From 73b472befa182332466aa64db7d9e8823df5a3ee Mon Sep 17 00:00:00 2001
From: shadowninja108 <shadowninja0108@gmail.com>
Date: Sat, 22 Sep 2018 20:19:27 -0700
Subject: [PATCH] Add partial NSO support

---
 LibHac/LibHac.csproj |   1 +
 libhac/Nso.cs        | 113 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 114 insertions(+)
 create mode 100644 libhac/Nso.cs

diff --git a/LibHac/LibHac.csproj b/LibHac/LibHac.csproj
index 59228d90..3f4cd941 100644
--- a/LibHac/LibHac.csproj
+++ b/LibHac/LibHac.csproj
@@ -27,6 +27,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="lz4net" Version="1.0.15.93" />
     <PackageReference Include="System.Numerics.Vectors" Version="4.5.0" Condition=" '$(TargetFramework)' == 'net46' " />
   </ItemGroup>
 
diff --git a/libhac/Nso.cs b/libhac/Nso.cs
new file mode 100644
index 00000000..8d983c32
--- /dev/null
+++ b/libhac/Nso.cs
@@ -0,0 +1,113 @@
+using LibHac.Streams;
+using LZ4;
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+
+namespace LibHac
+{
+    public class Nso
+    {
+        public NsoSection[] Sections;
+        public RodataRelativeExtent[] RodataRelativeExtents;
+        public uint BssSize;
+        public byte[] BuildID = new byte[0x20];
+
+        private BinaryReader reader;
+
+        public Nso(Stream stream)
+        {
+            reader = new BinaryReader(stream);
+            if (reader.ReadAscii(4) != "NSO0")
+                throw new InvalidDataException("NSO magic is incorrect!");
+            reader.ReadUInt32(); // Version
+            reader.ReadUInt32(); // Reserved/Unused
+            BitArray flags = new BitArray(new int[] { (int) reader.ReadUInt32() });
+            NsoSection textSection = new NsoSection(stream);
+            NsoSection rodataSection = new NsoSection(stream);
+            NsoSection dataSection = new NsoSection(stream);
+            textSection.IsCompressed = flags[0];
+            textSection.CheckHash = flags[3];
+            rodataSection.IsCompressed = flags[1];
+            rodataSection.CheckHash = flags[4];
+            dataSection.IsCompressed = flags[2];
+            dataSection.CheckHash = flags[5];
+
+            ReadSegmentHeader(textSection);
+            reader.ReadUInt32(); // Module offset (TODO)
+            ReadSegmentHeader(rodataSection);
+            reader.ReadUInt32(); // Module file size
+            ReadSegmentHeader(dataSection);
+            BssSize = reader.ReadUInt32();
+            reader.Read(BuildID, 0, 0x20);
+            textSection.CompressedSize = reader.ReadUInt32();
+            rodataSection.CompressedSize = reader.ReadUInt32();
+            dataSection.CompressedSize = reader.ReadUInt32();
+            reader.ReadBytes(0x1C); // Padding
+            RodataRelativeExtents = new RodataRelativeExtent[]
+            {
+                ReadRodataRelativeExtent(), ReadRodataRelativeExtent(), ReadRodataRelativeExtent()
+            };
+
+            reader.Read(textSection.Hash, 0, 0x20);
+            reader.Read(rodataSection.Hash, 0, 0x20);
+            reader.Read(dataSection.Hash, 0, 0x20);
+
+            Sections = new NsoSection[] {textSection, rodataSection, dataSection };
+        }
+
+        public void ReadSegmentHeader(NsoSection section)
+        {
+            section.FileOffset = reader.ReadUInt32();
+            section.MemoryOffset = reader.ReadUInt32();
+            section.DecompressedSize = reader.ReadUInt32();   
+        }
+
+        public RodataRelativeExtent ReadRodataRelativeExtent()
+        {
+            RodataRelativeExtent extent = new RodataRelativeExtent();
+            extent.RegionRodataOffset = reader.ReadUInt32();
+            extent.RegionSize = reader.ReadUInt32();
+            return extent;
+        }
+
+        public class NsoSection
+        {
+            private Stream Stream;
+
+            public bool IsCompressed,
+                 CheckHash;
+            public uint FileOffset,
+                MemoryOffset,
+                DecompressedSize,
+                CompressedSize;
+            public byte[] Hash = new byte[0x20];
+
+            public NsoSection(Stream stream)
+            {
+                Stream = stream;
+            }
+
+            public Stream OpenCompressedStream()
+            {
+                return new SubStream(Stream, FileOffset, CompressedSize);
+            }
+
+            public Stream OpenDecompressedStream()
+            {
+                return new LZ4Stream(OpenCompressedStream(), LZ4StreamMode.Decompress);
+            }
+        }
+
+        public class RodataRelativeExtent
+        {
+            public uint 
+                RegionRodataOffset,
+                RegionSize;
+        }
+
+
+    }
+}