Initial commit

arm7/source/loader/DsiWareSaveArranger.cpp

@@ -0,0 +1,235 @@
+#include "common.h"
+#include <string.h>
+#include <memory>
+#include "DsiWareSaveArranger.h"
+
+bool DsiWareSaveArranger::SetupDsiWareSave(const TCHAR* romPath, const nds_header_twl_t& romHeader, DsiWareSaveResult& result) const
+{
+    char path[256];
+    strcpy(path, romPath);
+    if (!CreateDeviceListPath(path, result.romFilePath))
+    {
+        return false;
+    }
+
+    if (romHeader.twlPrivateSavSize != 0)
+    {
+        char* extension = strrchr(path, '.');
+        if (!extension)
+            extension = &path[strlen(path)];
+        extension[0] = '.';
+        extension[1] = 'p';
+        extension[2] = 'r';
+        extension[3] = 'v';
+        extension[4] = 0;
+        if (!SetupDsiWareSaveFile(path, romHeader.twlPrivateSavSize) ||
+            !CreateDeviceListPath(path, result.privateSavePath))
+        {
+            return false;
+        }
+    }
+
+    if (romHeader.twlPublicSavSize != 0)
+    {
+        strcpy(path, romPath);
+        char* extension = strrchr(path, '.');
+        if (!extension)
+            extension = &path[strlen(path)];
+        extension[0] = '.';
+        extension[1] = 'p';
+        extension[2] = 'u';
+        extension[3] = 'b';
+        extension[4] = 0;
+        if (!SetupDsiWareSaveFile(path, romHeader.twlPublicSavSize) ||
+            !CreateDeviceListPath(path, result.publicSavePath))
+        {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool DsiWareSaveArranger::SetupDsiWareSaveFile(const TCHAR* savePath, u32 saveSize) const
+{
+    if (saveSize == 0)
+    {
+        return true;
+    }
+
+    auto file = std::make_unique<FIL>();
+    if (f_open(file.get(), savePath, FA_OPEN_ALWAYS | FA_READ | FA_WRITE) != FR_OK)
+    {
+        LOG_FATAL("Failed to open or create save file\n");
+        return false;
+    }
+
+    u32 initialSize = f_size(file.get());
+    if (initialSize < saveSize)
+    {
+        if (f_lseek(file.get(), saveSize) != FR_OK ||
+            f_lseek(file.get(), 0) != FR_OK)
+        {
+            LOG_FATAL("Failed to create private save file\n");
+            return false;
+        }
+
+        auto fatHeader = CreateFatHeader(saveSize);
+
+        UINT bytesWritten = 0;
+        if (f_write(file.get(), fatHeader.get(), sizeof(fat_header_t), &bytesWritten) != FR_OK ||
+            bytesWritten != sizeof(fat_header_t))
+        {
+            LOG_FATAL("Failed to format private save file\n");
+            return false;
+        }
+
+        memset(fatHeader.get(), 0, 512);
+
+        while (f_tell(file.get()) < saveSize)
+        {
+            bytesWritten = 0;
+            if (f_write(file.get(), fatHeader.get(), 512, &bytesWritten) != FR_OK ||
+                bytesWritten != 512)
+            {
+                LOG_FATAL("Failed to format private save file\n");
+                return false;
+            }
+        }
+    }
+
+    f_close(file.get());
+    return true;
+}
+
+std::unique_ptr<DsiWareSaveArranger::fat_header_t> DsiWareSaveArranger::CreateFatHeader(u32 saveSize) const
+{
+    // based on https://github.com/Epicpkmn11/NTM/blob/master/arm9/src/sav.c
+    const u32 maxSectors = saveSize >> 9;
+    u32 sectorCount = 1;
+    u32 secPerTrk = 1;
+    u32 numHeads = 1;
+    u32 sectorCountNext = 0;
+    while (sectorCountNext <= maxSectors)
+    {
+        sectorCountNext = secPerTrk * (numHeads + 1) * (numHeads + 1);
+        if (sectorCountNext <= maxSectors)
+        {
+            numHeads++;
+            sectorCount = sectorCountNext;
+
+            secPerTrk++;
+            sectorCountNext = secPerTrk * numHeads * numHeads;
+            if (sectorCountNext <= maxSectors)
+            {
+                sectorCount = sectorCountNext;
+            }
+        }
+    }
+    sectorCountNext = (secPerTrk + 1) * numHeads * numHeads;
+    if (sectorCountNext <= maxSectors)
+    {
+        secPerTrk++;
+        sectorCount = sectorCountNext;
+    }
+
+    u32 sectorsPerCluster;
+    u32 totalClusters;
+    if (sectorCount > 8192)
+    {
+        sectorsPerCluster = 8;
+        totalClusters = (sectorCount + 7) >> 3;
+    }
+    else if (sectorCount > 1024)
+    {
+        sectorsPerCluster = 4;
+        totalClusters = (sectorCount + 3) >> 2;
+    }
+    else
+    {
+        sectorsPerCluster = 1;
+        totalClusters = sectorCount;
+    }
+
+    u32 fatSizeInBytes = ((totalClusters + 1) >> 1) * 3; // 2 sectors -> 3 byte
+
+    auto fatHeader = std::make_unique<fat_header_t>();
+
+    fatHeader->jumpInstruction[0] = 0xE9;
+    fatHeader->jumpInstruction[1] = 0;
+    fatHeader->jumpInstruction[2] = 0;
+    memcpy(fatHeader->oemName, "MSWIN4.1", 8);
+    fatHeader->bytesPerSector = 512;
+    fatHeader->sectorsPerCluster = sectorsPerCluster;
+    fatHeader->reservedSectors = 1;
+    fatHeader->numberOfFats = 2;
+    fatHeader->rootEntries = saveSize < 0x8C000 ? 32 : 512;
+    fatHeader->totalSectorsSmall = sectorCount;
+    fatHeader->mediaType = 0xF8; // "hard drive"
+    fatHeader->fatSectorCount = (fatSizeInBytes + 511) >> 9;
+    fatHeader->sectorsPerTrack = secPerTrk;
+    fatHeader->numberOfHeads = numHeads;
+    fatHeader->hiddenSectors = 0;
+    fatHeader->totalSectorsLarge = 0;
+    fatHeader->diskNumber = 5;
+    fatHeader->BS_Reserved1 = 0;
+    fatHeader->bootSignature = 0x29;
+    fatHeader->volumeSerialNumber = 0x12345678;
+    memcpy(fatHeader->volumeLabel, "VOLUMELABEL", 11);
+    memcpy(fatHeader->fileSystemType, "FAT12   ", 8);
+    memset(fatHeader->bootCode, 0, sizeof(fatHeader->bootCode));
+    fatHeader->endOfSectorMarker = 0xAA55;
+
+    return fatHeader;
+}
+
+bool DsiWareSaveArranger::CreateDeviceListPath(TCHAR* savePath, char* deviceListPath) const
+{
+    auto fileInfo = std::make_unique<FILINFO>();
+    strcpy(deviceListPath, "nand:/");
+    char* shortPath = deviceListPath + 6;
+    char* currentPathSegment = strchr(savePath, '/');
+    do
+    {
+        currentPathSegment = strchr(currentPathSegment + 1, '/');
+        if (currentPathSegment)
+        {
+            *currentPathSegment = 0;
+        }
+
+        if (f_stat(savePath, fileInfo.get()) != FR_OK)
+        {
+            LOG_DEBUG("Failed to create short path\n");
+            return false;
+        }
+
+        LOG_DEBUG("%s\n", savePath);
+        // Use fname when altname is empty to handle short filenames.
+        const char* nameToUse = fileInfo->altname[0]
+            ? fileInfo->altname
+            : fileInfo->fname;
+        u32 length = strlen(nameToUse);
+        if (shortPath + length - deviceListPath >= 64)
+        {
+            LOG_DEBUG("Path too long\n");
+            return false;
+        }
+
+        strcpy(shortPath, nameToUse);
+        shortPath += length;
+        if (currentPathSegment)
+        {
+            if (shortPath + 1 - deviceListPath >= 64)
+            {
+                LOG_DEBUG("Path too long\n");
+                return false;
+            }
+
+            *shortPath++ = '/';
+            *currentPathSegment = '/';
+        }
+    } while (currentPathSegment);
+    LOG_DEBUG("%s\n", deviceListPath);
+
+    return true;
+}