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e3b9e89f5a6a1163cf966c424fec7f9e0f7d9174
dolphin/Source/Core/Core/HW/DVDInterface.cpp
JosJuice e3b9e89f5a Move DVDRead from DVDInterface to Boot 
It was previously an important part of DVDInterface,
but since its usage there was replaced with DVDThread,
the only remaining uses of it are in Boot and Boot_BS2Emu.
2015-11-16 23:22:53 +01:00

1401 lines
42 KiB
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// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#include <cinttypes>
#include <cmath>
#include <memory>
#include <string>
#include "AudioCommon/AudioCommon.h"
#include "Common/ChunkFile.h"
#include "Common/CommonTypes.h"
#include "Common/MathUtil.h"
#include "Core/ConfigManager.h"
#include "Core/Core.h"
#include "Core/CoreTiming.h"
#include "Core/Movie.h"
#include "Core/HW/AudioInterface.h"
#include "Core/HW/DVDInterface.h"
#include "Core/HW/DVDThread.h"
#include "Core/HW/Memmap.h"
#include "Core/HW/MMIO.h"
#include "Core/HW/ProcessorInterface.h"
#include "Core/HW/StreamADPCM.h"
#include "Core/HW/SystemTimers.h"
#include "Core/PowerPC/PowerPC.h"
#include "DiscIO/Volume.h"
#include "DiscIO/VolumeCreator.h"
static const double PI = 3.14159265358979323846264338328;
// Rate the drive can transfer data to main memory, given the data
// is already buffered. Measured in bytes per second.
static const u32 BUFFER_TRANSFER_RATE = 1024 * 1024 * 16;
// Disc access time measured in milliseconds
static const u32 DISC_ACCESS_TIME_MS = 50;
// The size of a Wii disc layer in bytes (is this correct?)
static const u64 WII_DISC_LAYER_SIZE = 4699979776;
// By knowing the disc read speed at two locations defined here,
// the program can calulate the speed at arbitrary locations.
// Offsets are in bytes, and speeds are in bytes per second.
//
// These speeds are approximations of speeds measured on real Wiis.
static const u32 GC_DISC_LOCATION_1_OFFSET = 0; // The beginning of a GC disc - 48 mm
static const u32 GC_DISC_LOCATION_1_READ_SPEED = (u32)(1024 * 1024 * 2.1);
static const u32 GC_DISC_LOCATION_2_OFFSET = 1459978239; // The end of a GC disc - 76 mm
static const u32 GC_DISC_LOCATION_2_READ_SPEED = (u32)(1024 * 1024 * 3.325);
static const u32 WII_DISC_LOCATION_1_OFFSET = 0; // The beginning of a Wii disc - 48 mm
static const u32 WII_DISC_LOCATION_1_READ_SPEED = (u32)(1024 * 1024 * 3.5);
static const u64 WII_DISC_LOCATION_2_OFFSET = WII_DISC_LAYER_SIZE; // The end of a Wii disc - 116 mm
static const u32 WII_DISC_LOCATION_2_READ_SPEED = (u32)(1024 * 1024 * 8.45);
// These values are used for disc read speed calculations. Calculations
// are done using an arbitrary length unit where the radius of a disc track
// is the same as the read speed at that track in bytes per second.
static const double GC_DISC_AREA_UP_TO_LOCATION_1 =
PI * GC_DISC_LOCATION_1_READ_SPEED * GC_DISC_LOCATION_1_READ_SPEED;
static const double GC_DISC_AREA_UP_TO_LOCATION_2 =
PI * GC_DISC_LOCATION_2_READ_SPEED * GC_DISC_LOCATION_2_READ_SPEED;
static const double GC_BYTES_PER_AREA_UNIT =
(GC_DISC_LOCATION_2_OFFSET - GC_DISC_LOCATION_1_OFFSET) /
(GC_DISC_AREA_UP_TO_LOCATION_2 - GC_DISC_AREA_UP_TO_LOCATION_1);
static const double WII_DISC_AREA_UP_TO_LOCATION_1 =
PI * WII_DISC_LOCATION_1_READ_SPEED * WII_DISC_LOCATION_1_READ_SPEED;
static const double WII_DISC_AREA_UP_TO_LOCATION_2 =
PI * WII_DISC_LOCATION_2_READ_SPEED * WII_DISC_LOCATION_2_READ_SPEED;
static const double WII_BYTES_PER_AREA_UNIT =
(WII_DISC_LOCATION_2_OFFSET - WII_DISC_LOCATION_1_OFFSET) /
(WII_DISC_AREA_UP_TO_LOCATION_2 - WII_DISC_AREA_UP_TO_LOCATION_1);
namespace DVDInterface
{
// internal hardware addresses
enum
{
DI_STATUS_REGISTER = 0x00,
DI_COVER_REGISTER = 0x04,
DI_COMMAND_0 = 0x08,
DI_COMMAND_1 = 0x0C,
DI_COMMAND_2 = 0x10,
DI_DMA_ADDRESS_REGISTER = 0x14,
DI_DMA_LENGTH_REGISTER = 0x18,
DI_DMA_CONTROL_REGISTER = 0x1C,
DI_IMMEDIATE_DATA_BUFFER = 0x20,
DI_CONFIG_REGISTER = 0x24
};
// debug commands which may be ORd
enum
{
STOP_DRIVE = 0,
START_DRIVE = 0x100,
ACCEPT_COPY = 0x4000,
DISC_CHECK = 0x8000,
};
// DI Status Register
union UDISR
{
u32 Hex;
struct
{
u32 BREAK : 1; // Stop the Device + Interrupt
u32 DEINITMASK : 1; // Access Device Error Int Mask
u32 DEINT : 1; // Access Device Error Int
u32 TCINTMASK : 1; // Transfer Complete Int Mask
u32 TCINT : 1; // Transfer Complete Int
u32 BRKINTMASK : 1;
u32 BRKINT : 1; // w 1: clear brkint
u32 : 25;
};
UDISR() {Hex = 0;}
UDISR(u32 _hex) {Hex = _hex;}
};
// DI Cover Register
union UDICVR
{
u32 Hex;
struct
{
u32 CVR : 1; // 0: Cover closed 1: Cover open
u32 CVRINTMASK : 1; // 1: Interrupt enabled
u32 CVRINT : 1; // r 1: Interrupt requested w 1: Interrupt clear
u32 : 29;
};
UDICVR() {Hex = 0;}
UDICVR(u32 _hex) {Hex = _hex;}
};
union UDICMDBUF
{
u32 Hex;
struct
{
u8 CMDBYTE3;
u8 CMDBYTE2;
u8 CMDBYTE1;
u8 CMDBYTE0;
};
};
// DI DMA Address Register
union UDIMAR
{
u32 Hex;
struct
{
u32 Zerobits : 5; // Must be zero (32byte aligned)
u32 : 27;
};
struct
{
u32 Address : 26;
u32 : 6;
};
};
// DI DMA Address Length Register
union UDILENGTH
{
u32 Hex;
struct
{
u32 Zerobits : 5; // Must be zero (32byte aligned)
u32 : 27;
};
struct
{
u32 Length : 26;
u32 : 6;
};
};
// DI DMA Control Register
union UDICR
{
u32 Hex;
struct
{
u32 TSTART : 1; // w:1 start r:0 ready
u32 DMA : 1; // 1: DMA Mode 0: Immediate Mode (can only do Access Register Command)
u32 RW : 1; // 0: Read Command (DVD to Memory) 1: Write Command (Memory to DVD)
u32 : 29;
};
};
union UDIIMMBUF
{
u32 Hex;
struct
{
u8 REGVAL3;
u8 REGVAL2;
u8 REGVAL1;
u8 REGVAL0;
};
};
// DI Config Register
union UDICFG
{
u32 Hex;
struct
{
u32 CONFIG : 8;
u32 : 24;
};
UDICFG() {Hex = 0;}
UDICFG(u32 _hex) {Hex = _hex;}
};
static std::unique_ptr<DiscIO::IVolume> s_inserted_volume;
// STATE_TO_SAVE
// hardware registers
static UDISR m_DISR;
static UDICVR m_DICVR;
static UDICMDBUF m_DICMDBUF[3];
static UDIMAR m_DIMAR;
static UDILENGTH m_DILENGTH;
static UDICR m_DICR;
static UDIIMMBUF m_DIIMMBUF;
static UDICFG m_DICFG;
static u32 AudioPos;
static u32 CurrentStart;
static u32 CurrentLength;
static u32 NextStart;
static u32 NextLength;
static u32 g_ErrorCode = 0;
static bool g_bDiscInside = false;
bool g_bStream = false;
static bool g_bStopAtTrackEnd = false;
static int finish_execute_command = 0;
static int dtk = 0;
static u64 g_last_read_offset;
static u64 g_last_read_time;
// GC-AM only
static unsigned char media_buffer[0x40];
static int ejectDisc;
static int insertDisc;
void EjectDiscCallback(u64 userdata, int cyclesLate);
void InsertDiscCallback(u64 userdata, int cyclesLate);
void SetLidOpen(bool _bOpen);
void UpdateInterrupts();
void GenerateDIInterrupt(DIInterruptType _DVDInterrupt);
void WriteImmediate(u32 value, u32 output_address, bool write_to_DIIMMBUF);
bool ExecuteReadCommand(u64 DVD_offset, u32 output_address, u32 DVD_length, u32 output_length, bool decrypt,
int callback_event_type, DIInterruptType* interrupt_type, u64* ticks_until_completion);
u64 SimulateDiscReadTime(u64 offset, u32 length);
s64 CalculateRawDiscReadTime(u64 offset, s64 length);
void DoState(PointerWrap &p)
{
p.DoPOD(m_DISR);
p.DoPOD(m_DICVR);
p.DoArray(m_DICMDBUF);
p.Do(m_DIMAR);
p.Do(m_DILENGTH);
p.Do(m_DICR);
p.Do(m_DIIMMBUF);
p.DoPOD(m_DICFG);
p.Do(NextStart);
p.Do(AudioPos);
p.Do(NextLength);
p.Do(g_ErrorCode);
p.Do(g_bDiscInside);
p.Do(g_bStream);
p.Do(CurrentStart);
p.Do(CurrentLength);
p.Do(g_last_read_offset);
p.Do(g_last_read_time);
p.Do(g_bStopAtTrackEnd);
DVDThread::DoState(p);
}
static void FinishExecuteCommand(u64 userdata, int cyclesLate)
{
if (m_DICR.TSTART)
{
m_DICR.TSTART = 0;
m_DILENGTH.Length = 0;
GenerateDIInterrupt((DIInterruptType)userdata);
}
}
static u32 ProcessDTKSamples(short *tempPCM, u32 num_samples)
{
// TODO: Read audio data using the DVD thread instead of blocking on it?
DVDThread::WaitUntilIdle();
u32 samples_processed = 0;
do
{
if (AudioPos >= CurrentStart + CurrentLength)
{
DEBUG_LOG(DVDINTERFACE,
"ProcessDTKSamples: NextStart=%08x,NextLength=%08x,CurrentStart=%08x,CurrentLength=%08x,AudioPos=%08x",
NextStart, NextLength, CurrentStart, CurrentLength, AudioPos);
AudioPos = NextStart;
CurrentStart = NextStart;
CurrentLength = NextLength;
if (g_bStopAtTrackEnd)
{
g_bStopAtTrackEnd = false;
g_bStream = false;
break;
}
StreamADPCM::InitFilter();
}
u8 tempADPCM[StreamADPCM::ONE_BLOCK_SIZE];
// TODO: What if we can't read from AudioPos?
s_inserted_volume->Read(AudioPos, sizeof(tempADPCM), tempADPCM, false);
AudioPos += sizeof(tempADPCM);
StreamADPCM::DecodeBlock(tempPCM + samples_processed * 2, tempADPCM);
samples_processed += StreamADPCM::SAMPLES_PER_BLOCK;
} while (samples_processed < num_samples);
for (unsigned i = 0; i < samples_processed * 2; ++i)
{
// TODO: Fix the mixer so it can accept non-byte-swapped samples.
tempPCM[i] = Common::swap16(tempPCM[i]);
}
return samples_processed;
}
static void DTKStreamingCallback(u64 userdata, int cyclesLate)
{
// Send audio to the mixer.
static const int NUM_SAMPLES = 48000 / 2000 * 7; // 3.5ms of 48kHz samples
short tempPCM[NUM_SAMPLES * 2];
unsigned samples_processed;
if (g_bStream && AudioInterface::IsPlaying())
{
samples_processed = ProcessDTKSamples(tempPCM, NUM_SAMPLES);
}
else
{
memset(tempPCM, 0, sizeof(tempPCM));
samples_processed = NUM_SAMPLES;
}
g_sound_stream->GetMixer()->PushStreamingSamples(tempPCM, samples_processed);
int ticks_to_dtk = int(SystemTimers::GetTicksPerSecond() * u64(samples_processed) / 48000);
CoreTiming::ScheduleEvent(ticks_to_dtk - cyclesLate, dtk);
}
void Init()
{
DVDThread::Start();
m_DISR.Hex = 0;
m_DICVR.Hex = 1; // Disc Channel relies on cover being open when no disc is inserted
m_DICMDBUF[0].Hex = 0;
m_DICMDBUF[1].Hex = 0;
m_DICMDBUF[2].Hex = 0;
m_DIMAR.Hex = 0;
m_DILENGTH.Hex = 0;
m_DICR.Hex = 0;
m_DIIMMBUF.Hex = 0;
m_DICFG.Hex = 0;
m_DICFG.CONFIG = 1; // Disable bootrom descrambler
AudioPos = 0;
NextStart = 0;
NextLength = 0;
CurrentStart = 0;
CurrentLength = 0;
g_ErrorCode = 0;
g_bDiscInside = false;
g_bStream = false;
g_bStopAtTrackEnd = false;
g_last_read_offset = 0;
g_last_read_time = 0;
ejectDisc = CoreTiming::RegisterEvent("EjectDisc", EjectDiscCallback);
insertDisc = CoreTiming::RegisterEvent("InsertDisc", InsertDiscCallback);
finish_execute_command = CoreTiming::RegisterEvent("FinishExecuteCommand", FinishExecuteCommand);
dtk = CoreTiming::RegisterEvent("StreamingTimer", DTKStreamingCallback);
CoreTiming::ScheduleEvent(0, dtk);
}
void Shutdown()
{
DVDThread::Stop();
s_inserted_volume.reset();
}
const DiscIO::IVolume& GetVolume()
{
return *s_inserted_volume;
}
bool SetVolumeName(const std::string& disc_path)
{
DVDThread::WaitUntilIdle();
s_inserted_volume = std::unique_ptr<DiscIO::IVolume>(DiscIO::CreateVolumeFromFilename(disc_path));
return VolumeIsValid();
}
bool SetVolumeDirectory(const std::string& full_path, bool is_wii, const std::string& apploader_path, const std::string& DOL_path)
{
DVDThread::WaitUntilIdle();
s_inserted_volume = std::unique_ptr<DiscIO::IVolume>(DiscIO::CreateVolumeFromDirectory(full_path, is_wii, apploader_path, DOL_path));
return VolumeIsValid();
}
bool VolumeIsValid()
{
return s_inserted_volume != nullptr;
}
void SetDiscInside(bool _DiscInside)
{
if (g_bDiscInside != _DiscInside)
SetLidOpen(!_DiscInside);
g_bDiscInside = _DiscInside;
}
bool IsDiscInside()
{
return g_bDiscInside;
}
// Take care of all logic of "swapping discs"
// We want this in the "backend", NOT the gui
// any !empty string will be deleted to ensure
// that the userdata string exists when called
void EjectDiscCallback(u64 userdata, int cyclesLate)
{
DVDThread::WaitUntilIdle();
s_inserted_volume.reset();
SetDiscInside(false);
}
void InsertDiscCallback(u64 userdata, int cyclesLate)
{
std::string& SavedFileName = SConfig::GetInstance().m_strFilename;
std::string *_FileName = (std::string *)userdata;
if (!SetVolumeName(*_FileName))
{
// Put back the old one
SetVolumeName(SavedFileName);
PanicAlertT("Invalid file");
}
SetDiscInside(VolumeIsValid());
delete _FileName;
}
void ChangeDisc(const std::string& newFileName)
{
bool is_cpu = Core::IsCPUThread();
bool was_unpaused = is_cpu ? false : Core::PauseAndLock(true);
std::string* _FileName = new std::string(newFileName);
CoreTiming::ScheduleEvent(0, ejectDisc);
CoreTiming::ScheduleEvent(500000000, insertDisc, (u64)_FileName);
if (Movie::IsRecordingInput())
{
Movie::g_bDiscChange = true;
std::string fileName = newFileName;
auto sizeofpath = fileName.find_last_of("/\\") + 1;
if (fileName.substr(sizeofpath).length() > 40)
{
PanicAlertT("The disc change to \"%s\" could not be saved in the .dtm file.\n"
"The filename of the disc image must not be longer than 40 characters.", newFileName.c_str());
}
Movie::g_discChange = fileName.substr(sizeofpath);
}
if (!is_cpu)
Core::PauseAndLock(false, was_unpaused);
}
void SetLidOpen(bool _bOpen)
{
m_DICVR.CVR = _bOpen ? 1 : 0;
GenerateDIInterrupt(INT_CVRINT);
}
bool ChangePartition(u64 offset)
{
DVDThread::WaitUntilIdle();
return s_inserted_volume->ChangePartition(offset);
}
void RegisterMMIO(MMIO::Mapping* mmio, u32 base)
{
mmio->Register(base | DI_STATUS_REGISTER,
MMIO::DirectRead<u32>(&m_DISR.Hex),
MMIO::ComplexWrite<u32>([](u32, u32 val) {
UDISR tmpStatusReg(val);
m_DISR.DEINITMASK = tmpStatusReg.DEINITMASK;
m_DISR.TCINTMASK = tmpStatusReg.TCINTMASK;
m_DISR.BRKINTMASK = tmpStatusReg.BRKINTMASK;
m_DISR.BREAK = tmpStatusReg.BREAK;
if (tmpStatusReg.DEINT)
m_DISR.DEINT = 0;
if (tmpStatusReg.TCINT)
m_DISR.TCINT = 0;
if (tmpStatusReg.BRKINT)
m_DISR.BRKINT = 0;
if (m_DISR.BREAK)
{
_dbg_assert_(DVDINTERFACE, 0);
}
UpdateInterrupts();
})
);
mmio->Register(base | DI_COVER_REGISTER,
MMIO::DirectRead<u32>(&m_DICVR.Hex),
MMIO::ComplexWrite<u32>([](u32, u32 val) {
UDICVR tmpCoverReg(val);
m_DICVR.CVRINTMASK = tmpCoverReg.CVRINTMASK;
if (tmpCoverReg.CVRINT)
m_DICVR.CVRINT = 0;
UpdateInterrupts();
})
);
// Command registers are very similar and we can register them with a
// simple loop.
for (int i = 0; i < 3; ++i)
mmio->Register(base | (DI_COMMAND_0 + 4 * i),
MMIO::DirectRead<u32>(&m_DICMDBUF[i].Hex),
MMIO::DirectWrite<u32>(&m_DICMDBUF[i].Hex)
);
// DMA related registers. Mostly direct accesses (+ masking for writes to
// handle things like address alignment) and complex write on the DMA
// control register that will trigger the DMA.
mmio->Register(base | DI_DMA_ADDRESS_REGISTER,
MMIO::DirectRead<u32>(&m_DIMAR.Hex),
MMIO::DirectWrite<u32>(&m_DIMAR.Hex, ~0xFC00001F)
);
mmio->Register(base | DI_DMA_LENGTH_REGISTER,
MMIO::DirectRead<u32>(&m_DILENGTH.Hex),
MMIO::DirectWrite<u32>(&m_DILENGTH.Hex, ~0x1F)
);
mmio->Register(base | DI_DMA_CONTROL_REGISTER,
MMIO::DirectRead<u32>(&m_DICR.Hex),
MMIO::ComplexWrite<u32>([](u32, u32 val) {
m_DICR.Hex = val & 7;
if (m_DICR.TSTART)
{
ExecuteCommand(m_DICMDBUF[0].Hex, m_DICMDBUF[1].Hex, m_DICMDBUF[2].Hex,
m_DIMAR.Hex, m_DILENGTH.Hex, true, finish_execute_command);
}
})
);
mmio->Register(base | DI_IMMEDIATE_DATA_BUFFER,
MMIO::DirectRead<u32>(&m_DIIMMBUF.Hex),
MMIO::DirectWrite<u32>(&m_DIIMMBUF.Hex)
);
// DI config register is read only.
mmio->Register(base | DI_CONFIG_REGISTER,
MMIO::DirectRead<u32>(&m_DICFG.Hex),
MMIO::InvalidWrite<u32>()
);
}
void UpdateInterrupts()
{
if ((m_DISR.DEINT & m_DISR.DEINITMASK) ||
(m_DISR.TCINT & m_DISR.TCINTMASK) ||
(m_DISR.BRKINT & m_DISR.BRKINTMASK) ||
(m_DICVR.CVRINT & m_DICVR.CVRINTMASK))
{
ProcessorInterface::SetInterrupt(ProcessorInterface::INT_CAUSE_DI, true);
}
else
{
ProcessorInterface::SetInterrupt(ProcessorInterface::INT_CAUSE_DI, false);
}
// Required for Summoner: A Goddess Reborn
CoreTiming::ForceExceptionCheck(50);
}
void GenerateDIInterrupt(DIInterruptType _DVDInterrupt)
{
switch (_DVDInterrupt)
{
case INT_DEINT: m_DISR.DEINT = 1; break;
case INT_TCINT: m_DISR.TCINT = 1; break;
case INT_BRKINT: m_DISR.BRKINT = 1; break;
case INT_CVRINT: m_DICVR.CVRINT = 1; break;
}
UpdateInterrupts();
}
void WriteImmediate(u32 value, u32 output_address, bool write_to_DIIMMBUF)
{
if (write_to_DIIMMBUF)
m_DIIMMBUF.Hex = value;
else
Memory::Write_U32(value, output_address);
}
// Iff false is returned, ScheduleEvent must be used to finish executing the command
bool ExecuteReadCommand(u64 DVD_offset, u32 output_address, u32 DVD_length, u32 output_length, bool decrypt,
int callback_event_type, DIInterruptType* interrupt_type, u64* ticks_until_completion)
{
if (!g_bDiscInside)
{
// Disc read fails
g_ErrorCode = ERROR_NO_DISK | ERROR_COVER_H;
*interrupt_type = INT_DEINT;
return false;
}
else
{
// Disc read succeeds
*interrupt_type = INT_TCINT;
}
if (DVD_length > output_length)
{
WARN_LOG(DVDINTERFACE, "Detected attempt to read more data from the DVD than fit inside the out buffer. Clamp.");
DVD_length = output_length;
}
if (SConfig::GetInstance().bFastDiscSpeed)
// An optional hack to speed up loading times
*ticks_until_completion = output_length * (SystemTimers::GetTicksPerSecond() / BUFFER_TRANSFER_RATE);
else
*ticks_until_completion = SimulateDiscReadTime(DVD_offset, DVD_length);
DVDThread::StartRead(DVD_offset, output_address, DVD_length, decrypt,
callback_event_type, (int)*ticks_until_completion);
return true;
}
// When the command has finished executing, callback_event_type
// will be called using CoreTiming::ScheduleEvent,
// with the userdata set to the interrupt type.
void ExecuteCommand(u32 command_0, u32 command_1, u32 command_2, u32 output_address, u32 output_length,
bool write_to_DIIMMBUF, int callback_event_type)
{
DIInterruptType interrupt_type = INT_TCINT;
u64 ticks_until_completion = SystemTimers::GetTicksPerSecond() / 15000;
bool command_handled_by_thread = false;
bool GCAM = (SConfig::GetInstance().m_SIDevice[0] == SIDEVICE_AM_BASEBOARD) &&
(SConfig::GetInstance().m_EXIDevice[2] == EXIDEVICE_AM_BASEBOARD);
// DVDLowRequestError needs access to the error code set by the previous command
if (command_0 >> 24 != DVDLowRequestError)
g_ErrorCode = 0;
if (GCAM)
{
ERROR_LOG(DVDINTERFACE, "DVD: %08x, %08x, %08x, DMA=addr:%08x,len:%08x,ctrl:%08x",
command_0, command_1, command_2, output_address, output_length, m_DICR.Hex);
// decrypt command. But we have a zero key, that simplifies things a lot.
// If you get crazy dvd command errors, make sure 0x80000000 - 0x8000000c is zero'd
command_0 <<= 24;
}
switch (command_0 >> 24)
{
// Seems to be used by both GC and Wii
case DVDLowInquiry:
if (GCAM)
{
// 0x29484100...
// was 21 i'm not entirely sure about this, but it works well.
WriteImmediate(0x21000000, output_address, write_to_DIIMMBUF);
}
else
{
// (shuffle2) Taken from my Wii
Memory::Write_U32(0x00000002, output_address);
Memory::Write_U32(0x20060526, output_address + 4);
// This was in the oubuf even though this cmd is only supposed to reply with 64bits
// However, this and other tests strongly suggest that the buffer is static, and it's never - or rarely cleared.
Memory::Write_U32(0x41000000, output_address + 8);
INFO_LOG(DVDINTERFACE, "DVDLowInquiry (Buffer 0x%08x, 0x%x)",
output_address, output_length);
}
break;
// Only seems to be used from WII_IPC, not through direct access
case DVDLowReadDiskID:
INFO_LOG(DVDINTERFACE, "DVDLowReadDiskID");
command_handled_by_thread = ExecuteReadCommand(0, output_address, 0x20, output_length, false,
callback_event_type, &interrupt_type, &ticks_until_completion);
break;
// Only used from WII_IPC. This is the only read command that decrypts data
case DVDLowRead:
INFO_LOG(DVDINTERFACE, "DVDLowRead: DVDAddr: 0x%09" PRIx64 ", Size: 0x%x", (u64)command_2 << 2, command_1);
command_handled_by_thread = ExecuteReadCommand((u64)command_2 << 2, output_address, command_1, output_length, true,
callback_event_type, &interrupt_type, &ticks_until_completion);
break;
// Probably only used by Wii
case DVDLowWaitForCoverClose:
INFO_LOG(DVDINTERFACE, "DVDLowWaitForCoverClose");
interrupt_type = (DIInterruptType)4; // ???
break;
// "Set Extension"...not sure what it does. GC only?
case 0x55:
INFO_LOG(DVDINTERFACE, "SetExtension");
break;
// Probably only used though WII_IPC
case DVDLowGetCoverReg:
WriteImmediate(m_DICVR.Hex, output_address, write_to_DIIMMBUF);
INFO_LOG(DVDINTERFACE, "DVDLowGetCoverReg 0x%08x", m_DICVR.Hex);
break;
// Probably only used by Wii
case DVDLowNotifyReset:
ERROR_LOG(DVDINTERFACE, "DVDLowNotifyReset");
PanicAlert("DVDLowNotifyReset");
break;
// Probably only used by Wii
case DVDLowReadDvdPhysical:
ERROR_LOG(DVDINTERFACE, "DVDLowReadDvdPhysical");
PanicAlert("DVDLowReadDvdPhysical");
break;
// Probably only used by Wii
case DVDLowReadDvdCopyright:
ERROR_LOG(DVDINTERFACE, "DVDLowReadDvdCopyright");
PanicAlert("DVDLowReadDvdCopyright");
break;
// Probably only used by Wii
case DVDLowReadDvdDiscKey:
ERROR_LOG(DVDINTERFACE, "DVDLowReadDvdDiscKey");
PanicAlert("DVDLowReadDvdDiscKey");
break;
// Probably only used by Wii
case DVDLowClearCoverInterrupt:
INFO_LOG(DVDINTERFACE, "DVDLowClearCoverInterrupt");
m_DICVR.CVRINT = 0;
break;
// Probably only used by Wii
case DVDLowGetCoverStatus:
WriteImmediate(g_bDiscInside ? 2 : 1, output_address, write_to_DIIMMBUF);
INFO_LOG(DVDINTERFACE, "DVDLowGetCoverStatus: Disc %sInserted", g_bDiscInside ? "" : "Not ");
break;
// Probably only used by Wii
case DVDLowReset:
INFO_LOG(DVDINTERFACE, "DVDLowReset");
break;
// Probably only used by Wii
case DVDLowClosePartition:
INFO_LOG(DVDINTERFACE, "DVDLowClosePartition");
break;
// Probably only used by Wii
case DVDLowUnencryptedRead:
INFO_LOG(DVDINTERFACE, "DVDLowUnencryptedRead: DVDAddr: 0x%09" PRIx64 ", Size: 0x%x", (u64)command_2 << 2, command_1);
// We must make sure it is in a valid area! (#001 check)
// Are these checks correct? They seem to mix 32-bit offsets and 8-bit lengths
// * 0x00000000 - 0x00014000 (limit of older IOS versions)
// * 0x460a0000 - 0x460a0008
// * 0x7ed40000 - 0x7ed40008
if (((command_2 > 0x00000000 && command_2 < 0x00014000) ||
(((command_2 + command_1) > 0x00000000) && (command_2 + command_1) < 0x00014000) ||
(command_2 > 0x460a0000 && command_2 < 0x460a0008) ||
(((command_2 + command_1) > 0x460a0000) && (command_2 + command_1) < 0x460a0008) ||
(command_2 > 0x7ed40000 && command_2 < 0x7ed40008) ||
(((command_2 + command_1) > 0x7ed40000) && (command_2 + command_1) < 0x7ed40008)))
{
command_handled_by_thread = ExecuteReadCommand((u64)command_2 << 2, output_address, command_1, output_length, false,
callback_event_type, &interrupt_type, &ticks_until_completion);
}
else
{
WARN_LOG(DVDINTERFACE, "DVDLowUnencryptedRead: trying to read out of bounds @ %09" PRIx64, (u64)command_2 << 2);
g_ErrorCode = ERROR_READY | ERROR_BLOCK_OOB;
// Should cause software to call DVDLowRequestError
interrupt_type = INT_BRKINT;
}
break;
// Probably only used by Wii
case DVDLowEnableDvdVideo:
ERROR_LOG(DVDINTERFACE, "DVDLowEnableDvdVideo");
break;
// New Super Mario Bros. Wii sends these commands,
// but it seems we don't need to implement anything.
// Probably only used by Wii
case 0x95:
case 0x96:
ERROR_LOG(DVDINTERFACE, "Unimplemented BCA command 0x%08x (Buffer 0x%08x, 0x%x)",
command_0, output_address, output_length);
break;
// Probably only used by Wii
case DVDLowReportKey:
INFO_LOG(DVDINTERFACE, "DVDLowReportKey");
// Does not work on retail discs/drives
// Retail games send this command to see if they are running on real retail hw
g_ErrorCode = ERROR_READY | ERROR_INV_CMD;
interrupt_type = INT_BRKINT;
break;
// DMA Read from Disc. Only seems to be used through direct access, not WII_IPC
case 0xA8:
switch (command_0 & 0xFF)
{
case 0x00: // Read Sector
{
u64 iDVDOffset = (u64)command_1 << 2;
INFO_LOG(DVDINTERFACE, "Read: DVDOffset=%08" PRIx64 ", DMABuffer = %08x, SrcLength = %08x, DMALength = %08x",
iDVDOffset, output_address, command_2, output_length);
if (GCAM)
{
if (iDVDOffset & 0x80000000) // read request to hardware buffer
{
switch (iDVDOffset)
{
case 0x80000000:
ERROR_LOG(DVDINTERFACE, "GC-AM: READ MEDIA BOARD STATUS (80000000)");
for (u32 i = 0; i < output_length; i += 4)
Memory::Write_U32(0, output_address + i);
break;
case 0x80000040:
ERROR_LOG(DVDINTERFACE, "GC-AM: READ MEDIA BOARD STATUS (2) (80000040)");
for (u32 i = 0; i < output_length; i += 4)
Memory::Write_U32(~0, output_address + i);
Memory::Write_U32(0x00000020, output_address); // DIMM SIZE, LE
Memory::Write_U32(0x4743414D, output_address + 4); // GCAM signature
break;
case 0x80000120:
ERROR_LOG(DVDINTERFACE, "GC-AM: READ FIRMWARE STATUS (80000120)");
for (u32 i = 0; i < output_length; i += 4)
Memory::Write_U32(0x01010101, output_address + i);
break;
case 0x80000140:
ERROR_LOG(DVDINTERFACE, "GC-AM: READ FIRMWARE STATUS (80000140)");
for (u32 i = 0; i < output_length; i += 4)
Memory::Write_U32(0x01010101, output_address + i);
break;
case 0x84000020:
ERROR_LOG(DVDINTERFACE, "GC-AM: READ MEDIA BOARD STATUS (1) (84000020)");
for (u32 i = 0; i < output_length; i += 4)
Memory::Write_U32(0x00000000, output_address + i);
break;
default:
ERROR_LOG(DVDINTERFACE, "GC-AM: UNKNOWN MEDIA BOARD LOCATION %" PRIx64, iDVDOffset);
break;
}
break;
}
else if ((iDVDOffset == 0x1f900000) || (iDVDOffset == 0x1f900020))
{
ERROR_LOG(DVDINTERFACE, "GC-AM: READ MEDIA BOARD COMM AREA (1f900020)");
u8* source = media_buffer + iDVDOffset - 0x1f900000;
Memory::CopyToEmu(output_address, source, output_length);
for (u32 i = 0; i < output_length; i += 4)
ERROR_LOG(DVDINTERFACE, "GC-AM: %08x", Memory::Read_U32(output_address + i));
break;
}
}
command_handled_by_thread = ExecuteReadCommand(iDVDOffset, output_address, command_2, output_length, false,
callback_event_type, &interrupt_type, &ticks_until_completion);
}
break;
case 0x40: // Read DiscID
INFO_LOG(DVDINTERFACE, "Read DiscID %08x", Memory::Read_U32(output_address));
command_handled_by_thread = ExecuteReadCommand(0, output_address, 0x20, output_length, false,
callback_event_type, &interrupt_type, &ticks_until_completion);
break;
default:
ERROR_LOG(DVDINTERFACE, "Unknown read subcommand: %08x", command_0);
break;
}
break;
// GC-AM only
case 0xAA:
if (GCAM)
{
ERROR_LOG(DVDINTERFACE, "GC-AM: 0xAA, DMABuffer=%08x, DMALength=%08x", output_address, output_length);
u64 iDVDOffset = (u64)command_1 << 2;
u32 len = output_length;
s64 offset = iDVDOffset - 0x1F900000;
/*
if (iDVDOffset == 0x84800000)
{
ERROR_LOG(DVDINTERFACE, "Firmware upload");
}
else*/
if ((offset < 0) || ((offset + len) > 0x40) || len > 0x40)
{
u32 addr = output_address;
if (iDVDOffset == 0x84800000)
{
ERROR_LOG(DVDINTERFACE, "FIRMWARE UPLOAD");
}
else
{
ERROR_LOG(DVDINTERFACE, "ILLEGAL MEDIA WRITE");
}
while (len >= 4)
{
ERROR_LOG(DVDINTERFACE, "GC-AM Media Board WRITE (0xAA): %08" PRIx64 ": %08x", iDVDOffset, Memory::Read_U32(addr));
addr += 4;
len -= 4;
iDVDOffset += 4;
}
}
else
{
u32 addr = m_DIMAR.Address;
Memory::CopyFromEmu(media_buffer + offset, addr, len);
while (len >= 4)
{
ERROR_LOG(DVDINTERFACE, "GC-AM Media Board WRITE (0xAA): %08" PRIx64 ": %08x", iDVDOffset, Memory::Read_U32(addr));
addr += 4;
len -= 4;
iDVDOffset += 4;
}
}
}
break;
// Seems to be used by both GC and Wii
case DVDLowSeek:
if (!GCAM)
{
// Currently unimplemented
INFO_LOG(DVDINTERFACE, "Seek: offset=%09" PRIx64 " (ignoring)", (u64)command_1 << 2);
}
else
{
memset(media_buffer, 0, 0x20);
media_buffer[0] = media_buffer[0x20]; // ID
media_buffer[2] = media_buffer[0x22];
media_buffer[3] = media_buffer[0x23] | 0x80;
int cmd = (media_buffer[0x23]<<8)|media_buffer[0x22];
ERROR_LOG(DVDINTERFACE, "GC-AM: execute buffer, cmd=%04x", cmd);
switch (cmd)
{
case 0x00:
media_buffer[4] = 1;
break;
case 0x1:
media_buffer[7] = 0x20; // DIMM Size
break;
case 0x100:
{
// urgh
static int percentage = 0;
static int status = 0;
percentage++;
if (percentage > 100)
{
status++;
percentage = 0;
}
media_buffer[4] = status;
/* status:
0 - "Initializing media board. Please wait.."
1 - "Checking network. Please wait..."
2 - "Found a system disc. Insert a game disc"
3 - "Testing a game program. %d%%"
4 - "Loading a game program. %d%%"
5 - go
6 - error xx
*/
media_buffer[8] = percentage;
media_buffer[4] = 0x05;
media_buffer[8] = 0x64;
break;
}
case 0x101:
media_buffer[4] = 3; // version
media_buffer[5] = 3;
media_buffer[6] = 1; // xxx
media_buffer[8] = 1;
media_buffer[16] = 0xFF;
media_buffer[17] = 0xFF;
media_buffer[18] = 0xFF;
media_buffer[19] = 0xFF;
break;
case 0x102: // get error code
media_buffer[4] = 1; // 0: download incomplete (31), 1: corrupted, other error 1
media_buffer[5] = 0;
break;
case 0x103:
memcpy(media_buffer + 4, "A89E27A50364511", 15); // serial
break;
#if 0
case 0x301: // unknown
memcpy(media_buffer + 4, media_buffer + 0x24, 0x1c);
break;
case 0x302:
break;
#endif
default:
ERROR_LOG(DVDINTERFACE, "GC-AM: execute buffer (unknown)");
break;
}
memset(media_buffer + 0x20, 0, 0x20);
WriteImmediate(0x66556677, output_address, write_to_DIIMMBUF); // just a random value that works.
}
break;
// Probably only used by Wii
case DVDLowReadDvd:
ERROR_LOG(DVDINTERFACE, "DVDLowReadDvd");
break;
// Probably only used by Wii
case DVDLowReadDvdConfig:
ERROR_LOG(DVDINTERFACE, "DVDLowReadDvdConfig");
break;
// Probably only used by Wii
case DVDLowStopLaser:
ERROR_LOG(DVDINTERFACE, "DVDLowStopLaser");
break;
// Probably only used by Wii
case DVDLowOffset:
ERROR_LOG(DVDINTERFACE, "DVDLowOffset");
break;
// Probably only used by Wii
case DVDLowReadDiskBca:
WARN_LOG(DVDINTERFACE, "DVDLowReadDiskBca");
Memory::Write_U32(1, output_address + 0x30);
break;
// Probably only used by Wii
case DVDLowRequestDiscStatus:
ERROR_LOG(DVDINTERFACE, "DVDLowRequestDiscStatus");
break;
// Probably only used by Wii
case DVDLowRequestRetryNumber:
ERROR_LOG(DVDINTERFACE, "DVDLowRequestRetryNumber");
break;
// Probably only used by Wii
case DVDLowSetMaximumRotation:
ERROR_LOG(DVDINTERFACE, "DVDLowSetMaximumRotation");
break;
// Probably only used by Wii
case DVDLowSerMeasControl:
ERROR_LOG(DVDINTERFACE, "DVDLowSerMeasControl");
break;
// Used by both GC and Wii
case DVDLowRequestError:
INFO_LOG(DVDINTERFACE, "Requesting error... (0x%08x)", g_ErrorCode);
WriteImmediate(g_ErrorCode, output_address, write_to_DIIMMBUF);
g_ErrorCode = 0;
break;
// Audio Stream (Immediate). Only seems to be used by some GC games
// (command_0 >> 16) & 0xFF = Subcommand
// command_1 << 2 = Offset on disc
// command_2 = Length of the stream
case 0xE1:
{
u8 cancel_stream = (command_0 >> 16) & 0xFF;
if (cancel_stream)
{
g_bStopAtTrackEnd = false;
g_bStream = false;
AudioPos = 0;
NextStart = 0;
NextLength = 0;
CurrentStart = 0;
CurrentLength = 0;
}
else
{
if ((command_1 == 0) && (command_2 == 0))
{
g_bStopAtTrackEnd = true;
}
else if (!g_bStopAtTrackEnd)
{
// Setting NextStart (a u32) like this discards two bits,
// but GC games can't be 4 GiB big, so it shouldn't matter
NextStart = command_1 << 2;
NextLength = command_2;
if (!g_bStream)
{
CurrentStart = NextStart;
CurrentLength = NextLength;
AudioPos = CurrentStart;
StreamADPCM::InitFilter();
g_bStream = true;
}
}
}
INFO_LOG(DVDINTERFACE, "(Audio) Stream cmd: %08x offset: %08" PRIx64 " length: %08x",
command_0, (u64)command_1 << 2, command_2);
}
break;
// Request Audio Status (Immediate). Only seems to be used by some GC games
case 0xE2:
{
switch (command_0 >> 16 & 0xFF)
{
case 0x00: // Returns streaming status
INFO_LOG(DVDINTERFACE, "(Audio): Stream Status: Request Audio status AudioPos:%08x/%08x CurrentStart:%08x CurrentLength:%08x", AudioPos, CurrentStart + CurrentLength, CurrentStart, CurrentLength);
WriteImmediate((g_bStream) ? 1 : 0, output_address, write_to_DIIMMBUF);
break;
case 0x01: // Returns the current offset
INFO_LOG(DVDINTERFACE, "(Audio): Stream Status: Request Audio status AudioPos:%08x", AudioPos);
WriteImmediate(AudioPos >> 2, output_address, write_to_DIIMMBUF);
break;
case 0x02: // Returns the start offset
INFO_LOG(DVDINTERFACE, "(Audio): Stream Status: Request Audio status CurrentStart:%08x", CurrentStart);
WriteImmediate(CurrentStart >> 2, output_address, write_to_DIIMMBUF);
break;
case 0x03: // Returns the total length
INFO_LOG(DVDINTERFACE, "(Audio): Stream Status: Request Audio status CurrentLength:%08x", CurrentLength);
WriteImmediate(CurrentLength >> 2, output_address, write_to_DIIMMBUF);
break;
default:
WARN_LOG(DVDINTERFACE, "(Audio): Subcommand: %02x Request Audio status %s", command_0 >> 16 & 0xFF, g_bStream ? "on" : "off");
break;
}
}
break;
case DVDLowStopMotor:
INFO_LOG(DVDINTERFACE, "DVDLowStopMotor %s %s",
command_1 ? "eject" : "", command_2 ? "kill!" : "");
if (command_1 && !command_2)
EjectDiscCallback(0, 0);
break;
// DVD Audio Enable/Disable (Immediate). GC uses this, and apparently Wii also does...?
case DVDLowAudioBufferConfig:
// For more information: http://www.crazynation.org/GC/GC_DD_TECH/GCTech.htm (dead link?)
//
// Upon Power up or reset , 2 commands must be issued for proper use of audio streaming:
// DVDReadDiskID A8000040,00000000,00000020
// DVDLowAudioBufferConfig E4xx00yy,00000000,00000020
//
// xx=byte 8 [0 or 1] from the disk header retrieved from DVDReadDiskID
// yy=0 (if xx=0) or 0xA (if xx=1)
if ((command_0 >> 16) & 0xFF)
{
// TODO: What is this actually supposed to do?
g_bStream = true;
WARN_LOG(DVDINTERFACE, "(Audio): Audio enabled");
}
else
{
// TODO: What is this actually supposed to do?
g_bStream = false;
WARN_LOG(DVDINTERFACE, "(Audio): Audio disabled");
}
break;
// yet another (GC?) command we prolly don't care about
case 0xEE:
INFO_LOG(DVDINTERFACE, "SetStatus");
break;
// Debug commands; see yagcd. We don't really care
// NOTE: commands to stream data will send...a raw data stream
// This will appear as unknown commands, unless the check is re-instated to catch such data.
// Can probably only be used through direct access
case 0xFE:
ERROR_LOG(DVDINTERFACE, "Unsupported DVD Drive debug command 0x%08x", command_0);
break;
// Unlock Commands. 1: "MATSHITA" 2: "DVD-GAME"
// Just for fun
// Can probably only be used through direct access
case 0xFF:
{
if (command_0 == 0xFF014D41 &&
command_1 == 0x54534849 &&
command_2 == 0x54410200)
{
INFO_LOG(DVDINTERFACE, "Unlock test 1 passed");
}
else if (command_0 == 0xFF004456 &&
command_1 == 0x442D4741 &&
command_2 == 0x4D450300)
{
INFO_LOG(DVDINTERFACE, "Unlock test 2 passed");
}
else
{
INFO_LOG(DVDINTERFACE, "Unlock test failed");
}
}
break;
default:
ERROR_LOG(DVDINTERFACE, "Unknown command 0x%08x (Buffer 0x%08x, 0x%x)",
command_0, output_address, output_length);
PanicAlertT("Unknown DVD command %08x - fatal error", command_0);
break;
}
// The command will finish executing after a delay
// to simulate the speed of a real disc drive
if (!command_handled_by_thread)
CoreTiming::ScheduleEvent((int)ticks_until_completion, callback_event_type, interrupt_type);
}
// Simulates the timing aspects of reading data from a disc.
// Returns the amount of ticks needed to finish executing the command,
// and sets some state that is used the next time this function runs.
u64 SimulateDiscReadTime(u64 offset, u32 length)
{
// The drive buffers 1 MiB (?) of data after every read request;
// if a read request is covered by this buffer (or if it's
// faster to wait for the data to be buffered), the drive
// doesn't seek; it returns buffered data. Data can be
// transferred from the buffer at up to 16 MiB/s.
//
// If the drive has to seek, the time this takes varies a lot.
// A short seek is around 50 ms; a long seek is around 150 ms.
// However, the time isn't purely dependent on the distance; the
// pattern of previous seeks seems to matter in a way I'm
// not sure how to explain.
//
// Metroid Prime is a good example of a game that's sensitive to
// all of these details; if there isn't enough latency in the
// right places, doors open too quickly, and if there's too
// much latency in the wrong places, the video before the
// save-file select screen lags.
//
// For now, just use a very rough approximation: 50 ms seek
// for reads outside 1 MiB, accelerated reads within 1 MiB.
// We can refine this if someone comes up with a more complete
// model for seek times.
u64 current_time = CoreTiming::GetTicks();
u64 ticks_until_completion;
// Number of ticks it takes to seek and read directly from the disk.
u64 disk_read_duration = CalculateRawDiscReadTime(offset, length) +
SystemTimers::GetTicksPerSecond() / 1000 * DISC_ACCESS_TIME_MS;
if (offset + length - g_last_read_offset > 1024 * 1024)
{
// No buffer; just use the simple seek time + read time.
DEBUG_LOG(DVDINTERFACE, "Seeking %" PRId64 " bytes",
s64(g_last_read_offset) - s64(offset));
ticks_until_completion = disk_read_duration;
g_last_read_time = current_time + ticks_until_completion;
}
else
{
// Possibly buffered; use the buffer if it saves time.
// It's not proven that the buffer actually behaves like this, but
// it appears to be a decent approximation.
// Time at which the buffer will contain the data we need.
u64 buffer_fill_time = g_last_read_time +
CalculateRawDiscReadTime(g_last_read_offset,
offset + length - g_last_read_offset);
// Number of ticks it takes to transfer the data from the buffer to memory.
u64 buffer_read_duration = length *
(SystemTimers::GetTicksPerSecond() / BUFFER_TRANSFER_RATE);
if (current_time > buffer_fill_time)
{
DEBUG_LOG(DVDINTERFACE, "Fast buffer read at %" PRIx64, offset);
ticks_until_completion = buffer_read_duration;
g_last_read_time = buffer_fill_time;
}
else if (current_time + disk_read_duration > buffer_fill_time)
{
DEBUG_LOG(DVDINTERFACE, "Slow buffer read at %" PRIx64, offset);
ticks_until_completion = std::max(buffer_fill_time - current_time,
buffer_read_duration);
g_last_read_time = buffer_fill_time;
}
else
{
DEBUG_LOG(DVDINTERFACE, "Short seek %" PRId64 " bytes",
s64(g_last_read_offset) - s64(offset));
ticks_until_completion = disk_read_duration;
g_last_read_time = current_time + ticks_until_completion;
}
}
g_last_read_offset = ROUND_DOWN(offset + length - 2048, 2048);
return ticks_until_completion;
}
// Returns the number of ticks it takes to read an amount of
// data from a disc, ignoring factors such as seek times.
// The result will be negative if the length is negative.
s64 CalculateRawDiscReadTime(u64 offset, s64 length)
{
// The speed will be calculated using the average offset. This is a bit
// inaccurate since the speed doesn't increase linearly with the offset,
// but since reads only span a small part of the disc, it's insignificant.
u64 average_offset = offset + (length / 2);
// Here, addresses on the second layer of Wii discs are replaced with equivalent
// addresses on the first layer so that the speed calculation works correctly.
// This is wrong for reads spanning two layers, but those should be rare.
average_offset %= WII_DISC_LAYER_SIZE;
// The area on the disc between position 1 and the arbitrary position X is:
// LOCATION_X_SPEED * LOCATION_X_SPEED * pi - AREA_UP_TO_LOCATION_1
//
// The number of bytes between position 1 and position X is:
// LOCATION_X_OFFSET - LOCATION_1_OFFSET
//
// This means that the following equation is true:
// (LOCATION_X_SPEED * LOCATION_X_SPEED * pi - AREA_UP_TO_LOCATION_1) *
// BYTES_PER_AREA_UNIT = LOCATION_X_OFFSET - LOCATION_1_OFFSET
//
// Solving this equation for LOCATION_X_SPEED results in this:
// LOCATION_X_SPEED = sqrt(((LOCATION_X_OFFSET - LOCATION_1_OFFSET) /
// BYTES_PER_AREA_UNIT + AREA_UP_TO_LOCATION_1) / pi)
//
// Note that the speed at a track (in bytes per second) is the same as
// the radius of that track because of the length unit used.
double speed;
if (s_inserted_volume->GetVolumeType() == DiscIO::IVolume::WII_DISC)
{
speed = std::sqrt(((average_offset - WII_DISC_LOCATION_1_OFFSET) /
WII_BYTES_PER_AREA_UNIT + WII_DISC_AREA_UP_TO_LOCATION_1) / PI);
}
else
{
speed = std::sqrt(((average_offset - GC_DISC_LOCATION_1_OFFSET) /
GC_BYTES_PER_AREA_UNIT + GC_DISC_AREA_UP_TO_LOCATION_1) / PI);
}
DEBUG_LOG(DVDINTERFACE, "Disc speed: %f MiB/s", speed / 1024 / 1024);
return (s64)(SystemTimers::GetTicksPerSecond() / speed * length);
}
} // namespace
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