diff --git a/.travis.yml b/.travis.yml
index 7b18fcd107b80a0edc03e4905471d30c387f08d1..67dd2defcb4ca26f778d54d69d8a4cd5b46f4e7a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,18 +6,21 @@ notifications:
 before_script:
 # travis has changed to 64-bit and we require 32-bit compatibility libraries
   - sudo apt-get update
-  - "sudo apt-get -qq install libc6:i386 libgcc1:i386 gcc-4.6-base:i386 libstdc++5:i386 libstdc++6:i386 || true"
+  - "sudo apt-get -qq install clang gcc-multilib libc6:i386 libgcc1:i386 gcc-4.6-base:i386 libstdc++5:i386 libstdc++6:i386 libsdl-dev || true"
   - "[ $RTT_TOOL_CHAIN = 'sourcery-arm' ] && curl -s https://sourcery.mentor.com/public/gnu_toolchain/arm-none-eabi/arm-2012.09-63-arm-none-eabi-i686-pc-linux-gnu.tar.bz2 | sudo tar xjf - -C /opt && export RTT_EXEC_PATH=/opt/arm-2012.09/bin && /opt/arm-2012.09/bin/arm-none-eabi-gcc --version || true"
   - "[ $RTT_TOOL_CHAIN = 'sourcery-mips' ] && curl -s https://sourcery.mentor.com/public/gnu_toolchain/mips-sde-elf/mips-2012.09-98-mips-sde-elf-i686-pc-linux-gnu.tar.bz2 | sudo tar xjf - -C /opt && export RTT_EXEC_PATH=/opt/mips-2012.09/bin && /opt/mips-2012.09/bin/mips-sde-elf-gcc --version || true"
   - "[ $RTT_TOOL_CHAIN = 'sourcery-ppc' ] && curl -s https://sourcery.mentor.com/public/gnu_toolchain/powerpc-eabi/freescale-2011.03-39-powerpc-eabi-i686-pc-linux-gnu.tar.bz2 | sudo tar xjf - -C /opt && export RTT_EXEC_PATH=/opt/freescale-2011.03/bin && /opt/freescale-2011.03/bin/powerpc-eabi-gcc --version || true"
   - "[ $RTT_TOOL_CHAIN = 'atmel-avr32' ] && curl -s http://www.atmel.com/images/avr32-gnu-toolchain-3.4.1.348-linux.any.x86.tar.gz | sudo tar xzf - -C /opt && export RTT_EXEC_PATH=/opt/avr32-gnu-toolchain-linux_x86/bin && /opt/avr32-gnu-toolchain-linux_x86/bin/avr32-gcc --version && curl -sO http://www.atmel.com/images/avr-headers-3.2.3.970.zip && unzip -qq avr-headers-3.2.3.970.zip -d bsp/$RTT_BSP || true"
   - export RTT_ROOT=`pwd`
-  - export RTT_CC='gcc'
+  - "[ x$RTT_CC == x ] && export RTT_CC='gcc' || true"
+  - git clone --depth 1 https://github.com/RT-Thread/RTGUI.git $HOME/RTGUI
+  - export RTT_RTGUI=$HOME/RTGUI/components/rtgui
 
 script:
   - scons -C bsp/$RTT_BSP
 
 env:
+  - RTT_BSP='simulator' RTT_CC='clang-analyze' RTT_EXEC_PATH=/usr/share/clang/scan-build
   - RTT_BSP='at91sam9260' RTT_TOOL_CHAIN='sourcery-arm' 
   - RTT_BSP='avr32uc3b0' RTT_TOOL_CHAIN='atmel-avr32'
 #  - RTT_BSP='bf533' # no scons
diff --git a/bsp/simulator/SConstruct b/bsp/simulator/SConstruct
index af6534906b20540bb96c01f35bdfb212bae56cdf..4db7328f2a72bd7919b263cf3cabeefa6703eebe 100755
--- a/bsp/simulator/SConstruct
+++ b/bsp/simulator/SConstruct
@@ -73,6 +73,10 @@ elif rtconfig.PLATFORM == 'mingw':
         LINK = rtconfig.LINK, LINKFLAGS = rtconfig.LFLAGS)
     env['LIBS']=libs
     env.PrependENVPath('PATH', rtconfig.EXEC_PATH)
+elif rtconfig.CROSS_TOOL == 'clang-analyze':
+    TARGET = 'rtthread'
+    env = Environment(toolpath=[os.path.join(RTT_ROOT, 'tools', 'tools')],
+                      tools = [rtconfig.CROSS_TOOL])
 else:
     TARGET = 'rtthread'
     env['CC']=rtconfig.CC
@@ -84,13 +88,6 @@ else:
 
 objs = PrepareBuilding(env, RTT_ROOT, has_libcpu=False, remove_components=['rtgui'])
 if GetDepend('RT_USING_RTGUI'):
-    sdl_lib = ['SDL', 'SDLmain']
-    sdl_lib_path = [os.path.abspath('SDL/lib/x86')]
-    sdl_include_path = [os.path.abspath('SDL/include')]
-    env.Append(LIBS=sdl_lib)
-    env.Append(LIBPATH=sdl_lib_path)
-    env.Append(CPPPATH=sdl_include_path)
-
     if RTT_RTGUI:
         objs += SConscript(os.path.join(RTT_RTGUI, 'SConscript'),
 						   variant_dir='build/components/rtgui',
diff --git a/bsp/simulator/applications/application.c b/bsp/simulator/applications/application.c
index 4abecb872e48977a1c955dd8e4b4284d5523d5de..ea07f01c5f1269aed3485555f4e541935d1ac2d6 100755
--- a/bsp/simulator/applications/application.c
+++ b/bsp/simulator/applications/application.c
@@ -30,6 +30,12 @@ void rt_init_thread_entry(void *parameter)
     /* initialization RT-Thread Components */
     rt_components_init();
 
+#ifdef RT_USING_RTGUI
+    /* start sdl thread to simulate an LCD. SDL may depend on DFS and should be
+     * called after rt_components_init. */
+    rt_hw_sdl_start();
+#endif /* RT_USING_RTGUI */
+
 #if defined(RT_USING_COMPONENTS_INIT) && defined(__GNUC__) && defined(RT_USING_FINSH)
     finsh_set_device(RT_CONSOLE_DEVICE_NAME);
 #endif
diff --git a/bsp/simulator/applications/platform.c b/bsp/simulator/applications/platform.c
index 3c7ffdb541a230df6aa6b007c1f4a123e884705d..fbc1003d2ad890927d4fdf5423baad840b0dc36d 100644
--- a/bsp/simulator/applications/platform.c
+++ b/bsp/simulator/applications/platform.c
@@ -17,11 +17,6 @@ void rt_platform_init(void)
 
 #endif /* RT_USING_DFS */
 
-#ifdef RT_USING_RTGUI
-    /* start sdl thread to simulate an LCD */
-    rt_hw_sdl_start();
-#endif /* RT_USING_RTGUI */
-
 #ifdef _WIN32
     rt_thread_idle_sethook(rt_hw_win32_low_cpu);
 #endif
diff --git a/bsp/simulator/drivers/SConscript b/bsp/simulator/drivers/SConscript
index d939535da8f84e4430550febfdfadc0d642bfddf..eb491b810e98d66f45131e48451e669147cb85a4 100644
--- a/bsp/simulator/drivers/SConscript
+++ b/bsp/simulator/drivers/SConscript
@@ -3,10 +3,19 @@ from building import *
 
 cwd = GetCurrentDir()
 src = Glob('*.c')
+LIBS = []
+LIBPATH = []
+CPPPATH = [cwd]
 
 # remove no need file.
 if GetDepend('RT_USING_RTGUI') == False:
     SrcRemove(src, 'sdl_fb.c')
+else:
+    LIBS.append('SDL')
+    if sys.platform == 'win32':
+        LIBPATH.append(os.path.abspath(os.path.join(cwd, '../SDL/lib/x86')))
+        CPPPATH.append(os.path.abspath(os.path.join(cwd, '../SDL/include')))
+
 if GetDepend('RT_USING_DFS') == False or GetDepend('RT_USING_DFS_ELMFAT') == False:
     SrcRemove(src, 'sd_sim.c')
 if GetDepend('RT_USING_DFS') == False or GetDepend('RT_USING_MTD_NAND') == False:
@@ -20,8 +29,7 @@ if GetDepend('RT_USING_MODULE') == False:
 if sys.platform[0:5]=="linux": #check whether under linux
     SrcRemove(src, ['module_win32.c', 'dfs_win32.c'])
 
-CPPPATH = [cwd]
-
-group = DefineGroup('Drivers', src, depend = [''], CPPPATH = CPPPATH)
+group = DefineGroup('Drivers', src, depend = [''],
+                    CPPPATH = CPPPATH, LIBS=LIBS, LIBPATH=LIBPATH)
 
 Return('group')
diff --git a/bsp/simulator/drivers/sdl_fb.c b/bsp/simulator/drivers/sdl_fb.c
index d7ebbc82453919e26c99c002f4bc5404f29c2992..78bca6f07f1360b475d480549137f3477807702b 100755
--- a/bsp/simulator/drivers/sdl_fb.c
+++ b/bsp/simulator/drivers/sdl_fb.c
@@ -152,8 +152,12 @@ static void sdlfb_hw_init(void)
 
 #ifdef _WIN32
 static HANDLE  sdl_ok_event = NULL;
+
 static DWORD WINAPI sdl_loop(LPVOID lpParam)
 #else
+static pthread_mutex_t sdl_ok_mutex;
+static pthread_cond_t sdl_ok_event;
+
 static void *sdl_loop(void *lpParam)
 #endif
 {
@@ -167,14 +171,19 @@ static void *sdl_loop(void *lpParam)
     /* set the getchar without buffer */
     sigfillset(&sigmask);
     pthread_sigmask(SIG_BLOCK, &sigmask, &oldmask);
+    pthread_mutex_lock(&sdl_ok_mutex);
 #endif
 
     sdlfb_hw_init();
 
     device = rt_device_find("sdl");
+    RT_ASSERT(device);
     rtgui_graphic_set_device(device);
 #ifdef _WIN32
     SetEvent(sdl_ok_event);
+#else
+    pthread_cond_signal(&sdl_ok_event);
+    pthread_mutex_unlock(&sdl_ok_mutex);
 #endif
     /* handle SDL event */
     while (!quit)
@@ -338,11 +347,20 @@ void rt_hw_sdl_start(void)
     /* Linux */
     pthread_t pid;
     int res;
+
+    pthread_mutex_init(&sdl_ok_mutex, NULL);
+    pthread_cond_init(&sdl_ok_event, NULL);
+
     res = pthread_create(&pid, NULL, &sdl_loop, NULL);
     if (res)
     {
         printf("pthread create sdl thread faild, <%d>\n", res);
         exit(EXIT_FAILURE);
     }
+    pthread_mutex_lock(&sdl_ok_mutex);
+    pthread_cond_wait(&sdl_ok_event, &sdl_ok_mutex);
+
+    pthread_mutex_destroy(&sdl_ok_mutex);
+    pthread_cond_destroy(&sdl_ok_event);
 #endif
 }
diff --git a/bsp/simulator/rtconfig.py b/bsp/simulator/rtconfig.py
index 7a42bddbcf6dcc925e862609467c09b5f2198380..d3ed2599d58367894b0651f409be6f92b43f9a18 100755
--- a/bsp/simulator/rtconfig.py
+++ b/bsp/simulator/rtconfig.py
@@ -1,3 +1,5 @@
+import os
+
 # toolchains options
 ARCH='sim'
 #CROSS_TOOL='msvc' or 'gcc' or 'mingw'
@@ -5,12 +7,15 @@ ARCH='sim'
 # 'gcc' is for linux
 CROSS_TOOL='msvc'
 
+if os.getenv('RTT_CC'):
+	CROSS_TOOL = os.getenv('RTT_CC')
+
 # cross_tool provides the cross compiler
 # EXEC_PATH is the compiler execute path 
-if  CROSS_TOOL == 'gcc':
+if  CROSS_TOOL == 'gcc' or CROSS_TOOL == 'clang-analyze':
     CPU       = 'posix'
     PLATFORM  = 'gcc'
-    EXEC_PATH = '/usr/bin/gcc'
+    EXEC_PATH = ''
 
 elif  CROSS_TOOL == 'mingw':
     CPU       = 'win32'
@@ -21,11 +26,13 @@ elif  CROSS_TOOL == 'msvc':
     CPU       = 'win32'
     PLATFORM  = 'cl'
     EXEC_PATH = ''
-
-else :
+else:
     print "bad CROSS TOOL!"
     exit(1)
 
+if os.getenv('RTT_EXEC_PATH'):
+	EXEC_PATH = os.getenv('RTT_EXEC_PATH')
+
 BUILD = 'debug'
 #BUILD = ''
 
diff --git a/bsp/stm32f10x/applications/application.c b/bsp/stm32f10x/applications/application.c
index 703171146034c69920567d8dc801cdcdd95d835e..d57bb4e4c02c2ed8b0479692b198b84322d2ffdf 100644
--- a/bsp/stm32f10x/applications/application.c
+++ b/bsp/stm32f10x/applications/application.c
@@ -111,7 +111,6 @@ void rt_init_thread_entry(void* parameter)
 
 #ifdef RT_USING_RTGUI
     {
-        extern void rtgui_system_server_init(void);
         extern void rt_hw_lcd_init();
         extern void rtgui_touch_hw_init(void);
 
@@ -132,8 +131,10 @@ void rt_init_thread_entry(void* parameter)
         /* set lcd device as rtgui graphic driver */
         rtgui_graphic_set_device(lcd);
 
+#ifndef RT_USING_COMPONENTS_INIT
         /* init rtgui system server */
         rtgui_system_server_init();
+#endif
 
         calibration_set_restore(cali_setup);
         calibration_set_after(cali_store);
diff --git a/components/drivers/include/rtdevice.h b/components/drivers/include/rtdevice.h
index f8a944f5a70daccaa02163c5ae269808013d53c8..60d4dc1e8a431e72069ff92bce1ba218fd7da1d3 100644
--- a/components/drivers/include/rtdevice.h
+++ b/components/drivers/include/rtdevice.h
@@ -45,9 +45,9 @@ struct rt_ringbuffer
     /* use the msb of the {read,write}_index as mirror bit. You can see this as
      * if the buffer adds a virtual mirror and the pointers point either to the
      * normal or to the mirrored buffer. If the write_index has the same value
-     * with the read_index, but in differenct mirro, the buffer is full. While
-     * if the write_index and the read_index are the same and within the same
-     * mirror, the buffer is empty. The ASCII art of the ringbuffer is:
+     * with the read_index, but in a different mirror, the buffer is full.
+     * While if the write_index and the read_index are the same and within the
+     * same mirror, the buffer is empty. The ASCII art of the ringbuffer is:
      *
      *          mirror = 0                    mirror = 1
      * +---+---+---+---+---+---+---+|+~~~+~~~+~~~+~~~+~~~+~~~+~~~+
@@ -73,31 +73,30 @@ struct rt_ringbuffer
     rt_int16_t buffer_size;
 };
 
-/** return the size of data in rb */
-rt_inline rt_uint16_t RT_RINGBUFFER_SIZE(struct rt_ringbuffer *rb)
+/* portal device */
+struct rt_portal_device
 {
-    if (rb->read_index == rb->write_index)
-    {
-        if (rb->read_mirror == rb->write_mirror)
-            /* we are in the same side, the ringbuffer is empty. */
-            return 0;
-        else
-            return rb->buffer_size;
-    }
-    else
-    {
-        if (rb->write_index > rb->read_index)
-            return rb->write_index - rb->read_index;
-        else
-            return rb->buffer_size - (rb->read_index - rb->write_index);
-    }
-}
-
-/** return the size of empty space in rb */
-#define RT_RINGBUFFER_EMPTY(rb) ((rb)->buffer_size - RT_RINGBUFFER_SIZE(rb))
+    struct rt_device parent;
+    struct rt_device *write_dev;
+    struct rt_device *read_dev;
+};
 
 /* pipe device */
 #define PIPE_DEVICE(device)          ((struct rt_pipe_device*)(device))
+enum rt_pipe_flag
+{
+    /* both read and write won't block */
+    RT_PIPE_FLAG_NONBLOCK_RDWR = 0x00,
+    /* read would block */
+    RT_PIPE_FLAG_BLOCK_RD = 0x01,
+    /* write would block */
+    RT_PIPE_FLAG_BLOCK_WR = 0x02,
+    /* write to this pipe will discard some data when the pipe is full.
+     * When this flag is set, RT_PIPE_FLAG_BLOCK_WR will be ignored since write
+     * operation will always be success. */
+    RT_PIPE_FLAG_FORCE_WR = 0x04,
+};
+
 struct rt_pipe_device
 {
     struct rt_device parent;
@@ -105,9 +104,14 @@ struct rt_pipe_device
     /* ring buffer in pipe device */
     struct rt_ringbuffer ringbuffer;
 
+    enum rt_pipe_flag flag;
+
     /* suspended list */
     rt_list_t suspended_read_list;
     rt_list_t suspended_write_list;
+
+    struct rt_portal_device *write_portal;
+    struct rt_portal_device *read_portal;
 };
 
 #define RT_DATAQUEUE_EVENT_UNKNOWN   0x00
@@ -157,31 +161,97 @@ void rt_ringbuffer_init(struct rt_ringbuffer *rb,
 rt_size_t rt_ringbuffer_put(struct rt_ringbuffer *rb,
                             const rt_uint8_t     *ptr,
                             rt_uint16_t           length);
+rt_size_t rt_ringbuffer_put_force(struct rt_ringbuffer *rb,
+                                  const rt_uint8_t     *ptr,
+                                  rt_uint16_t           length);
 rt_size_t rt_ringbuffer_putchar(struct rt_ringbuffer *rb,
                                 const rt_uint8_t      ch);
+rt_size_t rt_ringbuffer_putchar_force(struct rt_ringbuffer *rb,
+                                      const rt_uint8_t      ch);
 rt_size_t rt_ringbuffer_get(struct rt_ringbuffer *rb,
                             rt_uint8_t           *ptr,
                             rt_uint16_t           length);
 rt_size_t rt_ringbuffer_getchar(struct rt_ringbuffer *rb, rt_uint8_t *ch);
+
+enum rt_ringbuffer_state
+{
+    RT_RINGBUFFER_EMPTY,
+    RT_RINGBUFFER_FULL,
+    /* half full is neither full nor empty */
+    RT_RINGBUFFER_HALFFULL,
+};
+
 rt_inline rt_uint16_t rt_ringbuffer_get_size(struct rt_ringbuffer *rb)
 {
     RT_ASSERT(rb != RT_NULL);
     return rb->buffer_size;
 }
 
+rt_inline enum rt_ringbuffer_state
+rt_ringbuffer_status(struct rt_ringbuffer *rb)
+{
+    if (rb->read_index == rb->write_index)
+    {
+        if (rb->read_mirror == rb->write_mirror)
+            return RT_RINGBUFFER_EMPTY;
+        else
+            return RT_RINGBUFFER_FULL;
+    }
+    return RT_RINGBUFFER_HALFFULL;
+}
+
+/** return the size of data in rb */
+rt_inline rt_uint16_t rt_ringbuffer_data_len(struct rt_ringbuffer *rb)
+{
+    switch (rt_ringbuffer_status(rb))
+    {
+    case RT_RINGBUFFER_EMPTY:
+        return 0;
+    case RT_RINGBUFFER_FULL:
+        return rb->buffer_size;
+    case RT_RINGBUFFER_HALFFULL:
+    default:
+        if (rb->write_index > rb->read_index)
+            return rb->write_index - rb->read_index;
+        else
+            return rb->buffer_size - (rb->read_index - rb->write_index);
+    };
+}
+
+/** return the size of empty space in rb */
+#define rt_ringbuffer_space_len(rb) ((rb)->buffer_size - rt_ringbuffer_data_len(rb))
+
 /**
  * Pipe Device
  */
 rt_err_t rt_pipe_init(struct rt_pipe_device *pipe,
                       const char *name,
+                      enum rt_pipe_flag flag,
                       rt_uint8_t *buf,
                       rt_size_t size);
 rt_err_t rt_pipe_detach(struct rt_pipe_device *pipe);
 #ifdef RT_USING_HEAP
-rt_err_t rt_pipe_create(const char *name, rt_size_t size);
+rt_err_t rt_pipe_create(const char *name, enum rt_pipe_flag flag, rt_size_t size);
 void rt_pipe_destroy(struct rt_pipe_device *pipe);
 #endif
 
+/**
+ * Portal for DeviceDriver
+ */
+
+rt_err_t rt_portal_init(struct rt_portal_device *portal,
+                        const char *portal_name,
+                        const char *write_dev,
+                        const char *read_dev);
+rt_err_t rt_portal_detach(struct rt_portal_device *portal);
+
+#ifdef RT_USING_HEAP
+rt_err_t rt_portal_create(const char *name,
+                          const char *write_dev,
+                          const char *read_dev);
+void rt_portal_destroy(struct rt_portal_device *portal);
+#endif
+
 /**
  * DataQueue for DeviceDriver
  */
diff --git a/components/drivers/src/pipe.c b/components/drivers/src/pipe.c
index 469c2d06e67dedd4c2efa51ccb002c2e6efddb90..8a6c97aabfd1812dd61d935fdc4def5836b6a087 100644
--- a/components/drivers/src/pipe.c
+++ b/components/drivers/src/pipe.c
@@ -26,6 +26,26 @@
 #include <rtthread.h>
 #include <rtdevice.h>
 
+static void _rt_pipe_resume_writer(struct rt_pipe_device *pipe)
+{
+    if (!rt_list_isempty(&pipe->suspended_write_list))
+    {
+        rt_thread_t thread;
+
+        RT_ASSERT(pipe->flag & RT_PIPE_FLAG_BLOCK_WR);
+
+        /* get suspended thread */
+        thread = rt_list_entry(pipe->suspended_write_list.next,
+                struct rt_thread,
+                tlist);
+
+        /* resume the write thread */
+        rt_thread_resume(thread);
+
+        rt_schedule();
+    }
+}
+
 static rt_size_t rt_pipe_read(rt_device_t dev,
                               rt_off_t    pos,
                               void       *buffer,
@@ -39,13 +59,26 @@ static rt_size_t rt_pipe_read(rt_device_t dev,
     pipe = PIPE_DEVICE(dev);
     RT_ASSERT(pipe != RT_NULL);
 
+    if (!(pipe->flag & RT_PIPE_FLAG_BLOCK_RD))
+    {
+        level = rt_hw_interrupt_disable();
+        read_nbytes = rt_ringbuffer_get(&(pipe->ringbuffer), buffer, size);
+
+        /* if the ringbuffer is empty, there won't be any writer waiting */
+        if (read_nbytes)
+            _rt_pipe_resume_writer(pipe);
+
+        rt_hw_interrupt_enable(level);
+
+        return read_nbytes;
+    }
+
     thread = rt_thread_self();
 
     /* current context checking */
     RT_DEBUG_NOT_IN_INTERRUPT;
 
-    do 
-    {
+    do {
         level = rt_hw_interrupt_disable();
         read_nbytes = rt_ringbuffer_get(&(pipe->ringbuffer), buffer, size);
         if (read_nbytes == 0)
@@ -60,23 +93,8 @@ static rt_size_t rt_pipe_read(rt_device_t dev,
         }
         else
         {
-            if (!rt_list_isempty(&pipe->suspended_write_list))
-            {
-                /* get suspended thread */
-                thread = rt_list_entry(pipe->suspended_write_list.next,
-                                       struct rt_thread,
-                                       tlist);
-
-                /* resume the write thread */
-                rt_thread_resume(thread);
-                rt_hw_interrupt_enable(level);
-
-                rt_schedule();
-            }
-            else
-            {
-                rt_hw_interrupt_enable(level);
-            }
+            _rt_pipe_resume_writer(pipe);
+            rt_hw_interrupt_enable(level);
             break;
         }
     } while (read_nbytes == 0);
@@ -84,7 +102,30 @@ static rt_size_t rt_pipe_read(rt_device_t dev,
     return read_nbytes;
 }
 
-struct rt_pipe_device *_pipe = RT_NULL;
+static void _rt_pipe_resume_reader(struct rt_pipe_device *pipe)
+{
+    if (pipe->parent.rx_indicate)
+        pipe->parent.rx_indicate(&pipe->parent,
+                                 rt_ringbuffer_data_len(&pipe->ringbuffer));
+
+    if (!rt_list_isempty(&pipe->suspended_read_list))
+    {
+        rt_thread_t thread;
+
+        RT_ASSERT(pipe->flag & RT_PIPE_FLAG_BLOCK_RD);
+
+        /* get suspended thread */
+        thread = rt_list_entry(pipe->suspended_read_list.next,
+                struct rt_thread,
+                tlist);
+
+        /* resume the read thread */
+        rt_thread_resume(thread);
+
+        rt_schedule();
+    }
+}
+
 static rt_size_t rt_pipe_write(rt_device_t dev,
                                rt_off_t    pos,
                                const void *buffer,
@@ -97,16 +138,32 @@ static rt_size_t rt_pipe_write(rt_device_t dev,
 
     pipe = PIPE_DEVICE(dev);
     RT_ASSERT(pipe != RT_NULL);
-    if (_pipe == RT_NULL)
-        _pipe = pipe;
+
+    if ((pipe->flag & RT_PIPE_FLAG_FORCE_WR) ||
+       !(pipe->flag & RT_PIPE_FLAG_BLOCK_WR))
+    {
+        level = rt_hw_interrupt_disable();
+
+        if (pipe->flag & RT_PIPE_FLAG_FORCE_WR)
+            write_nbytes = rt_ringbuffer_put_force(&(pipe->ringbuffer),
+                                                   buffer, size);
+        else
+            write_nbytes = rt_ringbuffer_put(&(pipe->ringbuffer),
+                                             buffer, size);
+
+        _rt_pipe_resume_reader(pipe);
+
+        rt_hw_interrupt_enable(level);
+
+        return write_nbytes;
+    }
 
     thread = rt_thread_self();
 
     /* current context checking */
     RT_DEBUG_NOT_IN_INTERRUPT;
 
-    do
-    {
+    do {
         level = rt_hw_interrupt_disable();
         write_nbytes = rt_ringbuffer_put(&(pipe->ringbuffer), buffer, size);
         if (write_nbytes == 0)
@@ -122,26 +179,11 @@ static rt_size_t rt_pipe_write(rt_device_t dev,
         }
         else
         {
-            if (!rt_list_isempty(&pipe->suspended_read_list))
-            {
-                /* get suspended thread */
-                thread = rt_list_entry(pipe->suspended_read_list.next,
-                                       struct rt_thread,
-                                       tlist);
-
-                /* resume the read thread */
-                rt_thread_resume(thread);
-                rt_hw_interrupt_enable(level);
-
-                rt_schedule();
-            }
-            else
-            {
-                rt_hw_interrupt_enable(level);
-            }
+            _rt_pipe_resume_reader(pipe);
+            rt_hw_interrupt_enable(level);
             break;
         }
-    }while (write_nbytes == 0);
+    } while (write_nbytes == 0);
 
     return write_nbytes;
 }
@@ -157,6 +199,7 @@ static rt_err_t rt_pipe_control(rt_device_t dev, rt_uint8_t cmd, void *args)
  *
  * @param pipe the pipe device
  * @param name the name of pipe device
+ * @param flag the attribute of the pipe device
  * @param buf  the buffer of pipe device
  * @param size the size of pipe device buffer
  *
@@ -164,6 +207,7 @@ static rt_err_t rt_pipe_control(rt_device_t dev, rt_uint8_t cmd, void *args)
  */
 rt_err_t rt_pipe_init(struct rt_pipe_device *pipe,
                       const char *name,
+                      enum rt_pipe_flag flag,
                       rt_uint8_t *buf,
                       rt_size_t size)
 {
@@ -177,8 +221,10 @@ rt_err_t rt_pipe_init(struct rt_pipe_device *pipe,
     /* initialize ring buffer */
     rt_ringbuffer_init(&pipe->ringbuffer, buf, size);
 
+    pipe->flag = flag;
+
     /* create pipe */
-    pipe->parent.type    = RT_Device_Class_Char;
+    pipe->parent.type    = RT_Device_Class_Pipe;
     pipe->parent.init    = RT_NULL;
     pipe->parent.open    = RT_NULL;
     pipe->parent.close   = RT_NULL;
@@ -204,7 +250,7 @@ rt_err_t rt_pipe_detach(struct rt_pipe_device *pipe)
 RTM_EXPORT(rt_pipe_detach);
 
 #ifdef RT_USING_HEAP
-rt_err_t rt_pipe_create(const char *name, rt_size_t size)
+rt_err_t rt_pipe_create(const char *name, enum rt_pipe_flag flag, rt_size_t size)
 {
     rt_uint8_t *rb_memptr = RT_NULL;
     struct rt_pipe_device *pipe = RT_NULL;
@@ -223,7 +269,7 @@ rt_err_t rt_pipe_create(const char *name, rt_size_t size)
         return -RT_ENOMEM;
     }
 
-    return rt_pipe_init(pipe, name, rb_memptr, size);
+    return rt_pipe_init(pipe, name, flag, rb_memptr, size);
 }
 RTM_EXPORT(rt_pipe_create);
 
diff --git a/components/drivers/src/portal.c b/components/drivers/src/portal.c
new file mode 100644
index 0000000000000000000000000000000000000000..779812e9ca46fca2c5dc0e1a2a29ab9e752fe2a7
--- /dev/null
+++ b/components/drivers/src/portal.c
@@ -0,0 +1,256 @@
+/*
+ * File      : portal.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2013, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2013-08-19     Grissiom     initial version
+ */
+
+#include <rtthread.h>
+#include <rtdevice.h>
+
+#define PT_WRITE_DEV(pt)  (((struct rt_portal_device*)pt)->write_dev)
+#define PT_READ_DEV(pt)   (((struct rt_portal_device*)pt)->read_dev)
+
+static rt_err_t _portal_init(rt_device_t dev)
+{
+    rt_err_t err;
+    struct rt_portal_device *portal;
+
+    RT_ASSERT(dev);
+
+    portal = (struct rt_portal_device*)dev;
+
+    err = rt_device_init(portal->write_dev);
+    if (err != RT_EOK)
+        return err;
+
+    err = rt_device_init(portal->read_dev);
+
+    return err;
+}
+
+static rt_err_t _portal_open(rt_device_t dev, rt_uint16_t oflag)
+{
+    rt_err_t err;
+    struct rt_portal_device *portal;
+
+    RT_ASSERT(dev);
+
+    if (!oflag)
+        return -RT_ERROR;
+
+    portal = (struct rt_portal_device*)dev;
+
+    if (oflag & RT_DEVICE_OFLAG_RDONLY)
+    {
+        err = rt_device_open(portal->read_dev, RT_DEVICE_OFLAG_RDONLY);
+        if (err != RT_EOK)
+            return err;
+    }
+
+    if (oflag & RT_DEVICE_OFLAG_WRONLY)
+    {
+        err = rt_device_open(portal->write_dev, RT_DEVICE_OFLAG_WRONLY);
+        if (err != RT_EOK)
+            return err;
+    }
+
+    return RT_EOK;
+}
+
+static rt_err_t _portal_close(rt_device_t dev)
+{
+    struct rt_portal_device *portal;
+
+    RT_ASSERT(dev);
+
+    portal = (struct rt_portal_device*)dev;
+
+    rt_device_close(portal->write_dev);
+    rt_device_close(portal->read_dev);
+
+    return RT_EOK;
+}
+
+static rt_size_t _portal_read(rt_device_t dev,
+                              rt_off_t pos,
+                              void *buffer,
+                              rt_size_t size)
+{
+    return rt_device_read(PT_READ_DEV(dev),
+                          pos, buffer, size);
+}
+
+static rt_size_t _portal_write(rt_device_t dev,
+                               rt_off_t pos,
+                               const void *buffer,
+                               rt_size_t size)
+{
+    return rt_device_write(PT_WRITE_DEV(dev),
+                           pos, buffer, size);
+}
+
+static rt_err_t _portal_rx_indicate(rt_device_t dev, rt_size_t size)
+{
+    struct rt_pipe_device *pipe;
+
+    RT_ASSERT(dev && dev->type == RT_Device_Class_Pipe);
+
+    pipe = (struct rt_pipe_device*)dev;
+
+    if (pipe->read_portal->parent.rx_indicate)
+        return pipe->read_portal->parent.rx_indicate(
+                (rt_device_t)pipe->read_portal, size);
+
+    return -RT_ENOSYS;
+}
+
+static rt_err_t _portal_tx_complete(rt_device_t dev, void *buf)
+{
+    struct rt_pipe_device *pipe;
+
+    RT_ASSERT(dev && dev->type == RT_Device_Class_Pipe);
+
+    pipe = (struct rt_pipe_device*)dev;
+
+    if (pipe->write_portal->parent.tx_complete)
+        return pipe->write_portal->parent.tx_complete(
+                (rt_device_t)pipe->write_portal, buf);
+
+    return -RT_ENOSYS;
+}
+
+/**
+ * This function will initialize a portal device and put it under control of
+ * resource management.
+ *
+ * Portal is a device that connect devices
+ *
+ * Currently, you can only connect pipes in portal. Pipes are unidirectional.
+ * But with portal, you can construct a bidirectional device with two pipes.
+ * The inner connection is just like this:
+ *
+ *   portal0        portal1
+ * read   ||        || write
+ * <--<---||<---<---||<---<-- (pipe0)
+ *        ||        ||
+ * -->--->||--->--->||--->--> (pipe1)
+ * write  ||        || read
+ *
+ * You will always construct two portals on two pipes, say, "portal0" and
+ * "portal1". Data written into "portal0" can be retrieved in "portal1" and
+ * vice versa. `rx_indicate` and `tx_complete` events are propagated
+ * accordingly.
+ *
+ * @param portal the portal device
+ * @param portal_name the name of the portal device
+ * @param write_dev the name of the pipe device that this portal write into
+ * @param read_dev the name of the pipe device that this portal read from
+ *
+ * @return the operation status, RT_EOK on successful. -RT_ENOSYS on one pipe
+ * device could not be found.
+ */
+rt_err_t rt_portal_init(struct rt_portal_device *portal,
+                        const char *portal_name,
+                        const char *write_dev,
+                        const char *read_dev)
+{
+    rt_device_t dev;
+
+    RT_ASSERT(portal);
+
+    portal->parent.type        = RT_Device_Class_Portal;
+    portal->parent.init        = _portal_init;
+    portal->parent.open        = _portal_open;
+    portal->parent.close       = _portal_close;
+    portal->parent.write       = _portal_write;
+    portal->parent.read        = _portal_read;
+    /* single control of the two devices makes no sense */
+    portal->parent.control     = RT_NULL;
+
+    dev = rt_device_find(write_dev);
+    if (dev == RT_NULL)
+        return -RT_ENOSYS;
+    RT_ASSERT(dev->type == RT_Device_Class_Pipe);
+    portal->write_dev = dev;
+    rt_device_set_tx_complete(&portal->parent, dev->tx_complete);
+    rt_device_set_tx_complete(dev, _portal_tx_complete);
+    ((struct rt_pipe_device*)dev)->write_portal = portal;
+
+    dev = rt_device_find(read_dev);
+    if (dev == RT_NULL)
+    {
+        rt_device_set_tx_complete(dev, portal->parent.tx_complete);
+        return -RT_ENOSYS;
+    }
+    RT_ASSERT(dev->type == RT_Device_Class_Pipe);
+    portal->read_dev = dev;
+    rt_device_set_rx_indicate(&portal->parent, dev->rx_indicate);
+    rt_device_set_rx_indicate(dev, _portal_rx_indicate);
+    ((struct rt_pipe_device*)dev)->read_portal = portal;
+
+    return rt_device_register(&(portal->parent),
+                              portal_name,
+                              RT_DEVICE_FLAG_RDWR);
+}
+RTM_EXPORT(rt_portal_init);
+
+/**
+ * This function will detach a portal device from resource management
+ *
+ * @param portal the portal device
+ *
+ * @return the operation status, RT_EOK on successful
+ */
+rt_err_t rt_portal_detach(struct rt_portal_device *portal)
+{
+    return rt_device_unregister(&portal->parent);
+}
+RTM_EXPORT(rt_portal_detach);
+
+#ifdef RT_USING_HEAP
+rt_err_t rt_portal_create(const char *name,
+                          const char *write_dev,
+                          const char *read_dev)
+{
+    struct rt_portal_device *portal;
+
+    portal = (struct rt_portal_device*)rt_calloc(1, sizeof(*portal));
+    if (portal == RT_NULL)
+        return -RT_ENOMEM;
+
+    return rt_portal_init(portal, name, write_dev, read_dev);
+}
+RTM_EXPORT(rt_portal_create);
+
+void rt_portal_destroy(struct rt_portal_device *portal)
+{
+    if (portal == RT_NULL)
+        return;
+
+    rt_portal_detach(portal);
+
+    rt_free(portal);
+
+    return;
+}
+RTM_EXPORT(rt_portal_destroy);
+#endif /* RT_USING_HEAP */
+
diff --git a/components/drivers/src/ringbuffer.c b/components/drivers/src/ringbuffer.c
index 8e7e8c7895fa051f38964191a79271c962323c53..6212b10258a8d2b85a414293a6afbef24bb9dd6c 100644
--- a/components/drivers/src/ringbuffer.c
+++ b/components/drivers/src/ringbuffer.c
@@ -44,6 +44,9 @@ void rt_ringbuffer_init(struct rt_ringbuffer *rb,
 }
 RTM_EXPORT(rt_ringbuffer_init);
 
+/**
+ * put a block of data into ring buffer
+ */
 rt_size_t rt_ringbuffer_put(struct rt_ringbuffer *rb,
                             const rt_uint8_t     *ptr,
                             rt_uint16_t           length)
@@ -53,7 +56,7 @@ rt_size_t rt_ringbuffer_put(struct rt_ringbuffer *rb,
     RT_ASSERT(rb != RT_NULL);
 
     /* whether has enough space */
-    size = RT_RINGBUFFER_EMPTY(rb);
+    size = rt_ringbuffer_space_len(rb);
 
     /* no space */
     if (size == 0)
@@ -88,6 +91,59 @@ rt_size_t rt_ringbuffer_put(struct rt_ringbuffer *rb,
 }
 RTM_EXPORT(rt_ringbuffer_put);
 
+/**
+ * put a block of data into ring buffer
+ *
+ * When the buffer is full, it will discard the old data.
+ */
+rt_size_t rt_ringbuffer_put_force(struct rt_ringbuffer *rb,
+                            const rt_uint8_t     *ptr,
+                            rt_uint16_t           length)
+{
+    enum rt_ringbuffer_state old_state;
+
+    RT_ASSERT(rb != RT_NULL);
+
+    old_state = rt_ringbuffer_status(rb);
+
+    if (length > rb->buffer_size)
+        length = rb->buffer_size;
+
+    if (rb->buffer_size - rb->write_index > length)
+    {
+        /* read_index - write_index = empty space */
+        memcpy(&rb->buffer_ptr[rb->write_index], ptr, length);
+        /* this should not cause overflow because there is enough space for
+         * length of data in current mirror */
+        rb->write_index += length;
+
+        if (old_state == RT_RINGBUFFER_FULL)
+            rb->read_index = rb->write_index;
+
+        return length;
+    }
+
+    memcpy(&rb->buffer_ptr[rb->write_index],
+           &ptr[0],
+           rb->buffer_size - rb->write_index);
+    memcpy(&rb->buffer_ptr[0],
+           &ptr[rb->buffer_size - rb->write_index],
+           length - (rb->buffer_size - rb->write_index));
+
+    /* we are going into the other side of the mirror */
+    rb->write_mirror = ~rb->write_mirror;
+    rb->write_index = length - (rb->buffer_size - rb->write_index);
+
+    if (old_state == RT_RINGBUFFER_FULL)
+    {
+        rb->read_mirror = ~rb->read_mirror;
+        rb->read_index = rb->write_index;
+    }
+
+    return length;
+}
+RTM_EXPORT(rt_ringbuffer_put_force);
+
 /**
  *  get data from ring buffer
  */
@@ -100,7 +156,7 @@ rt_size_t rt_ringbuffer_get(struct rt_ringbuffer *rb,
     RT_ASSERT(rb != RT_NULL);
 
     /* whether has enough data  */
-    size = RT_RINGBUFFER_SIZE(rb);
+    size = rt_ringbuffer_data_len(rb);
 
     /* no data */
     if (size == 0)
@@ -143,7 +199,7 @@ rt_size_t rt_ringbuffer_putchar(struct rt_ringbuffer *rb, const rt_uint8_t ch)
     RT_ASSERT(rb != RT_NULL);
 
     /* whether has enough space */
-    if (!RT_RINGBUFFER_EMPTY(rb))
+    if (!rt_ringbuffer_space_len(rb))
         return 0;
 
     rb->buffer_ptr[rb->write_index] = ch;
@@ -163,6 +219,43 @@ rt_size_t rt_ringbuffer_putchar(struct rt_ringbuffer *rb, const rt_uint8_t ch)
 }
 RTM_EXPORT(rt_ringbuffer_putchar);
 
+/**
+ * put a character into ring buffer
+ *
+ * When the buffer is full, it will discard one old data.
+ */
+rt_size_t rt_ringbuffer_putchar_force(struct rt_ringbuffer *rb, const rt_uint8_t ch)
+{
+    enum rt_ringbuffer_state old_state;
+
+    RT_ASSERT(rb != RT_NULL);
+
+    old_state = rt_ringbuffer_status(rb);
+
+    rb->buffer_ptr[rb->write_index] = ch;
+
+    /* flip mirror */
+    if (rb->write_index == rb->buffer_size-1)
+    {
+        rb->write_mirror = ~rb->write_mirror;
+        rb->write_index = 0;
+        if (old_state == RT_RINGBUFFER_FULL)
+        {
+            rb->read_mirror = ~rb->read_mirror;
+            rb->read_index = rb->write_index;
+        }
+    }
+    else
+    {
+        rb->write_index++;
+        if (old_state == RT_RINGBUFFER_FULL)
+            rb->read_index = rb->write_index;
+    }
+
+    return 1;
+}
+RTM_EXPORT(rt_ringbuffer_putchar_force);
+
 /**
  * get a character from a ringbuffer
  */
@@ -171,7 +264,7 @@ rt_size_t rt_ringbuffer_getchar(struct rt_ringbuffer *rb, rt_uint8_t *ch)
     RT_ASSERT(rb != RT_NULL);
 
     /* ringbuffer is empty */
-    if (!RT_RINGBUFFER_SIZE(rb))
+    if (!rt_ringbuffer_data_len(rb))
         return 0;
 
     /* put character */
diff --git a/components/drivers/usb/usbdevice/class/cdc_vcom.c b/components/drivers/usb/usbdevice/class/cdc_vcom.c
index 1dee3a4d79a7c0b055e3d6cf56d20dca5935c504..5f284b029413161ffdfe6b18245187b773bba1d1 100644
--- a/components/drivers/usb/usbdevice/class/cdc_vcom.c
+++ b/components/drivers/usb/usbdevice/class/cdc_vcom.c
@@ -188,7 +188,7 @@ static rt_err_t _ep_in_handler(udevice_t device, uclass_t cls, rt_size_t size)
 
     eps = (cdc_eps_t)cls->eps;
     level = rt_hw_interrupt_disable();
-    remain = RT_RINGBUFFER_SIZE(&tx_ringbuffer);
+    remain = rt_ringbuffer_data_len(&tx_ringbuffer);
     if (remain != 0)
     {
         /* although vcom_in_sending is set in SOF handler in the very
@@ -453,7 +453,7 @@ static rt_err_t _class_sof_handler(udevice_t device, uclass_t cls)
 
     eps = (cdc_eps_t)cls->eps;
 
-    size = RT_RINGBUFFER_SIZE(&tx_ringbuffer);
+    size = rt_ringbuffer_data_len(&tx_ringbuffer);
     if (size == 0)
         return -RT_EFULL;
 
@@ -611,7 +611,7 @@ static int _vcom_putc(struct rt_serial_device *serial, char c)
      * data out soon. But we cannot rely on that and if we wait to long, just
      * return. */
     for (cnt = 500;
-         RT_RINGBUFFER_EMPTY(&tx_ringbuffer) == 0 && cnt;
+         rt_ringbuffer_space_len(&tx_ringbuffer) == 0 && cnt;
          cnt--)
     {
         /*rt_kprintf("wait for %d\n", cnt);*/
@@ -628,7 +628,7 @@ static int _vcom_putc(struct rt_serial_device *serial, char c)
     }
 
     level = rt_hw_interrupt_disable();
-    if (RT_RINGBUFFER_EMPTY(&tx_ringbuffer))
+    if (rt_ringbuffer_space_len(&tx_ringbuffer))
     {
         rt_ringbuffer_putchar(&tx_ringbuffer, c);
     }
@@ -646,7 +646,7 @@ static int _vcom_getc(struct rt_serial_device *serial)
     result = -1;
 
     level = rt_hw_interrupt_disable();
-    if (RT_RINGBUFFER_SIZE(&rx_ringbuffer))
+    if (rt_ringbuffer_data_len(&rx_ringbuffer))
     {
         rt_ringbuffer_getchar(&rx_ringbuffer, &ch);
         result = ch;
diff --git a/components/finsh/cmd.c b/components/finsh/cmd.c
index e6c576252caa69d7f7cb81dd239d405784ed7634..00dc384a1e90f8284ebccd0073fb33b683fe1c7f 100644
--- a/components/finsh/cmd.c
+++ b/components/finsh/cmd.c
@@ -455,6 +455,8 @@ static long _list_device(struct rt_list_node *list)
         "SPI Device",
         "SDIO Bus",
 		"PM Pseudo Device",
+        "Pipe",
+        "Portal Device",
 		"Miscellaneous Device",
         "Unknown"
     };
diff --git a/components/finsh/finsh.h b/components/finsh/finsh.h
index 99851e8d36b9a51a49b9d4c73d16de5707d6bfef..c93986de6ef7d56567492ebd037bba593e42b773 100644
--- a/components/finsh/finsh.h
+++ b/components/finsh/finsh.h
@@ -237,33 +237,34 @@ struct finsh_sysvar* finsh_sysvar_lookup(const char* name);
 		 */
         #ifdef _MSC_VER
             #define FINSH_FUNCTION_EXPORT_ALIAS(name, alias, desc)		\
-            const char __fsym_##name##_name[] = #alias;					 \
-            const char __fsym_##name##_desc[] = #desc;					 \
-            __declspec(allocate("FSymTab$f")) const struct finsh_syscall __fsym_##name = \
+            const char __fsym_##alias##_name[] = #alias;					 \
+            const char __fsym_##alias##_desc[] = #desc;					 \
+            __declspec(allocate("FSymTab$f")) \
+            const struct finsh_syscall __fsym_##alias = \
             {							\
-                __fsym_##name##_name,	\
-                __fsym_##name##_desc,	\
+                __fsym_##alias##_name,	\
+                __fsym_##alias##_desc,	\
                 (syscall_func)&name		\
             };
         #elif defined(__TI_COMPILER_VERSION__)
             #define FINSH_FUNCTION_EXPORT_ALIAS(name, alias, desc)     \
-            __TI_FINSH_EXPORT_FUNCTION(__fsym_##name);             \
-            const char __fsym_##name##_name[] = #alias;				   \
-            const char __fsym_##name##_desc[] = #desc;				   \
-            const struct finsh_syscall __fsym_##name = \
+            __TI_FINSH_EXPORT_FUNCTION(__fsym_##alias);             \
+            const char __fsym_##alias##_name[] = #alias;				   \
+            const char __fsym_##alias##_desc[] = #desc;				   \
+            const struct finsh_syscall __fsym_##alias = \
             {							\
-                __fsym_##name##_name,	\
-                __fsym_##name##_desc,	\
+                __fsym_##alias##_name,	\
+                __fsym_##alias##_desc,	\
                 (syscall_func)&name		\
             };
         #else
             #define FINSH_FUNCTION_EXPORT_ALIAS(name, alias, desc)		\
-            const char __fsym_##name##_name[] = #alias;					 \
-            const char __fsym_##name##_desc[] = #desc;					 \
-            const struct finsh_syscall __fsym_##name SECTION("FSymTab")= \
+            const char __fsym_##alias##_name[] = #alias;					 \
+            const char __fsym_##alias##_desc[] = #desc;					 \
+            const struct finsh_syscall __fsym_##alias SECTION("FSymTab")= \
             {							\
-                __fsym_##name##_name,	\
-                __fsym_##name##_desc,	\
+                __fsym_##alias##_name,	\
+                __fsym_##alias##_desc,	\
                 (syscall_func)&name		\
             };
         #endif /* FINSH_FUNCTION_EXPORT_ALIAS defines */
@@ -324,11 +325,11 @@ struct finsh_sysvar* finsh_sysvar_lookup(const char* name);
                 (syscall_func)&name		\
             };
             #define FINSH_FUNCTION_EXPORT_ALIAS(name, alias, desc)		\
-            const char __fsym_##name##_name[] = #alias;					 \
-            __TI_FINSH_EXPORT_FUNCTION(__fsym_##name);             \
-            const struct finsh_syscall __fsym_##name = \
+            const char __fsym_##alias##_name[] = #alias;					 \
+            __TI_FINSH_EXPORT_FUNCTION(__fsym_##alias);             \
+            const struct finsh_syscall __fsym_##alias = \
             {							\
-                __fsym_##name##_name,	\
+                __fsym_##alias##_name,	\
                 (syscall_func)&name		\
             };
 
@@ -351,10 +352,10 @@ struct finsh_sysvar* finsh_sysvar_lookup(const char* name);
             };
 
             #define FINSH_FUNCTION_EXPORT_ALIAS(name, alias, desc)		\
-            const char __fsym_##name##_name[] = #alias;					 \
-            const struct finsh_syscall __fsym_##name SECTION("FSymTab")= \
+            const char __fsym_##alias##_name[] = #alias;					 \
+            const struct finsh_syscall __fsym_##alias SECTION("FSymTab")= \
             {							\
-                __fsym_##name##_name,	\
+                __fsym_##alias##_name,	\
                 (syscall_func)&name		\
             };
 
diff --git a/components/libc/minilibc/sys/time.h b/components/libc/minilibc/sys/time.h
index 3df6d8c57007611632a26064c43af708164a8377..ada613251be4b6478848af05a49ba02605de238d 100644
--- a/components/libc/minilibc/sys/time.h
+++ b/components/libc/minilibc/sys/time.h
@@ -40,4 +40,6 @@ struct tm {
   const char *tm_zone;		/* Timezone abbreviation.  */
 };
 
+int gettimeofday(struct timeval *tp, void *ignore);
+
 #endif
diff --git a/components/utilities/logtrace/log_file.c b/components/utilities/logtrace/log_file.c
index 06789eee5737812facb920288e787c78763a62e7..72e4724b63bfc4ff82db42abdda762cd638b99e9 100644
--- a/components/utilities/logtrace/log_file.c
+++ b/components/utilities/logtrace/log_file.c
@@ -41,52 +41,56 @@ struct file_device
 static struct file_device _file_device;
 
 /* common device interface */
-rt_err_t fdevice_open(rt_device_t dev, rt_uint16_t oflag)
+static rt_err_t fdevice_open(rt_device_t dev, rt_uint16_t oflag)
 {
     int fd;
-    struct file_device *file = (struct file_device *)dev;
-    if (file->fd >= 0) return -RT_EBUSY;
+    struct file_device *fdev = (struct file_device *)dev;
 
-    fd = open(file->filename, O_RDONLY, 0);
+    if (fdev->fd >= 0)
+        return -RT_EBUSY;
+
+    /* test and open */
+    fd = open(fdev->filename, O_RDONLY, 0);
     if (fd >= 0)
     {
         close(fd);
-
-        /* file exists */
-        fd = open(file->filename, O_WRONLY | O_APPEND, 0);
+        fd = open(fdev->filename, O_WRONLY | O_APPEND, 0);
     }
     else
     {
         /* file not exists */
-        fd = open(file->filename, O_WRONLY | O_CREAT, 0);
+        fd = open(fdev->filename, O_WRONLY | O_CREAT, 0);
     }
+    fdev->fd = fd;
 
-    file->fd = fd;
     return RT_EOK;
 }
 
-rt_err_t fdevice_close(rt_device_t dev)
+static rt_err_t fdevice_close(rt_device_t dev)
 {
     rt_err_t result;
+    struct file_device *fdev = (struct file_device *)dev;
 
-    struct file_device *file = (struct file_device *)dev;
-    if (file->fd < 0) return -RT_EBUSY;
+    if (fdev->fd < 0)
+        return -RT_EBUSY;
 
-    result = close(file->fd);
+    result = close(fdev->fd);
     if (result == 0)
     {
-        file->fd = -1;
+        fdev->fd = -1;
     }
 
     return result;
 }
 
-rt_size_t fdevice_write(rt_device_t dev, rt_off_t pos, const void *buffer, rt_size_t size)
+static rt_size_t fdevice_write(rt_device_t dev, rt_off_t pos, const void *buffer, rt_size_t size)
 {
-    struct file_device *file = (struct file_device *)dev;
-    if (file->fd < 0) return 0;
+    struct file_device *fdev = (struct file_device *)dev;
+
+    if (fdev->fd < 0)
+        return 0;
 
-    return write(file->fd, buffer, size);
+    return write(fdev->fd, buffer, size);
 }
 
 void log_trace_file_init(const char *filename)
@@ -112,4 +116,11 @@ void log_trace_file_init(const char *filename)
     _file_device.fd = -1;
 }
 
-#endif // RT_USING_DFS
+void log_trace_set_file(const char *filename)
+{
+    log_trace_file_init(filename);
+    log_trace_set_device("logfile");
+}
+FINSH_FUNCTION_EXPORT_ALIAS(log_trace_set_file, log_file, set output filename of log trace);
+
+#endif /* RT_USING_DFS */
diff --git a/components/utilities/logtrace/log_trace.c b/components/utilities/logtrace/log_trace.c
index 7b17874445f16b730a1df4c056c32b5920d22f26..79d5a2188469a965292e5a51013f9145d324eb18 100644
--- a/components/utilities/logtrace/log_trace.c
+++ b/components/utilities/logtrace/log_trace.c
@@ -416,12 +416,3 @@ rt_err_t log_trace_set_device(const char *device_name)
 }
 FINSH_FUNCTION_EXPORT_ALIAS(log_trace_set_device, log_device, set device of log trace);
 
-#ifdef RT_USING_DFS
-void log_trace_set_file(const char *filename)
-{
-    log_trace_file_init(filename);
-    log_trace_set_device("logfile");
-}
-FINSH_FUNCTION_EXPORT_ALIAS(log_trace_set_file, log_file, set output filename of log trace);
-#endif // RT_USING_DFS
-
diff --git a/include/rtdef.h b/include/rtdef.h
index a3d13bfc445e4c25b6338f81e3b4d78b0a5c2686..09574d223355cd29e69032b7e694a600b8199a61 100644
--- a/include/rtdef.h
+++ b/include/rtdef.h
@@ -739,6 +739,8 @@ enum rt_device_class_type
     RT_Device_Class_SPIDevice,                          /**< SPI device */
     RT_Device_Class_SDIO,                               /**< SDIO bus device */
     RT_Device_Class_PM,                                 /**< PM pseudo device */
+    RT_Device_Class_Pipe,                               /**< Pipe device */
+    RT_Device_Class_Portal,                             /**< Portal device */
     RT_Device_Class_Miscellaneous,                      /**< Miscellaneous device */
     RT_Device_Class_Unknown                             /**< unknown device */
 };
diff --git a/libcpu/sim/posix/cpu_port.c b/libcpu/sim/posix/cpu_port.c
index e094edb6bc62f275d47683d849092d5d58fd22b7..eb1ae4865ca0afb1af996fd139cebd1af842b5e1 100644
--- a/libcpu/sim/posix/cpu_port.c
+++ b/libcpu/sim/posix/cpu_port.c
@@ -363,12 +363,6 @@ void rt_hw_interrupt_enable(rt_base_t level)
     /*TODO: It may need to unmask the signal */
 }
 
-void rt_hw_context_switch_interrupt(rt_uint32_t from,
-                                    rt_uint32_t to)
-{
-    rt_hw_context_switch(from, to);
-}
-
 void rt_hw_context_switch(rt_uint32_t from,
                           rt_uint32_t to)
 {
@@ -400,6 +394,12 @@ void rt_hw_context_switch(rt_uint32_t from,
     pthread_mutex_unlock(ptr_int_mutex);
 }
 
+void rt_hw_context_switch_interrupt(rt_uint32_t from,
+                                    rt_uint32_t to)
+{
+    rt_hw_context_switch(from, to);
+}
+
 void rt_hw_context_switch_to(rt_uint32_t to)
 {
     //set to thread
diff --git a/src/ipc.c b/src/ipc.c
index 54cad042ba65acd3230781d967202a5031f64950..116bde863ba75146ff4b04d8235387a3eba3c425 100644
--- a/src/ipc.c
+++ b/src/ipc.c
@@ -45,6 +45,7 @@
  * 2010-10-26     yi.qiu       add module support in rt_mp_delete and rt_mq_delete
  * 2010-11-10     Bernard      add IPC reset command implementation.
  * 2011-12-18     Bernard      add more parameter checking in message queue
+ * 2013-09-14     Grissiom     add an option check in rt_event_recv
  */
 
 #include <rtthread.h>
@@ -1079,7 +1080,8 @@ RTM_EXPORT(rt_event_send);
  *
  * @param event the fast event object
  * @param set the interested event set
- * @param option the receive option
+ * @param option the receive option, either RT_EVENT_FLAG_AND or
+ *        RT_EVENT_FLAG_OR should be set.
  * @param timeout the waiting time
  * @param recved the received event
  *
@@ -1125,6 +1127,11 @@ rt_err_t rt_event_recv(rt_event_t   event,
         if (event->set & set)
             status = RT_EOK;
     }
+    else
+    {
+        /* either RT_EVENT_FLAG_AND or RT_EVENT_FLAG_OR should be set */
+        RT_ASSERT(0);
+    }
 
     if (status == RT_EOK)
     {
diff --git a/tools/building.py b/tools/building.py
index 56b4ebdc8dc4227e0459c411eeea337906c27aa4..65bd14d882c5bf56d2bc052888daccc8e0b4606a 100644
--- a/tools/building.py
+++ b/tools/building.py
@@ -113,8 +113,11 @@ def PrepareBuilding(env, root_directory, has_libcpu=False, remove_components = [
                 AS   = 'true',)
         env["ENV"].update(x for x in os.environ.items() if x[0].startswith("CCC_"))
         # only check, don't compile. ccc-analyzer use CCC_CC as the CC.
-        env['ENV']['CCC_CC']  = 'true'
-        env['ENV']['CCC_CXX'] = 'true'
+        # fsyntax-only will give us some additional warning messages
+        env['ENV']['CCC_CC']  = 'clang'
+        env.Append(CFLAGS=['-fsyntax-only', '-Wall', '-Wno-invalid-source-encoding'])
+        env['ENV']['CCC_CXX'] = 'clang++'
+        env.Append(CXXFLAGS=['-fsyntax-only', '-Wall', '-Wno-invalid-source-encoding'])
         # remove the POST_ACTION as it will cause meaningless errors(file not
         # found or something like that).
         rtconfig.POST_ACTION = ''
diff --git a/tools/tools/clang-analyze.py b/tools/tools/clang-analyze.py
new file mode 100644
index 0000000000000000000000000000000000000000..a966a7b56a4a861e47429ee7f231011c514fa2fe
--- /dev/null
+++ b/tools/tools/clang-analyze.py
@@ -0,0 +1,69 @@
+"""
+Tool-specific initialization for Clang static analyzer
+
+There normally shouldn't be any need to import this module directly.
+It will usually be imported through the generic SCons.Tool.Tool()
+selection method.
+"""
+
+__revision__ = "tools/clang-analyze.py 2013-09-06 grissiom"
+
+import os
+import os.path
+
+import SCons.Action
+import SCons.Builder
+import SCons.Defaults
+import SCons.Tool
+import SCons.Util
+
+import rtconfig
+
+def generate(env):
+    assert(rtconfig.CROSS_TOOL == 'clang-analyze')
+    # let gnu_tools setup a basic env(learnt from SCons/Tools/mingw.py)
+    gnu_tools = ['gcc', 'g++', 'gnulink', 'ar', 'gas', 'm4']
+    for tool in gnu_tools:
+        SCons.Tool.Tool(tool)(env)
+
+    # then we could stand on the shoulders of gaints
+    env['CC']   = 'ccc-analyzer'
+    env['CXX']  = 'c++-analyzer'
+    env['AS']   = 'true'
+    env['AR']   = 'true'
+    env['LINK'] = 'true'
+
+    env['CFLAGS']    = ['-fsyntax-only', '-Wall', '-Wno-invalid-source-encoding']
+    env['LINKFLAGS'] = '-Wl,--gc-sections'
+    env['ARFLAGS']   = '-rc'
+
+    # only check, don't compile. ccc-analyzer use CCC_CC as the CC.
+    # fsyntax-only will give us some additional warning messages
+    env['ENV']['CCC_CC'] = 'clang'
+    env['ENV']['CCC_CXX'] = 'clang++'
+
+    # setup the output dir and format
+    env['ENV']['CCC_ANALYZER_HTML'] = './build/'
+    env['ENV']['CCC_ANALYZER_OUTPUT_FORMAT'] = 'html'
+
+    # Some setting from the platform also have to be overridden:
+    env['OBJSUFFIX'] = '.o'
+    env['LIBPREFIX'] = 'lib'
+    env['LIBSUFFIX'] = '.a'
+
+    if rtconfig.EXEC_PATH:
+        if not os.path.exists(rtconfig.EXEC_PATH):
+            print
+            print 'warning: rtconfig.EXEC_PATH(%s) does not exists.' % rtconfig.EXEC_PATH
+            print
+            return
+        env.AppendENVPath('PATH', rtconfig.EXEC_PATH)
+
+def exists(env):
+    return env.Detect(['ccc-analyzer', 'c++-analyzer'])
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4: