Duckstation/src/core/bus.h
2022-07-21 17:29:58 +10:00

182 lines
5 KiB
C++

#pragma once
#include "common/bitfield.h"
#include "util/memory_arena.h"
#include "types.h"
#include <array>
#include <bitset>
#include <optional>
#include <string>
#include <vector>
class StateWrapper;
namespace Bus {
enum : u32
{
RAM_BASE = 0x00000000,
RAM_2MB_SIZE = 0x200000,
RAM_2MB_MASK = RAM_2MB_SIZE - 1,
RAM_8MB_SIZE = 0x800000,
RAM_8MB_MASK = RAM_8MB_SIZE - 1,
RAM_MIRROR_END = 0x800000,
EXP1_BASE = 0x1F000000,
EXP1_SIZE = 0x800000,
EXP1_MASK = EXP1_SIZE - 1,
MEMCTRL_BASE = 0x1F801000,
MEMCTRL_SIZE = 0x40,
MEMCTRL_MASK = MEMCTRL_SIZE - 1,
PAD_BASE = 0x1F801040,
PAD_SIZE = 0x10,
PAD_MASK = PAD_SIZE - 1,
SIO_BASE = 0x1F801050,
SIO_SIZE = 0x10,
SIO_MASK = SIO_SIZE - 1,
MEMCTRL2_BASE = 0x1F801060,
MEMCTRL2_SIZE = 0x10,
MEMCTRL2_MASK = MEMCTRL2_SIZE - 1,
INTERRUPT_CONTROLLER_BASE = 0x1F801070,
INTERRUPT_CONTROLLER_SIZE = 0x10,
INTERRUPT_CONTROLLER_MASK = INTERRUPT_CONTROLLER_SIZE - 1,
DMA_BASE = 0x1F801080,
DMA_SIZE = 0x80,
DMA_MASK = DMA_SIZE - 1,
TIMERS_BASE = 0x1F801100,
TIMERS_SIZE = 0x40,
TIMERS_MASK = TIMERS_SIZE - 1,
CDROM_BASE = 0x1F801800,
CDROM_SIZE = 0x10,
CDROM_MASK = CDROM_SIZE - 1,
GPU_BASE = 0x1F801810,
GPU_SIZE = 0x10,
GPU_MASK = GPU_SIZE - 1,
MDEC_BASE = 0x1F801820,
MDEC_SIZE = 0x10,
MDEC_MASK = MDEC_SIZE - 1,
SPU_BASE = 0x1F801C00,
SPU_SIZE = 0x400,
SPU_MASK = 0x3FF,
EXP2_BASE = 0x1F802000,
EXP2_SIZE = 0x2000,
EXP2_MASK = EXP2_SIZE - 1,
EXP3_BASE = 0x1FA00000,
EXP3_SIZE = 0x1,
EXP3_MASK = EXP3_SIZE - 1,
BIOS_BASE = 0x1FC00000,
BIOS_SIZE = 0x80000,
BIOS_MASK = 0x7FFFF,
};
enum : u32
{
MEMCTRL_REG_COUNT = 9
};
enum : TickCount
{
RAM_READ_TICKS = 6
};
enum : size_t
{
// Our memory arena contains storage for RAM.
MEMORY_ARENA_SIZE = RAM_8MB_SIZE,
// Offsets within the memory arena.
MEMORY_ARENA_RAM_OFFSET = 0,
#ifdef WITH_MMAP_FASTMEM
// Fastmem region size is 4GB to cover the entire 32-bit address space.
FASTMEM_REGION_SIZE = UINT64_C(0x100000000),
#endif
};
enum : u32
{
RAM_2MB_CODE_PAGE_COUNT = (RAM_2MB_SIZE + (HOST_PAGE_SIZE + 1)) / HOST_PAGE_SIZE,
RAM_8MB_CODE_PAGE_COUNT = (RAM_8MB_SIZE + (HOST_PAGE_SIZE + 1)) / HOST_PAGE_SIZE,
FASTMEM_LUT_NUM_PAGES = 0x100000, // 0x100000000 >> 12
FASTMEM_LUT_NUM_SLOTS = FASTMEM_LUT_NUM_PAGES * 2,
};
bool Initialize();
void Shutdown();
void Reset();
bool DoState(StateWrapper& sw);
CPUFastmemMode GetFastmemMode();
u8* GetFastmemBase();
void UpdateFastmemViews(CPUFastmemMode mode);
bool CanUseFastmemForAddress(VirtualMemoryAddress address);
void SetExpansionROM(std::vector<u8> data);
void SetBIOS(const std::vector<u8>& image);
extern std::bitset<RAM_8MB_CODE_PAGE_COUNT> m_ram_code_bits;
extern u8* g_ram; // 2MB-8MB RAM
extern u32 g_ram_size; // Active size of RAM.
extern u32 g_ram_mask; // Active address bits for RAM.
extern u8 g_bios[BIOS_SIZE]; // 512K BIOS ROM
/// Returns true if the address specified is writable (RAM).
ALWAYS_INLINE static bool IsRAMAddress(PhysicalMemoryAddress address)
{
return address < RAM_MIRROR_END;
}
/// Returns the code page index for a RAM address.
ALWAYS_INLINE static u32 GetRAMCodePageIndex(PhysicalMemoryAddress address)
{
return (address & g_ram_mask) / HOST_PAGE_SIZE;
}
/// Returns true if the specified page contains code.
bool IsRAMCodePage(u32 index);
/// Flags a RAM region as code, so we know when to invalidate blocks.
void SetRAMCodePage(u32 index);
/// Unflags a RAM region as code, the code cache will no longer be notified when writes occur.
void ClearRAMCodePage(u32 index);
/// Clears all code bits for RAM regions.
void ClearRAMCodePageFlags();
/// Returns true if the specified address is in a code page.
bool IsCodePageAddress(PhysicalMemoryAddress address);
/// Returns true if the range specified overlaps with a code page.
bool HasCodePagesInRange(PhysicalMemoryAddress start_address, u32 size);
/// Returns the number of cycles stolen by DMA RAM access.
ALWAYS_INLINE TickCount GetDMARAMTickCount(u32 word_count)
{
// DMA is using DRAM Hyper Page mode, allowing it to access DRAM rows at 1 clock cycle per word (effectively around
// 17 clks per 16 words, due to required row address loading, probably plus some further minimal overload due to
// refresh cycles). This is making DMA much faster than CPU memory accesses (CPU DRAM access takes 1 opcode cycle
// plus 6 waitstates, ie. 7 cycles in total).
return static_cast<TickCount>(word_count + ((word_count + 15) / 16));
}
enum class MemoryRegion
{
RAM,
RAMMirror1,
RAMMirror2,
RAMMirror3,
EXP1,
Scratchpad,
BIOS,
Count
};
std::optional<MemoryRegion> GetMemoryRegionForAddress(PhysicalMemoryAddress address);
PhysicalMemoryAddress GetMemoryRegionStart(MemoryRegion region);
PhysicalMemoryAddress GetMemoryRegionEnd(MemoryRegion region);
u8* GetMemoryRegionPointer(MemoryRegion region);
std::optional<PhysicalMemoryAddress> SearchMemory(PhysicalMemoryAddress start_address, const u8* pattern,
const u8* mask, u32 pattern_length);
} // namespace Bus