waterbox - expose read-only information about the guest memory page table

src/BizHawk.Emulation.Cores/Consoles/Nintendo/SNES/LibsnesApi.cs

@@ -437,5 +437,10 @@ namespace BizHawk.Emulation.Cores.Nintendo.SNES
 			_exe.LoadStateBinary(reader);
 			_core.PostLoadState();
 		}
+
+		public MemoryDomain GetPagesDomain()
+		{
+			return _exe.GetPagesDomain();
+		}
 	}
 }

src/BizHawk.Emulation.Cores/Consoles/Nintendo/SNES/LibsnesCore.IMemoryDomains.cs

@@ -73,7 +73,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.SNES
 				MakeMemoryDomain("SGB CARTRAM", LibsnesApi.SNES_MEMORY.SGB_CARTRAM, MemoryDomain.Endian.Little);
 			}
 
-
+			_memoryDomainList.Add(Api.GetPagesDomain());
 
 			_memoryDomains = new MemoryDomainList(_memoryDomainList);
 			((BasicServiceProvider) ServiceProvider).Register(_memoryDomains);

src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GPGX.IMemoryDomains.cs

@@ -94,6 +94,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 
 					mm.Add(s68Bus);
 				}
+				mm.Add(_elf.GetPagesDomain());
 
 				_memoryDomains = new MemoryDomainList(mm) { SystemBus = m68Bus };
 				((BasicServiceProvider) ServiceProvider).Register(_memoryDomains);

src/BizHawk.Emulation.Cores/Waterbox/WaterboxCore.cs

@@ -73,8 +73,12 @@ namespace BizHawk.Emulation.Cores.Waterbox
 				var primaryDomain = memoryDomains
 					.Where(md => md.Definition.Flags.HasFlag(LibWaterboxCore.MemoryDomainFlags.Primary))
 					.Single();
-	
-				var mdl = new MemoryDomainList(memoryDomains.Cast<MemoryDomain>().ToList());
+
+				var mdl = new MemoryDomainList(
+					memoryDomains.Cast<MemoryDomain>()
+						.Concat(new[] { _exe.GetPagesDomain() })
+						.ToList()
+				);
 				mdl.MainMemory = primaryDomain;
 				_serviceProvider.Register<IMemoryDomains>(mdl);
 

src/BizHawk.Emulation.Cores/Waterbox/WaterboxHost.cs

@@ -218,11 +218,12 @@ namespace BizHawk.Emulation.Cores.Waterbox
 			return ms.ToArray();
 		}
 
-		// public class MissingFileResult
-		// {
-		// 	public byte[] data;
-		// 	public bool writable;
-		// }
+#if false
+		public class MissingFileResult
+		{
+			public byte[] data;
+			public bool writable;
+		}
 
 		/// <summary>
 		/// Can be set by the frontend and will be called if the core attempts to open a missing file.
@@ -233,29 +234,65 @@ namespace BizHawk.Emulation.Cores.Waterbox
 		/// if it was for firmware only.
 		/// writable == false is equivalent to AddReadonlyFile, writable == true is equivalent to AddTransientFile
 		/// </summary>
-		// public Func<string, MissingFileResult> MissingFileCallback
-		// {
-		// 	set
-		// 	{
-		// 		// TODO
-		// 		using (this.EnterExit())
-		// 		{
-		// 			var mfc_o = value == null ? null : new WaterboxHostNative.MissingFileCallback
-		// 			{
-		// 				callback = (_unused, name) =>
-		// 				{
-		// 					var res = value(name);
-		// 				}
-		// 			};
+		public Func<string, MissingFileResult> MissingFileCallback
+		{
+			set
+			{
+				// TODO
+				using (this.EnterExit())
+				{
+					var mfc_o = value == null ? null : new WaterboxHostNative.MissingFileCallback
+					{
+						callback = (_unused, name) =>
+						{
+							var res = value(name);
+						}
+					};
 
-		// 			NativeImpl.wbx_set_missing_file_callback(_activatedNativeHost, value == null
-		// 				? null
-		// 				: )
-		// 		}
-		// 	}
-		// 	get => _syscalls.MissingFileCallback;
-		// 	set => _syscalls.MissingFileCallback = value;
-		// }
+					NativeImpl.wbx_set_missing_file_callback(_activatedNativeHost, value == null
+						? null
+						: )
+				}
+			}
+			get => _syscalls.MissingFileCallback;
+			set => _syscalls.MissingFileCallback = value;
+		}
+#endif
+
+		public MemoryDomain GetPagesDomain()
+		{
+			return new WaterboxPagesDomain(this);
+		}
+
+		private class WaterboxPagesDomain : MemoryDomain
+		{
+			protected readonly WaterboxHost _host;
+			public WaterboxPagesDomain(WaterboxHost host)
+			{
+				_host = host;
+
+				var retobj = new ReturnData();
+				NativeImpl.wbx_get_page_len(_host._nativeHost, retobj);
+
+				Name = "Waterbox PageData";
+				Size = (long)retobj.GetDataOrThrow();
+				WordSize = 1;
+				EndianType = Endian.Unknown;
+				Writable = false;
+			}
+
+			public override byte PeekByte(long addr)
+			{
+				var retobj = new ReturnData();
+				NativeImpl.wbx_get_page_data(_host._nativeHost, Z.SU(addr), retobj);
+				return (byte)retobj.GetDataOrThrow();
+			}
+
+			public override void PokeByte(long addr, byte val)
+			{
+				throw new InvalidOperationException();
+			}
+		}
 
 		public void SaveStateBinary(BinaryWriter bw)
 		{

src/BizHawk.Emulation.Cores/Waterbox/WaterboxHostNative.cs

@@ -235,5 +235,24 @@ namespace BizHawk.Emulation.Cores.Waterbox
 		/// </summary>
 		[BizImport(CallingConvention.Cdecl)]
 		public abstract void wbx_set_always_evict_blocks(bool val);
+
+		/// <summary>
+		/// Retrieve the number of pages of guest memory that this host is tracking
+		/// </summary>
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void wbx_get_page_len(IntPtr /*WaterboxHost*/ obj, ReturnData /*UIntPtr*/ ret);
+
+		/// <summary>
+		/// Retrieve basic information for a tracked guest page.  Index should be in 0..wbx_get_page_len().
+		/// 1 - readable, implies allocated
+		/// 2 - writable
+		/// 4 - executable
+		/// 0x10 - stack
+		/// 0x20 - allocated but not readable (guest-generated "guard")
+		/// 0x40 - invisible
+		/// 0x80 - dirty
+		/// </summary>
+		[BizImport(CallingConvention.Cdecl)]
+		public abstract void wbx_get_page_data(IntPtr /*WaterboxHost*/ obj, UIntPtr index, ReturnData /*byte*/ ret);
 	}
 }

waterbox/waterboxhost/src/cinterface.rs

@@ -354,3 +354,26 @@ pub extern fn wbx_set_always_evict_blocks(_val: bool) {
 		unsafe { ALWAYS_EVICT_BLOCKS = _val; }
 	}
 }
+
+/// Retrieve the number of pages of guest memory that this host is tracking
+#[no_mangle]
+pub extern fn wbx_get_page_len(obj: &mut WaterboxHost, ret: &mut Return<usize>) {
+	ret.put(Ok(obj.page_len()))
+}
+
+/// Retrieve basic information for a tracked guest page.  Index should be in 0..wbx_get_page_len().
+/// 1 - readable, implies allocated
+/// 2 - writable
+/// 4 - executable
+/// 0x10 - stack
+/// 0x20 - allocated but not readable (guest-generated "guard")
+/// 0x40 - invisible
+/// 0x80 - dirty
+#[no_mangle]
+pub extern fn wbx_get_page_data(obj: &mut WaterboxHost, index: usize, ret: &mut Return<u8>) {
+	if index >= obj.page_len() {
+		ret.put(Err(anyhow!("Index out of range")))
+	} else {
+		ret.put(Ok(obj.page_info(index)))
+	}
+}

waterbox/waterboxhost/src/host.rs

@@ -154,6 +154,14 @@ impl WaterboxHost {
 	pub fn run_guest_simple(&mut self, entry_point: usize) {
 		context::call_guest_simple(entry_point, &mut self.context);
 	}
+
+	pub fn page_len(&self) -> usize {
+		self.memory_block.page_len()
+	}
+
+	pub fn page_info(&self, index: usize) -> u8 {
+		self.memory_block.page_info(index)
+	}
 }
 
 const SAVE_START_MAGIC: &str = "ActivatedWaterboxHost_v1";

waterbox/waterboxhost/src/memory_block/mod.rs

@@ -492,6 +492,32 @@ impl MemoryBlock {
 			}
 		}
 	}
+
+	pub fn page_len(&self) -> usize {
+		self.pages.len()
+	}
+
+	pub fn page_info(&self, index: usize) -> u8 {
+		let p = &self.pages[index];
+		let mut res = match p.status {
+			PageAllocation::Free => 0,
+			PageAllocation::Allocated(prot) => match prot {
+				Protection::None => 0x20,
+				Protection::R => 1,
+				Protection::RW => 3,
+				Protection::RX => 5,
+				Protection::RWX => 7,
+				Protection::RWStack => 0x13,
+			}
+		};
+		if p.dirty {
+			res |= 0x80;
+		}
+		if p.invisible {
+			res |= 0x40;
+		}
+		res
+	}
 }
 
 impl Drop for MemoryBlock {