diff --git a/trunk/bootrom/build/bootrom/Makefile b/trunk/bootrom/build/bootrom/Makefile
index 7ca0f86..9c76056 100644
--- a/trunk/bootrom/build/bootrom/Makefile
+++ b/trunk/bootrom/build/bootrom/Makefile
@@ -21,8 +21,9 @@ include	$(CTRBROM_ROOT)/build/buildtools/commondefs
 #----------------------------------------------------------------------------
 
 SUBDIRS		= \
-		  teg-dev \
 		  jtag-only \
+		  thread \
+		  teg-dev \
 		  ctr_bootrom \
 
 #----------------------------------------------------------------------------
diff --git a/trunk/bootrom/build/bootrom/thread/ARM11/Makefile b/trunk/bootrom/build/bootrom/thread/ARM11/Makefile
new file mode 100644
index 0000000..cf38a50
--- /dev/null
+++ b/trunk/bootrom/build/bootrom/thread/ARM11/Makefile
@@ -0,0 +1,48 @@
+#! make -f
+#----------------------------------------------------------------------------
+# Project:  CtrBrom - bootrom - thread
+# File:     Makefile
+#
+# Copyright 2008 Nintendo.  All rights reserved.
+#
+# These coded instructions, statements, and computer programs contain
+# proprietary information of Nintendo of America Inc. and/or Nintendo
+# Company Ltd., and are protected by Federal copyright law.  They may
+# not be disclosed to third parties or copied or duplicated in any form,
+# in whole or in part, without the prior written consent of Nintendo.
+#
+# $Date::            $
+# $Rev$
+# $Author$
+#----------------------------------------------------------------------------
+
+
+#BROM_DEF_LINK_SCATLD = TRUE
+
+SUBDIRS		=
+
+
+#----------------------------------------------------------------------------
+
+TARGET_BIN	=	thread11.padbin
+
+SRCS		=	\
+                main.c \
+
+#SRCDIR		=	# using default
+#LCFILE		=	# using default
+
+include	$(CTRBROM_ROOT)/build/buildtools/commondefs
+
+INSTALL_DIR	= ..
+INSTALL_TARGETS	= $(BINDIR)/$(TARGET_BIN_BASENAME).axf
+
+#----------------------------------------------------------------------------
+
+do-build:		$(TARGETS)
+
+
+include	$(CTRBROM_ROOT)/build/buildtools/modulerules
+
+
+#===== End of Makefile =====
diff --git a/trunk/bootrom/build/bootrom/thread/ARM11/main.c b/trunk/bootrom/build/bootrom/thread/ARM11/main.c
new file mode 100644
index 0000000..8aad0b0
--- /dev/null
+++ b/trunk/bootrom/build/bootrom/thread/ARM11/main.c
@@ -0,0 +1,32 @@
+/*---------------------------------------------------------------------------*
+  Project:  TwlBrom - thread
+  File:     main.c
+
+  Copyright 2008 Nintendo.  All rights reserved.
+
+  These coded instructions, statements, and computer programs contain
+  proprietary information of Nintendo of America Inc. and/or Nintendo
+  Company Ltd., and are protected by Federal copyright law.  They may
+  not be disclosed to third parties or copied or duplicated in any form,
+  in whole or in part, without the prior written consent of Nintendo.
+
+  $Date::            $
+  $Rev$
+  $Author$
+ *---------------------------------------------------------------------------*/
+#include <brom.h>
+
+void BromMain( void )
+{
+    osInitException();
+    osInitBROM();
+
+    osPrintf( "ARM11: start\n" );
+
+    osInitThread();
+    while (1)
+    {
+        osSleep(1);
+    }
+}
+
diff --git a/trunk/bootrom/build/bootrom/thread/ARM9/Makefile b/trunk/bootrom/build/bootrom/thread/ARM9/Makefile
new file mode 100644
index 0000000..bedac83
--- /dev/null
+++ b/trunk/bootrom/build/bootrom/thread/ARM9/Makefile
@@ -0,0 +1,50 @@
+#! make -f
+#----------------------------------------------------------------------------
+# Project:  CtrBrom - bootrom - thread
+# File:     Makefile
+#
+# Copyright 2008 Nintendo.  All rights reserved.
+#
+# These coded instructions, statements, and computer programs contain
+# proprietary information of Nintendo of America Inc. and/or Nintendo
+# Company Ltd., and are protected by Federal copyright law.  They may
+# not be disclosed to third parties or copied or duplicated in any form,
+# in whole or in part, without the prior written consent of Nintendo.
+#
+# $Date::            $
+# $Rev$
+# $Author$
+#----------------------------------------------------------------------------
+
+
+#BROM_DEF_LINK_SCATLD = TRUE
+
+BROM_PROC		= ARM9
+
+SUBDIRS		=
+
+
+#----------------------------------------------------------------------------
+
+TARGET_BIN	=	thread9.padbin
+
+SRCS		=	\
+                main.c \
+
+#SRCDIR		=	# using default
+#LCFILE		=	# using default
+
+include	$(CTRBROM_ROOT)/build/buildtools/commondefs
+
+INSTALL_DIR	= ..
+INSTALL_TARGETS	= $(BINDIR)/$(TARGET_BIN_BASENAME).axf
+
+#----------------------------------------------------------------------------
+
+do-build:		$(TARGETS)
+
+
+include	$(CTRBROM_ROOT)/build/buildtools/modulerules
+
+
+#===== End of Makefile =====
diff --git a/trunk/bootrom/build/bootrom/thread/ARM9/main.c b/trunk/bootrom/build/bootrom/thread/ARM9/main.c
new file mode 100644
index 0000000..caef025
--- /dev/null
+++ b/trunk/bootrom/build/bootrom/thread/ARM9/main.c
@@ -0,0 +1,30 @@
+/*---------------------------------------------------------------------------*
+  Project:  TwlBrom - thread
+  File:     main.c
+
+  Copyright 2008 Nintendo.  All rights reserved.
+
+  These coded instructions, statements, and computer programs contain
+  proprietary information of Nintendo of America Inc. and/or Nintendo
+  Company Ltd., and are protected by Federal copyright law.  They may
+  not be disclosed to third parties or copied or duplicated in any form,
+  in whole or in part, without the prior written consent of Nintendo.
+
+  $Date::            $
+  $Rev$
+  $Author$
+ *---------------------------------------------------------------------------*/
+#include <brom.h>
+
+void BromSpMain( void )
+{
+    osInitException();
+    osInitBROM();
+
+    osInitThread();
+    while (1)
+    {
+        osSleep(1);
+    }
+}
+
diff --git a/trunk/bootrom/build/bootrom/thread/Makefile b/trunk/bootrom/build/bootrom/thread/Makefile
new file mode 100644
index 0000000..75a0861
--- /dev/null
+++ b/trunk/bootrom/build/bootrom/thread/Makefile
@@ -0,0 +1,34 @@
+#! make -f
+#----------------------------------------------------------------------------
+# Project:  CtrBrom - build
+# File:     Makefile
+#
+# Copyright 2008 Nintendo.  All rights reserved.
+#
+# These coded instructions, statements, and computer programs contain
+# proprietary information of Nintendo of America Inc. and/or Nintendo
+# Company Ltd., and are protected by Federal copyright law.  They may
+# not be disclosed to third parties or copied or duplicated in any form,
+# in whole or in part, without the prior written consent of Nintendo.
+#
+# $Date::            $
+# $Rev$
+# $Author$
+#----------------------------------------------------------------------------
+
+include	$(CTRBROM_ROOT)/build/buildtools/commondefs
+
+
+#----------------------------------------------------------------------------
+
+SUBDIRS =	\
+            ARM11 \
+            ARM9 \
+            rom \
+
+#----------------------------------------------------------------------------
+
+include	$(CTRBROM_ROOT)/build/buildtools/modulerules
+
+
+#===== End of Makefile =====
diff --git a/trunk/bootrom/build/bootrom/thread/rom/Makefile b/trunk/bootrom/build/bootrom/thread/rom/Makefile
new file mode 100644
index 0000000..c0789e1
--- /dev/null
+++ b/trunk/bootrom/build/bootrom/thread/rom/Makefile
@@ -0,0 +1,62 @@
+#! make -f
+#----------------------------------------------------------------------------
+# Project:  CtrBrom - bootrom - thread
+# File:     Makefile
+#
+# Copyright 2008 Nintendo.  All rights reserved.
+#
+# These coded instructions, statements, and computer programs contain
+# proprietary information of Nintendo of America Inc. and/or Nintendo
+# Company Ltd., and are protected by Federal copyright law.  They may
+# not be disclosed to third parties or copied or duplicated in any form,
+# in whole or in part, without the prior written consent of Nintendo.
+#
+# $Date::            $
+# $Rev$
+# $Author$
+#----------------------------------------------------------------------------
+
+BROM_PROMGEN = TRUE
+
+SUBDIRS		=
+
+LINCLUDES	=   ../include
+
+#----------------------------------------------------------------------------
+
+TARGET_BIN	=	thread.exo
+
+CRT0_O		=  
+
+SRCS		=	\
+                crt0.c \
+
+#SRCDIR		=	# using default
+#LCFILE		=	# using default
+
+BROM_PADBIN_ARM11 = ../ARM11/bin/$(BROM_BUILDTYPE_ARM11)/thread11.padbin
+BROM_PADBIN_ARM9  = ../ARM9/bin/$(BROM_BUILDTYPE_ARM9)/thread9.padbin
+BROM_DEPENDS = $(BROM_PADBIN_ARM11) $(BROM_PADBIN_ARM9)
+
+MACRO_FLAGS += -DBROM_PADBIN_ARM11=$(BROM_PADBIN_ARM11) \
+               -DBROM_PADBIN_ARM9=$(BROM_PADBIN_ARM9) \
+
+
+include	$(CTRBROM_ROOT)/build/buildtools/commondefs
+
+INSTALL_TARGETS		= $(TARGETS)
+INSTALL_DIR		= $(BROM_INSTALL_PROMDIR)
+
+#----------------------------------------------------------------------------
+
+do-build:		$(TARGETS)
+
+
+include	$(CTRBROM_ROOT)/build/buildtools/modulerules
+
+
+crt0.c : $(BROM_DEPENDS)
+	touch crt0.c
+
+
+#===== End of Makefile =====
diff --git a/trunk/bootrom/build/bootrom/thread/rom/crt0.c b/trunk/bootrom/build/bootrom/thread/rom/crt0.c
new file mode 100644
index 0000000..6fc177c
--- /dev/null
+++ b/trunk/bootrom/build/bootrom/thread/rom/crt0.c
@@ -0,0 +1,41 @@
+/*---------------------------------------------------------------------------*
+  Project:  CtrBrom - bootrom - init
+  File:     crt0.c
+
+  Copyright 2008 Nintendo.  All rights reserved.
+
+  These coded instructions, statements, and computer programs contain
+  proprietary information of Nintendo of America Inc. and/or Nintendo
+  Company Ltd., and are protected by Federal copyright law.  They may
+  not be disclosed to third parties or copied or duplicated in any form,
+  in whole or in part, without the prior written consent of Nintendo.
+
+  $Date::            $
+  $Rev$
+  $Author$
+ *---------------------------------------------------------------------------*/
+#include <brom/code32.h>
+#include <brom/types.h>
+#include <brom/hw/common/mmap_prom.h>
+
+/*---------------------------------------------------------------------------*
+  Name:         _start
+
+  Description:  Start up
+
+  Arguments:    None
+
+  Returns:      None.
+ *---------------------------------------------------------------------------*/
+asm void _start( void )
+{
+        PRESERVE8
+
+        EXPORT  CTR_BROM_ARM11
+        EXPORT  CTR_BROM_ARM9
+
+CTR_BROM_ARM11
+        INCBIN  BROM_PADBIN_ARM11
+CTR_BROM_ARM9
+        INCBIN  BROM_PADBIN_ARM9
+}
diff --git a/trunk/bootrom/build/buildtools/commondefs.config b/trunk/bootrom/build/buildtools/commondefs.config
index e7cebd3..3d7fe07 100644
--- a/trunk/bootrom/build/buildtools/commondefs.config
+++ b/trunk/bootrom/build/buildtools/commondefs.config
@@ -22,7 +22,6 @@ BROM_COMMONDEFS_CONFIG_ = TRUE
 #BROM_DEV_EARLY_RELEASE = TRUE
 #BROM_DEF_LINK_SCATLD = TRUE
 BROM_ENABLE_SCATLD_VFP = TRUE
-#BROM_ENABLE_THREAD = TRUE
 
 ifdef BROM_ENABLE_BOOTROM_WRITE
 MACRO_FLAGS	+= -DBROM_ENABLE_BOOTROM_WRITE
@@ -33,9 +32,6 @@ endif
 ifdef BROM_DEF_LINK_SCATLD
 MACRO_FLAGS	+= -DBROM_DEF_LINK_SCATLD
 endif
-ifdef BROM_ENABLE_THREAD
-MACRO_FLAGS	+= -DBROM_ENABLE_THREAD
-endif
 ifdef BROM_ENABLE_SCATLD_VFP
 MACRO_FLAGS	+= -DBROM_ENABLE_SCATLD_VFP
 endif
diff --git a/trunk/bootrom/build/libraries/os/ARM11/Makefile b/trunk/bootrom/build/libraries/os/ARM11/Makefile
index cf2d107..78658ba 100644
--- a/trunk/bootrom/build/libraries/os/ARM11/Makefile
+++ b/trunk/bootrom/build/libraries/os/ARM11/Makefile
@@ -34,6 +34,7 @@ SRCS			= \
 				os_tick.c \
 				os_alarm.c \
 				os_irqHandler.c \
+				os_irqThreadSwitch.c \
 				os_interrupt.c \
 				os_exception.c \
 				os_thread.c \
diff --git a/trunk/bootrom/build/libraries/os/ARM9/Makefile b/trunk/bootrom/build/libraries/os/ARM9/Makefile
index d6de8b3..c153996 100644
--- a/trunk/bootrom/build/libraries/os/ARM9/Makefile
+++ b/trunk/bootrom/build/libraries/os/ARM9/Makefile
@@ -37,6 +37,7 @@ SRCS			= \
 				os_tick.c \
 				os_alarm.c \
 				os_irqHandler.c \
+				os_irqThreadSwitch.c \
 				os_interrupt.c \
 				os_exception.c \
 				os_thread.c \
diff --git a/trunk/bootrom/build/libraries/os/common/os_irqHandler.c b/trunk/bootrom/build/libraries/os/common/os_irqHandler.c
index c2549e8..012964e 100644
--- a/trunk/bootrom/build/libraries/os/common/os_irqHandler.c
+++ b/trunk/bootrom/build/libraries/os/common/os_irqHandler.c
@@ -23,15 +23,13 @@
 #include    <brom/dtcm_begin.h>
 #endif
 
-//---- thread queue for interrupt
-OSThreadQueue i_osIrqThreadQueue;
-
 #ifdef      SDK_ARM9
 #include    <brom/dtcm_end.h>
 #include    <brom/itcm_begin.h>
 #endif
 
 extern OSIntrFunction osIntrTable[OS_INTR_ID_NUM];
+OSIntrFunction i_osIrqThreadSwitch;
 
 /*---------------------------------------------------------------------------*
   Name:         osIrqHandler
@@ -47,6 +45,9 @@ asm void osIrqHandler( void )
         PRESERVE8
 
         INASM_EXTERN( osIntrTable )
+        INASM_EXTERN( i_osIrqThreadSwitch )
+
+        EXPORT  i_osIrqHandlerReturn
 
 #ifdef SDK_ARM11
         // 不正確データアボート有効化（clear HW_PSR_IMPRECISE_ABORT）
@@ -63,7 +64,7 @@ asm void osIrqHandler( void )
         ldr     r1, =REG_OS_CPUI_ACK_ID_MASK
         and     r4, r1, lr                    // r4に割り込み要因番号が入ってる
         cmp     r4, #__cpp(OS_INTR_ID_NUM)
-        bge     my_undefined_interrupt_1
+        bge     i_osIrqHandlerReturn
 
 #else // SDK_ARM9
         // get IE address
@@ -104,193 +105,17 @@ LSYM(1) clz     r0, r1                  // count zero of high bit
         str     r4, [lr]
 #endif // SDK_ARM11
 
-#ifdef BROM_ENABLE_THREAD
-        bl      osIrqHandler_ThreadSwitch
-#endif // BROM_ENABLE_THREAD
+        // call osIrqHandler_ThreadSwitch
+        ldr     r1, =i_osIrqThreadSwitch
+        ldr     r1, [r1, #0]
+        cmp     r1, #0
+        blxne   r1
 
-my_undefined_interrupt_1
+i_osIrqHandlerReturn
         ldmfd   sp!, { r0-r4,r12,lr }   // return to interrupted address
         subs    pc, lr, #4
 }
 
-#ifdef BROM_ENABLE_THREAD
-
-/*---------------------------------------------------------------------------*
-  Name:         OS_IRQHandler_ThreadSwitch
-
-  Description:  割り込み分岐処理（テーブル OS_InterruptTable 引き）
-
-  Arguments:    なし
-
-  Returns:      なし
- *---------------------------------------------------------------------------*/
-asm void osIrqHandler_ThreadSwitch(void)
-{
-        INASM_EXTERN( i_osIrqThreadQueue )
-        INASM_EXTERN( i_osThreadInfo )
-        INASM_EXTERN( i_osSaveContextVFP )
-        INASM_EXTERN( i_osLoadContextVFP )
-
-        //--------------------------------------------------
-        // wakeup threads in i_osIrqThreadQueue
-        //--------------------------------------------------
-           ldr             r12, =i_osIrqThreadQueue
-           mov             r3,  #0                      // avoid stall
-           ldr             r12, [r12, #__cpp(offsetof(OSThreadQueue,head))] // r12 = i_osIrqThreadQueue.head
-           mov             r2,  #__cpp(OS_THREAD_STATE_READY)  // avoid stall
-           cmp             r12, #0
-
-           beq             thread_switch                                   // if r12 == 0 exit
-
-LSYM(1)    str             r2,  [r12, #__cpp(offsetof(OSThread,state))]
-           str             r3,  [r12, #__cpp(offsetof(OSThread,queue))]
-           str             r3,  [r12, #__cpp(offsetof(OSThread,link.prev))]
-           ldr             r0,  [r12, #__cpp(offsetof(OSThread,link.next))]
-           str             r3,  [r12, #__cpp(offsetof(OSThread,link.next))]
-           mov             r12,  r0
-
-           cmp             r12, #0
-           bne             BSYM(1)
-
-           ldr             r12, =i_osIrqThreadQueue
-           str             r3, [r12, #__cpp(offsetof(OSThreadQueue,head))]  // clear i_osIrqThreadQueue.head
-           str             r3, [r12, #__cpp(offsetof(OSThreadQueue,tail))]  // clear i_osIrqThreadQueue.tail
-
-           ldr             r12, =i_osThreadInfo                    // need to do scheduling
-           mov             r1, #1
-           strh            r1, [ r12, #OS_THREADINFO_OFFSET_ISNEEDRESCHEDULING ]
-
-
-thread_switch
-        //--------------------------------------------------
-        // THREAD SWITCH
-        //--------------------------------------------------
-        // pseudo code
-        //
-        // if ( isNeedRescheduling == FALSE ) return;
-        // isNeedRescheduling = FALSE;
-        //
-        // // OS_SelectThread
-        // OSThread* t = i_osThreadInfo.list;
-        // while( t && ! OS_IsThreadRunnable( t ) ){ t = t->next; }
-        // return t;
-        //
-        // select:
-        // current = CurrentThread;
-        // if ( next == current ) return;
-        // CurrentThread = next;
-        // OS_SaveContext( current );
-        // OS_LoadContext( next );
-        // 
-        
-        // [[[ new OS_SelectThread ]]]
-        ldr     r12, =i_osThreadInfo
-        ldrh    r1, [ r12, #OS_THREADINFO_OFFSET_ISNEEDRESCHEDULING ]
-        cmp     r1, #0
-        beq     _dont_switched_         // return if i_osIsNeedResceduling == 0
-        
-        mov     r1, #0
-        strh    r1, [ r12, #OS_THREADINFO_OFFSET_ISNEEDRESCHEDULING ]
-
-        // ---- OS_SelectThread (disable FIQ to support IS-Debugger snooping thread information)
-        mov     r3, #HW_PSR_IRQ_MODE|HW_PSR_FIQ_DISABLE|HW_PSR_IRQ_DISABLE|HW_PSR_ARM_STATE
-        msr     cpsr_c, r3
-
-        add     r2, r12, #OS_THREADINFO_OFFSET_LIST // r2 = &i_osThreadInfo.list
-        ldr     r1, [r2]                            // r1 = *r2 = TopOfList
-LSYM(11)
-        cmp     r1, #0
-        ldrneh  r0, [ r1, #__cpp(OS_THREAD_OFFSET_STATE) ] // r0 = t->state
-        cmpne   r0, #__cpp(OS_THREAD_STATE_READY)
-        ldrne   r1, [ r1, #__cpp(OS_THREAD_OFFSET_NEXT) ]
-        bne     BSYM(11)
-
-        cmp     r1, #0
-        bne     FSYM(12)
-
-_dont_switched_
-        mov     r3, #HW_PSR_IRQ_MODE|HW_PSR_IRQ_DISABLE|HW_PSR_ARM_STATE
-        msr     cpsr_c, r3
-
-        bx      lr
-//        ldmfd   sp!, { lr }
-//        ldmfd   sp!, { r0-r3,r12,pc }   // return to interrupted address
-        // not reach here
-
-
-LSYM(12)
-        // ---- OS_GetCurrentThread
-        ldr     r0, [ r12, #OS_THREADINFO_OFFSET_CURRENT ]
-        cmp     r1, r0
-        beq     _dont_switched_         // return if no thread switching
-
-        // call thread switch callback (need to save register r0, r1, r12)
-        ldr     r3, [ r12, #OS_THREADINFO_OFFSET_SWITCHCALLBACK ]
-        cmp     r3, #0
-        beq     FSYM(13)                // skip calling callback when callback == 0
-        stmfd   sp!, { r0, r1, r12 }
-        mov     lr, pc
-        bx      r3
-        ldmfd   sp!, { r0, r1, r12 }
-
-LSYM(13)
-        // ---- OS_SetCurrentThread
-        str     r1, [ r12, #OS_THREADINFO_OFFSET_CURRENT ]
-        
-        // ---- OS_SaveContext 
-        // r0=currentThread  r1=nextThread
-        // stack=Lo[LR,R0,R1,R2,R3,R12,LR]Hi
-        mrs     r2, SPSR
-        str     r2, [ r0, #OS_THREAD_OFFSET_CONTEXT ]!  // *r0=context:CPSR
-
-#ifdef SDK_CONTEXT_HAS_VFP
-        // first, save CP context
-        stmfd   sp!, { r0, r1 }
-        add     r0, r0, #OS_THREAD_OFFSET_CONTEXT
-        bl      i_osSaveContextVFP
-        ldmfd   sp!, { r0, r1 }
-#endif
-
-        ldmib   sp!, { r2,r3 }          // Get R0,R1    // *sp=stack:R1
-        stmib   r0!, { r2,r3 }          // Put R0,R1    // *r0=context:R1
-        
-        ldmib   sp!, { r2,r3,r12,r14 }  // Get R2,R3,R12,LR / *sp=stack:LR
-        stmib   r0!, { r2-r14        }^ // Put R2-R14^  // *r0=context:R14
-        stmib   r0!, { r14           }  // Put R14_irq  // *r0=context:R15+4
-#ifdef  SDK_CONTEXT_HAS_SP_SVC
-        mov     r3, #HW_PSR_SVC_MODE|HW_PSR_FIQ_DISABLE|HW_PSR_IRQ_DISABLE|HW_PSR_ARM_STATE
-        msr     cpsr_c, r3
-        stmib   r0!, { sp }
-#endif
-
-        // ---- OS_LoadContext
-#ifdef SDK_CONTEXT_HAS_VFP
-        // first, load CP context
-        stmfd   sp!, { r1 }
-        add     r0, r1, #OS_THREAD_OFFSET_CONTEXT
-        bl      i_osLoadContextVFP
-        ldmfd   sp!, { r1 }
-#endif
-
-#ifdef  SDK_CONTEXT_HAS_SP_SVC
-        ldr     sp, [ r1, #OS_THREAD_OFFSET_CONTEXT+OS_CONTEXT_SP_SVC ]
-        mov     r3, #HW_PSR_IRQ_MODE|HW_PSR_FIQ_DISABLE|HW_PSR_IRQ_DISABLE|HW_PSR_ARM_STATE
-        msr     cpsr_c, r3
-#endif
-
-        ldr     r2, [ r1, #OS_THREAD_OFFSET_CONTEXT ]!  // *r1=context:CPSR
-        msr     SPSR_cxsf, r2                           // Put SPSR
-        
-        ldr     r14, [ r1, #OS_CONTEXT_PC_PLUS4 - OS_CONTEXT_CPSR ]   // Get R15
-        ldmib   r1, { r0-r14 }^         // Get R0-R14^  // *r1=over written
-        nop
-        stmda   sp!, { r0-r3,r12,r14 }  // Put R0-R3,R12,LR / *sp=stack:LR
-        
-        ldmfd   sp!, { pc }             // return to irq master handler
-}
-
-#endif // BROM_ENABLE_THREAD
-
 #ifdef      SDK_ARM9
 #include    <brom/itcm_end.h>
 #endif
diff --git a/trunk/bootrom/build/libraries/os/common/os_irqThreadSwitch.c b/trunk/bootrom/build/libraries/os/common/os_irqThreadSwitch.c
new file mode 100644
index 0000000..46fbaa9
--- /dev/null
+++ b/trunk/bootrom/build/libraries/os/common/os_irqThreadSwitch.c
@@ -0,0 +1,228 @@
+/*---------------------------------------------------------------------------*
+  Project:  CtrBrom - libraries - OS
+  File:     os_irqThreadSwitch.c
+
+  Copyright 2008 Nintendo.  All rights reserved.
+
+  These coded instructions, statements, and computer programs contain
+  proprietary information of Nintendo of America Inc. and/or Nintendo
+  Company Ltd., and are protected by Federal copyright law.  They may
+  not be disclosed to third parties or copied or duplicated in any form,
+  in whole or in part, without the prior written consent of Nintendo.
+
+  $Date::            $
+  $Rev$
+  $Author$
+ *---------------------------------------------------------------------------*/
+#include <brom/code32.h>
+#include <brom/os.h>
+
+//#define BROM_ENABLE_THREAD
+
+#ifdef      SDK_ARM9
+#include    <brom/dtcm_begin.h>
+#endif
+
+//---- thread queue for interrupt
+OSThreadQueue i_osIrqThreadQueue;
+
+#ifdef      SDK_ARM9
+#include    <brom/dtcm_end.h>
+#include    <brom/itcm_begin.h>
+#endif
+
+// osIrqHandler_ThreadSwitch リンク防止のため外部宣言に
+extern OSIntrFunction i_osIrqThreadSwitch;
+void osIrqHandler_ThreadSwitch( void );
+
+/*---------------------------------------------------------------------------*
+  Name:         i_osEnableIrqThreadSwitch
+
+  Description:  割り込み割り込みスレッドスイッチ有効化
+                osInitThread 呼び出し時のみリンクされるようにファイルを分離
+
+  Arguments:    なし
+
+  Returns:      なし
+ *---------------------------------------------------------------------------*/
+void i_osEnableIrqThreadSwitch( void )
+{
+    i_osIrqThreadSwitch = osIrqHandler_ThreadSwitch;
+}
+
+/*---------------------------------------------------------------------------*
+  Name:         osIRQHandler_ThreadSwitch
+
+  Description:  割り込み分岐処理（テーブル OS_InterruptTable 引き）
+
+  Arguments:    なし
+
+  Returns:      なし
+ *---------------------------------------------------------------------------*/
+asm void osIrqHandler_ThreadSwitch( void )
+{
+        INASM_EXTERN( i_osIrqThreadQueue )
+        INASM_EXTERN( i_osThreadInfo )
+        INASM_EXTERN( i_osSaveContextVFP )
+        INASM_EXTERN( i_osLoadContextVFP )
+        INASM_EXTERN( i_osIrqHandlerReturn )
+
+        //--------------------------------------------------
+        // wakeup threads in i_osIrqThreadQueue
+        //--------------------------------------------------
+           ldr             r12, =i_osIrqThreadQueue
+           mov             r3,  #0                      // avoid stall
+           ldr             r12, [r12, #__cpp(offsetof(OSThreadQueue,head))] // r12 = i_osIrqThreadQueue.head
+           mov             r2,  #__cpp(OS_THREAD_STATE_READY)  // avoid stall
+           cmp             r12, #0
+
+           beq             thread_switch                                   // if r12 == 0 exit
+
+LSYM(1)    str             r2,  [r12, #__cpp(offsetof(OSThread,state))]
+           str             r3,  [r12, #__cpp(offsetof(OSThread,queue))]
+           str             r3,  [r12, #__cpp(offsetof(OSThread,link.prev))]
+           ldr             r0,  [r12, #__cpp(offsetof(OSThread,link.next))]
+           str             r3,  [r12, #__cpp(offsetof(OSThread,link.next))]
+           mov             r12,  r0
+
+           cmp             r12, #0
+           bne             BSYM(1)
+
+           ldr             r12, =i_osIrqThreadQueue
+           str             r3, [r12, #__cpp(offsetof(OSThreadQueue,head))]  // clear i_osIrqThreadQueue.head
+           str             r3, [r12, #__cpp(offsetof(OSThreadQueue,tail))]  // clear i_osIrqThreadQueue.tail
+
+           ldr             r12, =i_osThreadInfo                    // need to do scheduling
+           mov             r1, #1
+           strh            r1, [ r12, #OS_THREADINFO_OFFSET_ISNEEDRESCHEDULING ]
+
+
+thread_switch
+        //--------------------------------------------------
+        // THREAD SWITCH
+        //--------------------------------------------------
+        // pseudo code
+        //
+        // if ( isNeedRescheduling == FALSE ) return;
+        // isNeedRescheduling = FALSE;
+        //
+        // // OS_SelectThread
+        // OSThread* t = i_osThreadInfo.list;
+        // while( t && ! OS_IsThreadRunnable( t ) ){ t = t->next; }
+        // return t;
+        //
+        // select:
+        // current = CurrentThread;
+        // if ( next == current ) return;
+        // CurrentThread = next;
+        // OS_SaveContext( current );
+        // OS_LoadContext( next );
+        // 
+        
+        // [[[ new OS_SelectThread ]]]
+        ldr     r12, =i_osThreadInfo
+        ldrh    r1, [ r12, #OS_THREADINFO_OFFSET_ISNEEDRESCHEDULING ]
+        cmp     r1, #0
+        beq     _dont_switched_         // return if i_osIsNeedResceduling == 0
+        
+        mov     r1, #0
+        strh    r1, [ r12, #OS_THREADINFO_OFFSET_ISNEEDRESCHEDULING ]
+
+        // ---- OS_SelectThread (disable FIQ to support IS-Debugger snooping thread information)
+        mov     r3, #HW_PSR_IRQ_MODE|HW_PSR_FIQ_DISABLE|HW_PSR_IRQ_DISABLE|HW_PSR_ARM_STATE
+        msr     cpsr_c, r3
+
+        add     r2, r12, #OS_THREADINFO_OFFSET_LIST // r2 = &i_osThreadInfo.list
+        ldr     r1, [r2]                            // r1 = *r2 = TopOfList
+LSYM(11)
+        cmp     r1, #0
+        ldrneh  r0, [ r1, #__cpp(OS_THREAD_OFFSET_STATE) ] // r0 = t->state
+        cmpne   r0, #__cpp(OS_THREAD_STATE_READY)
+        ldrne   r1, [ r1, #__cpp(OS_THREAD_OFFSET_NEXT) ]
+        bne     BSYM(11)
+
+        cmp     r1, #0
+        bne     FSYM(12)
+
+_dont_switched_
+        mov     r3, #HW_PSR_IRQ_MODE|HW_PSR_IRQ_DISABLE|HW_PSR_ARM_STATE
+        msr     cpsr_c, r3
+
+        b       i_osIrqHandlerReturn    // return to interrupted address
+        // not reach here
+
+
+LSYM(12)
+        // ---- OS_GetCurrentThread
+        ldr     r0, [ r12, #OS_THREADINFO_OFFSET_CURRENT ]
+        cmp     r1, r0
+        beq     _dont_switched_         // return if no thread switching
+
+        // call thread switch callback (need to save register r0, r1, r12)
+        ldr     r3, [ r12, #OS_THREADINFO_OFFSET_SWITCHCALLBACK ]
+        cmp     r3, #0
+        beq     FSYM(13)                // skip calling callback when callback == 0
+        stmfd   sp!, { r0, r1, r12 }
+        mov     lr, pc
+        bx      r3
+        ldmfd   sp!, { r0, r1, r12 }
+
+LSYM(13)
+        // ---- OS_SetCurrentThread
+        str     r1, [ r12, #OS_THREADINFO_OFFSET_CURRENT ]
+        
+        // ---- OS_SaveContext 
+        // r0=currentThread  r1=nextThread
+        // stack=Lo[LR,R0,R1,R2,R3,R12,LR]Hi
+        mrs     r2, SPSR
+        str     r2, [ r0, #OS_THREAD_OFFSET_CONTEXT ]!  // *r0=context:CPSR
+
+#ifdef SDK_CONTEXT_HAS_VFP
+        // first, save CP context
+        stmfd   sp!, { r0, r1 }
+        add     r0, r0, #OS_THREAD_OFFSET_CONTEXT
+        bl      i_osSaveContextVFP
+        ldmfd   sp!, { r0, r1 }
+#endif
+
+        ldmia   sp!, { r2,r3 }          // Get R0,R1    // *sp=stack:R1
+        stmib   r0!, { r2,r3 }          // Put R0,R1    // *r0=context:R1
+        
+        ldmia   sp!, { r2-r4,r12,r14 }  // Get R2-R4,R12,LR / *sp=stack:LR
+        stmib   r0!, { r2-r14        }^ // Put R2-R14^  // *r0=context:R14
+        stmib   r0!, { r14           }  // Put R14_irq  // *r0=context:R15+4
+#ifdef  SDK_CONTEXT_HAS_SP_SVC
+        mov     r3, #HW_PSR_SVC_MODE|HW_PSR_FIQ_DISABLE|HW_PSR_IRQ_DISABLE|HW_PSR_ARM_STATE
+        msr     cpsr_c, r3
+        stmib   r0!, { sp }
+#endif
+
+        // ---- OS_LoadContext
+#ifdef SDK_CONTEXT_HAS_VFP
+        // first, load CP context
+        stmfd   sp!, { r1 }
+        add     r0, r1, #OS_THREAD_OFFSET_CONTEXT
+        bl      i_osLoadContextVFP
+        ldmfd   sp!, { r1 }
+#endif
+
+#ifdef  SDK_CONTEXT_HAS_SP_SVC
+        ldr     sp, [ r1, #OS_THREAD_OFFSET_CONTEXT+OS_CONTEXT_SP_SVC ]
+        mov     r3, #HW_PSR_IRQ_MODE|HW_PSR_FIQ_DISABLE|HW_PSR_IRQ_DISABLE|HW_PSR_ARM_STATE
+        msr     cpsr_c, r3
+#endif
+
+        ldr     r2, [ r1, #OS_THREAD_OFFSET_CONTEXT ]!  // *r1=context:CPSR
+        msr     SPSR_cxsf, r2                           // Put SPSR
+        
+        ldr     r14, [ r1, #OS_CONTEXT_PC_PLUS4 - OS_CONTEXT_CPSR ]   // Get R15
+        ldmib   r1, { r0-r14 }^         // Get R0-R14^  // *r1=over written
+        nop
+        stmfd   sp!, { r0-r4,r12,r14 }  // Put R0-R4,R12,LR / *sp=stack:LR
+        
+        b       i_osIrqHandlerReturn    // return to irq master handler
+}
+
+#ifdef      SDK_ARM9
+#include    <brom/itcm_end.h>
+#endif
diff --git a/trunk/bootrom/build/libraries/os/common/os_thread.c b/trunk/bootrom/build/libraries/os/common/os_thread.c
index ba51230..c8f7431 100644
--- a/trunk/bootrom/build/libraries/os/common/os_thread.c
+++ b/trunk/bootrom/build/libraries/os/common/os_thread.c
@@ -105,7 +105,6 @@ static int i_osThreadIdCount = 0;
 
 void   *i_osStackForDestructor = NULL;
 
-
 #ifndef SDK_THREAD_INFINITY
 static int i_osSearchFreeEntry(void);
 #endif
@@ -505,6 +504,9 @@ void osInitThread(void)
     osInitAlarm();
     i_osIsThreadInitialized = TRUE;
 
+    //---- Enable irq thread swith
+    i_osEnableIrqThreadSwitch();
+
 #ifndef SDK_THREAD_INFINITY
     //---- Set thread info
     for (i = 0; i < OS_THREAD_MAX_NUM; i++)
diff --git a/trunk/bootrom/include/brom/os/common/interrupt.h b/trunk/bootrom/include/brom/os/common/interrupt.h
index 2b9f0e4..183a57b 100644
--- a/trunk/bootrom/include/brom/os/common/interrupt.h
+++ b/trunk/bootrom/include/brom/os/common/interrupt.h
@@ -59,6 +59,7 @@ typedef void (*OSIntrFunction) (void);
 //IRQ void osInterruptHandler( void );
 void osInterruptHandler( void );
 void i_osInitInterruptTable( void );
+void i_osEnableIrqThreadSwitch( void );
 
 OSIntrMode osEnableIrq( void );
 OSIntrMode osDisableIrq( void );