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#pragma once
#include "nes/sys/types/cycle-count.hh"
#include "nes/sys/types/address.hh"
#include "nes/sys/types/snapshot.hh"
#include "nes/common/status.hh"
#include "nes/common/types.hh"
namespace nes::sys
{
class ppu;
class controller;
class cartridge;
class cpu
{
static constexpr auto ram_size = u32{ 0x800 };
static constexpr auto stack_offset = address{ 0x100 };
cycle_count current_cycles_;
ppu& ppu_;
cartridge& cartridge_;
controller& controller_1_;
controller& controller_2_;
u8 ram_[ram_size]{};
bool nmi_pending_{ false };
// Registers
struct
{
u16 pc{ 0 };
u8 sp{ 0xFD };
u8 a{ 0 };
u8 x{ 0 };
u8 y{ 0 };
struct
{
auto get_c() const -> bool { return value & 0b00000001; } // carry
auto get_z() const -> bool { return value & 0b00000010; } // zero
auto get_i() const -> bool { return value & 0b00000100; } // interrupt inhibit
auto get_d() const -> bool { return value & 0b00001000; } // decimal
auto get_b() const -> bool { return value & 0b00010000; } // break
auto get_v() const -> bool { return value & 0b01000000; } // overflow
auto get_n() const -> bool { return value & 0b10000000; } // negative
auto set_c(bool const v) -> void { value = (value & ~0b00000001) | (v ? 0b00000001 : 0); }
auto set_z(bool const v) -> void { value = (value & ~0b00000010) | (v ? 0b00000010 : 0); }
auto set_i(bool const v) -> void { value = (value & ~0b00000100) | (v ? 0b00000100 : 0); }
auto set_d(bool const v) -> void { value = (value & ~0b00001000) | (v ? 0b00001000 : 0); }
auto set_b(bool const v) -> void { value = (value & ~0b00010000) | (v ? 0b00010000 : 0); }
auto set_v(bool const v) -> void { value = (value & ~0b01000000) | (v ? 0b01000000 : 0); }
auto set_n(bool const v) -> void { value = (value & ~0b10000000) | (v ? 0b10000000 : 0); }
u8 value{ 0b00100100 };
} p{};
} registers_{};
enum class addressing_mode
{
accumulator, // A
immediate, // #v
zero_page, // d
absolute, // a
relative, // *+d
indirect, // (a)
zero_page_indexed_x, // d,x
zero_page_indexed_y, // d,y
absolute_indexed_x, // a,x
absolute_indexed_y, // a,y
indexed_indirect, // (d,x)
indirect_indexed, // (d),y
};
enum class force_page_crossing
{
no,
yes,
};
template<addressing_mode>
class operand
{
cpu& cpu_;
address address_;
cycle_count cycles_;
public:
explicit operand(cpu& cpu, address const address, cycle_count const cycles)
: cpu_{ cpu }
, address_{ address }
, cycles_{ cycles }
{
}
auto read() -> u8 { return cpu_.read8(address_); }
auto write(u8 const value) -> void { cpu_.write8(address_, value); }
auto get_address() -> address { return address_; }
auto get_cycles() -> cycle_count { return cycles_; }
};
template<>
class operand<addressing_mode::accumulator>
{
cpu& cpu_;
public:
explicit operand(cpu& cpu)
: cpu_{ cpu }
{
}
auto read() -> u8 { return cpu_.registers_.a; }
auto write(u8 const value) -> void { cpu_.registers_.a = value; }
auto get_cycles() -> cycle_count { return cycle_count::from_cpu(2); }
};
template<>
class operand<addressing_mode::immediate>
{
u8 value_{ 0 };
public:
explicit operand(u8 const value)
: value_{ value }
{
}
auto read() -> u8 { return value_; }
auto get_cycles() -> cycle_count { return cycle_count::from_cpu(2); }
};
public:
explicit cpu(ppu&, cartridge&, controller& controller_1, controller& controller_2);
cpu(cpu const&) = delete;
cpu(cpu&&) = delete;
auto operator=(cpu const&) -> cpu& = delete;
auto operator=(cpu&&) -> cpu& = delete;
auto get_cycles() const -> cycle_count { return current_cycles_; }
#ifdef NES_ENABLE_SNAPSHOTS
auto build_snapshot(snapshot&) -> void;
#endif
auto stall_cycles(cycle_count) -> void;
auto trigger_nmi() -> void;
auto step() -> status;
auto is_nmi_pending() const -> bool { return nmi_pending_; } // XXX: Debugging
// Memory access
auto read8(address) -> u8;
auto read16(address) -> u16;
auto write8(address, u8) -> void;
auto write16(address, u16) -> void;
private:
// Instructions
#define DEFINE_SIMPLE_INSTRUCTION(name) \
auto run_##name() -> status;
#define DEFINE_OPERAND_INSTRUCTION(name) \
template<addressing_mode Mode> auto run_##name() -> status;
DEFINE_OPERAND_INSTRUCTION(brk)
DEFINE_OPERAND_INSTRUCTION(ora)
DEFINE_SIMPLE_INSTRUCTION(stp)
DEFINE_OPERAND_INSTRUCTION(slo)
DEFINE_OPERAND_INSTRUCTION(nop)
DEFINE_SIMPLE_INSTRUCTION(nop)
DEFINE_SIMPLE_INSTRUCTION(php)
DEFINE_OPERAND_INSTRUCTION(asl)
DEFINE_OPERAND_INSTRUCTION(anc)
DEFINE_OPERAND_INSTRUCTION(bpl)
DEFINE_SIMPLE_INSTRUCTION(clc)
DEFINE_OPERAND_INSTRUCTION(jsr)
DEFINE_OPERAND_INSTRUCTION(and)
DEFINE_OPERAND_INSTRUCTION(rla)
DEFINE_OPERAND_INSTRUCTION(bit)
DEFINE_OPERAND_INSTRUCTION(rol)
DEFINE_SIMPLE_INSTRUCTION(plp)
DEFINE_OPERAND_INSTRUCTION(bmi)
DEFINE_SIMPLE_INSTRUCTION(sec)
DEFINE_SIMPLE_INSTRUCTION(rti)
DEFINE_OPERAND_INSTRUCTION(eor)
DEFINE_OPERAND_INSTRUCTION(sre)
DEFINE_OPERAND_INSTRUCTION(lsr)
DEFINE_OPERAND_INSTRUCTION(alr)
DEFINE_SIMPLE_INSTRUCTION(pha)
DEFINE_OPERAND_INSTRUCTION(jmp)
DEFINE_OPERAND_INSTRUCTION(bvc)
DEFINE_SIMPLE_INSTRUCTION(cli)
DEFINE_SIMPLE_INSTRUCTION(rts)
DEFINE_OPERAND_INSTRUCTION(adc)
DEFINE_OPERAND_INSTRUCTION(rra)
DEFINE_OPERAND_INSTRUCTION(ror)
DEFINE_OPERAND_INSTRUCTION(arr)
DEFINE_SIMPLE_INSTRUCTION(pla)
DEFINE_OPERAND_INSTRUCTION(bvs)
DEFINE_SIMPLE_INSTRUCTION(sei)
DEFINE_OPERAND_INSTRUCTION(sta)
DEFINE_OPERAND_INSTRUCTION(ahx)
DEFINE_OPERAND_INSTRUCTION(sax)
DEFINE_OPERAND_INSTRUCTION(sty)
DEFINE_OPERAND_INSTRUCTION(stx)
DEFINE_SIMPLE_INSTRUCTION(dey)
DEFINE_SIMPLE_INSTRUCTION(txa)
DEFINE_OPERAND_INSTRUCTION(xaa)
DEFINE_OPERAND_INSTRUCTION(bcc)
DEFINE_SIMPLE_INSTRUCTION(tya)
DEFINE_SIMPLE_INSTRUCTION(txs)
DEFINE_OPERAND_INSTRUCTION(tas)
DEFINE_OPERAND_INSTRUCTION(shy)
DEFINE_OPERAND_INSTRUCTION(shx)
DEFINE_OPERAND_INSTRUCTION(ldy)
DEFINE_OPERAND_INSTRUCTION(lda)
DEFINE_OPERAND_INSTRUCTION(ldx)
DEFINE_OPERAND_INSTRUCTION(lax)
DEFINE_SIMPLE_INSTRUCTION(tay)
DEFINE_SIMPLE_INSTRUCTION(tax)
DEFINE_OPERAND_INSTRUCTION(bcs)
DEFINE_SIMPLE_INSTRUCTION(clv)
DEFINE_SIMPLE_INSTRUCTION(tsx)
DEFINE_OPERAND_INSTRUCTION(las)
DEFINE_OPERAND_INSTRUCTION(cpy)
DEFINE_OPERAND_INSTRUCTION(axs)
DEFINE_OPERAND_INSTRUCTION(cmp)
DEFINE_OPERAND_INSTRUCTION(dcp)
DEFINE_OPERAND_INSTRUCTION(dec)
DEFINE_SIMPLE_INSTRUCTION(iny)
DEFINE_SIMPLE_INSTRUCTION(dex)
DEFINE_OPERAND_INSTRUCTION(bne)
DEFINE_SIMPLE_INSTRUCTION(cld)
DEFINE_OPERAND_INSTRUCTION(cpx)
DEFINE_OPERAND_INSTRUCTION(sbc)
DEFINE_OPERAND_INSTRUCTION(isc)
DEFINE_OPERAND_INSTRUCTION(inc)
DEFINE_SIMPLE_INSTRUCTION(inx)
DEFINE_OPERAND_INSTRUCTION(beq)
DEFINE_SIMPLE_INSTRUCTION(sed)
#undef DEFINE_SIMPLE_INSTRUCTION
#undef DEFINE_OPERAND_INSTRUCTION
// Helpers
auto advance_pc8() -> u8;
auto advance_pc16() -> u16;
auto push_stack8(u8) -> void;
auto push_stack16(u16) -> void;
auto pop_stack8() -> u8;
auto pop_stack16() -> u16;
auto update_zn(u8 value) -> void;
template<addressing_mode Mode>
auto branch(bool condition) -> void;
auto execute_interrupt(address) -> void;
auto eval_ror(u8 arg) -> u8;
auto eval_rol(u8 arg) -> u8;
auto eval_asl(u8 arg) -> u8;
auto eval_lsr(u8 arg) -> u8;
auto eval_adc(u8 arg) -> void;
auto eval_and(u8 arg) -> void;
auto eval_ora(u8 arg) -> void;
auto eval_eor(u8 arg) -> void;
auto eval_cmp(u8 a, u8 b) -> void;
auto eval_plp() -> void;
auto eval_php() -> void;
// Operands
#define DEFINE_CYCLE_COUNT(name) \
template<addressing_mode Mode> static auto name##_cycle_count() -> cycle_count;
#define DEFINE_CYCLE_COUNT_INSTANCE(name, mode, value) \
template<> auto name##_cycle_count<addressing_mode::mode>() -> cycle_count { return cycle_count::from_cpu(value); }
DEFINE_CYCLE_COUNT(jump)
DEFINE_CYCLE_COUNT_INSTANCE(jump, absolute, 3)
DEFINE_CYCLE_COUNT_INSTANCE(jump, indirect, 5)
DEFINE_CYCLE_COUNT(shift)
DEFINE_CYCLE_COUNT_INSTANCE(shift, accumulator, 2)
DEFINE_CYCLE_COUNT_INSTANCE(shift, zero_page, 5)
DEFINE_CYCLE_COUNT_INSTANCE(shift, zero_page_indexed_x, 6)
DEFINE_CYCLE_COUNT_INSTANCE(shift, absolute, 6)
DEFINE_CYCLE_COUNT_INSTANCE(shift, absolute_indexed_x, 7)
DEFINE_CYCLE_COUNT(inc_dec)
DEFINE_CYCLE_COUNT_INSTANCE(inc_dec, zero_page, 5)
DEFINE_CYCLE_COUNT_INSTANCE(inc_dec, zero_page_indexed_x, 6)
DEFINE_CYCLE_COUNT_INSTANCE(inc_dec, absolute, 6)
DEFINE_CYCLE_COUNT_INSTANCE(inc_dec, absolute_indexed_x, 7)
#undef DEFINE_CYCLE_COUNT
#undef DEFINE_CYCLE_COUNT_INSTANCE
template<addressing_mode Mode>
auto fetch_operand(force_page_crossing = force_page_crossing::no) -> operand<Mode>;
template<>
auto fetch_operand<addressing_mode::accumulator>(force_page_crossing) -> operand<addressing_mode::accumulator>;
template<>
auto fetch_operand<addressing_mode::immediate>(force_page_crossing) -> operand<addressing_mode::immediate>;
};
} // namespace nes::sys
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