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-rw-r--r--src/CMakeLists.txt1
-rw-r--r--src/FATStorage.cpp47
-rw-r--r--src/FATStorage.h3
-rw-r--r--src/NDSCart.cpp230
-rw-r--r--src/NDSCart.h87
-rw-r--r--src/NDSCartR4.cpp371
6 files changed, 617 insertions, 122 deletions
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index ddb1b3c..b1ae4c4 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -38,6 +38,7 @@ add_library(core STATIC
melonDLDI.h
NDS.cpp
NDSCart.cpp
+ NDSCartR4.cpp
Platform.h
ROMList.h
ROMList.cpp
diff --git a/src/FATStorage.cpp b/src/FATStorage.cpp
index 2de42e8..52011a8 100644
--- a/src/FATStorage.cpp
+++ b/src/FATStorage.cpp
@@ -144,6 +144,48 @@ bool FATStorage::InjectFile(const std::string& path, u8* data, u32 len)
return nwrite==len;
}
+u32 FATStorage::ReadFile(const std::string& path, u32 start, u32 len, u8* data)
+{
+ if (!File) return false;
+ if (FF_File) return false;
+
+ FF_File = File;
+ FF_FileSize = FileSize;
+ ff_disk_open(FF_ReadStorage, FF_WriteStorage, (LBA_t)(FileSize>>9));
+
+ FRESULT res;
+ FATFS fs;
+
+ res = f_mount(&fs, "0:", 1);
+ if (res != FR_OK)
+ {
+ ff_disk_close();
+ FF_File = nullptr;
+ return false;
+ }
+
+ std::string prefixedPath("0:/");
+ prefixedPath += path;
+ FF_FIL file;
+ res = f_open(&file, prefixedPath.c_str(), FA_READ);
+ if (res != FR_OK)
+ {
+ f_unmount("0:");
+ ff_disk_close();
+ FF_File = nullptr;
+ return false;
+ }
+
+ u32 nread;
+ f_lseek(&file, start);
+ f_read(&file, data, len, &nread);
+ f_close(&file);
+
+ f_unmount("0:");
+ ff_disk_close();
+ FF_File = nullptr;
+ return nread;
+}
u32 FATStorage::ReadSectors(u32 start, u32 num, u8* data) const
{
@@ -156,6 +198,11 @@ u32 FATStorage::WriteSectors(u32 start, u32 num, const u8* data)
return WriteSectorsInternal(File, FileSize, start, num, data);
}
+u64 FATStorage::GetSectorCount() const
+{
+ return FileSize / 0x200;
+}
+
FileHandle* FATStorage::FF_File;
u64 FATStorage::FF_FileSize;
diff --git a/src/FATStorage.h b/src/FATStorage.h
index 0774df3..1e89b76 100644
--- a/src/FATStorage.h
+++ b/src/FATStorage.h
@@ -57,10 +57,13 @@ public:
~FATStorage();
bool InjectFile(const std::string& path, u8* data, u32 len);
+ u32 ReadFile(const std::string& path, u32 start, u32 len, u8* data);
u32 ReadSectors(u32 start, u32 num, u8* data) const;
u32 WriteSectors(u32 start, u32 num, const u8* data);
+
[[nodiscard]] bool IsReadOnly() const noexcept { return ReadOnly; }
+ u64 GetSectorCount() const;
private:
std::string FilePath;
diff --git a/src/NDSCart.cpp b/src/NDSCart.cpp
index c0e1c5f..4474f97 100644
--- a/src/NDSCart.cpp
+++ b/src/NDSCart.cpp
@@ -1145,12 +1145,12 @@ u8 CartRetailBT::SPIWrite(u8 val, u32 pos, bool last)
return 0;
}
-CartHomebrew::CartHomebrew(const u8* rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard) :
- CartHomebrew(CopyToUnique(rom, len), len, chipid, romparams, std::move(sdcard))
-{
-}
-CartHomebrew::CartHomebrew(std::unique_ptr<u8[]>&& rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard) :
+CartSD::CartSD(const u8* rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard) :
+ CartSD(CopyToUnique(rom, len), len, chipid, romparams, std::move(sdcard))
+{}
+
+CartSD::CartSD(std::unique_ptr<u8[]>&& rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard) :
CartCommon(std::move(rom), len, chipid, false, romparams, CartType::Homebrew),
SD(std::move(sdcard))
{
@@ -1158,112 +1158,11 @@ CartHomebrew::CartHomebrew(std::unique_ptr<u8[]>&& rom, u32 len, u32 chipid, ROM
// std::move on optionals usually results in an optional with a moved-from object
}
-CartHomebrew::~CartHomebrew() = default;
+CartSD::~CartSD() = default;
// The SD card is destroyed by the optional's destructor
-void CartHomebrew::Reset()
-{
- CartCommon::Reset();
-
- if (SD)
- {
- ApplyDLDIPatch(melonDLDI, sizeof(melonDLDI), SD->IsReadOnly());
- }
-}
-
-void CartHomebrew::SetupDirectBoot(const std::string& romname, NDS& nds)
-{
- CartCommon::SetupDirectBoot(romname, nds);
-
- if (SD)
- {
- // add the ROM to the SD volume
-
- if (!SD->InjectFile(romname, ROM.get(), ROMLength))
- return;
-
- // setup argv command line
-
- char argv[512] = {0};
- int argvlen;
-
- strncpy(argv, "fat:/", 511);
- strncat(argv, romname.c_str(), 511);
- argvlen = strlen(argv);
-
- const NDSHeader& header = GetHeader();
-
- u32 argvbase = header.ARM9RAMAddress + header.ARM9Size;
- argvbase = (argvbase + 0xF) & ~0xF;
-
- for (u32 i = 0; i <= argvlen; i+=4)
- nds.ARM9Write32(argvbase+i, *(u32*)&argv[i]);
-
- nds.ARM9Write32(0x02FFFE70, 0x5F617267);
- nds.ARM9Write32(0x02FFFE74, argvbase);
- nds.ARM9Write32(0x02FFFE78, argvlen+1);
- // The DSi version of ARM9Write32 will be called if nds is really a DSi
- }
-}
-
-int CartHomebrew::ROMCommandStart(NDS& nds, NDSCart::NDSCartSlot& cartslot, const u8* cmd, u8* data, u32 len)
-{
- if (CmdEncMode != 2) return CartCommon::ROMCommandStart(nds, cartslot, cmd, data, len);
-
- switch (cmd[0])
- {
- case 0xB7:
- {
- u32 addr = (cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4];
- memset(data, 0, len);
-
- if (((addr + len - 1) >> 12) != (addr >> 12))
- {
- u32 len1 = 0x1000 - (addr & 0xFFF);
- ReadROM_B7(addr, len1, data, 0);
- ReadROM_B7(addr+len1, len-len1, data, len1);
- }
- else
- ReadROM_B7(addr, len, data, 0);
- }
- return 0;
-
- case 0xC0: // SD read
- {
- u32 sector = (cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4];
- if (SD) SD->ReadSectors(sector, len>>9, data);
- }
- return 0;
-
- case 0xC1: // SD write
- return 1;
-
- default:
- return CartCommon::ROMCommandStart(nds, cartslot, cmd, data, len);
- }
-}
-
-void CartHomebrew::ROMCommandFinish(const u8* cmd, u8* data, u32 len)
-{
- if (CmdEncMode != 2) return CartCommon::ROMCommandFinish(cmd, data, len);
-
- // TODO: delayed SD writing? like we have for SRAM
-
- switch (cmd[0])
- {
- case 0xC1:
- {
- u32 sector = (cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4];
- if (SD && !SD->IsReadOnly()) SD->WriteSectors(sector, len>>9, data);
- }
- break;
-
- default:
- return CartCommon::ROMCommandFinish(cmd, data, len);
- }
-}
-void CartHomebrew::ApplyDLDIPatchAt(u8* binary, u32 dldioffset, const u8* patch, u32 patchlen, bool readonly) const
+void CartSD::ApplyDLDIPatchAt(u8* binary, u32 dldioffset, const u8* patch, u32 patchlen, bool readonly) const
{
if (patch[0x0D] > binary[dldioffset+0x0F])
{
@@ -1364,7 +1263,7 @@ void CartHomebrew::ApplyDLDIPatchAt(u8* binary, u32 dldioffset, const u8* patch,
Log(LogLevel::Debug, "applied DLDI patch at %08X\n", dldioffset);
}
-void CartHomebrew::ApplyDLDIPatch(const u8* patch, u32 patchlen, bool readonly)
+void CartSD::ApplyDLDIPatch(const u8* patch, u32 patchlen, bool readonly)
{
if (*(u32*)&patch[0] != 0xBF8DA5ED ||
*(u32*)&patch[4] != 0x69684320 ||
@@ -1394,7 +1293,7 @@ void CartHomebrew::ApplyDLDIPatch(const u8* patch, u32 patchlen, bool readonly)
}
}
-void CartHomebrew::ReadROM_B7(u32 addr, u32 len, u8* data, u32 offset) const
+void CartSD::ReadROM_B7(u32 addr, u32 len, u8* data, u32 offset) const
{
// TODO: how strict should this be for homebrew?
@@ -1403,7 +1302,115 @@ void CartHomebrew::ReadROM_B7(u32 addr, u32 len, u8* data, u32 offset) const
memcpy(data+offset, ROM.get()+addr, len);
}
+CartHomebrew::CartHomebrew(const u8* rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard) :
+ CartSD(rom, len, chipid, romparams, std::move(sdcard))
+{}
+
+CartHomebrew::CartHomebrew(std::unique_ptr<u8[]>&& rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard) :
+ CartSD(std::move(rom), len, chipid, romparams, std::move(sdcard))
+{}
+
+CartHomebrew::~CartHomebrew() = default;
+
+void CartHomebrew::Reset()
+{
+ CartSD::Reset();
+
+ if (SD)
+ ApplyDLDIPatch(melonDLDI, sizeof(melonDLDI), SD->IsReadOnly());
+}
+
+void CartHomebrew::SetupDirectBoot(const std::string& romname, NDS& nds)
+{
+ CartCommon::SetupDirectBoot(romname, nds);
+
+ if (SD)
+ {
+ // add the ROM to the SD volume
+
+ if (!SD->InjectFile(romname, ROM.get(), ROMLength))
+ return;
+
+ // setup argv command line
+
+ char argv[512] = {0};
+ int argvlen;
+
+ strncpy(argv, "fat:/", 511);
+ strncat(argv, romname.c_str(), 511);
+ argvlen = strlen(argv);
+
+ const NDSHeader& header = GetHeader();
+
+ u32 argvbase = header.ARM9RAMAddress + header.ARM9Size;
+ argvbase = (argvbase + 0xF) & ~0xF;
+
+ for (u32 i = 0; i <= argvlen; i+=4)
+ nds.ARM9Write32(argvbase+i, *(u32*)&argv[i]);
+
+ nds.ARM9Write32(0x02FFFE70, 0x5F617267);
+ nds.ARM9Write32(0x02FFFE74, argvbase);
+ nds.ARM9Write32(0x02FFFE78, argvlen+1);
+ // The DSi version of ARM9Write32 will be called if nds is really a DSi
+ }
+}
+
+int CartHomebrew::ROMCommandStart(NDS& nds, NDSCart::NDSCartSlot& cartslot, const u8* cmd, u8* data, u32 len)
+{
+ if (CmdEncMode != 2) return CartCommon::ROMCommandStart(nds, cartslot, cmd, data, len);
+ switch (cmd[0])
+ {
+ case 0xB7:
+ {
+ u32 addr = (cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4];
+ memset(data, 0, len);
+
+ if (((addr + len - 1) >> 12) != (addr >> 12))
+ {
+ u32 len1 = 0x1000 - (addr & 0xFFF);
+ ReadROM_B7(addr, len1, data, 0);
+ ReadROM_B7(addr+len1, len-len1, data, len1);
+ }
+ else
+ ReadROM_B7(addr, len, data, 0);
+ }
+ return 0;
+
+ case 0xC0: // SD read
+ {
+ u32 sector = (cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4];
+ if (SD) SD->ReadSectors(sector, len>>9, data);
+ }
+ return 0;
+
+ case 0xC1: // SD write
+ return 1;
+
+ default:
+ return CartCommon::ROMCommandStart(nds, cartslot, cmd, data, len);
+ }
+}
+
+void CartHomebrew::ROMCommandFinish(const u8* cmd, u8* data, u32 len)
+{
+ if (CmdEncMode != 2) return CartCommon::ROMCommandFinish(cmd, data, len);
+
+ // TODO: delayed SD writing? like we have for SRAM
+
+ switch (cmd[0])
+ {
+ case 0xC1:
+ {
+ u32 sector = (cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4];
+ if (SD && !SD->IsReadOnly()) SD->WriteSectors(sector, len>>9, data);
+ }
+ break;
+
+ default:
+ return CartCommon::ROMCommandFinish(cmd, data, len);
+ }
+}
NDSCartSlot::NDSCartSlot(melonDS::NDS& nds, std::unique_ptr<CartCommon>&& rom) noexcept : NDS(nds)
{
@@ -1588,6 +1595,7 @@ std::unique_ptr<CartCommon> ParseROM(std::unique_ptr<u8[]>&& romdata, u32 romlen
dsi = false;
}
+ const char *gametitle = header.GameTitle;
u32 gamecode = header.GameCodeAsU32();
u32 arm9base = header.ARM9ROMOffset;
@@ -1645,6 +1653,8 @@ std::unique_ptr<CartCommon> ParseROM(std::unique_ptr<u8[]>&& romdata, u32 romlen
auto [sram, sramlen] = args ? std::move(*args->SRAM) : std::make_pair(nullptr, 0);
if (homebrew)
cart = std::make_unique<CartHomebrew>(std::move(cartrom), cartromsize, cartid, romparams, args ? std::move(args->SDCard) : std::nullopt);
+ else if (gametitle[0] == 0 && !strncmp("SD/TF-NDS", gametitle + 1, 9) && gamecode == 0x414D5341)
+ cart = std::make_unique<CartR4>(std::move(cartrom), cartromsize, cartid, romparams, CartR4TypeR4, CartR4LanguageEnglish, args ? std::move(args->SDCard) : std::nullopt);
else if (cartid & 0x08000000)
cart = std::make_unique<CartRetailNAND>(std::move(cartrom), cartromsize, cartid, romparams, std::move(sram), sramlen);
else if (irversion != 0)
diff --git a/src/NDSCart.h b/src/NDSCart.h
index dcbc1eb..7d482ab 100644
--- a/src/NDSCart.h
+++ b/src/NDSCart.h
@@ -45,6 +45,7 @@ enum CartType
RetailIR = 0x103,
RetailBT = 0x104,
Homebrew = 0x201,
+ UnlicensedR4 = 0x301
};
class NDSCartSlot;
@@ -236,19 +237,13 @@ public:
u8 SPIWrite(u8 val, u32 pos, bool last) override;
};
-// CartHomebrew -- homebrew 'cart' (no SRAM, DLDI)
-class CartHomebrew : public CartCommon
+// CartSD -- any 'cart' with an SD card slot
+class CartSD : public CartCommon
{
public:
- CartHomebrew(const u8* rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard = std::nullopt);
- CartHomebrew(std::unique_ptr<u8[]>&& rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard = std::nullopt);
- ~CartHomebrew() override;
-
- void Reset() override;
- void SetupDirectBoot(const std::string& romname, NDS& nds) override;
-
- int ROMCommandStart(NDS& nds, NDSCart::NDSCartSlot& cartslot, const u8* cmd, u8* data, u32 len) override;
- void ROMCommandFinish(const u8* cmd, u8* data, u32 len) override;
+ CartSD(const u8* rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard = std::nullopt);
+ CartSD(std::unique_ptr<u8[]>&& rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard = std::nullopt);
+ ~CartSD() override;
[[nodiscard]] const std::optional<FATStorage>& GetSDCard() const noexcept { return SD; }
void SetSDCard(FATStorage&& sdcard) noexcept { SD = std::move(sdcard); }
@@ -260,7 +255,7 @@ public:
// it just leaves behind an optional with a moved-from value
}
-private:
+protected:
void ApplyDLDIPatchAt(u8* binary, u32 dldioffset, const u8* patch, u32 patchlen, bool readonly) const;
void ApplyDLDIPatch(const u8* patch, u32 patchlen, bool readonly);
void ReadROM_B7(u32 addr, u32 len, u8* data, u32 offset) const;
@@ -268,6 +263,74 @@ private:
std::optional<FATStorage> SD {};
};
+// CartHomebrew -- homebrew 'cart' (no SRAM, DLDI)
+class CartHomebrew : public CartSD
+{
+public:
+ CartHomebrew(const u8* rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard = std::nullopt);
+ CartHomebrew(std::unique_ptr<u8[]>&& rom, u32 len, u32 chipid, ROMListEntry romparams, std::optional<FATStorage>&& sdcard = std::nullopt);
+ ~CartHomebrew() override;
+
+ void Reset() override;
+ void SetupDirectBoot(const std::string& romname, NDS& nds) override;
+
+ int ROMCommandStart(NDS& nds, NDSCart::NDSCartSlot& cartslot, const u8* cmd, u8* data, u32 len) override;
+ void ROMCommandFinish(const u8* cmd, u8* data, u32 len) override;
+};
+
+// CartR4 -- unlicensed R4 'cart' (NDSCartR4.cpp)
+enum CartR4Type
+{
+ /* non-SDHC carts */
+ CartR4TypeM3Simply = 0,
+ CartR4TypeR4 = 1,
+ /* SDHC carts */
+ CartR4TypeAce3DS = 2
+};
+
+enum CartR4Language
+{
+ CartR4LanguageJapanese = (7 << 3) | 1,
+ CartR4LanguageEnglish = (7 << 3) | 2,
+ CartR4LanguageFrench = (2 << 3) | 2,
+ CartR4LanguageKorean = (4 << 3) | 2,
+ CartR4LanguageSimplifiedChinese = (6 << 3) | 3,
+ CartR4LanguageTraditionalChinese = (7 << 3) | 3
+};
+
+class CartR4 : public CartSD
+{
+public:
+ CartR4(std::unique_ptr<u8[]>&& rom, u32 len, u32 chipid, ROMListEntry romparams, CartR4Type ctype, CartR4Language clanguage,
+ std::optional<FATStorage>&& sdcard = std::nullopt);
+ ~CartR4() override;
+
+ void Reset() override;
+
+ void DoSavestate(Savestate* file) override;
+
+ int ROMCommandStart(NDS& nds, NDSCart::NDSCartSlot& cartslot, const u8* cmd, u8* data, u32 len) override;
+ void ROMCommandFinish(const u8* cmd, u8* data, u32 len) override;
+
+private:
+ inline u32 GetAdjustedSector(u32 sector) const
+ {
+ return R4CartType >= CartR4TypeAce3DS ? sector : sector >> 9;
+ }
+
+ u16 GetEncryptionKey(u16 sector);
+ void ReadSDToBuffer(u32 sector, bool rom);
+ u64 SDFATEntrySectorGet(u32 entry, u32 addr);
+
+ s32 EncryptionKey;
+ u32 FATEntryOffset[2];
+ u8 Buffer[512];
+ u8 InitStatus;
+ CartR4Type R4CartType;
+ CartR4Language CartLanguage;
+ bool BufferInitialized;
+};
+
class NDSCartSlot
{
public:
diff --git a/src/NDSCartR4.cpp b/src/NDSCartR4.cpp
new file mode 100644
index 0000000..8497f55
--- /dev/null
+++ b/src/NDSCartR4.cpp
@@ -0,0 +1,371 @@
+/*
+ Copyright 2016-2023 melonDS team
+
+ This file is part of melonDS.
+
+ melonDS is free software: you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free
+ Software Foundation, either version 3 of the License, or (at your option)
+ any later version.
+
+ melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#include <string.h>
+#include "NDS.h"
+#include "DSi.h"
+#include "NDSCart.h"
+#include "Platform.h"
+
+namespace melonDS
+{
+using Platform::Log;
+using Platform::LogLevel;
+
+namespace NDSCart
+{
+
+/*
+ Original algorithm discovered by yasu, 2007
+
+ http://hp.vector.co.jp/authors/VA013928/
+ http://www.usay.jp/
+ http://www.yasu.nu/
+*/
+static void DecryptR4Sector(u8* dest, u8* src, u16 key1)
+{
+ for (int i = 0; i < 512; i++)
+ {
+ // Derive key2 from key1.
+ u8 key2 = ((key1 >> 7) & 0x80)
+ | ((key1 >> 6) & 0x60)
+ | ((key1 >> 5) & 0x10)
+ | ((key1 >> 4) & 0x0C)
+ | (key1 & 0x03);
+
+ // Decrypt byte.
+ dest[i] = src[i] ^ key2;
+
+ // Derive next key1 from key2.
+ u16 tmp = ((src[i] << 8) ^ key1);
+ u16 tmpXor = 0;
+ for (int ii = 0; ii < 16; ii++)
+ tmpXor ^= (tmp >> ii);
+
+ u16 newKey1 = 0;
+ newKey1 |= ((tmpXor & 0x80) | (tmp & 0x7C)) << 8;
+ newKey1 |= ((tmp ^ (tmpXor >> 14)) << 8) & 0x0300;
+ newKey1 |= (((tmp >> 1) ^ tmp) >> 6) & 0xFC;
+ newKey1 |= ((tmp ^ (tmpXor >> 1)) >> 8) & 0x03;
+
+ key1 = newKey1;
+ }
+}
+
+CartR4::CartR4(std::unique_ptr<u8[]>&& rom, u32 len, u32 chipid, ROMListEntry romparams, CartR4Type ctype, CartR4Language clanguage,
+ std::optional<FATStorage>&& sdcard)
+ : CartSD(std::move(rom), len, chipid, romparams, std::move(sdcard))
+{
+ InitStatus = 0;
+ R4CartType = ctype;
+ CartLanguage = clanguage;
+}
+
+CartR4::~CartR4()
+{
+}
+
+void CartR4::Reset()
+{
+ CartSD::Reset();
+
+ BufferInitialized = false;
+ EncryptionKey = -1;
+ FATEntryOffset[0] = 0xFFFFFFFF;
+ FATEntryOffset[1] = 0xFFFFFFFF;
+
+ if (!SD)
+ InitStatus = 1;
+ else
+ {
+ u8 buffer[512];
+ if (!SD->ReadFile("_DS_MENU.DAT", 0, 512, buffer))
+ InitStatus = 3;
+ else
+ InitStatus = 4;
+ }
+}
+
+void CartR4::DoSavestate(Savestate* file)
+{
+ CartCommon::DoSavestate(file);
+
+ file->Var32(&FATEntryOffset[0]);
+ file->Var32(&FATEntryOffset[1]);
+ file->VarArray(Buffer, 512);
+}
+
+// FIXME: Ace3DS/clone behavior is only partially verified.
+int CartR4::ROMCommandStart(NDS& nds, NDSCart::NDSCartSlot& cartslot, const u8* cmd, u8* data, u32 len)
+{
+ if (CmdEncMode != 2)
+ return CartCommon::ROMCommandStart(nds, cartslot, cmd, data, len);
+
+ switch (cmd[0])
+ {
+ case 0xB0: /* Get card information */
+ {
+ u32 info = 0x75A00000 | (((R4CartType >= 1 ? 4 : 0) | CartLanguage) << 3) | InitStatus;
+ for (u32 pos = 0; pos < len; pos += 4)
+ *(u32*)&data[pos] = info;
+ return 0;
+ }
+ case 0xB4: /* FAT entry */
+ {
+ u8 entryBuffer[512];
+ u32 sector = ((cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4]) & (~0x1F);
+ // set FAT entry offset to the starting cluster, to gain a bit of speed
+ SD->ReadSectors(sector >> 9, 1, entryBuffer);
+ u16 fileEntryOffset = sector & 0x1FF;
+ u32 clusterStart = (entryBuffer[fileEntryOffset + 27] << 8)
+ | entryBuffer[fileEntryOffset + 26]
+ | (entryBuffer[fileEntryOffset + 21] << 24)
+ | (entryBuffer[fileEntryOffset + 20] << 16);
+ FATEntryOffset[cmd[4] & 0x01] = clusterStart;
+ for (u32 pos = 0; pos < len; pos += 4)
+ *(u32*)&data[pos] = 0;
+ return 0;
+ }
+ case 0xB8: /* ? Get chip ID ? */
+ {
+ for (u32 pos = 0; pos < len; pos += 4)
+ *(u32*)&data[pos] = ChipID;
+ return 0;
+ }
+ case 0xB2: /* Save read request */
+ case 0xB6: /* ROM read request */
+ {
+ u32 sector = ((cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4]);
+ ReadSDToBuffer(sector, cmd[0] == 0xB6);
+ for (u32 pos = 0; pos < len; pos += 4)
+ *(u32*)&data[pos] = 0;
+ return 0;
+ }
+ case 0xB9: /* SD read request */
+ {
+ u32 sector = (cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4];
+ if (SD)
+ SD->ReadSectors(GetAdjustedSector(sector), 1, Buffer);
+ for (u32 pos = 0; pos < len; pos += 4)
+ *(u32*)&data[pos] = 0;
+ return 0;
+ }
+ case 0xBB: /* SD write start */
+ case 0xBD: /* Save write start */
+ return 1;
+ case 0xBC: /* SD write status */
+ case 0xBE: /* Save write status */
+ {
+ if (R4CartType == CartR4TypeAce3DS && cmd[0] == 0xBC)
+ {
+ uint8_t checksum = 0;
+ for (int i = 0; i < 7; i++)
+ checksum ^= cmd[i];
+ if (checksum != cmd[7])
+ Log(LogLevel::Warn, "R4: invalid 0xBC command checksum (%d != %d)", cmd[7], checksum);
+ }
+ for (u32 pos = 0; pos < len; pos += 4)
+ *(u32*)&data[pos] = 0;
+ return 0;
+ }
+ case 0xB7: /* ROM read data */
+ {
+ /* If the buffer has not been initialized yet, emulate ROM. */
+ /* TODO: When does the R4 do this exactly? */
+ if (!BufferInitialized)
+ {
+ u32 addr = (cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4];
+ memcpy(data, &ROM[addr & (ROMLength-1)], len);
+ return 0;
+ }
+ /* Otherwise, fall through. */
+ }
+ case 0xB3: /* Save read data */
+ case 0xBA: /* SD read data */
+ {
+ // TODO: Do these use separate buffers?
+ for (u32 pos = 0; pos < len; pos++)
+ data[pos] = Buffer[pos & 0x1FF];
+ return 0;
+ }
+ case 0xBF: /* ROM read decrypted data */
+ {
+ // TODO: Is decryption done using the sector from 0xBF or 0xB6?
+ u32 sector = (cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4];
+ if (len >= 512)
+ DecryptR4Sector(data, Buffer, GetEncryptionKey(sector >> 9));
+ return 0;
+ }
+ default:
+ Log(LogLevel::Warn, "R4: unknown command %02X %02X %02X %02X %02X %02X %02X %02X (%d)\n", cmd[0], cmd[1], cmd[2], cmd[3], cmd[4], cmd[5], cmd[6], cmd[7], len);
+ for (u32 pos = 0; pos < len; pos += 4)
+ *(u32*)&data[pos] = 0;
+ return 0;
+ }
+}
+
+void CartR4::ROMCommandFinish(const u8* cmd, u8* data, u32 len)
+{
+ if (CmdEncMode != 2) return CartCommon::ROMCommandFinish(cmd, data, len);
+
+ switch (cmd[0])
+ {
+ case 0xBB: /* SD write start */
+ {
+ u32 sector = (cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4];
+
+ // The official R4 firmware sends a superfluous write to card
+ // (sector 0, byte 1) on boot. TODO: Is this correct?
+ if (GetAdjustedSector(sector) != sector && (sector & 0x1FF)) break;
+
+ if (SD && !SD->IsReadOnly())
+ SD->WriteSectors(GetAdjustedSector(sector), 1, data);
+ break;
+ }
+ case 0xBD: /* Save write start */
+ {
+ u32 sector = (cmd[1]<<24) | (cmd[2]<<16) | (cmd[3]<<8) | cmd[4];
+
+ if (sector & 0x1FF) break;
+
+ if (SD && !SD->IsReadOnly())
+ SD->WriteSectors(
+ SDFATEntrySectorGet(FATEntryOffset[1], sector) >> 9,
+ 1, data
+ );
+ break;
+ }
+ }
+}
+
+u16 CartR4::GetEncryptionKey(u16 sector)
+{
+ if (EncryptionKey == -1)
+ {
+ u8 encryptedBuffer[512];
+ u8 decryptedBuffer[512];
+ SD->ReadFile("_DS_MENU.DAT", 0, 512, encryptedBuffer);
+ for (u32 key = 0; key < 0x10000; key++)
+ {
+ DecryptR4Sector(decryptedBuffer, encryptedBuffer, key);
+ if (decryptedBuffer[12] == '#' && decryptedBuffer[13] == '#'
+ && decryptedBuffer[14] == '#' && decryptedBuffer[15] == '#')
+ {
+ EncryptionKey = key;
+ break;
+ }
+ }
+
+ if (EncryptionKey != -1)
+ {
+ Log(LogLevel::Warn, "R4: found cartridge key = %04X\n", EncryptionKey);
+ }
+ else
+ {
+ EncryptionKey = -2;
+ Log(LogLevel::Warn, "R4: could not find cartridge key\n");
+ }
+ }
+ return EncryptionKey ^ sector;
+}
+
+void CartR4::ReadSDToBuffer(u32 sector, bool rom)
+{
+ if (SD)
+ {
+ if (rom && FATEntryOffset[0] == 0xFFFFFFFF)
+ {
+ // On first boot, read from _DS_MENU.DAT.
+ SD->ReadFile("_DS_MENU.DAT", sector & ~0x1FF, 512, Buffer);
+ }
+ else
+ {
+ // Default mode.
+ SD->ReadSectors(
+ SDFATEntrySectorGet(FATEntryOffset[rom ? 0 : 1], sector) >> 9,
+ 1, Buffer
+ );
+ }
+ BufferInitialized = true;
+ }
+}
+
+u64 CartR4::SDFATEntrySectorGet(u32 entry, u32 addr)
+{
+ u8 buffer[512];
+ u32 bufferSector = 0xFFFFFFFF;
+
+ // Parse FAT header.
+ SD->ReadSectors(0, 1, buffer);
+ u16 bytesPerSector = (buffer[12] << 8) | buffer[11];
+ u8 sectorsPerCluster = buffer[13];
+ u16 firstFatSector = (buffer[15] << 8) | buffer[14];
+ u8 fatTableCount = buffer[16];
+ u32 clustersTotal = SD->GetSectorCount() / sectorsPerCluster;
+ bool isFat32 = clustersTotal >= 65526;
+
+ u32 fatTableSize = (buffer[23] << 8) | buffer[22];
+ if (fatTableSize == 0 && isFat32)
+ fatTableSize = (buffer[39] << 24) | (buffer[38] << 16) | (buffer[37] << 8) | buffer[36];
+ u32 bytesPerCluster = bytesPerSector * sectorsPerCluster;
+ u32 rootDirSectors = 0;
+ if (!isFat32) {
+ u32 rootDirEntries = (buffer[18] << 8) | buffer[17];
+ rootDirSectors = ((rootDirEntries * 32) + (bytesPerSector - 1)) / bytesPerSector;
+ }
+ u32 firstDataSector = firstFatSector + fatTableCount * fatTableSize + rootDirSectors;
+
+ // Parse file entry (done when processing command 0xB4).
+ u32 clusterStart = entry;
+
+ // Parse cluster table.
+ u32 currentCluster = clusterStart;
+ while (true)
+ {
+ currentCluster &= isFat32 ? 0x0FFFFFFF : 0xFFFF;
+ if (addr < bytesPerCluster)
+ {
+ // Read from this cluster.
+ return (u64) (firstDataSector + ((currentCluster - 2) * sectorsPerCluster)) * bytesPerSector + addr;
+ }
+ else if (currentCluster >= 2 && currentCluster <= (isFat32 ? 0x0FFFFFF6 : 0xFFF6))
+ {
+ // Follow into next cluster.
+ u32 nextClusterOffset = firstFatSector * bytesPerSector + currentCluster * (isFat32 ? 4 : 2);
+ u32 nextClusterTableSector = nextClusterOffset >> 9;
+ if (bufferSector != nextClusterTableSector)
+ {
+ SD->ReadSectors(nextClusterTableSector, 1, buffer);
+ bufferSector = nextClusterTableSector;
+ }
+ nextClusterOffset &= 0x1FF;
+ currentCluster = (buffer[nextClusterOffset + 1] << 8) | buffer[nextClusterOffset];
+ if (isFat32)
+ currentCluster |= (buffer[nextClusterOffset + 3] << 24) | (buffer[nextClusterOffset + 2] << 16);
+ addr -= bytesPerCluster;
+ }
+ else
+ {
+ // End of cluster table.
+ return 0;
+ }
+ }
+}
+
+}
+}