PER_68K * REFRESH_INTERVAL)); refresh_counter = refresh_counter % (MCLKS_PER_68K * REFRESH_INTERVAL); last_sync_cycle = context->current_cycle; #endif genesis_context *gen = context->system; vdp_context * v_context = gen->vdp; if (vdp_port < 0x10) { if (vdp_port < 4) { sync_components(context, 0); uint32_t before_cycle = v_context->cycles; value = vdp_data_port_read(v_context); if (v_context->cycles != before_cycle) { //printf("68K paused for %d (%d) cycles at cycle %d (%d) for read\n", v_context->cycles - context->current_cycle, v_context->cycles - before_cycle, context->current_cycle, before_cycle); context->current_cycle = v_context->cycles; //Lock the Z80 out of the bus until the VDP access is complete genesis_context *gen = context->system; gen->bus_busy = 1; sync_z80(gen->z80, v_context->cycles); gen->bus_busy = 0; } } else if(vdp_port < 8) { vdp_run_context(v_context, context->current_cycle); value = vdp_control_port_read(v_context); } else { vdp_run_context(v_context, context->current_cycle); value = vdp_hv_counter_read(v_context); //printf("HV Counter: %X at cycle %d\n", value, v_context->cycles); } } else if (vdp_port < 0x18){ fatal_error("Illegal read from PSG port %X\n", vdp_port); } else { value = get_open_bus_value(&gen->header); } #ifdef REFRESH_EMULATION last_sync_cycle -= 4; //refresh may have happened while we were waiting on the VDP, //so advance refresh_counter but don't add any delays refresh_counter += (context->current_cycle - last_sync_cycle); refresh_counter = refresh_counter % (MCLKS_PER_68K * REFRESH_INTERVAL); last_sync_cycle = context->current_cycle; #endif return value; } static uint8_t vdp_port_read_b(uint32_t vdp_port, m68k_context * context) { uint16_t value = vdp_port_read(vdp_port, context); if (vdp_port & 1) { return value; } else { return value >> 8; } } static uint8_t z80_vdp_port_read(uint32_t vdp_port, void * vcontext) { z80_context * context = vcontext; if (vdp_port & 0xE0) { fatal_error("machine freeze due to read from Z80 address %X\n", 0x7F00 | vdp_port); } genesis_context * gen = context->system; //VDP access goes over the 68K bus like a bank area access //typical delay from bus arbitration context->Z80_CYCLE += 3 * MCLKS_PER_Z80; //TODO: add cycle for an access right after a previous one //TODO: Below cycle time is an estimate based on the time between 68K !BG goes low and Z80 !MREQ goes high // Needs a new logic analyzer capture to get the actual delay on the 68K side gen->m68k->current_cycle += 8 * MCLKS_PER_68K; vdp_port &= 0x1F; uint16_t ret; if (vdp_port < 0x10) { //These probably won't currently interact well with the 68K accessing the VDP vdp_run_context(gen->vdp, context->Z80_CYCLE); if (vdp_port < 4) { ret = vdp_data_port_read(gen->vdp); } else if (vdp_port < 8) { ret = vdp_control_port_read(gen->vdp); } else { ret = vdp_hv_counter_read(gen->vdp); } } else { //TODO: Figure out the correct value today ret = 0xFFFF; } return vdp_port & 1 ? ret : ret >> 8; } //TODO: Move this inside the system context static uint32_t zram_counter = 0; static m68k_context * io_write(uint32_t location, m68k_context * context, uint8_t value) { genesis_context * gen = context->system; if (location < 0x10000) { //Access to Z80 memory incurs a one 68K cycle wait state context->current_cycle += MCLKS_PER_68K; if (!z80_enabled || z80_get_busack(gen->z80, context->current_cycle)) { location &= 0x7FFF; if (location < 0x4000) { gen->zram[location & 0x1FFF] = value; #ifndef NO_Z80 z80_handle_code_write(location & 0x1FFF, gen->z80); #endif } else if (location < 0x6000) { sync_sound(gen, context->current_cycle); if (location & 1) { ym_data_write(gen->ym, value); } else if(location & 2) { ym_address_write_part2(gen->ym, value); } else { ym_address_write_part1(gen->ym, value); } } else if (location == 0x6000) { gen->z80_bank_reg = (gen->z80_bank_reg >> 1 | value << 8) & 0x1FF; if (gen->z80_bank_reg < 0x80) { gen->z80->mem_pointers[1] = (gen->z80_bank_reg << 15) + ((char *)gen->z80->mem_pointers[2]); } else { gen->z80->mem_pointers[1] = NULL; } } else { fatal_error("68K write to unhandled Z80 address %X\n", location); } } } else { location &= 0x1FFF; if (location < 0x100) { switch(location/2) { case 0x1: io_data_write(gen->io.ports, value, context->current_cycle); break; case 0x2: io_data_write(gen->io.ports+1, value, context->current_cycle); break; case 0x3: io_data_write(gen->io.ports+2, value, context->current_cycle); break; case 0x4: io_control_write(gen->io.ports, value, context->current_cycle); break; case 0x5: io_control_write(gen->io.ports+1, value, context->current_cycle); break; case 0x6: io_control_write(gen->io.ports+2, value, context->current_cycle); break; case 0x7: gen->io.ports[0].serial_out = value; break; case 0x8: case 0xB: case 0xE: //serial input port is not writeable break; case 0x9: gen->io.ports[0].serial_ctrl = value; break; case 0xA: gen->io.ports[1].serial_out = value; break; case 0xC: gen->io.ports[1].serial_ctrl = value; break; case 0xD: gen->io.ports[2].serial_out = value; break; case 0xF: gen->io.ports[2].serial_ctrl = value; break; } } else { if (location == 0x1100) { if (value & 1) { dputs("bus requesting Z80"); if (z80_enabled) { z80_assert_busreq(gen->z80, context->current_cycle); } else { gen->z80->busack = 1; } } else { if (gen->z80->busreq) { dputs("releasing z80 bus"); #ifdef DO_DEBUG_PRINT char fname[20]; sprintf(fname, "zram-%d", zram_counter++); FILE * f = fopen(fname, "wb"); fwrite(z80_ram, 1, sizeof(z80_ram), f); fclose(f); #endif } if (z80_enabled) { z80_clear_busreq(gen->z80, context->current_cycle); } else { gen->z80->busack = 0; } } } else if (location == 0x1200) { sync_z80(gen->z80, context->current_cycle); if (value & 1) { if (z80_enabled) { z80_clear_reset(gen->z80, context->current_cycle); } else { gen->z80->reset = 0; } } else { if (z80_enabled) { z80_assert_reset(gen->z80, context->current_cycle); } else { gen->z80->reset = 1; } ym_reset(gen->ym); } } } } return context; } static m68k_context * io_write_w(uint32_t location, m68k_context * context, uint16_t value) { if (location < 0x10000 || (location & 0x1FFF) >= 0x100) { return io_write(location, context, value >> 8); } else { return io_write(location, context, value); } } #define FOREIGN 0x80 #define HZ50 0x40 #define USA FOREIGN #define JAP 0x00 #define EUR (HZ50|FOREIGN) #define NO_DISK 0x20 static uint8_t io_read(uint32_t location, m68k_context * context) { uint8_t value; genesis_context *gen = context->system; if (location < 0x10000) { //Access to Z80 memory incurs a one 68K cycle wait state context->current_cycle += MCLKS_PER_68K; if (!z80_enabled || z80_get_busack(gen->z80, context->current_cycle)) { location &= 0x7FFF; if (location < 0x4000) { value = gen->zram[location & 0x1FFF]; } else if (location < 0x6000) { sync_sound(gen, context->current_cycle); value = ym_read_status(gen->ym); } else { value = 0xFF; } } else { value = 0xFF; } } else { location &= 0x1FFF; if (location < 0x100) { switch(location/2) { case 0x0: //version bits should be 0 for now since we're not emulating TMSS value = gen->version_reg; break; case 0x1: value = io_data_read(gen->io.ports, context->current_cycle); break; case 0x2: value = io_data_read(gen->io.ports+1, context->current_cycle); break; case 0x3: value = io_data_read(gen->io.ports+2, context->current_cycle); break; case 0x4: value = gen->io.ports[0].control; break; case 0x5: value = gen->io.ports[1].control; break; case 0x6: value = gen->io.ports[2].control; break; case 0x7: value = gen->io.ports[0].serial_out; break; case 0x8: value = gen->io.ports[0].serial_in; break; case 0x9: value = gen->io.ports[0].serial_ctrl; break; case 0xA: value = gen->io.ports[1].serial_out; break; case 0xB: value = gen->io.ports[1].serial_in; break; case 0xC: value = gen->io.ports[1].serial_ctrl; break; case 0xD: value = gen->io.ports[2].serial_out; break; case 0xE: value = gen->io.ports[2].serial_in; break; case 0xF: value = gen->io.ports[2].serial_ctrl; break; default: value = 0xFF; } } else { if (location == 0x1100) { value = z80_enabled ? !z80_get_busack(gen->z80, context->current_cycle) : !gen->z80->busack; value |= (get_open_bus_value(&gen->header) >> 8) & 0xFE; dprintf("Byte read of BUSREQ returned %d @ %d (reset: %d)\n", value, context->current_cycle, gen->z80->reset); } else if (location == 0x1200) { value = !gen->z80->reset; } else { value = 0xFF; printf("Byte read of unknown IO location: %X\n", location); } } } return value; } static uint16_t io_read_w(uint32_t location, m68k_context * context) { genesis_context *gen = context->system; uint16_t value = io_read(location, context); if (location < 0x10000 || (location & 0x1FFF) < 0x100) { value = value | (value << 8); } else { value <<= 8; value |= get_open_bus_value(&gen->header) & 0xFF; } return value; } static void * z80_write_ym(uint32_t location, void * vcontext, uint8_t value) { z80_context * context = vcontext; genesis_context * gen = context->system; sync_sound(gen, context->Z80_CYCLE); if (location & 1) { ym_data_write(gen->ym, value); } else if (location & 2) { ym_address_write_part2(gen->ym, value); } else { ym_address_write_part1(gen->ym, value); } return context; } static uint8_t z80_read_ym(uint32_t location, void * vcontext) { z80_context * context = vcontext; genesis_context * gen = context->system; sync_sound(gen, context->Z80_CYCLE); return ym_read_status(gen->ym); } static uint8_t z80_read_bank(uint32_t location, void * vcontext) { z80_context * context = vcontext; genesis_context *gen = context->system; if (gen->bus_busy) { context->Z80_CYCLE = gen->m68k->current_cycle; } //typical delay from bus arbitration context->Z80_CYCLE += 3 * MCLKS_PER_Z80; //TODO: add cycle for an access right after a previous one //TODO: Below cycle time is an estimate based on the time between 68K !BG goes low and Z80 !MREQ goes high // Needs a new logic analyzer capture to get the actual delay on the 68K side gen->m68k->current_cycle += 8 * MCLKS_PER_68K; location &= 0x7FFF; if (context->mem_pointers[1]) { return context->mem_pointers[1][location ^ 1]; } uint32_t address = gen->z80_bank_reg << 15 | location; if (address >= 0xC00000 && address < 0xE00000) { return z80_vdp_port_read(location & 0xFF, context); } else if (address >= 0xA10000 && address <= 0xA10001) { //Apparently version reg can be read through Z80 banked area //TODO: Check rest of IO region addresses return gen->version_reg; } else { fprintf(stderr, "Unhandled read by Z80 from address %X through banked memory area (%X)\n", address, gen->z80_bank_reg << 15); } return 0; } static void *z80_write_bank(uint32_t location, void * vcontext, uint8_t value) { z80_context * context = vcontext; genesis_context *gen = context->system; if (gen->bus_busy) { context->Z80_CYCLE = gen->m68k->current_cycle; } //typical delay from bus arbitration context->Z80_CYCLE += 3 * MCLKS_PER_Z80; //TODO: add cycle for an access right after a previous one //TODO: Below cycle time is an estimate based on the time between 68K !BG goes low and Z80 !MREQ goes high // Needs a new logic analyzer capture to get the actual delay on the 68K side gen->m68k->current_cycle += 8 * MCLKS_PER_68K; location &= 0x7FFF; uint32_t address = gen->z80_bank_reg << 15 | location; if (address >= 0xE00000) { address &= 0xFFFF; ((uint8_t *)gen->work_ram)[address ^ 1] = value; } else if (address >= 0xC00000) { z80_vdp_port_write(location & 0xFF, context, value); } else { fprintf(stderr, "Unhandled write by Z80 to address %X through banked memory area\n", address); } return context; } static void *z80_write_bank_reg(uint32_t location, void * vcontext, uint8_t value) { z80_context * context = vcontext; genesis_context *gen = context->system; gen->z80_bank_reg = (gen->z80_bank_reg >> 1 | value << 8) & 0x1FF; update_z80_bank_pointer(context->system); return context; } static void set_speed_percent(system_header * system, uint32_t percent) { genesis_context *context = (genesis_context *)system; uint32_t old_clock = context->master_clock; context->master_clock = ((uint64_t)context->normal_clock * (uint64_t)percent) / 100; while (context->ym->current_cycle != context->psg->cycles) { sync_sound(context, context->psg->cycles + MCLKS_PER_PSG); } ym_adjust_master_clock(context->ym, context->master_clock); psg_adjust_master_clock(context->psg, context->master_clock); } void set_region(genesis_context *gen, rom_info *info, uint8_t region) { if (!region) { char * def_region = tern_find_path_default(config, "system\0default_region\0", (tern_val){.ptrval = "U"}, TVAL_PTR).ptrval; if (!info->regions || (info->regions & translate_region_char(toupper(*def_region)))) { region = translate_region_char(toupper(*def_region)); } else { region = info->regions; } } if (region & REGION_E) { gen->version_reg = NO_DISK | EUR; } else if (region & REGION_J) { gen->version_reg = NO_DISK | JAP; } else { gen->version_reg = NO_DISK | USA; } if (region & HZ50) { gen->normal_clock = MCLKS_PAL; } else { gen->normal_clock = MCLKS_NTSC; } gen->master_clock = gen->normal_clock; } static uint8_t load_state(system_header *system, uint8_t slot) { genesis_context *gen = (genesis_context *)system; char *statepath = get_slot_name(system, slot, "state"); deserialize_buffer state; uint32_t pc = 0; uint8_t ret; if (!gen->m68k->resume_pc) { system->delayed_load_slot = slot + 1; gen->m68k->should_return = 1; ret = get_modification_time(statepath) != 0; if (!ret) { strcpy(statepath + strlen(statepath)-strlen("state"), "gst"); ret = get_modification_time(statepath) != 0; } goto done; } if (load_from_file(&state, statepath)) { genesis_deserialize(&state, gen); free(state.data); //HACK pc = gen->m68k->last_prefetch_address; ret = 1; } else { strcpy(statepath + strlen(statepath)-strlen("state"), "gst"); pc = load_gst(gen, statepath); ret = pc != 0; } if (ret) { gen->m68k->resume_pc = get_native_address_trans(gen->m68k, pc); } done: free(statepath); return ret; } static void handle_reset_requests(genesis_context *gen) { while (gen->reset_requested || gen->header.delayed_load_slot) { if (gen->reset_requested) { gen->reset_requested = 0; gen->m68k->should_return = 0; z80_assert_reset(gen->z80, gen->m68k->current_cycle); z80_clear_busreq(gen->z80, gen->m68k->current_cycle); ym_reset(gen->ym); //Is there any sort of VDP reset? m68k_reset(gen->m68k); } if (gen->header.delayed_load_slot) { load_state(&gen->header, gen->header.delayed_load_slot - 1); gen->header.delayed_load_slot = 0; resume_68k(gen->m68k); } } #ifndef IS_LIB bindings_release_capture(); vdp_release_framebuffer(gen->vdp); render_pause_source(gen->ym->audio); render_pause_source(gen->psg->audio); #endif } static void start_genesis(system_header *system, char *statefile) { genesis_context *gen = (genesis_context *)system; if (statefile) { //first try loading as a native format savestate deserialize_buffer state; uint32_t pc; if (load_from_file(&state, statefile)) { genesis_deserialize(&state, gen); free(state.data); //HACK pc = gen->m68k->last_prefetch_address; } else { pc = load_gst(gen, statefile); if (!pc) { fatal_error("Failed to load save state %s\n", statefile); } } printf("Loaded %s\n", statefile); if (gen->header.enter_debugger) { gen->header.enter_debugger = 0; insert_breakpoint(gen->m68k, pc, gen->header.debugger_type == DEBUGGER_NATIVE ? debugger : gdb_debug_enter); } adjust_int_cycle(gen->m68k, gen->vdp); start_68k_context(gen->m68k, pc); } else { if (gen->header.enter_debugger) { gen->header.enter_debugger = 0; uint32_t address = gen->cart[2] << 16 | gen->cart[3]; insert_breakpoint(gen->m68k, address, gen->header.debugger_type == DEBUGGER_NATIVE ? debugger : gdb_debug_enter); } m68k_reset(gen->m68k); } handle_reset_requests(gen); return; } static void resume_genesis(system_header *system) { genesis_context *gen = (genesis_context *)system; #ifndef IS_LIB render_set_video_standard((gen->version_reg & HZ50) ? VID_PAL : VID_NTSC); bindings_reacquire_capture(); vdp_reacquire_framebuffer(gen->vdp); render_resume_source(gen->ym->audio); render_resume_source(gen->psg->audio); #endif resume_68k(gen->m68k); handle_reset_requests(gen); } static void inc_debug_mode(system_header *system) { genesis_context *gen = (genesis_context *)system; vdp_inc_debug_mode(gen->vdp); } static void request_exit(system_header *system) { genesis_context *gen = (genesis_context *)system; gen->m68k->target_cycle = gen->m68k->current_cycle; gen->m68k->should_return = 1; } static void persist_save(system_header *system) { genesis_context *gen = (genesis_context *)system; if (gen->save_type == SAVE_NONE) { return; } FILE * f = fopen(save_filename, "wb"); if (!f) { fprintf(stderr, "Failed to open %s file %s for writing\n", save_type_name(gen->save_type), save_filename); return; } if (gen->save_type == RAM_FLAG_BOTH) { byteswap_rom(gen->save_size, (uint16_t *)gen->save_storage); } fwrite(gen->save_storage, 1, gen->save_size, f); if (gen->save_type == RAM_FLAG_BOTH) { byteswap_rom(gen->save_size, (uint16_t *)gen->save_storage); } fclose(f); printf("Saved %s to %s\n", save_type_name(gen->save_type), save_filename); } static void load_save(system_header *system) { genesis_context *gen = (genesis_context *)system; FILE * f = fopen(save_filename, "rb"); if (f) { uint32_t read = fread(gen->save_storage, 1, gen->save_size, f); fclose(f); if (read > 0) { if (gen->save_type == RAM_FLAG_BOTH) { byteswap_rom(gen->save_size, (uint16_t *)gen->save_storage); } printf("Loaded %s from %s\n", save_type_name(gen->save_type), save_filename); } } } static void soft_reset(system_header *system) { genesis_context *gen = (genesis_context *)system; if (gen->reset_cycle == CYCLE_NEVER) { double random = (double)rand()/(double)RAND_MAX; gen->reset_cycle = gen->m68k->current_cycle + random * MCLKS_LINE * (gen->version_reg & HZ50 ? LINES_PAL : LINES_NTSC); if (gen->reset_cycle < gen->m68k->target_cycle) { gen->m68k->target_cycle = gen->reset_cycle; } } } static void free_genesis(system_header *system) { genesis_context *gen = (genesis_context *)system; vdp_free(gen->vdp); memmap_chunk *map = (memmap_chunk *)gen->m68k->options->gen.memmap; m68k_options_free(gen->m68k->options); free(gen->cart); free(gen->m68k); free(gen->work_ram); z80_options_free(gen->z80->Z80_OPTS); free(gen->z80); free(gen->zram); ym_free(gen->ym); psg_free(gen->psg); free(gen->header.save_dir); free_rom_info(&gen->header.info); free(gen->lock_on); free(gen); } static void gamepad_down(system_header *system, uint8_t gamepad_num, uint8_t button) { genesis_context *gen = (genesis_context *)system; io_gamepad_down(&gen->io, gamepad_num, button); if (gen->mapper_type == MAPPER_JCART) { jcart_gamepad_down(gen, gamepad_num, button); } } static void gamepad_up(system_header *system, uint8_t gamepad_num, uint8_t button) { genesis_context *gen = (genesis_context *)system; io_gamepad_up(&gen->io, gamepad_num, button); if (gen->mapper_type == MAPPER_JCART) { jcart_gamepad_up(gen, gamepad_num, button); } } static void mouse_down(system_header *system, uint8_t mouse_num, uint8_t button) { genesis_context *gen = (genesis_context *)system; io_mouse_down(&gen->io, mouse_num, button); } static void mouse_up(system_header *system, uint8_t mouse_num, uint8_t button) { genesis_context *gen = (genesis_context *)system; io_mouse_up(&gen->io, mouse_num, button); } static void mouse_motion_absolute(system_header *system, uint8_t mouse_num, uint16_t x, uint16_t y) { genesis_context *gen = (genesis_context *)system; io_mouse_motion_absolute(&gen->io, mouse_num, x, y); } static void mouse_motion_relative(system_header *system, uint8_t mouse_num, int32_t x, int32_t y) { genesis_context *gen = (genesis_context *)system; io_mouse_motion_relative(&gen->io, mouse_num, x, y); } static void keyboard_down(system_header *system, uint8_t scancode) { genesis_context *gen = (genesis_context *)system; io_keyboard_down(&gen->io, scancode); } static void keyboard_up(system_header *system, uint8_t scancode) { genesis_context *gen = (genesis_context *)system; io_keyboard_up(&gen->io, scancode); } static void set_audio_config(genesis_context *gen) { char *config_gain; config_gain = tern_find_path(config, "audio\0psg_gain\0", TVAL_PTR).ptrval; render_audio_source_gaindb(gen->psg->audio, config_gain ? atof(config_gain) : 0.0f); config_gain = tern_find_path(config, "audio\0fm_gain\0", TVAL_PTR).ptrval; render_audio_source_gaindb(gen->ym->audio, config_gain ? atof(config_gain) : 0.0f); char *config_dac = tern_find_path_default(config, "audio\0fm_dac\0", (tern_val){.ptrval="zero_offset"}, TVAL_PTR).ptrval; ym_enable_zero_offset(gen->ym, !strcmp(config_dac, "zero_offset")); } static void config_updated(system_header *system) { genesis_context *gen = (genesis_context *)system; setup_io_devices(config, &system->info, &gen->io); set_audio_config(gen); } genesis_context *alloc_init_genesis(rom_info *rom, void *main_rom, void *lock_on, uint32_t system_opts, uint8_t force_region) { static memmap_chunk z80_map[] = { { 0x0000, 0x4000, 0x1FFF, 0, 0, MMAP_READ | MMAP_WRITE | MMAP_CODE, NULL, NULL, NULL, NULL, NULL }, { 0x8000, 0x10000, 0x7FFF, 0, 0, 0, NULL, NULL, NULL, z80_read_bank, z80_write_bank}, { 0x4000, 0x6000, 0x0003, 0, 0, 0, NULL, NULL, NULL, z80_read_ym, z80_write_ym}, { 0x6000, 0x6100, 0xFFFF, 0, 0, 0, NULL, NULL, NULL, NULL, z80_write_bank_reg}, { 0x7F00, 0x8000, 0x00FF, 0, 0, 0, NULL, NULL, NULL, z80_vdp_port_read, z80_vdp_port_write} }; genesis_context *gen = calloc(1, sizeof(genesis_context)); gen->header.set_speed_percent = set_speed_percent; gen->header.start_context = start_genesis; gen->header.resume_context = resume_genesis; gen->header.load_save = load_save; gen->header.persist_save = persist_save; gen->header.load_state = load_state; gen->header.soft_reset = soft_reset; gen->header.free_context = free_genesis; gen->header.get_open_bus_value = get_open_bus_value; gen->header.request_exit = request_exit; gen->header.inc_debug_mode = inc_debug_mode; gen->header.gamepad_down = gamepad_down; gen->header.gamepad_up = gamepad_up; gen->header.mouse_down = mouse_down; gen->header.mouse_up = mouse_up; gen->header.mouse_motion_absolute = mouse_motion_absolute; gen->header.mouse_motion_relative = mouse_motion_relative; gen->header.keyboard_down = keyboard_down; gen->header.keyboard_up = keyboard_up; gen->header.config_updated = config_updated; gen->header.serialize = serialize; gen->header.deserialize = deserialize; gen->header.type = SYSTEM_GENESIS; gen->header.info = *rom; set_region(gen, rom, force_region); gen->vdp = init_vdp_context(gen->version_reg & 0x40); gen->vdp->system = &gen->header; gen->frame_end = vdp_cycles_to_frame_end(gen->vdp); char * config_cycles = tern_find_path(config, "clocks\0max_cycles\0", TVAL_PTR).ptrval; gen->max_cycles = config_cycles ? atoi(config_cycles) : DEFAULT_SYNC_INTERVAL; gen->int_latency_prev1 = MCLKS_PER_68K * 32; gen->int_latency_prev2 = MCLKS_PER_68K * 16; render_set_video_standard((gen->version_reg & HZ50) ? VID_PAL : VID_NTSC); gen->ym = malloc(sizeof(ym2612_context)); ym_init(gen->ym, gen->master_clock, MCLKS_PER_YM, system_opts); gen->psg = malloc(sizeof(psg_context)); psg_init(gen->psg, gen->master_clock, MCLKS_PER_PSG); set_audio_config(gen); z80_map[0].buffer = gen->zram = calloc(1, Z80_RAM_BYTES); #ifndef NO_Z80 z80_options *z_opts = malloc(sizeof(z80_options)); init_z80_opts(z_opts, z80_map, 5, NULL, 0, MCLKS_PER_Z80, 0xFFFF); gen->z80 = init_z80_context(z_opts); #ifndef NEW_CORE gen->z80->next_int_pulse = z80_next_int_pulse; #endif z80_assert_reset(gen->z80, 0); #else gen->z80 = calloc(1, sizeof(z80_context)); #endif gen->z80->system = gen; gen->z80->mem_pointers[0] = gen->zram; gen->z80->mem_pointers[1] = gen->z80->mem_pointers[2] = (uint8_t *)main_rom; gen->cart = main_rom; gen->lock_on = lock_on; gen->work_ram = calloc(2, RAM_WORDS); if (!strcmp("random", tern_find_path_default(config, "system\0ram_init\0", (tern_val){.ptrval = "zero"}, TVAL_PTR).ptrval)) { srand(time(NULL)); for (int i = 0; i < RAM_WORDS; i++) { gen->work_ram[i] = rand(); } for (int i = 0; i < Z80_RAM_BYTES; i++) { gen->zram[i] = rand(); } for (int i = 0; i < VRAM_SIZE; i++) { gen->vdp->vdpmem[i] = rand(); } for (int i = 0; i < SAT_CACHE_SIZE; i++) { gen->vdp->sat_cache[i] = rand(); } for (int i = 0; i < CRAM_SIZE; i++) { write_cram_internal(gen->vdp, i, rand()); } for (int i = 0; i < VSRAM_SIZE; i++) { gen->vdp->vsram[i] = rand(); } } setup_io_devices(config, rom, &gen->io); gen->header.has_keyboard = io_has_keyboard(&gen->io); gen->mapper_type = rom->mapper_type; gen->save_type = rom->save_type; if (gen->save_type != SAVE_NONE) { gen->save_ram_mask = rom->save_mask; gen->save_size = rom->save_size; gen->save_storage = rom->save_buffer; gen->eeprom_map = rom->eeprom_map; gen->num_eeprom = rom->num_eeprom; if (gen->save_type == SAVE_I2C) { eeprom_init(&gen->eeprom, gen->save_storage, gen->save_size); } else if (gen->save_type == SAVE_NOR) { memcpy(&gen->nor, rom->nor, sizeof(gen->nor)); //nor_flash_init(&gen->nor, gen->save_storage, gen->save_size, rom->save_page_size, rom->save_product_id, rom->save_bus); } } else { gen->save_storage = NULL; } //This must happen before we generate memory access functions in init_m68k_opts for (int i = 0; i < rom->map_chunks; i++) { if (rom->map[i].start == 0xE00000) { rom->map[i].buffer = gen->work_ram; break; } } m68k_options *opts = malloc(sizeof(m68k_options)); init_m68k_opts(opts, rom->map, rom->map_chunks, MCLKS_PER_68K); //TODO: make this configurable opts->gen.flags |= M68K_OPT_BROKEN_READ_MODIFY; gen->m68k = init_68k_context(opts, NULL); gen->m68k->system = gen; opts->address_log = (system_opts & OPT_ADDRESS_LOG) ? fopen("address.log", "w") : NULL; //This must happen after the 68K context has been allocated for (int i = 0; i < rom->map_chunks; i++) { if (rom->map[i].flags & MMAP_PTR_IDX) { gen->m68k->mem_pointers[rom->map[i].ptr_index] = rom->map[i].buffer; } } if (gen->mapper_type == MAPPER_SEGA) { //initialize bank registers for (int i = 1; i < sizeof(gen->bank_regs); i++) { gen->bank_regs[i] = i; } } return gen; } genesis_context *alloc_config_genesis(void *rom, uint32_t rom_size, void *lock_on, uint32_t lock_on_size, uint32_t ym_opts, uint8_t force_region) { static memmap_chunk base_map[] = { {0xE00000, 0x1000000, 0xFFFF, 0, 0, MMAP_READ | MMAP_WRITE | MMAP_CODE, NULL, NULL, NULL, NULL, NULL}, {0xC00000, 0xE00000, 0x1FFFFF, 0, 0, 0, NULL, (read_16_fun)vdp_port_read, (write_16_fun)vdp_port_write, (read_8_fun)vdp_port_read_b, (write_8_fun)vdp_port_write_b}, {0xA00000, 0xA12000, 0x1FFFF, 0, 0, 0, NULL, (read_16_fun)io_read_w, (write_16_fun)io_write_w, (read_8_fun)io_read, (write_8_fun)io_write} }; static tern_node *rom_db; if (!rom_db) { rom_db = load_rom_db(); } rom_info info = configure_rom(rom_db, rom, rom_size, lock_on, lock_on_size, base_map, sizeof(base_map)/sizeof(base_map[0])); rom = info.rom; rom_size = info.rom_size; #ifndef BLASTEM_BIG_ENDIAN byteswap_rom(rom_size, rom); if (lock_on) { byteswap_rom(lock_on_size, lock_on); } #endif char *m68k_divider = tern_find_path(config, "clocks\0m68k_divider\0", TVAL_PTR).ptrval; if (!m68k_divider) { m68k_divider = "7"; } MCLKS_PER_68K = atoi(m68k_divider); if (!MCLKS_PER_68K) { MCLKS_PER_68K = 7; } return alloc_init_genesis(&info, rom, lock_on, ym_opts, force_region); }