Mercurial > repos > blastem
view sega_mapper.c @ 1863:d60f2d7c02a5
Differentiate between the full Sega mapper and the SRAM only one. Fixes crash on save state load for Phantasy Star IV and other games that use the same mapper
author | Michael Pavone <pavone@retrodev.com> |
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date | Tue, 14 May 2019 23:20:35 -0700 |
parents | 14a2834d010c |
children | 374a5ae694e8 3748a2a8a4b7 |
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#include "genesis.h" uint16_t read_sram_w(uint32_t address, m68k_context * context) { genesis_context * gen = context->system; address &= gen->save_ram_mask; switch(gen->save_type) { case RAM_FLAG_BOTH: return gen->save_storage[address] << 8 | gen->save_storage[address+1]; case RAM_FLAG_EVEN: return gen->save_storage[address >> 1] << 8 | 0xFF; case RAM_FLAG_ODD: return gen->save_storage[address >> 1] | 0xFF00; } return 0xFFFF;//We should never get here } uint8_t read_sram_b(uint32_t address, m68k_context * context) { genesis_context * gen = context->system; address &= gen->save_ram_mask; switch(gen->save_type) { case RAM_FLAG_BOTH: return gen->save_storage[address]; case RAM_FLAG_EVEN: if (address & 1) { return 0xFF; } else { return gen->save_storage[address >> 1]; } case RAM_FLAG_ODD: if (address & 1) { return gen->save_storage[address >> 1]; } else { return 0xFF; } } return 0xFF;//We should never get here } m68k_context * write_sram_area_w(uint32_t address, m68k_context * context, uint16_t value) { genesis_context * gen = context->system; if ((gen->bank_regs[0] & 0x3) == 1) { address &= gen->save_ram_mask; switch(gen->save_type) { case RAM_FLAG_BOTH: gen->save_storage[address] = value >> 8; gen->save_storage[address+1] = value; break; case RAM_FLAG_EVEN: gen->save_storage[address >> 1] = value >> 8; break; case RAM_FLAG_ODD: gen->save_storage[address >> 1] = value; break; } } return context; } m68k_context * write_sram_area_b(uint32_t address, m68k_context * context, uint8_t value) { genesis_context * gen = context->system; if ((gen->bank_regs[0] & 0x3) == 1) { address &= gen->save_ram_mask; switch(gen->save_type) { case RAM_FLAG_BOTH: gen->save_storage[address] = value; break; case RAM_FLAG_EVEN: if (!(address & 1)) { gen->save_storage[address >> 1] = value; } break; case RAM_FLAG_ODD: if (address & 1) { gen->save_storage[address >> 1] = value; } break; } } return context; } m68k_context * write_bank_reg_w(uint32_t address, m68k_context * context, uint16_t value) { genesis_context * gen = context->system; address &= 0xE; address >>= 1; gen->bank_regs[address] = value; if (!address) { if (value & 1) { //Used for games that only use the mapper for SRAM if (context->mem_pointers[gen->mapper_start_index]) { gen->mapper_temp = context->mem_pointers[gen->mapper_start_index]; } context->mem_pointers[gen->mapper_start_index] = NULL; //For games that need more than 4MB for (int i = 4; i < 8; i++) { context->mem_pointers[gen->mapper_start_index + i] = NULL; } } else { //Used for games that only use the mapper for SRAM if (!context->mem_pointers[gen->mapper_start_index]) { context->mem_pointers[gen->mapper_start_index] = gen->mapper_temp; } //For games that need more than 4MB for (int i = 4; i < 8; i++) { context->mem_pointers[gen->mapper_start_index + i] = gen->cart + 0x40000*gen->bank_regs[i]; } } } else if (gen->mapper_type == MAPPER_SEGA) { void *new_ptr = gen->cart + 0x40000*value; if (context->mem_pointers[gen->mapper_start_index + address] != new_ptr) { m68k_invalidate_code_range(gen->m68k, address * 0x80000, (address + 1) * 0x80000); context->mem_pointers[gen->mapper_start_index + address] = new_ptr; } } return context; } m68k_context * write_bank_reg_b(uint32_t address, m68k_context * context, uint8_t value) { if (address & 1) { write_bank_reg_w(address, context, value); } return context; } void sega_mapper_serialize(genesis_context *gen, serialize_buffer *buf) { save_buffer8(buf, gen->bank_regs, sizeof(gen->bank_regs)); } void sega_mapper_deserialize(deserialize_buffer *buf, genesis_context *gen) { for (int i = 0; i < sizeof(gen->bank_regs); i++) { write_bank_reg_w(i * 2, gen->m68k, load_int8(buf)); } }