Implement modding support (#1249)

* Implement Modding Support

* Executables: Rewrite to use contiguous mem and Spans

* Reorder ExeFs, Npdm, ControlData and SaveData calls

After discussion with gdkchan, it was decided it's best to call
LoadExeFs after all other loads are done as it starts the guest process.

* Build RomFs manually instead of Layering FS

Layered FS approach has considerable latency when building the final
romfs. So, we manually replace files in a single romfs instance.

* Add RomFs modding via storage file

* Fix and cleanup MemPatch

* Add dynamically loaded NRO patching

* Support exefs file replacement

* Rewrite ModLoader to use mods-search architecture

* Disable PPTC when exefs patches are detected

Disable PPTC on exefs replacements too

* Rewrite ModLoader, again

* Increased maintainability and matches Atmosphere closely
* Creates base mods structure if it doesn't exist
* Add Exefs partition replacement
* IPSwitch: Fix nsobid parsing

* Move mod logs to new LogClass

* Allow custom suffixes to title dirs again

* Address nits

* Add a per-App "Open Mods Directory" context menu item

Creates the path if not present.

* Normalize tooltips verbiage

* Use LocalStorage and remove unused namespaces

1 files changed, 21 insertions, 50 deletions

diff --git a/Ryujinx.HLE/Loaders/Executables/NroExecutable.cs b/Ryujinx.HLE/Loaders/Executables/NroExecutable.cs
index 4a7f2116..b7a887b7 100644
--- a/Ryujinx.HLE/Loaders/Executables/NroExecutable.cs
+++ b/Ryujinx.HLE/Loaders/Executables/NroExecutable.cs
@@ -1,67 +1,38 @@
-using System.IO;
+using LibHac;
+using LibHac.Fs;
+using System;
 
 namespace Ryujinx.HLE.Loaders.Executables
 {
-    class NroExecutable : IExecutable
+    class NroExecutable : Nro, IExecutable
     {
-        public byte[] Text { get; private set; }
-        public byte[] Ro   { get; private set; }
-        public byte[] Data { get; private set; }
+        public byte[] Program { get; }
+        public Span<byte> Text => Program.AsSpan().Slice(TextOffset, (int)Header.NroSegments[0].Size);
+        public Span<byte> Ro   => Program.AsSpan().Slice(RoOffset,   (int)Header.NroSegments[1].Size);
+        public Span<byte> Data => Program.AsSpan().Slice(DataOffset, (int)Header.NroSegments[2].Size);
 
-        public int Mod0Offset { get; private set; }
-        public int TextOffset { get; private set; }
-        public int RoOffset   { get; private set; }
-        public int DataOffset { get; private set; }
-        public int BssSize    { get; private set; }
-        public int FileSize   { get; private set; }
+        public int TextOffset => (int)Header.NroSegments[0].FileOffset;
+        public int RoOffset   => (int)Header.NroSegments[1].FileOffset;
+        public int DataOffset => (int)Header.NroSegments[2].FileOffset;
+        public int BssOffset  => DataOffset + Data.Length;     
+        public int BssSize    => (int)Header.BssSize;
 
-        public int BssOffset => DataOffset + Data.Length;
+        public int Mod0Offset => Start.Mod0Offset;
+        public int FileSize   => (int)Header.Size;
 
         public ulong SourceAddress { get; private set; }
         public ulong BssAddress    { get; private set; }
 
-        public NroExecutable(Stream input, ulong sourceAddress = 0, ulong bssAddress = 0)
+        public NroExecutable(IStorage inStorage, ulong sourceAddress = 0, ulong bssAddress = 0) : base(inStorage)
         {
+            Program = new byte[FileSize];
+
             SourceAddress = sourceAddress;
             BssAddress    = bssAddress;
 
-            BinaryReader reader = new BinaryReader(input);
-
-            input.Seek(4, SeekOrigin.Begin);
-
-            int mod0Offset = reader.ReadInt32();
-            int padding8   = reader.ReadInt32();
-            int paddingC   = reader.ReadInt32();
-            int nroMagic   = reader.ReadInt32();
-            int unknown14  = reader.ReadInt32();
-            int fileSize   = reader.ReadInt32();
-            int unknown1C  = reader.ReadInt32();
-            int textOffset = reader.ReadInt32();
-            int textSize   = reader.ReadInt32();
-            int roOffset   = reader.ReadInt32();
-            int roSize     = reader.ReadInt32();
-            int dataOffset = reader.ReadInt32();
-            int dataSize   = reader.ReadInt32();
-            int bssSize    = reader.ReadInt32();
-
-            Mod0Offset = mod0Offset;
-            TextOffset = textOffset;
-            RoOffset   = roOffset;
-            DataOffset = dataOffset;
-            BssSize    = bssSize;
-
-            byte[] Read(long position, int size)
-            {
-                input.Seek(position, SeekOrigin.Begin);
-
-                return reader.ReadBytes(size);
-            }
-
-            Text = Read(textOffset, textSize);
-            Ro   = Read(roOffset,   roSize);
-            Data = Read(dataOffset, dataSize);
-
-            FileSize = fileSize;
+            OpenNroSegment(NroSegmentType.Text, false).Read(0, Text);
+            OpenNroSegment(NroSegmentType.Ro  , false).Read(0, Ro);
+            OpenNroSegment(NroSegmentType.Data, false).Read(0, Data);
         }
     }
 }
\ No newline at end of file