More work on FAT32 formatter

BadBuilder.Formatter/FAT32FsInfoSector.cs

@@ -0,0 +1,26 @@
+using System.Runtime.InteropServices;
+
+namespace BadBuilder.Formatter
+{
+    // Reference: https://cscie92.dce.harvard.edu/spring2024/K70F120M/fsInfo.h
+
+    [StructLayout(LayoutKind.Explicit, Pack = 1, Size = 512)]
+    internal struct FAT32FsInfoSector
+    {
+        [FieldOffset(0)] public uint LeadSignature;
+
+        [FieldOffset(4)]
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 480)]
+        public byte[] Reserved1; // Zeros
+
+        [FieldOffset(484)] public uint StructureSignature;
+        [FieldOffset(488)] public uint FreeClusterCount;
+        [FieldOffset(492)] public uint NextFreeCluster;
+
+        [FieldOffset(496)]
+        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 12)]
+        public byte[] Reserved2;
+
+        [FieldOffset(508)] public uint TrailSignature;
+    }
+}