change libco to use an msvc-compiled dll so that it doesnt get wrecked whenever the .net GC process suspends a thread in a coroutine. cant figure out how to get that same code working compiled by mingw32.

BizHawk.Emulation/Consoles/Nintendo/SNES/SNESGraphicsDecoder.cs

@@ -51,6 +51,11 @@ namespace BizHawk.Emulation.Consoles.Nintendo.SNES
 
 		public class BGInfo
 		{
+			/// <summary>
+			/// Is the layer even enabled?
+			/// </summary>
+			public bool Enabled { get { return Bpp != 0; } }
+
 			/// <summary>
 			/// screen and tiledata register values
 			/// </summary>

BizHawk.MultiClient/SNESTools/SNESGraphicsDebugger.cs

@@ -112,11 +112,13 @@ namespace BizHawk.MultiClient
 				allocate(256, 256);
 				gd.RenderTilesToScreen(pixelptr, stride / 4, 8, 0);
 			}
-			if (selection == "BG1" || selection == "BG2" || selection == "BG3" /*|| selection == "BG4"*/)
+			if (selection == "BG1" || selection == "BG2" || selection == "BG3" || selection == "BG4")
 			{
 				int bgnum = int.Parse(selection.Substring(2));
 				var si = gd.ScanScreenInfo();
 				var bg = si.BG[bgnum];
+				if (bg.Enabled)
+				{
 					var dims = bg.ScreenSizeInPixels;
 					allocate(dims.Width, dims.Height);
 					int numPixels = dims.Width * dims.Height;
@@ -128,6 +130,7 @@ namespace BizHawk.MultiClient
 					gd.Paletteize(pixelptr, 0, 0, numPixels);
 					gd.Colorize(pixelptr, 0, numPixels);
 				}
+			}
 
 			if (bmp != null)
 			{

libsnes/bizwinclean.sh

@@ -0,0 +1 @@
+rm bsnes/obj/*.o

libsnes/bizwinmake.sh

@@ -1,4 +1,6 @@
 cd bsnes
+export BIZWINCFLAGS="-I. -O3 -masm=intel -DLIBCO_IMPORT -DLIBCO_MSVC"
+export TARGET_LIBSNES_LIBDEPS="-L ../libco_msvc_win32/release/ -llibco_msvc_win32"
 profile=compatibility platform=win target=libsnes make -e -j
 cd ..
 cp bsnes/out/snes.dll ../BizHawk.MultiClient/output

libsnes/bsnes/Makefile

@@ -9,12 +9,16 @@ target := ui
 # options += console
 
 # compiler
-c       := $(compiler) -std=gnu99
+c       := $(compiler) -std=gnu99 $(BIZWINCFLAGS)
 cpp     := $(subst cc,++,$(compiler)) -std=gnu++0x
 flags   := -I. -O3 -fomit-frame-pointer
 link    :=
 objects := libco
 
+ifneq ($(BIZWINCFLAGS),)
+  flags := $(BIZWINCFLAGS)
+endif
+
 # profile-guided optimization mode
 # pgo := instrument
 # pgo := optimize

libsnes/bsnes/libco/libco.c

@@ -4,8 +4,12 @@
   license: public domain
 */
 
-#if defined(__GNUC__) && defined(__i386__)
+#if (defined(__ARM_EABI__) || defined(__ARMCC_VERSION) )
+  #include "sjlj-multi.c"
+#elif defined(__GNUC__) && defined(__i386__)
+  #if !defined(LIBCO_MSVC)
     #include "x86.c"
+  #endif
 #elif defined(__GNUC__) && defined(__amd64__)
   #include "amd64.c"
 #elif defined(__GNUC__) && defined(_ARCH_PPC)

libsnes/bsnes/libco/libco.h

@@ -20,11 +20,20 @@ extern "C" {
 #endif
 
 typedef void* cothread_t;
+typedef void (*coentry_t)(void);
 
-cothread_t co_active();
+#if defined(LIBCO_IMPORT)
-cothread_t co_create(unsigned int, void (*)(void));
+#define LIBCO_IMPORTDECL __declspec(dllimport)
-void co_delete(cothread_t);
+#elif defined(LIBCO_EXPORT)
-void co_switch(cothread_t);
+#define LIBCO_IMPORTDECL __declspec(dllexport)
+#else
+#define LIBCO_IMPORTDECL
+#endif
+
+LIBCO_IMPORTDECL cothread_t co_active();
+LIBCO_IMPORTDECL cothread_t co_create(unsigned int, coentry_t);
+LIBCO_IMPORTDECL void co_delete(cothread_t);
+LIBCO_IMPORTDECL void co_switch(cothread_t);
 
 #ifdef __cplusplus
 }

libsnes/bsnes/libco/sjlj-multi.c

@@ -0,0 +1,120 @@
+#define LIBCO_C
+#include "libco.h"
+#include <stdlib.h>
+#include <setjmp.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct
+{
+	jmp_buf context;
+	coentry_t coentry;
+	void *stack;
+	unsigned long seh_frame, stack_top, stack_bottom;
+	cothread_t caller;
+} cothread_struct;
+
+static thread_local cothread_struct co_primary;
+static thread_local cothread_struct *co_running = 0;
+
+//-------------------
+#if defined(_MSC_VER) || defined(MINGW32)
+
+__declspec(dllimport) cothread_t os_co_create();
+__declspec(dllimport) void os_pre_setjmp(cothread_t target);
+__declspec(dllimport) void os_pre_longjmp(cothread_struct* rec);
+
+#elif defined(__ARM_EABI__) || defined(__ARMCC_VERSION)
+
+//http://sourceware.org/cgi-bin/cvsweb.cgi/src/newlib/libc/machine/arm/setjmp.S?rev=1.5&content-type=text/x-cvsweb-markup&cvsroot=src
+
+typedef struct 
+{
+#ifdef LIBCO_ARM_JUMBLED
+	int r8,r9,r10,r11,lr,r4,r5,r6,r7,sp;
+#else
+	int r4,r5,r6,r7,r8,r9,r10,fp;
+	#ifndef LIBCO_ARM_NOIP
+		int ip;
+	#endif
+	int sp,lr;
+#endif
+} _JUMP_BUFFER;
+
+static void os_co_create(cothread_struct* rec, unsigned int size, coentry_t coentry)
+{
+	_JUMP_BUFFER* jb = (_JUMP_BUFFER*)&rec->context;
+	
+	jb->sp = (unsigned long)rec->stack + size - 4;
+	jb->lr = (unsigned long)coentry;
+}
+
+static void os_pre_setjmp(cothread_t target)
+{
+	cothread_struct* rec = (cothread_struct*)target;
+	rec->caller = co_running;
+}
+
+static void os_pre_longjmp(cothread_struct* rec)
+{
+}
+
+#else
+#error "sjlj-multi: unsupported processor, compiler or operating system"
+#endif
+//-------------------
+
+cothread_t co_active()
+{
+	if(!co_running) co_running = &co_primary;
+	return (cothread_t)co_running;
+}
+
+cothread_t co_create(unsigned int size, void (*coentry)(void))
+{
+	cothread_struct *thread;
+
+	if(!co_running) co_running = &co_primary;
+
+	thread = (cothread_struct*)malloc(sizeof(cothread_struct));
+	if(thread)
+	{
+		thread->coentry = coentry;
+		thread->stack = malloc(size);
+		{
+			setjmp(thread->context);
+			os_co_create(thread,size,coentry);
+		}
+	}
+
+	return (cothread_t)thread;
+}
+
+void co_delete(cothread_t cothread)
+{
+	if(cothread)
+	{
+		if(((cothread_struct*)cothread)->stack)
+		{
+			free(((cothread_struct*)cothread)->stack);
+		}
+		free(cothread);
+	}
+}
+
+void co_switch(cothread_t cothread)
+{
+	os_pre_setjmp(cothread);
+	if(!setjmp(co_running->context))
+	{
+		co_running = (cothread_struct*)cothread;
+		os_pre_longjmp(co_running);
+		longjmp(co_running->context,0);
+	}
+}
+
+#ifdef __cplusplus
+}
+#endif

libsnes/bsnes/target-libsnes/Makefile

@@ -24,7 +24,7 @@ else ifeq ($(platform),osx)
 	ar rcs out/libsnes.a $(objects)
 	$(cpp) -o out/libsnes.dylib -install_name @executable_path/../Libraries/libsnes.dylib -shared -dynamiclib $(objects)
 else ifeq ($(platform),win)
-	$(cpp) -o out/snes.dll -shared -Wl,--out-implib,libsnes.a $(objects)
+	$(cpp) -o out/snes.dll -shared -Wl,--out-implib,libsnes.a $(objects) $(TARGET_LIBSNES_LIBDEPS)
 endif
 
 install:

libsnes/bsnes/target-libsnes/libsnes.cpp

@@ -126,7 +126,31 @@ void snes_set_cartridge_basename(const char *basename) {
   interface.basename = basename;
 }
 
+#include <setjmp.h>
+static jmp_buf buf;
+ 
+void second(void) {
+    printf("second\n");         // prints
+    longjmp(buf,1);             // jumps back to where setjmp was called - making setjmp now return 1
+}
+ 
+void first(void) {
+    second();
+    printf("first\n");          // does not print
+}
+ 
+void test() {   
+    if ( ! setjmp(buf) ) {
+        first();                // when executed, setjmp returns 0
+    } else {                    // when longjmp jumps back, setjmp returns 1
+        printf("main\n");       // prints
+    }
+ 
+
+}
+
 void snes_init(void) {
+	test();
   SNES::interface = &interface;
   SNES::system.init();
   SNES::input.connect(SNES::Controller::Port1, SNES::Input::Device::Joypad);

libsnes/libco_msvc_win32/libco_msvc_win32.c

@@ -0,0 +1,178 @@
+/*
+libco.sjlj (2008-01-28)
+author: Nach
+license: public domain
+*/
+
+/*
+* Note this was designed for UNIX systems. Based on ideas expressed in a paper
+* by Ralf Engelschall.
+* For SJLJ on other systems, one would want to rewrite springboard() and
+* co_create() and hack the jmb_buf stack pointer.
+*/
+
+#define LIBCO_C
+#define LIBCO_EXPORT
+#include "../bsnes/libco/libco.h"
+#include <stdlib.h>
+#include <setjmp.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct
+{
+	jmp_buf context;
+	coentry_t coentry;
+	void *stack;
+	unsigned long seh_frame, stack_top, stack_bottom;
+	cothread_t caller;
+} cothread_struct;
+
+static thread_local cothread_struct co_primary;
+static thread_local cothread_struct *co_running = 0;
+
+
+//links of interest
+//http://connect.microsoft.com/VisualStudio/feedback/details/100319/really-wierd-behaviour-in-crt-io-coupled-with-some-inline-assembly
+//http://en.wikipedia.org/wiki/Thread_Information_Block
+//http://social.msdn.microsoft.com/Forums/en-US/vclanguage/thread/72093e46-4524-4f54-9f36-c7e8a309d1db/   //FS warning
+
+
+#define WINVER 0x0400
+#define _WIN32_WINNT 0x0400
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#pragma warning(disable:4733)
+#pragma warning(disable:4311)
+
+static void capture_fs(cothread_struct* rec)
+{
+	int temp;
+	__asm mov eax, dword ptr fs:[0];
+	__asm mov temp, eax;
+	rec->seh_frame = temp;
+	__asm mov eax, dword ptr fs:[4];
+	__asm mov temp, eax;
+	rec->stack_top = temp;
+	__asm mov eax, dword ptr fs:[8];
+	__asm mov temp, eax;
+	rec->stack_bottom = temp;
+}
+
+static void restore_fs(cothread_struct* rec)
+{
+	int temp;
+	temp = rec->seh_frame;
+	__asm mov eax, temp;
+	__asm mov dword ptr fs:[0], eax
+	temp = rec->stack_top;
+	__asm mov eax, temp;
+	__asm mov dword ptr fs:[4], eax
+	temp = rec->stack_bottom;
+	__asm mov eax, temp;
+	__asm mov dword ptr fs:[8], eax
+}
+
+static void os_co_wrapper()
+{
+	cothread_struct* rec = (cothread_struct*)co_active();
+	//__try
+	//{
+		rec->coentry();
+	//}
+	//__except(EXCEPTION_EXECUTE_HANDLER)
+	//{
+	//	//unhandled win32 exception in coroutine. 
+	//	//this coroutine will now be suspended permanently and control will be yielded to caller, for lack of anything better to do. 
+	//	//perhaps the process should just terminate.
+	//	for(;;)
+	//	{
+	//		//dead coroutine
+	//		co_switch(rec->caller);
+	//	}
+	//}
+}
+
+static void os_co_create(cothread_struct* rec, unsigned int size, coentry_t coentry)
+{
+	_JUMP_BUFFER* jb = (_JUMP_BUFFER*)&rec->context;
+	cothread_struct temp;
+
+	jb->Esp = (unsigned long)rec->stack + size - 4;
+	jb->Eip = (unsigned long)os_co_wrapper;
+
+	rec->stack_top = jb->Esp + 4;
+	rec->stack_bottom = (unsigned long)rec->stack;
+
+	//wild assumption about SEH frame.. seems to work
+	capture_fs(&temp);
+	rec->seh_frame = temp.seh_frame;
+}
+
+static void os_pre_setjmp(cothread_t target)
+{
+	cothread_struct* rec = (cothread_struct*)target;
+	capture_fs(co_running);
+	rec->caller = co_running;
+}
+
+static void os_pre_longjmp(cothread_struct* rec)
+{
+	restore_fs(rec);
+}
+
+__declspec(dllexport) cothread_t co_active()
+{
+	if(!co_running) co_running = &co_primary;
+	return (cothread_t)co_running;
+}
+
+__declspec(dllexport) cothread_t co_create(unsigned int size, void (*coentry)(void))
+{
+	cothread_struct *thread;
+
+	if(!co_running) co_running = &co_primary;
+
+	thread = (cothread_struct*)malloc(sizeof(cothread_struct));
+	if(thread)
+	{
+		thread->coentry = coentry;
+		thread->stack = malloc(size);
+		{
+			setjmp(thread->context);
+			os_co_create(thread,size,coentry);
+		}
+	}
+
+	return (cothread_t)thread;
+}
+
+__declspec(dllexport) void co_delete(cothread_t cothread)
+{
+	if(cothread)
+	{
+		if(((cothread_struct*)cothread)->stack)
+		{
+			free(((cothread_struct*)cothread)->stack);
+		}
+		free(cothread);
+	}
+}
+
+__declspec(dllexport) void co_switch(cothread_t cothread)
+{
+	os_pre_setjmp(cothread);
+	if(!setjmp(co_running->context))
+	{
+		co_running = (cothread_struct*)cothread;
+		os_pre_longjmp(co_running);
+		longjmp(co_running->context,0);
+	}
+}
+
+#ifdef __cplusplus
+}
+#endif

libsnes/libco_msvc_win32/libco_msvc_win32.sln

@@ -0,0 +1,20 @@
+
+Microsoft Visual Studio Solution File, Format Version 9.00
+# Visual Studio 2005
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "libco_msvc", "libco_msvc_win32.vcproj", "{C5D03072-BBF9-4DED-8CE6-5467736251BF}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Win32 = Debug|Win32
+		Release|Win32 = Release|Win32
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{C5D03072-BBF9-4DED-8CE6-5467736251BF}.Debug|Win32.ActiveCfg = Debug|Win32
+		{C5D03072-BBF9-4DED-8CE6-5467736251BF}.Debug|Win32.Build.0 = Debug|Win32
+		{C5D03072-BBF9-4DED-8CE6-5467736251BF}.Release|Win32.ActiveCfg = Release|Win32
+		{C5D03072-BBF9-4DED-8CE6-5467736251BF}.Release|Win32.Build.0 = Release|Win32
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal

libsnes/libco_msvc_win32/libco_msvc_win32.vcproj

@@ -0,0 +1,187 @@
+<?xml version="1.0" encoding="Windows-1252"?>
+<VisualStudioProject
+	ProjectType="Visual C++"
+	Version="8.00"
+	Name="libco_msvc_win32"
+	ProjectGUID="{C5D03072-BBF9-4DED-8CE6-5467736251BF}"
+	RootNamespace="libco_msvc_win32"
+	Keyword="Win32Proj"
+	>
+	<Platforms>
+		<Platform
+			Name="Win32"
+		/>
+	</Platforms>
+	<ToolFiles>
+	</ToolFiles>
+	<Configurations>
+		<Configuration
+			Name="Debug|Win32"
+			OutputDirectory="$(SolutionDir)$(ConfigurationName)"
+			IntermediateDirectory="$(ConfigurationName)"
+			ConfigurationType="2"
+			CharacterSet="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+				CommandLine=""
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				PreprocessorDefinitions="WIN32;_DEBUG;_WINDOWS;_USRDLL;LIBCO_MSVC_EXPORTS"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="3"
+				RuntimeLibrary="3"
+				UsePrecompiledHeader="0"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="4"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				LinkIncremental="2"
+				GenerateDebugInformation="true"
+				SubSystem="2"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+				CommandLine="copy $(TargetPath) ..\..\BizHawk.MultiClient\output"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Win32"
+			OutputDirectory="$(SolutionDir)$(ConfigurationName)"
+			IntermediateDirectory="$(ConfigurationName)"
+			ConfigurationType="2"
+			CharacterSet="1"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+				CommandLine=""
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				PreprocessorDefinitions="WIN32;NDEBUG;_WINDOWS;_USRDLL;LIBCO_MSVC_EXPORTS"
+				RuntimeLibrary="2"
+				UsePrecompiledHeader="0"
+				WarningLevel="3"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				LinkIncremental="1"
+				GenerateDebugInformation="true"
+				SubSystem="2"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+				CommandLine="copy $(TargetPath) ..\..\BizHawk.MultiClient\output"
+			/>
+		</Configuration>
+	</Configurations>
+	<References>
+	</References>
+	<Files>
+		<File
+			RelativePath=".\libco_msvc_win32.c"
+			>
+		</File>
+		<File
+			RelativePath=".\readme.txt"
+			>
+		</File>
+	</Files>
+	<Globals>
+	</Globals>
+</VisualStudioProject>

libsnes/libco_msvc_win32/readme.txt

@@ -0,0 +1,11 @@
+* Why does this exist?
+
+Because zeromus can't figure out how to successfully compile this code in mingw32.
+My efforts are in trying-to-port-to-mingw-win32.c; I don't know why it isn't working.
+
+* Why do we need this code?
+
+Because libco needs to be a bit more properly win32 in order for it to get used from .net code.
+.net throws exceptions in each thread when it needs to suspend them for GC. 
+Those exceptions get garbled without more proper win32 stack frame setup, and the process terminates.
+Additionally, you wont be able to debug very well from callbacks out of a coroutine into c# without this.

libsnes/libco_msvc_win32/trying-to-port-to-mingw-win32.c

@@ -0,0 +1,178 @@
+//links of interest
+//http://connect.microsoft.com/VisualStudio/feedback/details/100319/really-wierd-behaviour-in-crt-io-coupled-with-some-inline-assembly
+//http://en.wikipedia.org/wiki/Thread_Information_Block
+//http://social.msdn.microsoft.com/Forums/en-US/vclanguage/thread/72093e46-4524-4f54-9f36-c7e8a309d1db/   //FS warning
+
+#define LIBCO_C
+#define LIBCO_EXPORT
+#include "../bsnes/libco/libco.h"
+#include <stdlib.h>
+#include <setjmp.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void (*coentry_t)(void);
+
+typedef struct
+{
+	jmp_buf context;
+	coentry_t coentry;
+	void *stack;
+	unsigned long seh_frame, stack_top, stack_bottom;
+	cothread_t caller;
+} cothread_struct;
+
+static thread_local cothread_struct co_primary;
+static thread_local cothread_struct *co_running = 0;
+
+#define WINVER 0x0400
+#define _WIN32_WINNT 0x0400
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#ifndef _MSC_VER
+typedef struct __JUMP_BUFFER {
+    unsigned long Ebp;
+    unsigned long Ebx;
+    unsigned long Edi;
+    unsigned long Esi;
+    unsigned long Esp;
+    unsigned long Eip;
+    unsigned long Registration;
+    unsigned long TryLevel;
+    unsigned long Cookie;
+    unsigned long UnwindFunc;
+    unsigned long UnwindData[6];
+} _JUMP_BUFFER;
+#endif
+
+#pragma warning(disable:4733)
+#pragma warning(disable:4311)
+
+static void capture_fs(cothread_struct* rec)
+{
+	asm(
+		"mov %0, dword ptr fs:[0];"
+		"mov %1, dword ptr fs:[4];"
+		"mov %2, dword ptr fs:[8];"
+		:"=r"(rec->seh_frame), "=r"(rec->stack_top), "=r"(rec->stack_bottom)
+		:
+		:
+		);
+}
+
+static void restore_fs(cothread_struct* rec)
+{
+	asm(
+		"mov dword ptr fs:[0], %0;"
+		"mov dword ptr fs:[4], %1;"
+		"mov dword ptr fs:[8], %2;"
+		:
+		:"r"(rec->seh_frame), "r"(rec->stack_top), "r"(rec->stack_bottom)
+		:
+		);
+}
+
+static void os_co_wrapper()
+{
+	cothread_struct* rec = (cothread_struct*)co_active();
+	//__try
+	//{
+		rec->coentry();
+	//}
+	//__except(EXCEPTION_EXECUTE_HANDLER)
+	//{
+	//	//unhandled win32 exception in coroutine. 
+	//	//this coroutine will now be suspended permanently and control will be yielded to caller, for lack of anything better to do. 
+	//	//perhaps the process should just terminate.
+	//	for(;;)
+	//	{
+	//		//dead coroutine
+	//		co_switch(rec->caller);
+	//	}
+	//}
+}
+
+static void os_co_create(cothread_struct* rec, unsigned int size, coentry_t coentry)
+{
+	_JUMP_BUFFER* jb = (_JUMP_BUFFER*)&rec->context;
+	cothread_struct temp;
+
+	jb->Esp = (unsigned long)rec->stack + size - 4;
+	jb->Eip = (unsigned long)os_co_wrapper;
+
+	rec->stack_top = jb->Esp + 4;
+	rec->stack_bottom = (unsigned long)rec->stack;
+
+	//wild assumption about SEH frame.. seems to work
+	capture_fs(&temp);
+	rec->seh_frame = temp.seh_frame;
+}
+
+static void os_pre_setjmp(cothread_t target)
+{
+	cothread_struct* rec = (cothread_struct*)target;
+	capture_fs(co_running);
+	rec->caller = co_running;
+}
+
+static void os_pre_longjmp(cothread_struct* rec)
+{
+	restore_fs(rec);
+}
+
+cothread_t co_active()
+{
+	if(!co_running) co_running = &co_primary;
+	return (cothread_t)co_running;
+}
+
+
+cothread_t co_create(unsigned int size, void (*coentry)(void))
+{
+	cothread_struct *thread;
+
+	if(!co_running) co_running = &co_primary;
+
+	thread = (cothread_struct*)malloc(sizeof(cothread_struct));
+	if(thread)
+	{
+		thread->coentry = coentry;
+		thread->stack = malloc(size);
+		{
+			setjmp(thread->context);
+			os_co_create(thread,size,coentry);
+		}
+	}
+
+	return (cothread_t)thread;
+}
+
+void co_delete(cothread_t cothread)
+{
+	if(cothread)
+	{
+		if(((cothread_struct*)cothread)->stack)
+		{
+			free(((cothread_struct*)cothread)->stack);
+		}
+		free(cothread);
+	}
+}
+
+void co_switch(cothread_t cothread)
+{
+	os_pre_setjmp(cothread);
+	if(!setjmp(co_running->context))
+	{
+		co_running = (cothread_struct*)cothread;
+		os_pre_longjmp(co_running);
+		longjmp(co_running->context,0);
+	}
+}
+
+#ifdef __cplusplus
+}
+#endif