Correctly calculate install size

It's now correct down to the byte, before you could cause the menu to error if you installed something within 16KiB or so of the limit

arm9/src/install.c

@@ -447,10 +447,14 @@ bool install(char* fpath, bool systemTitle)
 		//get install size
 		iprintf("Install Size: ");
 		swiWaitForVBlank();
-		
+
+		u32 clusterSize = getDsiClusterSize();
 		unsigned long long fileSize = getRomSize(fpath);
-		unsigned long long installSize = fileSize + _getSaveDataSize(h);
-		if (tmdFound) installSize += 708;
+		if ((fileSize % clusterSize) != 0)
+			fileSize += clusterSize - (fileSize % clusterSize);
+		//file + saves + TMD (rounded up to cluster size)
+		unsigned long long installSize = fileSize + _getSaveDataSize(h) + clusterSize;
+		if (tmdFound) installSize += clusterSize; //ticket, rounded up to cluster size
 
 		printBytes(installSize);
 		iprintf("\n");

arm9/src/storage.c

@@ -514,10 +514,7 @@ unsigned long long getDsiSize()
 
 unsigned long long getDsiFree()
 {
-	u32 blockSize = 0;
-	struct statvfs st;
-	if (statvfs("nand:/", &st) == 0)
-		blockSize = st.f_bsize;
+	u32 blockSize = getDsiClusterSize();
 
 	//Get free space by subtracting file sizes in nand folders
 	unsigned long long size = getDsiSize();
@@ -534,4 +531,13 @@ unsigned long long getDsiFree()
 	}
 
 	return size;
-}
+}
+
+u32 getDsiClusterSize()
+{
+	struct statvfs st;
+	if (statvfs(sdnandMode ? "sd:/" : "nand:/", &st) == 0)
+		return st.f_bsize;
+
+	return 0;
+}

arm9/src/storage.h

@@ -42,6 +42,7 @@ unsigned long long getSDCardFree();
 //internal storage
 unsigned long long getDsiSize();
 unsigned long long getDsiFree();
+u32 getDsiClusterSize();
 #define getDsiUsed() (getDSIStorageSize() - getDSIStorageFree())
 
 #endif