static void op_writemem(dword opcode,int bytes) { int a,*d; a=op_memaddr(opcode); if(bytes>0x10) { // fpu d =&st.f[OP_RT(opcode)].d; bytes-=0x10; } else { d =&st.g[OP_RT(opcode)].d; } switch(bytes) { case 1: mem_write8(a,d[0]); break; case 2: mem_write16(a,d[0]); break; case 4: mem_write32(a,d[0]); break; case 8: mem_write32(a,d[1]); mem_write32(a+4,d[0]); break; } cpu_notify_writemem(a,bytes); }
inline void stack_push16(const uint16_t value, Gameboy* const gb) { gb->cpu.sp -= 2; mem_write16(gb->cpu.sp, value, gb); }
void cpu_push(context_t *ctx, uint16_t value) { ctx->cpu.SP -= 2; mem_write16(&ctx->mem, ctx->cpu.SP, value); }
u32int process_opcode(farcpu *cpu) { u8int op = cpu->regs.IR; u8int mem_add = 1; //amount to add to memory to get to next OpCode u32int PC = cpu->regs.PC + 1; //just skip the opcode, to make things easier char *memory = cpu->memory; if(op == EXOP) return process_extended_opcode(cpu); switch(op) { case NOP: asm("nop"); break; //might just remove the asm statement sometime, just fo-sho right now /* * Aritmatic functions * TODO: OVERFLOW, EXCEPTION Handeling */ case INC: set_register(cpu, mem_get8(memory, PC), get_register(cpu, mem_get8(memory, PC)) + 1); mem_add++; break; case DEC: set_register(cpu, mem_get8(memory, PC), get_register(cpu, mem_get8(memory, PC)) - 1); mem_add++; break; case ADD: set_register(cpu, AL, process_in_loc(cpu, memory, PC, &mem_add) + process_in_loc(cpu, memory, PC + mem_add-1 , &mem_add)); break; case SUB: set_register(cpu, AL, process_in_loc(cpu, memory, PC, &mem_add) - process_in_loc(cpu, memory, PC + mem_add-1, &mem_add)); break; case MUL: //TODO:OPTIMIZE set_register(cpu, AL, process_in_loc(cpu, memory, PC, &mem_add) * process_in_loc(cpu, memory, PC + mem_add-1, &mem_add)); break; case DIV: //TODO:OPTIMIZE, DIV BY 0 set_register(cpu, AL, (u32int)(process_in_loc(cpu, memory, PC, &mem_add) / process_in_loc(cpu, memory, PC + mem_add-1, &mem_add))); break; //Moving data around: TODO:ADD CONTENT!!! case MOVNM: switch(mem_read8(cpu->memory, PC)){ case 0: mem_write8(cpu->memory, mem_read32(cpu->memory, PC + 2),mem_read8(cpu->memory, PC + 1)); mem_add+=6; break; case 1: mem_write16(cpu->memory, mem_read32(cpu->memory, PC + 3), mem_read16(cpu->memory, PC + 1)); mem_add+=7; break; case 2: mem_write32(cpu->memory, mem_read32(cpu->memory, PC + 6), mem_read32(cpu->memory, PC + 1)); mem_add+=9; break; } mem_add++; break; case MOVRM: switch(reg_sizes[mem_read8(cpu->memory, PC)]){ case 1: mem_write8(cpu->memory, mem_read32(cpu->memory, PC + 1), get_register(cpu, mem_read8(cpu->memory, PC))); break; case 2: mem_write16(cpu->memory, mem_read32(cpu->memory, PC + 1), get_register(cpu, mem_read8(cpu->memory, PC))); break; case 4: mem_write32(cpu->memory, mem_read32(cpu->memory, PC + 1), get_register(cpu, mem_read8(cpu->memory, PC))); break; } mem_add += 5; break; case MOVIM: mem_write8(cpu->memory, mem_read32(cpu->memory, PC), cpu->IO); mem_add += 4; break; case MOVMM: break; case MOVMR: break; case MOVNR: switch(mem_read8(cpu->memory, PC)) { case 0: set_register(cpu, mem_read8(cpu->memory, PC+2), mem_read8(cpu->memory, PC+1)); mem_add += 3; break; //byte case 1: set_register(cpu, mem_read8(cpu->memory, PC+3), mem_read16(cpu->memory, PC+1)); mem_add += 4; break; //short case 2: set_register(cpu, mem_read8(cpu->memory, PC+5), mem_read32(cpu->memory, PC+1)); mem_add += 6; break; //long } break; case MOVIR: set_register(cpu, mem_read8(cpu->memory, PC), cpu->IO); mem_add += 1; break; case MOVRR: set_register(cpu, mem_read8(cpu->memory, PC + 1), get_register(cpu, mem_read8(cpu->memory, PC))); mem_add += 2; break; //bit-minipulating: case SHL: break; case SHR: break; case AND: break; case OR: break; case XOR: break; case NOT: break; //Low-Level: case HWU: switch(mem_read16(cpu->memory, PC)) { case 0x08: gfx_upd(cpu); } mem_add += 2; break; //branching: case JMP: cpu->regs.PC = mem_read32(cpu->memory, PC); return 1; case SJP: cpu->regs.JP = mem_read32(cpu->memory, PC); mem_add += 4; break; case JZ: if(cpu->regs.AL == 0){ cpu->regs.PC = cpu->regs.JP; return 1; }break; case JNZ: if(cpu->regs.AL != 0){ cpu->regs.PC = cpu->regs.JP; return 1; }break; case JFE: if(cpu->regs.AL == cpu->regs.BL){ cpu->regs.PC = cpu->regs.JP; return 1; }break; case JNE: if(cpu->regs.AL != cpu->regs.BL){ cpu->regs.PC = cpu->regs.JP; return 1; }break; case JGT: if(cpu->regs.AL > cpu->regs.BL){ cpu->regs.PC = cpu->regs.JP; return 1; }break; break; case JNG: if(!(cpu->regs.AL > cpu->regs.BL)){ cpu->regs.PC = cpu->regs.JP; return 1; }break; case JGE: if(cpu->regs.AL >= cpu->regs.BL){ cpu->regs.PC = cpu->regs.JP; return 1; }break; case JNGE: if(!(cpu->regs.AL >= cpu->regs.BL)){ cpu->regs.PC = cpu->regs.JP; return 1; }break; case JLT: if(cpu->regs.AL < cpu->regs.BL){ cpu->regs.PC = cpu->regs.JP; return 1; }break; case JNL: if(!(cpu->regs.AL < cpu->regs.BL)){ cpu->regs.PC = cpu->regs.JP; return 1; }break; break; case JLE: if(cpu->regs.AL <= cpu->regs.BL){ cpu->regs.PC = cpu->regs.JP; return 1; }break; break; case JNLE: if(!(cpu->regs.AL <= cpu->regs.BL)){ cpu->regs.PC = cpu->regs.JP; return 1; }break; break; case MOVNRM: switch(mem_read8(cpu->memory, PC)) { case 0: set_register(cpu, get_register(cpu, mem_get8(cpu->memory, PC + 2)), mem_read8(cpu->memory, PC+1)); mem_add += 4; break; //byte case 1: set_register(cpu, get_register(cpu, mem_get8(cpu->memory, PC + 3)), mem_read16(cpu->memory, PC+1)); mem_add += 5; break; //short case 2: set_register(cpu, get_register(cpu, mem_get8(cpu->memory, PC + 5)), mem_read32(cpu->memory, PC+1)); mem_add += 7; break; //long } break; case MOVRRM: switch(reg_sizes[mem_read8(cpu->memory, PC)]){ case 1: mem_write8(cpu->memory, get_register(cpu, mem_get8(cpu->memory, PC + 1)), get_register(cpu, mem_read8(cpu->memory, PC))); break; case 2: mem_write16(cpu->memory, get_register(cpu, mem_get8(cpu->memory, PC + 1)), get_register(cpu, mem_read8(cpu->memory, PC))); break; case 4: mem_write32(cpu->memory, get_register(cpu, mem_get8(cpu->memory, PC + 1)), get_register(cpu, mem_read8(cpu->memory, PC))); break; } mem_add += 2; break; case MOVIRM: break; case MOVMRM: break; case OUTN: D("G"); cpu->IO = mem_read8(cpu->memory, PC); D("Y"); mem_add += 1; D("H"); break; case OUTR: cpu->IO = get_register(cpu, mem_read8(cpu->memory, PC)); mem_add += 1; break; case OUTM: cpu->IO = mem_read8(cpu->memory, mem_read32(cpu->memory, PC)); mem_add += 4; break; case RET: break; } cpu->regs.PC += mem_add + 0; return 0; }