Ported runtime to Windows.

R=rsc
CC=golang-dev
https://golang.org/cl/176066

20 files changed, 600 insertions, 60 deletions

diff --git a/src/pkg/runtime/386/asm.s b/src/pkg/runtime/386/asm.s
index 7ec62161d9..11ce3f6b6f 100644
--- a/src/pkg/runtime/386/asm.s
+++ b/src/pkg/runtime/386/asm.s
@@ -26,17 +26,19 @@ TEXT _rt0_386(SB),7,$0
 	CALL	ldt0setup(SB)
 
 	// store through it, to make sure it works
-	MOVL	$0x123, 0(GS)
+	get_tls(BX)
+	MOVL	$0x123, g(BX)
 	MOVL	tls0(SB), AX
 	CMPL	AX, $0x123
 	JEQ	ok
 	MOVL	AX, 0	// abort
 ok:
 	// set up m and g "registers"
+	get_tls(BX)
 	LEAL	g0(SB), CX
-	MOVL	CX, g
+	MOVL	CX, g(BX)
 	LEAL	m0(SB), AX
-	MOVL	AX, m
+	MOVL	AX, m(BX)
 
 	// save m->g0 = g0
 	MOVL	CX, m_g0(AX)
@@ -100,7 +102,8 @@ TEXT gosave(SB), 7, $0
 	MOVL	BX, gobuf_sp(AX)
 	MOVL	0(SP), BX		// caller's PC
 	MOVL	BX, gobuf_pc(AX)
-	MOVL	g, BX
+	get_tls(CX)
+	MOVL	g(CX), BX
 	MOVL	BX, gobuf_g(AX)
 	MOVL	$0, AX			// return 0
 	RET
@@ -112,7 +115,8 @@ TEXT gogo(SB), 7, $0
 	MOVL	4(SP), BX		// gobuf
 	MOVL	gobuf_g(BX), DX
 	MOVL	0(DX), CX		// make sure g != nil
-	MOVL	DX, g
+	get_tls(CX)
+	MOVL	DX, g(CX)
 	MOVL	gobuf_sp(BX), SP	// restore SP
 	MOVL	gobuf_pc(BX), BX
 	JMP	BX
@@ -124,7 +128,8 @@ TEXT gogocall(SB), 7, $0
 	MOVL	8(SP), AX		// fn
 	MOVL	4(SP), BX		// gobuf
 	MOVL	gobuf_g(BX), DX
-	MOVL	DX, g
+	get_tls(CX)
+	MOVL	DX, g(CX)
 	MOVL	0(DX), CX		// make sure g != nil
 	MOVL	gobuf_sp(BX), SP	// restore SP
 	MOVL	gobuf_pc(BX), BX
@@ -139,9 +144,10 @@ TEXT gogocall(SB), 7, $0
 // Called during function prolog when more stack is needed.
 TEXT runtime·morestack(SB),7,$0
 	// Cannot grow scheduler stack (m->g0).
-	MOVL	m, BX
+	get_tls(CX)
+	MOVL	m(CX), BX
 	MOVL	m_g0(BX), SI
-	CMPL	g, SI
+	CMPL	g(CX), SI
 	JNE	2(PC)
 	INT	$3
 
@@ -158,7 +164,8 @@ TEXT runtime·morestack(SB),7,$0
 	LEAL	8(SP), CX	// f's caller's SP
 	MOVL	CX, (m_morebuf+gobuf_sp)(BX)
 	MOVL	CX, (m_morefp)(BX)
-	MOVL	g, SI
+	get_tls(CX)
+	MOVL	g(CX), SI
 	MOVL	SI, (m_morebuf+gobuf_g)(BX)
 
 	// Set m->morepc to f's PC.
@@ -167,7 +174,7 @@ TEXT runtime·morestack(SB),7,$0
 
 	// Call newstack on m's scheduling stack.
 	MOVL	m_g0(BX), BP
-	MOVL	BP, g
+	MOVL	BP, g(CX)
 	MOVL	(m_sched+gobuf_sp)(BX), SP
 	CALL	newstack(SB)
 	MOVL	$0, 0x1003	// crash if newstack returns
@@ -179,7 +186,8 @@ TEXT runtime·morestack(SB),7,$0
 //
 // func call(fn *byte, arg *byte, argsize uint32).
 TEXT reflect·call(SB), 7, $0
-	MOVL	m, BX
+	get_tls(CX)
+	MOVL	m(CX), BX
 
 	// Save our caller's state as the PC and SP to
 	// restore when returning from f.
@@ -187,7 +195,7 @@ TEXT reflect·call(SB), 7, $0
 	MOVL	AX, (m_morebuf+gobuf_pc)(BX)
 	LEAL	4(SP), AX	// our caller's SP
 	MOVL	AX, (m_morebuf+gobuf_sp)(BX)
-	MOVL	g, AX
+	MOVL	g(CX), AX
 	MOVL	AX, (m_morebuf+gobuf_g)(BX)
 
 	// Set up morestack arguments to call f on a new stack.
@@ -207,7 +215,8 @@ TEXT reflect·call(SB), 7, $0
 
 	// Call newstack on m's scheduling stack.
 	MOVL	m_g0(BX), BP
-	MOVL	BP, g
+	get_tls(CX)
+	MOVL	BP, g(CX)
 	MOVL	(m_sched+gobuf_sp)(BX), SP
 	CALL	newstack(SB)
 	MOVL	$0, 0x1103	// crash if newstack returns
@@ -217,12 +226,13 @@ TEXT reflect·call(SB), 7, $0
 // Return point when leaving stack.
 TEXT runtime·lessstack(SB), 7, $0
 	// Save return value in m->cret
-	MOVL	m, BX
+	get_tls(CX)
+	MOVL	m(CX), BX
 	MOVL	AX, m_cret(BX)
 
 	// Call oldstack on m's scheduling stack.
 	MOVL	m_g0(BX), DX
-	MOVL	DX, g
+	MOVL	DX, g(CX)
 	MOVL	(m_sched+gobuf_sp)(BX), SP
 	CALL	oldstack(SB)
 	MOVL	$0, 0x1004	// crash if oldstack returns
@@ -248,6 +258,25 @@ TEXT cas(SB), 7, $0
 	MOVL	$1, AX
 	RET
 
+// bool casp(void **p, void *old, void *new)
+// Atomically:
+//	if(*p == old){
+//		*p = new;
+//		return 1;
+//	}else
+//		return 0;
+TEXT casp(SB), 7, $0
+	MOVL	4(SP), BX
+	MOVL	8(SP), AX
+	MOVL	12(SP), CX
+	LOCK
+	CMPXCHGL	CX, 0(BX)
+	JZ 3(PC)
+	MOVL	$0, AX
+	RET
+	MOVL	$1, AX
+	RET
+
 // void jmpdefer(fn, sp);
 // called from deferreturn.
 // 1. pop the caller
@@ -308,9 +337,10 @@ TEXT	runcgo(SB),7,$16
 	MOVL	SP, CX
 
 	// Figure out if we need to switch to m->g0 stack.
-	MOVL	m, DX
+	get_tls(DI)
+	MOVL	m(DI), DX
 	MOVL	m_g0(DX), SI
-	CMPL	g, SI
+	CMPL	g(DI), SI
 	JEQ	2(PC)
 	MOVL	(m_sched+gobuf_sp)(DX), SP
 
@@ -325,7 +355,8 @@ TEXT	runcgo(SB),7,$16
 
 // check that SP is in range [g->stackbase, g->stackguard)
 TEXT stackcheck(SB), 7, $0
-	MOVL g, AX
+	get_tls(CX)
+	MOVL g(CX), AX
 	CMPL g_stackbase(AX), SP
 	JHI 2(PC)
 	INT $3
diff --git a/src/pkg/runtime/Makefile b/src/pkg/runtime/Makefile
index a85c441904..80bb521b31 100644
--- a/src/pkg/runtime/Makefile
+++ b/src/pkg/runtime/Makefile
@@ -17,7 +17,8 @@ CFLAGS_64=-D_64BIT
 # TODO(kaib): fix register allocation to honor extern register so we
 # can enable optimizations again.
 CFLAGS_arm=-N
-CFLAGS=-I$(GOOS) -I$(GOOS)/$(GOARCH) -wF $(CFLAGS_$(SIZE)) $(CFLAGS_$(GOARCH))
+CFLAGS_mingw=-D__MINGW__
+CFLAGS=-I$(GOOS) -I$(GOOS)/$(GOARCH) -wF $(CFLAGS_$(SIZE)) $(CFLAGS_$(GOARCH)) $(CFLAGS_$(GOOS))
 
 GOFILES=\
 	extern.go\
@@ -118,4 +119,4 @@ cgo2c: cgo2c.c
 
 # for discovering offsets inside structs when debugging
 runtime.acid.$(GOARCH): runtime.h proc.c
-	$(QUOTED_GOBIN)/$(CC) -a proc.c >$@
+	$(QUOTED_GOBIN)/$(CC) $(CFLAGS) -a proc.c >$@
diff --git a/src/pkg/runtime/darwin/386/sys.s b/src/pkg/runtime/darwin/386/sys.s
index 38459447f8..b18f390709 100644
--- a/src/pkg/runtime/darwin/386/sys.s
+++ b/src/pkg/runtime/darwin/386/sys.s
@@ -64,9 +64,10 @@ TEXT sigtramp(SB),7,$40
 	MOVW	BX, GS
 
 	// g = m->gsignal
-	MOVL	m, BP
+	get_tls(CX)
+	MOVL	m(CX), BP
 	MOVL	m_gsignal(BP), BP
-	MOVL	BP, g
+	MOVL	BP, g(CX)
 
 	MOVL	handler+0(FP), DI
 	// 4(FP) is sigstyle
@@ -80,9 +81,10 @@ TEXT sigtramp(SB),7,$40
 	CALL	DI
 
 	// g = m->curg
-	MOVL	m, BP
+	get_tls(CX)
+	MOVL	m(CX), BP
 	MOVL	m_curg(BP), BP
-	MOVL	BP, g
+	MOVL	BP, g(CX)
 
 	MOVL	context+16(FP), CX
 	MOVL	style+4(FP), BX
@@ -150,8 +152,9 @@ TEXT bsdthread_start(SB),7,$0
 	POPAL
 
 	// Now segment is established.  Initialize m, g.
-	MOVL	AX, g
-	MOVL	DX, m
+	get_tls(BP)
+	MOVL	AX, g(BP)
+	MOVL	DX, m(BP)
 	MOVL	BX, m_procid(DX)	// m->procid = thread port (for debuggers)
 	CALL	stackcheck(SB)		// smashes AX
 	CALL	CX	// fn()
diff --git a/src/pkg/runtime/darwin/thread.c b/src/pkg/runtime/darwin/thread.c
index bf66f86732..f68b63f7ab 100644
--- a/src/pkg/runtime/darwin/thread.c
+++ b/src/pkg/runtime/darwin/thread.c
@@ -36,21 +36,6 @@ initsema(uint32 *psema)
 }
 
 
-// Atomic add and return new value.
-static uint32
-xadd(uint32 volatile *val, int32 delta)
-{
-	uint32 oval, nval;
-
-	for(;;){
-		oval = *val;
-		nval = oval + delta;
-		if(cas(val, oval, nval))
-			return nval;
-	}
-}
-
-
 // Blocking locks.
 
 // Implement Locks, using semaphores.
diff --git a/src/pkg/runtime/freebsd/386/sys.s b/src/pkg/runtime/freebsd/386/sys.s
index 651ccb2348..7328a90467 100644
--- a/src/pkg/runtime/freebsd/386/sys.s
+++ b/src/pkg/runtime/freebsd/386/sys.s
@@ -33,8 +33,10 @@ TEXT thr_start(SB),7,$0
 	POPL	AX
 	POPL	AX
 	POPAL
-	MOVL	BX, g
-	MOVL	AX, m
+	get_tls(CX)
+	MOVL	BX, g(CX)
+	
+	MOVL	AX, m(CX)
 	CALL	stackcheck(SB)		// smashes AX
 	CALL	mstart(SB)
 	MOVL	0, AX			// crash (not reached)
@@ -80,9 +82,10 @@ TEXT sigaction(SB),7,$-4
 
 TEXT sigtramp(SB),7,$40
 	// g = m->gsignal
-	MOVL	m, BP
+	get_tls(DX)
+	MOVL	m(DX), BP
 	MOVL	m_gsignal(BP), BP
-	MOVL	BP, g
+	MOVL	BP, g(DX)
 
 	MOVL	signo+0(FP), AX
 	MOVL	siginfo+4(FP), BX
@@ -94,9 +97,10 @@ TEXT sigtramp(SB),7,$40
 	CALL	sighandler(SB)
 
 	// g = m->curg
-	MOVL	m, BP
+	get_tls(DX)
+	MOVL	m(DX), BP
 	MOVL	m_curg(BP), BP
-	MOVL	BP, g
+	MOVL	BP, g(DX)
 
 	MOVL	context+8(FP), AX
 
diff --git a/src/pkg/runtime/linux/386/sys.s b/src/pkg/runtime/linux/386/sys.s
index 72882cb9dc..f734a68338 100644
--- a/src/pkg/runtime/linux/386/sys.s
+++ b/src/pkg/runtime/linux/386/sys.s
@@ -40,9 +40,10 @@ TEXT rt_sigaction(SB),7,$0
 	RET
 
 TEXT sigtramp(SB),7,$0
-	MOVL	m, BP
+	get_tls(CX)
+	MOVL	m(CX), BP
 	MOVL	m_gsignal(BP), AX
-	MOVL	AX, g
+	MOVL	AX, g(CX)
 	JMP	sighandler(SB)
 
 TEXT sigignore(SB),7,$0
@@ -50,9 +51,10 @@ TEXT sigignore(SB),7,$0
 
 TEXT sigreturn(SB),7,$0
 	// g = m->curg
-	MOVL	m, BP
+	get_tls(CX)
+	MOVL	m(CX), BP
 	MOVL	m_curg(BP), BP
-	MOVL	BP, g
+	MOVL	BP, g(CX)
 	MOVL	$173, AX	// rt_sigreturn
 	INT $0x80
 	INT $3	// not reached
@@ -149,8 +151,9 @@ TEXT clone(SB),7,$0
 	MOVW	DI, GS
 
 	// Now segment is established.  Initialize m, g.
-	MOVL	DX, g
-	MOVL	BX, m
+	get_tls(AX)
+	MOVL	DX, g(AX)
+	MOVL	BX, m(AX)
 
 	CALL	stackcheck(SB)	// smashes AX
 	MOVL	0(DX), DX	// paranoia; check they are not nil
diff --git a/src/pkg/runtime/mgc0.c b/src/pkg/runtime/mgc0.c
index f0eafe3fd6..91898270d2 100644
--- a/src/pkg/runtime/mgc0.c
+++ b/src/pkg/runtime/mgc0.c
@@ -73,8 +73,12 @@ scanstack(G *gp)
 {
 	Stktop *stk;
 	byte *sp;
+	// TODO(rsc): Change 8g not to assume that extern register
+	// variables are directly addressable.  Declaring the
+	// local variable here works around the bug.
+	G* gg = g;
 
-	if(gp == g)
+	if(gp == gg)
 		sp = (byte*)&gp;
 	else
 		sp = gp->sched.sp;
@@ -89,7 +93,11 @@ scanstack(G *gp)
 static void
 mark(void)
 {
-	G *gp;
+	G* gp;
+	// TODO(rsc): Change 8g not to assume that extern register
+	// variables are directly addressable.  Declaring the
+	// local variable here works around the bug.
+	G* gg = g;
 
 	// mark data+bss.
 	// skip mheap itself, which has no interesting pointers
@@ -106,7 +114,7 @@ mark(void)
 		case Gdead:
 			break;
 		case Grunning:
-			if(gp != g)
+			if(gp != gg)
 				throw("mark - world not stopped");
 			scanstack(gp);
 			break;
diff --git a/src/pkg/runtime/mingw/386/defs.h b/src/pkg/runtime/mingw/386/defs.h
new file mode 100644
index 0000000000..f5a16367eb
--- /dev/null
+++ b/src/pkg/runtime/mingw/386/defs.h
@@ -0,0 +1,17 @@
+// c:\Users\Hector\Code\go\bin\godefs.exe defs.c
+
+// MACHINE GENERATED - DO NOT EDIT.
+
+// Constants
+enum {
+	PROT_NONE = 0,
+	PROT_READ = 0x1,
+	PROT_WRITE = 0x2,
+	PROT_EXEC = 0x4,
+	MAP_ANON = 0x1,
+	MAP_PRIVATE = 0x2,
+};
+
+// Types
+#pragma pack on
+#pragma pack off
diff --git a/src/pkg/runtime/mingw/386/rt0.s b/src/pkg/runtime/mingw/386/rt0.s
new file mode 100644
index 0000000000..efd8ce3e68
--- /dev/null
+++ b/src/pkg/runtime/mingw/386/rt0.s
@@ -0,0 +1,6 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+TEXT	_rt0_386_mingw(SB),7,$0
+	JMP	_rt0_386(SB)
diff --git a/src/pkg/runtime/mingw/386/signal.c b/src/pkg/runtime/mingw/386/signal.c
new file mode 100644
index 0000000000..ba38823911
--- /dev/null
+++ b/src/pkg/runtime/mingw/386/signal.c
@@ -0,0 +1,8 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+void
+initsig(void)
+{
+}
diff --git a/src/pkg/runtime/mingw/386/sys.s b/src/pkg/runtime/mingw/386/sys.s
new file mode 100644
index 0000000000..9bbafc2785
--- /dev/null
+++ b/src/pkg/runtime/mingw/386/sys.s
@@ -0,0 +1,87 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "386/asm.h"
+
+TEXT get_kernel_module(SB),7,$0
+	MOVL	0x30(FS), AX		// get PEB
+	MOVL	0x0c(AX), AX		// get PEB_LDR_DATA
+	MOVL	0x1c(AX), AX		// get init order module list
+	MOVL	(AX), AX		// get next entry (kernel module)
+	MOVL	0x08(AX), AX		// get base of module
+	RET
+
+// TODO(rsc,hectorchu): Switch to m stack before call.
+TEXT stdcall(SB),7,$0
+	CALL	runtime·entersyscall(SB)
+	get_tls(CX)
+	MOVL	m(CX), CX
+	POPL	m_return_address(CX)	// save return address
+	POPL	AX			// first arg is function pointer
+	MOVL	SP, m_stack_pointer(CX)	// save stack pointer
+	CALL	AX
+	get_tls(CX)
+	MOVL	m(CX), CX
+	MOVL	m_stack_pointer(CX), SP
+	PUSHL	AX
+	PUSHL	m_return_address(CX)
+	CALL	runtime·exitsyscall(SB)
+	MOVL	4(SP), AX
+	RET
+
+// TODO(rsc,hectorchu): Switch to m stack before call.
+TEXT stdcall_raw(SB),7,$0
+	get_tls(CX)
+	MOVL	m(CX), CX
+	POPL	m_return_address(CX)	// save return address
+	POPL	AX			// first arg is function pointer
+	MOVL	SP, m_stack_pointer(CX)	// save stack pointer
+	CALL	AX
+	get_tls(CX)
+	MOVL	m(CX), CX
+	MOVL	m_stack_pointer(CX), SP
+	PUSHL	AX
+	PUSHL	m_return_address(CX)
+	RET
+
+TEXT threadstart(SB),7,$0
+	MOVL	4(SP), AX		// threadstart param
+	MOVL	0(AX), BX		// newosproc arg stack
+	MOVL	0(BX), CX		// m
+	MOVL	4(BX), DX		// g
+
+	// set up tls
+	LEAL	m_tls(CX), SI
+	MOVL	SI, 0x2c(FS)
+	MOVL	CX, m(SI)
+	MOVL	DX, g(SI)
+	MOVL	SP, m_os_stack_pointer(CX)
+
+	PUSHL	8(BX)			// stk
+	PUSHL	12(BX)			// fn
+	PUSHL	4(AX)			// event_handle
+
+	// signal that we're done with thread args
+	MOVL	SetEvent(SB), BX
+	CALL	BX			// SetEvent(event_handle)
+	POPL	BX			// fn
+	POPL	SP			// stk
+
+	CALL	stackcheck(SB)		// clobbers AX,CX
+	CALL	BX			// fn()
+
+	// cleanup stack before returning as we are stdcall
+	get_tls(CX)
+	MOVL	m(CX), CX
+	MOVL	m_os_stack_pointer(CX), SP
+	POPL	AX			// return address
+	MOVL	AX, (SP)
+	XORL	AX, AX
+	RET
+
+// setldt(int entry, int address, int limit)
+TEXT setldt(SB),7,$0
+	MOVL	address+4(FP), CX
+	MOVL	CX, 0x2c(FS)
+	RET
diff --git a/src/pkg/runtime/mingw/defs.c b/src/pkg/runtime/mingw/defs.c
new file mode 100644
index 0000000000..db5f1400ef
--- /dev/null
+++ b/src/pkg/runtime/mingw/defs.c
@@ -0,0 +1,13 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+enum {
+	$PROT_NONE = 0,
+	$PROT_READ = 1,
+	$PROT_WRITE = 2,
+	$PROT_EXEC = 4,
+
+	$MAP_ANON = 1,
+	$MAP_PRIVATE = 2,
+};
diff --git a/src/pkg/runtime/mingw/os.h b/src/pkg/runtime/mingw/os.h
new file mode 100644
index 0000000000..8470cc0e58
--- /dev/null
+++ b/src/pkg/runtime/mingw/os.h
@@ -0,0 +1,18 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The following function allows one to dynamically
+// resolve DLL function names.
+// The arguments are strings.
+void *get_proc_addr(void *library, void *name);
+
+// Call a Windows function with stdcall conventions.
+void *stdcall(void *fn, ...);
+void *stdcall_raw(void *fn, ...);
+
+#define goargs mingw_goargs
+void mingw_goargs(void);
+
+// Get start address of symbol data in memory.
+void *get_symdat_addr(void);
diff --git a/src/pkg/runtime/mingw/thread.c b/src/pkg/runtime/mingw/thread.c
new file mode 100644
index 0000000000..979fd42247
--- /dev/null
+++ b/src/pkg/runtime/mingw/thread.c
@@ -0,0 +1,265 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "runtime.h"
+#include "os.h"
+
+#define stdcall stdcall_raw
+
+extern void *get_kernel_module(void);
+
+// Also referenced by external packages
+void *CloseHandle;
+void *ExitProcess;
+void *GetStdHandle;
+void *SetEvent;
+void *WriteFile;
+
+static void *CreateEvent;
+static void *CreateThread;
+static void *GetModuleHandle;
+static void *GetProcAddress;
+static void *LoadLibraryEx;
+static void *VirtualAlloc;
+static void *WaitForSingleObject;
+
+static void*
+get_proc_addr2(byte *base, byte *name)
+{
+	byte *pe_header, *exports;
+	uint32 entries, *addr, *names, i;
+	uint16 *ordinals;
+
+	pe_header = base+*(uint32*)(base+0x3c);
+	exports = base+*(uint32*)(pe_header+0x78);
+	entries = *(uint32*)(exports+0x18);
+	addr = (uint32*)(base+*(uint32*)(exports+0x1c));
+	names = (uint32*)(base+*(uint32*)(exports+0x20));
+	ordinals = (uint16*)(base+*(uint32*)(exports+0x24));
+	for(i=0; i<entries; i++) {
+		byte *s = base+names[i];
+		if(!strcmp(name, s))
+			break;
+	}
+	if(i == entries)
+		return 0;
+	return base+addr[ordinals[i]];
+}
+
+void
+osinit(void)
+{
+	void *base;
+
+	base = get_kernel_module();
+	GetProcAddress = get_proc_addr2(base, (byte*)"GetProcAddress");
+	LoadLibraryEx = get_proc_addr2(base, (byte*)"LoadLibraryExA");
+	CloseHandle = get_proc_addr("kernel32.dll", "CloseHandle");
+	CreateEvent = get_proc_addr("kernel32.dll", "CreateEventA");
+	CreateThread = get_proc_addr("kernel32.dll", "CreateThread");
+	ExitProcess = get_proc_addr("kernel32.dll", "ExitProcess");
+	GetModuleHandle = get_proc_addr("kernel32.dll", "GetModuleHandleA");
+	GetStdHandle = get_proc_addr("kernel32.dll", "GetStdHandle");
+	SetEvent = get_proc_addr("kernel32.dll", "SetEvent");
+	VirtualAlloc = get_proc_addr("kernel32.dll", "VirtualAlloc");
+	WaitForSingleObject = get_proc_addr("kernel32.dll", "WaitForSingleObject");
+	WriteFile = get_proc_addr("kernel32.dll", "WriteFile");
+}
+
+// The arguments are strings.
+void*
+get_proc_addr(void *library, void *name)
+{
+	void *base;
+
+	base = stdcall(LoadLibraryEx, library, 0, 0);
+	return stdcall(GetProcAddress, base, name);
+}
+
+void
+mingw_goargs(void)
+{
+	extern Slice os·Args;
+	extern Slice os·Envs;
+
+	void *gcl, *clta, *ges;
+	uint16 *cmd, *env, **argv;
+	String *gargv;
+	String *genvv;
+	int32 i, argc, envc;
+	uint16 *envp;
+
+	gcl = get_proc_addr("kernel32.dll", "GetCommandLineW");
+	clta = get_proc_addr("shell32.dll", "CommandLineToArgvW");
+	ges = get_proc_addr("kernel32.dll", "GetEnvironmentStringsW");
+
+	cmd = stdcall(gcl);
+	env = stdcall(ges);
+	argv = stdcall(clta, cmd, &argc);
+
+	envc = 0;
+	for(envp=env; *envp; envc++)
+		envp += findnullw(envp)+1;
+
+	gargv = malloc(argc*sizeof gargv[0]);
+	genvv = malloc(envc*sizeof genvv[0]);
+
+	for(i=0; i<argc; i++)
+		gargv[i] = gostringw(argv[i]);
+	os·Args.array = (byte*)gargv;
+	os·Args.len = argc;
+	os·Args.cap = argc;
+
+	envp = env;
+	for(i=0; i<envc; i++) {
+		genvv[i] = gostringw(envp);
+		envp += findnullw(envp)+1;
+	}
+	os·Envs.array = (byte*)genvv;
+	os·Envs.len = envc;
+	os·Envs.cap = envc;
+}
+
+void
+exit(int32 code)
+{
+	stdcall(ExitProcess, code);
+}
+
+int32
+write(int32 fd, void *buf, int32 n)
+{
+	void *handle;
+	uint32 written;
+
+	written = 0;
+	switch(fd) {
+	case 1:
+		handle = stdcall(GetStdHandle, -11);
+		break;
+	case 2:
+		handle = stdcall(GetStdHandle, -12);
+		break;
+	default:
+		return -1;
+	}
+	stdcall(WriteFile, handle, buf, n, &written, 0);
+	return written;
+}
+
+uint8*
+runtime_mmap(byte *addr, uint32 len, int32 prot,
+	int32 flags, int32 fd, uint32 off)
+{
+	USED(prot, flags, fd, off);
+	return stdcall(VirtualAlloc, addr, len, 0x3000, 0x40);
+}
+
+void*
+get_symdat_addr(void)
+{
+	byte *mod, *p;
+	uint32 peh, add;
+	uint16 oph;
+
+	mod = stdcall(GetModuleHandle, 0);
+	peh = *(uint32*)(mod+0x3c);
+	p = mod+peh+4;
+	oph = *(uint16*)(p+0x10);
+	p += 0x14+oph;
+	while(strcmp(p, (byte*)".symdat"))
+		p += 40;
+	add = *(uint32*)(p+0x0c);
+	return mod+add;
+}
+
+// Thread-safe allocation of an event.
+static void
+initevent(void **pevent)
+{
+	void *event;
+
+	event = stdcall(CreateEvent, 0, 0, 0, 0);
+	if(!casp(pevent, 0, event)) {
+		// Someone else filled it in.  Use theirs.
+		stdcall(CloseHandle, event);
+	}
+}
+
+static void
+eventlock(Lock *l)
+{
+	// Allocate event if needed.
+	if(l->event == 0)
+		initevent(&l->event);
+
+	if(xadd(&l->key, 1) > 1)	// someone else has it; wait
+		stdcall(WaitForSingleObject, l->event, -1);
+}
+
+static void
+eventunlock(Lock *l)
+{
+	if(xadd(&l->key, -1) > 0)	// someone else is waiting
+		stdcall(SetEvent, l->event);
+}
+
+void
+lock(Lock *l)
+{
+	if(m->locks < 0)
+		throw("lock count");
+	m->locks++;
+	eventlock(l);
+}
+
+void
+unlock(Lock *l)
+{
+	m->locks--;
+	if(m->locks < 0)
+		throw("lock count");
+	eventunlock(l);
+}
+
+void
+noteclear(Note *n)
+{
+	eventlock(&n->lock);
+}
+
+void
+notewakeup(Note *n)
+{
+	eventunlock(&n->lock);
+}
+
+void
+notesleep(Note *n)
+{
+	eventlock(&n->lock);
+	eventunlock(&n->lock);	// Let other sleepers find out too.
+}
+
+void
+newosproc(M *m, G *g, void *stk, void (*fn)(void))
+{
+	struct {
+		void *args;
+		void *event_handle;
+	} param = { &m };
+	extern uint32 threadstart(void *p);
+
+	USED(g, stk, fn);
+	param.event_handle = stdcall(CreateEvent, 0, 0, 0, 0);
+	stdcall(CreateThread, 0, 0, threadstart, &param, 0, 0);
+	stdcall(WaitForSingleObject, param.event_handle, -1);
+	stdcall(CloseHandle, param.event_handle);
+}
+
+// Called to initialize a new m (including the bootstrap m).
+void
+minit(void)
+{
+}
diff --git a/src/pkg/runtime/mkasmh.sh b/src/pkg/runtime/mkasmh.sh
index cb4b6d214f..fdd2668406 100755
--- a/src/pkg/runtime/mkasmh.sh
+++ b/src/pkg/runtime/mkasmh.sh
@@ -18,8 +18,18 @@ case "$GOARCH" in
 	#	../../cmd/8l/pass.c:/D_GS
 	#	../../libcgo/linux_386.c:/^start
 	#	../../libcgo/darwin_386.c:/^start
-	echo '#define	g	0(GS)'
-	echo '#define	m	4(GS)'
+	case "$GOOS" in
+	mingw)
+		echo '#define	get_tls(r)	MOVL 0x2c(FS), r'
+		echo '#define	g(r)	0(r)'
+		echo '#define	m(r)	4(r)'
+		;;
+	*)
+		echo '#define	get_tls(r)'
+		echo '#define	g(r)	0(GS)'
+		echo '#define	m(r)	4(GS)'
+		;;
+	esac
 	;;
 amd64)
 	# These registers are also known to:
diff --git a/src/pkg/runtime/proc.c b/src/pkg/runtime/proc.c
index 60d76bc0f7..8dc9243261 100644
--- a/src/pkg/runtime/proc.c
+++ b/src/pkg/runtime/proc.c
@@ -3,7 +3,9 @@
 // license that can be found in the LICENSE file.
 
 #include "runtime.h"
+#include "defs.h"
 #include "malloc.h"
+#include "os.h"
 
 typedef struct Sched Sched;
 
@@ -386,7 +388,12 @@ starttheworld(void)
 void
 mstart(void)
 {
-	if(g != m->g0)
+	// TODO(rsc): Change 8g not to assume that extern register
+	// variables are directly addressable.  Declaring the
+	// local variable here works around the bug.
+	G* gg = g;
+
+	if(gg != m->g0)
 		throw("bad mstart");
 	if(m->mcache == nil)
 		m->mcache = allocmcache();
@@ -517,7 +524,12 @@ scheduler(void)
 void
 gosched(void)
 {
-	if(g == m->g0)
+	// TODO(rsc): Change 8g not to assume that extern register
+	// variables are directly addressable.  Declaring the
+	// local variable here works around the bug.
+	G* gg = g;
+
+	if(gg == m->g0)
 		throw("gosched of g0");
 	if(gosave(&g->sched) == 0)
 		gogo(&m->sched, 1);
diff --git a/src/pkg/runtime/runtime.c b/src/pkg/runtime/runtime.c
index 4a0309e0c7..8588894624 100644
--- a/src/pkg/runtime/runtime.c
+++ b/src/pkg/runtime/runtime.c
@@ -165,6 +165,20 @@ goargs(void)
 	os·Envs.cap = envc;
 }
 
+// Atomic add and return new value.
+uint32
+xadd(uint32 volatile *val, int32 delta)
+{
+	uint32 oval, nval;
+
+	for(;;){
+		oval = *val;
+		nval = oval + delta;
+		if(cas(val, oval, nval))
+			return nval;
+	}
+}
+
 byte*
 getenv(int8 *s)
 {
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index 8052fd09ca..2d956ea980 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -109,7 +109,11 @@ enum
 struct	Lock
 {
 	uint32	key;
+#ifdef __MINGW__
+	void*	event;
+#else
 	uint32	sema;	// for OS X
+#endif
 };
 struct	Usema
 {
@@ -204,6 +208,11 @@ struct	M
 	uint32	machport;	// Return address for Mach IPC (OS X)
 	MCache	*mcache;
 	G*	lockedg;
+#ifdef __MINGW__
+	void*	return_address;	// saved return address and stack
+	void*	stack_pointer;	// pointer for Windows stdcall
+	void*	os_stack_pointer;
+#endif
 };
 struct	Stktop
 {
@@ -314,6 +323,7 @@ int8*	goos;
  */
 int32	strcmp(byte*, byte*);
 int32	findnull(byte*);
+int32	findnullw(uint16*);
 void	dump(byte*, int32);
 int32	runetochar(byte*, int32);
 int32	charntorune(int32*, uint8*, int32);
@@ -339,6 +349,7 @@ void	memmove(void*, void*, uint32);
 void*	mal(uint32);
 uint32	cmpstring(String, String);
 String	gostring(byte*);
+String	gostringw(uint16*);
 void	initsig(void);
 int32	gotraceback(void);
 void	traceback(uint8 *pc, uint8 *sp, G* gp);
@@ -346,6 +357,8 @@ void	tracebackothers(G*);
 int32	open(byte*, int32, ...);
 int32	write(int32, void*, int32);
 bool	cas(uint32*, uint32, uint32);
+bool	casp(void**, void*, void*);
+uint32	xadd(uint32 volatile*, int32);
 void	jmpdefer(byte*, void*);
 void	exit1(int32);
 void	ready(G*);
diff --git a/src/pkg/runtime/string.cgo b/src/pkg/runtime/string.cgo
index 6e380a1075..03b05618d8 100644
--- a/src/pkg/runtime/string.cgo
+++ b/src/pkg/runtime/string.cgo
@@ -19,6 +19,18 @@ findnull(byte *s)
 	return l;
 }
 
+int32
+findnullw(uint16 *s)
+{
+	int32 l;
+
+	if(s == nil)
+		return 0;
+	for(l=0; s[l]!=0; l++)
+		;
+	return l;
+}
+
 int32 maxstring;
 
 String
@@ -47,6 +59,24 @@ gostring(byte *str)
 	return s;
 }
 
+String
+gostringw(uint16 *str)
+{
+	int32 n, i;
+	byte buf[8];
+	String s;
+
+	n = 0;
+	for(i=0; str[i]; i++)
+		n += runetochar(buf, str[i]);
+	s = gostringsize(n+4);
+	n = 0;
+	for(i=0; str[i]; i++)
+		n += runetochar(s.str+n, str[i]);
+	s.len = n;
+	return s;
+}
+
 func catstring(s1 String, s2 String) (s3 String) {
 	if(s1.len == 0) {
 		s3 = s2;
diff --git a/src/pkg/runtime/symtab.c b/src/pkg/runtime/symtab.c
index 0b5499474f..1a547f230b 100644
--- a/src/pkg/runtime/symtab.c
+++ b/src/pkg/runtime/symtab.c
@@ -13,6 +13,8 @@
 // and figure out exactly what we want.
 
 #include "runtime.h"
+#include "defs.h"
+#include "os.h"
 
 // TODO(rsc): Move this *under* the text segment.
 // Then define names for these addresses instead of hard-coding magic ones.
@@ -45,8 +47,13 @@ walksymtab(void (*fn)(Sym*))
 	if(goos != nil && strcmp((uint8*)goos, (uint8*)"nacl") == 0)
 		return;
 
+#ifdef __MINGW__
+	v = get_symdat_addr();
+	p = (byte*)v+8;
+#else
 	v = SYMCOUNTS;
 	p = SYMDATA;
+#endif
 	ep = p + v[0];
 	while(p < ep) {
 		if(p + 7 > ep)
@@ -246,8 +253,13 @@ splitpcln(void)
 		return;
 
 	// pc/ln table bounds
+#ifdef __MINGW__
+	v = get_symdat_addr();
+	p = (byte*)v+8;
+#else
 	v = SYMCOUNTS;
 	p = SYMDATA;
+#endif
 	p += v[0];
 	ep = p+v[1];