diff --git a/_test/bdwgc.go b/_test/bdwgc.go
index 01bdcb2f..17d2759f 100644
--- a/_test/bdwgc.go
+++ b/_test/bdwgc.go
@@ -5,7 +5,7 @@ import (
 
 	"github.com/goplus/llgo/_test/testing"
 	"github.com/goplus/llgo/c"
-	"github.com/goplus/llgo/internal/runtime/bdwgc"
+	"github.com/goplus/llgo/c/bdwgc"
 )
 
 // ------ Test malloc ------
diff --git a/internal/runtime/bdwgc/bdwgc.go b/c/bdwgc/bdwgc.go
similarity index 95%
rename from internal/runtime/bdwgc/bdwgc.go
rename to c/bdwgc/bdwgc.go
index 6b947962..f939dffb 100644
--- a/internal/runtime/bdwgc/bdwgc.go
+++ b/c/bdwgc/bdwgc.go
@@ -23,7 +23,7 @@ import (
 )
 
 const (
-	LLGoPackage = "link: $LLGO_LIB_BDWGC; $(pkg-config --libs bdw-gc); -lgc"
+	LLGoPackage = "link: $(pkg-config --libs bdw-gc); -lgc"
 )
 
 // -----------------------------------------------------------------------------
@@ -99,3 +99,5 @@ func StartIncrementalCollection()
 
 //go:linkname CollectALittle C.GC_collect_a_little
 func CollectALittle()
+
+// -----------------------------------------------------------------------------
diff --git a/internal/runtime/bdwgc/llgo_autogen.lla b/c/bdwgc/llgo_autogen.lla
similarity index 100%
rename from internal/runtime/bdwgc/llgo_autogen.lla
rename to c/bdwgc/llgo_autogen.lla
diff --git a/c/c.go b/c/c.go
index a38958ed..ed2d4cff 100644
--- a/c/c.go
+++ b/c/c.go
@@ -77,6 +77,9 @@ func Memset(s Pointer, c Int, n uintptr) Pointer
 //go:linkname GoStringData llgo.stringData
 func GoStringData(string) *Char
 
+//go:linkname GoDeferData llgo.deferData
+func GoDeferData() Pointer
+
 // -----------------------------------------------------------------------------
 
 //go:linkname AllocaSigjmpBuf llgo.sigjmpbuf
diff --git a/cl/_testdata/print/in.go b/cl/_testdata/print/in.go
index c258a02e..99682586 100644
--- a/cl/_testdata/print/in.go
+++ b/cl/_testdata/print/in.go
@@ -3,7 +3,7 @@ package main
 import (
 	"unsafe"
 
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func gwrite(b []byte) {
diff --git a/cl/_testdata/vargs/in.go b/cl/_testdata/vargs/in.go
index 417911cb..8f7c3ac4 100644
--- a/cl/_testdata/vargs/in.go
+++ b/cl/_testdata/vargs/in.go
@@ -1,6 +1,6 @@
 package main
 
-import "github.com/goplus/llgo/internal/runtime/c"
+import "github.com/goplus/llgo/c"
 
 func test(a ...any) {
 	for _, v := range a {
diff --git a/cl/_testlibc/defer/in.go b/cl/_testlibc/defer/in.go
index ab8362c3..592ac32d 100644
--- a/cl/_testlibc/defer/in.go
+++ b/cl/_testlibc/defer/in.go
@@ -1,6 +1,6 @@
 package main
 
-import "github.com/goplus/llgo/internal/runtime/c"
+import "github.com/goplus/llgo/c"
 
 func f(s string) bool {
 	return len(s) > 2
diff --git a/cl/_testrt/alloca/in.go b/cl/_testrt/alloca/in.go
index 95a3dcf1..c16d07b8 100644
--- a/cl/_testrt/alloca/in.go
+++ b/cl/_testrt/alloca/in.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func main() {
diff --git a/cl/_testrt/allocstr/in.go b/cl/_testrt/allocstr/in.go
index 41bcdd61..d97577d2 100644
--- a/cl/_testrt/allocstr/in.go
+++ b/cl/_testrt/allocstr/in.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func hello() string {
diff --git a/cl/_testrt/any/in.go b/cl/_testrt/any/in.go
index 4120c735..0edaadad 100644
--- a/cl/_testrt/any/in.go
+++ b/cl/_testrt/any/in.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func hi(a any) *c.Char {
diff --git a/cl/_testrt/callback/in.go b/cl/_testrt/callback/in.go
index 833bb900..5bd17e57 100644
--- a/cl/_testrt/callback/in.go
+++ b/cl/_testrt/callback/in.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func callback(msg *c.Char, f func(*c.Char)) {
diff --git a/cl/_testrt/cast/in.go b/cl/_testrt/cast/in.go
index 7d3a846e..89196f62 100644
--- a/cl/_testrt/cast/in.go
+++ b/cl/_testrt/cast/in.go
@@ -1,6 +1,6 @@
 package main
 
-//"github.com/goplus/llgo/internal/runtime/c"
+//"github.com/goplus/llgo/c"
 
 func main() {
 	cvt64to8(0, 0)
diff --git a/cl/_testrt/closure/in.go b/cl/_testrt/closure/in.go
index 0db4b4cd..85eb0a4e 100644
--- a/cl/_testrt/closure/in.go
+++ b/cl/_testrt/closure/in.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func main() {
diff --git a/cl/_testrt/gblarray/in.go b/cl/_testrt/gblarray/in.go
index dcb43160..067f60ca 100644
--- a/cl/_testrt/gblarray/in.go
+++ b/cl/_testrt/gblarray/in.go
@@ -1,8 +1,8 @@
 package main
 
 import (
+	"github.com/goplus/llgo/c"
 	"github.com/goplus/llgo/internal/abi"
-	"github.com/goplus/llgo/internal/runtime/c"
 )
 
 func Basic(kind abi.Kind) *abi.Type {
diff --git a/cl/_testrt/index/in.go b/cl/_testrt/index/in.go
index af7c83e2..db5019e1 100644
--- a/cl/_testrt/index/in.go
+++ b/cl/_testrt/index/in.go
@@ -1,6 +1,6 @@
 package main
 
-import "github.com/goplus/llgo/internal/runtime/c"
+import "github.com/goplus/llgo/c"
 
 type point struct {
 	x int
diff --git a/cl/_testrt/intgen/in.go b/cl/_testrt/intgen/in.go
index 7e43a06b..12a5b034 100644
--- a/cl/_testrt/intgen/in.go
+++ b/cl/_testrt/intgen/in.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 type generator struct {
diff --git a/cl/_testrt/linkname/in.go b/cl/_testrt/linkname/in.go
index cc4f836e..26c3b75f 100644
--- a/cl/_testrt/linkname/in.go
+++ b/cl/_testrt/linkname/in.go
@@ -3,8 +3,8 @@ package main
 import (
 	_ "unsafe"
 
+	"github.com/goplus/llgo/c"
 	_ "github.com/goplus/llgo/cl/internal/linktarget"
-	"github.com/goplus/llgo/internal/runtime/c"
 )
 
 //go:linkname print github.com/goplus/llgo/cl/internal/linktarget.F
diff --git a/cl/_testrt/map/in.go b/cl/_testrt/map/in.go
index 34b98520..826ba8aa 100644
--- a/cl/_testrt/map/in.go
+++ b/cl/_testrt/map/in.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func main() {
diff --git a/cl/_testrt/named/in.go b/cl/_testrt/named/in.go
index 9a958d8d..658cdfe7 100644
--- a/cl/_testrt/named/in.go
+++ b/cl/_testrt/named/in.go
@@ -1,6 +1,6 @@
 package main
 
-import "github.com/goplus/llgo/internal/runtime/c"
+import "github.com/goplus/llgo/c"
 
 type mSpanList struct {
 	first *mspan
diff --git a/cl/_testrt/qsort/in.go b/cl/_testrt/qsort/in.go
index b4c65417..8fa4f775 100644
--- a/cl/_testrt/qsort/in.go
+++ b/cl/_testrt/qsort/in.go
@@ -3,7 +3,7 @@ package main
 import (
 	"unsafe"
 
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 //go:linkname qsort C.qsort
diff --git a/cl/_testrt/result/in.go b/cl/_testrt/result/in.go
index e4e9ec7d..15bcb81b 100644
--- a/cl/_testrt/result/in.go
+++ b/cl/_testrt/result/in.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func main() {
diff --git a/cl/_testrt/sum/in.go b/cl/_testrt/sum/in.go
index 435310bd..c3536fa8 100644
--- a/cl/_testrt/sum/in.go
+++ b/cl/_testrt/sum/in.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func sum(args ...int) (ret int) {
diff --git a/cl/_testrt/unreachable/in.go b/cl/_testrt/unreachable/in.go
index 3f62b8a8..8a6dbdc6 100644
--- a/cl/_testrt/unreachable/in.go
+++ b/cl/_testrt/unreachable/in.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func foo() {
diff --git a/cl/internal/linktarget/foo.go b/cl/internal/linktarget/foo.go
index b3eb725c..fa89c8e8 100644
--- a/cl/internal/linktarget/foo.go
+++ b/cl/internal/linktarget/foo.go
@@ -1,7 +1,7 @@
 package linktarget
 
 import (
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func F(a, b *c.Char) {
diff --git a/internal/runtime/c/c.go b/internal/runtime/c/c.go
deleted file mode 100644
index cea55d8b..00000000
--- a/internal/runtime/c/c.go
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package c
-
-import "C"
-import "unsafe"
-
-const (
-	LLGoPackage = "decl"
-)
-
-type (
-	Char    = int8
-	Int     = C.int
-	Pointer = unsafe.Pointer
-	FilePtr = unsafe.Pointer
-)
-
-//go:linkname Str llgo.cstr
-func Str(string) *Char
-
-// llgo:link Advance llgo.advance
-func Advance[PtrT any](ptr PtrT, offset int) PtrT { return ptr }
-
-//go:linkname Alloca llgo.alloca
-func Alloca(size uintptr) Pointer
-
-//go:linkname AllocaCStr llgo.allocaCStr
-func AllocaCStr(s string) *Char
-
-//go:linkname GoDeferData llgo.deferData
-func GoDeferData() Pointer
-
-//go:linkname Unreachable llgo.unreachable
-func Unreachable()
-
-//go:linkname Exit C.exit
-func Exit(Int)
-
-//go:linkname AllocaSigjmpBuf llgo.sigjmpbuf
-func AllocaSigjmpBuf() Pointer
-
-//go:linkname Sigsetjmp llgo.sigsetjmp
-func Sigsetjmp(jb Pointer, savemask Int) Int
-
-//go:linkname Siglongjmp llgo.siglongjmp
-func Siglongjmp(jb Pointer, retval Int)
-
-//go:linkname Rand C.rand
-func Rand() Int
-
-//go:linkname Malloc C.malloc
-func Malloc(size uintptr) Pointer
-
-//go:linkname Free C.free
-func Free(ptr Pointer)
-
-//go:linkname Memcpy C.memcpy
-func Memcpy(dst, src Pointer, n uintptr) Pointer
-
-//go:linkname Memmove C.memmove
-func Memmove(dst, src Pointer, n uintptr) Pointer
-
-//go:linkname Memset C.memset
-func Memset(s Pointer, c Int, n uintptr) Pointer
-
-//go:linkname Printf C.printf
-func Printf(format *Char, __llgo_va_list ...any) Int
-
-//go:linkname Fprintf C.fprintf
-func Fprintf(fp FilePtr, format *Char, __llgo_va_list ...any) Int
-
-//go:linkname Fwrite C.fwrite
-func Fwrite(data Pointer, size, count uintptr, fp FilePtr) uintptr
-
-//go:linkname Fputc C.fputc
-func Fputc(c Int, fp FilePtr) Int
diff --git a/internal/runtime/c/c_default.go b/internal/runtime/c/c_default.go
deleted file mode 100644
index 45286fe9..00000000
--- a/internal/runtime/c/c_default.go
+++ /dev/null
@@ -1,31 +0,0 @@
-//go:build !linux
-// +build !linux
-
-/*
- * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package c
-
-import _ "unsafe"
-
-//go:linkname Stdin __stdinp
-var Stdin FilePtr
-
-//go:linkname Stdout __stdoutp
-var Stdout FilePtr
-
-//go:linkname Stderr __stderrp
-var Stderr FilePtr
diff --git a/internal/runtime/c/c_linux.go b/internal/runtime/c/c_linux.go
deleted file mode 100644
index 70cc9bea..00000000
--- a/internal/runtime/c/c_linux.go
+++ /dev/null
@@ -1,31 +0,0 @@
-//go:build linux
-// +build linux
-
-/*
- * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package c
-
-import _ "unsafe"
-
-//go:linkname Stdin stdin
-var Stdin FilePtr
-
-//go:linkname Stdout stdout
-var Stdout FilePtr
-
-//go:linkname Stderr stderr
-var Stderr FilePtr
diff --git a/internal/runtime/z_face.go b/internal/runtime/z_face.go
index 7542aa5d..b81dc818 100644
--- a/internal/runtime/z_face.go
+++ b/internal/runtime/z_face.go
@@ -19,8 +19,8 @@ package runtime
 import (
 	"unsafe"
 
+	"github.com/goplus/llgo/c"
 	"github.com/goplus/llgo/internal/abi"
-	"github.com/goplus/llgo/internal/runtime/c"
 )
 
 type eface struct {
diff --git a/internal/runtime/z_gc.go b/internal/runtime/z_gc.go
index 3eb1c856..6f5a8d88 100644
--- a/internal/runtime/z_gc.go
+++ b/internal/runtime/z_gc.go
@@ -22,8 +22,8 @@ package runtime
 import (
 	"unsafe"
 
-	"github.com/goplus/llgo/internal/runtime/bdwgc"
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/c/bdwgc"
 )
 
 // AllocU allocates uninitialized memory.
diff --git a/internal/runtime/z_nogc.go b/internal/runtime/z_nogc.go
index 1c591387..81261bd6 100644
--- a/internal/runtime/z_nogc.go
+++ b/internal/runtime/z_nogc.go
@@ -22,7 +22,7 @@ package runtime
 import (
 	"unsafe"
 
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 // AllocU allocates uninitialized memory.
diff --git a/internal/runtime/z_print.go b/internal/runtime/z_print.go
index 65a5a9a4..cbf9d83d 100644
--- a/internal/runtime/z_print.go
+++ b/internal/runtime/z_print.go
@@ -19,7 +19,7 @@ package runtime
 import (
 	"unsafe"
 
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 func PrintByte(v byte) {
diff --git a/internal/runtime/z_rt.go b/internal/runtime/z_rt.go
index 222c6e5c..9d9eea33 100644
--- a/internal/runtime/z_rt.go
+++ b/internal/runtime/z_rt.go
@@ -19,9 +19,9 @@ package runtime
 import (
 	"unsafe"
 
+	"github.com/goplus/llgo/c"
 	"github.com/goplus/llgo/c/pthread"
 	"github.com/goplus/llgo/internal/abi"
-	"github.com/goplus/llgo/internal/runtime/c"
 )
 
 // -----------------------------------------------------------------------------
diff --git a/internal/runtime/z_slice.go b/internal/runtime/z_slice.go
index f4711e47..f2934822 100644
--- a/internal/runtime/z_slice.go
+++ b/internal/runtime/z_slice.go
@@ -19,7 +19,7 @@ package runtime
 import (
 	"unsafe"
 
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 // -----------------------------------------------------------------------------
diff --git a/internal/runtime/z_string.go b/internal/runtime/z_string.go
index e34ae730..da56b161 100644
--- a/internal/runtime/z_string.go
+++ b/internal/runtime/z_string.go
@@ -19,7 +19,7 @@ package runtime
 import (
 	"unsafe"
 
-	"github.com/goplus/llgo/internal/runtime/c"
+	"github.com/goplus/llgo/c"
 )
 
 // -----------------------------------------------------------------------------