PC Engine CD-ROM Header Support (#91)

2026-07-08 18:06:41 +00:00 · 2026-04-28 22:24:36 +09:00
parent 49ea4302b6
commit a2b9db3afd
13 changed files with 903 additions and 11 deletions
--- a/SabreTools.Serialization.Readers/PCEngineCDROM.cs
+++ b/SabreTools.Serialization.Readers/PCEngineCDROM.cs
@@ -0,0 +1,90 @@
+using System.IO;
+using System.Text;
+using SabreTools.Data.Models.PCEngineCDROM;
+using SabreTools.IO.Extensions;
+using SabreTools.Matching;
+using SabreTools.Numerics.Extensions;
+
+namespace SabreTools.Serialization.Readers
+{
+    public class PCEngineCDROM : BaseBinaryReader<Header>
+    {
+        /// <inheritdoc/>
+        public override Header? Deserialize(Stream? data)
+        {
+            // If the data is invalid
+            if (data is null || !data.CanRead)
+                return null;
+
+            // Simple check for a valid stream length
+            if (data.Length - data.Position < 2 * Constants.SectorSize)
+                return null;
+
+            try
+            {
+                // Verify expected signature
+                var magic = data.PeekBytes(16);
+                if (!magic.EqualsExactly(Constants.MagicBytes))
+                    return null;
+
+                // Deserialize the Header
+                var header = new Header();
+                header.BootSector = ParseBootSector(data);
+                header.IPL = ParseIPL(data);
+
+                return header;
+            }
+            catch
+            {
+                // Ignore the actual error
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// Parse a Stream into a BootSector
+        /// </summary>
+        /// <param name="data">Stream to parse</param>
+        /// <returns>Filled BootSector on success, null on error</returns>
+        public static BootSector ParseBootSector(Stream data)
+        {
+            var bootSector = new BootSector();
+
+            bootSector.CopyrightString = data.ReadBytes(806);
+            bootSector.BootROM = data.ReadBytes(432);
+            bootSector.Padding = data.ReadBytes(810);
+
+            return bootSector;
+        }
+
+        /// <summary>
+        /// Parse a Stream into a IPL
+        /// </summary>
+        /// <param name="data">Stream to parse</param>
+        /// <returns>Filled IPL on success, null on error</returns>
+        public static IPL ParseIPL(Stream data)
+        {
+            var ipl = new IPL();
+
+            ipl.IPLBLK = data.ReadUInt24BigEndian();
+            ipl.IPLBLN = data.ReadByteValue();
+            ipl.IPLSTA = data.ReadUInt16LittleEndian();
+            ipl.IPLJMP = data.ReadUInt16LittleEndian();
+            ipl.IPLMPR = data.ReadBytes(5);
+            ipl.OpenMode = (OpenMode)data.ReadByteValue();
+            ipl.GRPBLK = data.ReadUInt24BigEndian();
+            ipl.GRPBLN = data.ReadByteValue();
+            ipl.GRPADR = data.ReadUInt16LittleEndian();
+            ipl.ADPBLK = data.ReadUInt24BigEndian();
+            ipl.ADPBLN = data.ReadByteValue();
+            ipl.ADPRATE = data.ReadByteValue();
+            ipl.Reserved = data.ReadBytes(7);
+            ipl.SystemString = data.ReadBytes(24);
+            ipl.CopyrightString = data.ReadBytes(50);
+            ipl.ProgramName = data.ReadBytes(16);
+            ipl.AdditionalString = data.ReadBytes(6);
+
+            return ipl;
+        }
+    }
+}