diff --git a/arch/arm/src/imx/imx_gpio.h b/arch/arm/src/imx/imx_gpio.h
index 415d166793a..a7f3193a31f 100644
--- a/arch/arm/src/imx/imx_gpio.h
+++ b/arch/arm/src/imx/imx_gpio.h
@@ -2,7 +2,7 @@
  * arch/arm/src/imx/imx_gpio.h
  * arch/arm/src/chip/imx_gpio.h
  *
- *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2009, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -551,11 +551,11 @@ static inline void imxgpio_clroutput(int port, int bit)
 
 /* Useful functions for normal configurations */
 
-extern void imxgpio_configoutput(int port, int bit, int value);
-extern void imxgpio_configinput(int port, int bit);
+void imxgpio_configoutput(int port, int bit, int value);
+void imxgpio_configinput(int port, int bit);
 
-extern void imxgpio_configpfoutput(int port, int bit);
-extern void imxgpio_configpfinput(int port, int bit);
+void imxgpio_configpfoutput(int port, int bit);
+void imxgpio_configpfinput(int port, int bit);
 
 #endif
 
diff --git a/arch/arm/src/lpc2378/internal.h b/arch/arm/src/lpc2378/internal.h
index 47bf8b7f57f..12f2632fa8c 100644
--- a/arch/arm/src/lpc2378/internal.h
+++ b/arch/arm/src/lpc2378/internal.h
@@ -1,7 +1,7 @@
 /****************************************************************************************************
  * arch/arm/src/lpc2378/chip.h
  *
- *   Copyright (C) 2010 Rommel Marcelo. All rights reserved.
+ *   Copyright (C) 2010, 2015 Rommel Marcelo. All rights reserved.
  *   Author: Rommel Marcelo
  *
  * This file is part of the NuttX RTOS and based on the lpc2148 port:
@@ -61,8 +61,8 @@
 #ifndef __ASSEMBLY__
 
 #ifdef CONFIG_ARCH_LEDS
-extern void lpc2378_statledoff(void);
-extern void lpc2378_statledon(void);
+void lpc2378_statledoff(void);
+void lpc2378_statledon(void);
 #endif
 
 #endif
diff --git a/arch/arm/src/str71x/str71x_internal.h b/arch/arm/src/str71x/str71x_internal.h
index aadf37baffb..51f508ae35d 100644
--- a/arch/arm/src/str71x/str71x_internal.h
+++ b/arch/arm/src/str71x/str71x_internal.h
@@ -1,7 +1,7 @@
 /************************************************************************************
  * arch/arm/src/str71x/str71x_internal.h
  *
- *   Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -105,7 +105,7 @@
  ********************************************************************************/
 
 #ifdef CONFIG_STR71X_XTI
-extern int str71x_xtiinitialize(void);
+int str71x_xtiinitialize(void);
 #else
 #  define str71x_xtiinitialize()
 #endif /* CONFIG_STR71X_XTI */
@@ -120,7 +120,7 @@ extern int str71x_xtiinitialize(void);
  ********************************************************************************/
 
 #ifdef CONFIG_STR71X_XTI
-extern int str71x_xticonfig(int irq, bool rising);
+int str71x_xticonfig(int irq, bool rising);
 #else
 #  define str71x_xticonfig(irq,rising)
 #endif /* CONFIG_STR71X_XTI */
@@ -134,7 +134,7 @@ extern int str71x_xticonfig(int irq, bool rising);
  ****************************************************************************/
 
 #ifdef CONFIG_STR71X_XTI
-extern void str71x_enable_xtiirq(int irq);
+void str71x_enable_xtiirq(int irq);
 #else
 #  define str71x_enable_xtiirq(irq)
 #endif /* CONFIG_STR71X_XTI */
@@ -148,7 +148,7 @@ extern void str71x_enable_xtiirq(int irq);
  ****************************************************************************/
 
 #ifdef CONFIG_STR71X_XTI
-extern void str71x_disable_xtiirq(int irq);
+void str71x_disable_xtiirq(int irq);
 #else
 #  define str71x_disable_xtiirq(irq)
 #endif /* CONFIG_STR71X_XTI */
diff --git a/arch/avr/src/common/up_internal.h b/arch/avr/src/common/up_internal.h
index 1434d29ce4b..98936cb59fe 100644
--- a/arch/avr/src/common/up_internal.h
+++ b/arch/avr/src/common/up_internal.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/avr/src/common/up_internal.h
  *
- *   Copyright (C) 2010-2011 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2010-2011, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -182,7 +182,7 @@ void lowconsole_init(void);
 
 /* Defined in chip/xxx_timerisr.c */
 
-extern void up_timer_initialize(void);
+void up_timer_initialize(void);
 
 /* Defined in chip/xxx_ethernet.c */
 
diff --git a/arch/hc/src/common/up_internal.h b/arch/hc/src/common/up_internal.h
index ea46f43fd92..e076c5e36ec 100644
--- a/arch/hc/src/common/up_internal.h
+++ b/arch/hc/src/common/up_internal.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/hc/src/common/up_internal.h
  *
- *   Copyright (C) 2009, 2011-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2009, 2011-2013, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -159,49 +159,49 @@ extern uint32_t g_intstackbase;
 
 /* Start-up functions */
 
-extern void up_boot(void);
+void up_boot(void);
 
 /* Context switching functions */
 
-extern void up_copystate(uint8_t *dest, uint8_t *src);
-extern void up_decodeirq(uint8_t *regs);
-extern void up_irqinitialize(void);
-extern int  up_saveusercontext(uint8_t *saveregs);
-extern void up_fullcontextrestore(uint8_t *restoreregs) noreturn_function;
-extern void up_switchcontext(uint8_t *saveregs, uint8_t *restoreregs);
+void up_copystate(uint8_t *dest, uint8_t *src);
+void up_decodeirq(uint8_t *regs);
+void up_irqinitialize(void);
+int  up_saveusercontext(uint8_t *saveregs);
+void up_fullcontextrestore(uint8_t *restoreregs) noreturn_function;
+void up_switchcontext(uint8_t *saveregs, uint8_t *restoreregs);
 
 /* Interrupt handling */
 
-extern uint8_t *up_doirq(int irq, uint8_t *regs);
+uint8_t *up_doirq(int irq, uint8_t *regs);
 
 /* Signal handling */
 
-extern void up_sigdeliver(void);
+void up_sigdeliver(void);
 
 /* System timer initialization */
 
-extern void up_timer_initialize(void);
-extern int  up_timerisr(int irq, uint32_t *regs);
+void up_timer_initialize(void);
+int  up_timerisr(int irq, uint32_t *regs);
 
 /* Debug output */
 
 #if CONFIG_NFILE_DESCRIPTORS > 0
-extern void up_earlyserialinit(void);
-extern void up_serialinit(void);
+void up_earlyserialinit(void);
+void up_serialinit(void);
 #else
 # define up_earlyserialinit()
 # define up_serialinit()
 #endif
 
 #ifdef CONFIG_DEV_LOWCONSOLE
-extern void lowconsole_init(void);
+void lowconsole_init(void);
 #else
 # define lowconsole_init()
 #endif
 
-extern void up_lowputc(char ch);
-extern void up_puts(const char *str);
-extern void up_lowputs(const char *str);
+void up_lowputc(char ch);
+void up_puts(const char *str);
+void up_lowputs(const char *str);
 
 /* Memory configuration */
 
@@ -214,20 +214,20 @@ void up_addregion(void);
 /* Sub-system/driver initialization */
 
 #ifdef CONFIG_ARCH_DMA
-extern void weak_function up_dmainitialize(void);
+void weak_function up_dmainitialize(void);
 #endif
 
-extern void up_wdtinit(void);
+void up_wdtinit(void);
 
 #ifdef CONFIG_NET
-extern void up_netinitialize(void);
+void up_netinitialize(void);
 #else
 # define up_netinitialize()
 #endif
 
 #ifdef CONFIG_USBDEV
-extern void up_usbinitialize(void);
-extern void up_usbuninitialize(void);
+void up_usbinitialize(void);
+void up_usbuninitialize(void);
 #else
 # define up_usbinitialize()
 # define up_usbuninitialize()
diff --git a/arch/mips/src/common/up_internal.h b/arch/mips/src/common/up_internal.h
index ef6df275982..c8b9a32e735 100644
--- a/arch/mips/src/common/up_internal.h
+++ b/arch/mips/src/common/up_internal.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/mips/common/up_internal.h
  *
- *   Copyright (C) 2011, 2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011, 2012, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -193,17 +193,17 @@ extern uint32_t _bmxdupba_address;  /* BMX register setting */
 
 /* Context switching */
 
-extern void up_copystate(uint32_t *dest, uint32_t *src);
+void up_copystate(uint32_t *dest, uint32_t *src);
 
 /* Serial output */
 
-extern void up_puts(const char *str);
-extern void up_lowputs(const char *str);
+void up_puts(const char *str);
+void up_lowputs(const char *str);
 
 /* Defined in drivers/lowconsole.c */
 
 #ifdef CONFIG_DEV_LOWCONSOLE
-extern void lowconsole_init(void);
+void lowconsole_init(void);
 #else
 # define lowconsole_init()
 #endif
@@ -211,7 +211,7 @@ extern void lowconsole_init(void);
 /* Debug */
 
 #ifdef CONFIG_ARCH_STACKDUMP
-extern void up_dumpstate(void);
+void up_dumpstate(void);
 #else
 #  define up_dumpstate()
 #endif
@@ -219,28 +219,28 @@ extern void up_dumpstate(void);
 /* Common MIPS32 functions defined in arch/mips/src/MIPS32 */
 /* IRQs */
 
-extern uint32_t *up_doirq(int irq, uint32_t *regs);
+uint32_t *up_doirq(int irq, uint32_t *regs);
 
 /* Software interrupt 0 handler */
 
-extern int up_swint0(int irq, FAR void *context);
+int up_swint0(int irq, FAR void *context);
 
 /* Signals */
 
-extern void up_sigdeliver(void);
+void up_sigdeliver(void);
 
 /* Chip-specific functions **************************************************/
 /* Chip specific functions defined in arch/mips/src/<chip> */
 /* IRQs */
 
-extern void up_irqinitialize(void);
-extern bool up_pending_irq(int irq);
-extern void up_clrpend_irq(int irq);
+void up_irqinitialize(void);
+bool up_pending_irq(int irq);
+void up_clrpend_irq(int irq);
 
 /* DMA */
 
 #ifdef CONFIG_ARCH_DMA
-extern void weak_function up_dmainitialize(void);
+void weak_function up_dmainitialize(void);
 #endif
 
 /* Memory management */
@@ -253,10 +253,10 @@ void up_addregion(void);
 
 /* Serial output */
 
-extern void up_lowputc(char ch);
+void up_lowputc(char ch);
 #if CONFIG_NFILE_DESCRIPTORS > 0
-extern void up_earlyserialinit(void);
-extern void up_serialinit(void);
+void up_earlyserialinit(void);
+void up_serialinit(void);
 #else
 # define up_earlyserialinit()
 # define up_serialinit()
@@ -264,12 +264,12 @@ extern void up_serialinit(void);
 
 /* System timer */
 
-extern void up_timer_initialize(void);
+void up_timer_initialize(void);
 
 /* Network */
 
 #ifdef CONFIG_NET
-extern void up_netinitialize(void);
+void up_netinitialize(void);
 #else
 # define up_netinitialize()
 #endif
@@ -277,8 +277,8 @@ extern void up_netinitialize(void);
 /* USB */
 
 #ifdef CONFIG_USBDEV
-extern void up_usbinitialize(void);
-extern void up_usbuninitialize(void);
+void up_usbinitialize(void);
+void up_usbuninitialize(void);
 #else
 # define up_usbinitialize()
 # define up_usbuninitialize()
diff --git a/arch/x86/src/common/up_internal.h b/arch/x86/src/common/up_internal.h
index 147c186ba23..d60968ff019 100644
--- a/arch/x86/src/common/up_internal.h
+++ b/arch/x86/src/common/up_internal.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/x86/src/common/up_internal.h
  *
- *   Copyright (C) 2011-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011-2013, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -192,24 +192,24 @@ void x86_boardinitialize(void);
 
 /* Defined in files with the same name as the function */
 
-extern void up_boot(void);
-extern void up_copystate(uint32_t *dest, uint32_t *src);
-extern void up_savestate(uint32_t *regs);
-extern void up_decodeirq(uint32_t *regs);
-extern void up_irqinitialize(void);
+void up_boot(void);
+void up_copystate(uint32_t *dest, uint32_t *src);
+void up_savestate(uint32_t *regs);
+void up_decodeirq(uint32_t *regs);
+void up_irqinitialize(void);
 #ifdef CONFIG_ARCH_DMA
-extern void weak_function up_dmainitialize(void);
+void weak_function up_dmainitialize(void);
 #endif
-extern int  up_saveusercontext(uint32_t *saveregs);
-extern void up_fullcontextrestore(uint32_t *restoreregs) noreturn_function;
-extern void up_switchcontext(uint32_t *saveregs, uint32_t *restoreregs);
-extern void up_sigdeliver(void);
-extern void up_lowputc(char ch);
-extern void up_puts(const char *str);
-extern void up_lowputs(const char *str);
+int  up_saveusercontext(uint32_t *saveregs);
+void up_fullcontextrestore(uint32_t *restoreregs) noreturn_function;
+void up_switchcontext(uint32_t *saveregs, uint32_t *restoreregs);
+void up_sigdeliver(void);
+void up_lowputc(char ch);
+void up_puts(const char *str);
+void up_lowputs(const char *str);
 
-extern void up_syscall(uint32_t *regs);
-extern void up_registerdump(uint32_t *regs);
+void up_syscall(uint32_t *regs);
+void up_registerdump(uint32_t *regs);
 
 /* Defined in up_allocateheap.c */
 
@@ -222,8 +222,8 @@ void up_addregion(void);
 /* Defined in up_serial.c */
 
 #if CONFIG_NFILE_DESCRIPTORS > 0
-extern void up_earlyserialinit(void);
-extern void up_serialinit(void);
+void up_earlyserialinit(void);
+void up_serialinit(void);
 #else
 # define up_earlyserialinit()
 # define up_serialinit()
@@ -232,30 +232,30 @@ extern void up_serialinit(void);
 /* Defined in drivers/lowconsole.c */
 
 #ifdef CONFIG_DEV_LOWCONSOLE
-extern void lowconsole_init(void);
+void lowconsole_init(void);
 #else
 # define lowconsole_init()
 #endif
 
 /* Defined in up_watchdog.c */
 
-extern void up_wdtinit(void);
+void up_wdtinit(void);
 
 /* Defined in up_timerisr.c */
 
-extern void up_timer_initialize(void);
+void up_timer_initialize(void);
 
 /* Defined in board/up_network.c */
 
 #ifdef CONFIG_NET
-extern void up_netinitialize(void);
+void up_netinitialize(void);
 #else
 # define up_netinitialize()
 #endif
 
 #ifdef CONFIG_USBDEV
-extern void up_usbinitialize(void);
-extern void up_usbuninitialize(void);
+void up_usbinitialize(void);
+void up_usbuninitialize(void);
 #else
 # define up_usbinitialize()
 # define up_usbuninitialize()
diff --git a/arch/z16/src/common/up_internal.h b/arch/z16/src/common/up_internal.h
index 9ec8965fe37..5e368b05da3 100644
--- a/arch/z16/src/common/up_internal.h
+++ b/arch/z16/src/common/up_internal.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  * common/up_internal.h
  *
- *   Copyright (C) 2008-2009, 2011-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2011-2013, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -143,16 +143,16 @@ extern volatile FAR chipreg_t *current_regs;
 
 /* Defined in files with the same name as the function */
 
-extern void up_copystate(FAR chipreg_t *dest, FAR chipreg_t *src);
-extern FAR chipreg_t *up_doirq(int irq, FAR chipreg_t *regs);
-extern void up_restoreusercontext(FAR chipreg_t *regs);
-extern void up_irqinitialize(void);
-extern int  up_saveusercontext(FAR chipreg_t *regs);
-extern void up_sigdeliver(void);
-extern int  up_timerisr(int irq, FAR chipreg_t *regs);
+void up_copystate(FAR chipreg_t *dest, FAR chipreg_t *src);
+FAR chipreg_t *up_doirq(int irq, FAR chipreg_t *regs);
+void up_restoreusercontext(FAR chipreg_t *regs);
+void up_irqinitialize(void);
+int  up_saveusercontext(FAR chipreg_t *regs);
+void up_sigdeliver(void);
+int  up_timerisr(int irq, FAR chipreg_t *regs);
 
 #if defined(CONFIG_Z16_LOWPUTC) || defined(CONFIG_Z16_LOWGETC)
-extern void up_lowputc(char ch);
+void up_lowputc(char ch);
 #else
 # define up_lowputc(ch)
 #endif
@@ -166,39 +166,39 @@ void up_addregion(void);
 /* Defined in up_serial.c */
 
 #ifdef USE_SERIALDRIVER
-extern void up_earlyserialinit(void);
-extern void up_serialinit(void);
+void up_earlyserialinit(void);
+void up_serialinit(void);
 #endif
 
 #ifdef USE_LOWCONSOLE
-extern void lowconsole_init(void);
+void lowconsole_init(void);
 #endif
 
 /* Defined in up_timerisr.c */
 
-extern void up_timer_initialize(void);
+void up_timer_initialize(void);
 
 /* Defined in up_irq.c */
 
-extern void up_ack_irq(int irq);
+void up_ack_irq(int irq);
 
 /* Defined in board/up_network.c */
 
 #ifdef CONFIG_NET
-extern void up_netinitialize(void);
+void up_netinitialize(void);
 #else
 # define up_netinitialize()
 #endif
 
 /* Return the current value of the stack pointer (used in stack dump logic) */
 
-extern chipreg_t up_getsp(void);
+chipreg_t up_getsp(void);
 
 /* Dump stack and registers */
 
 #ifdef CONFIG_ARCH_STACKDUMP
-extern void up_stackdump(void);
-extern void up_registerdump(void);
+void up_stackdump(void);
+void up_registerdump(void);
 #else
 # define up_stackdump()
 # define up_registerdump()
diff --git a/arch/z80/src/common/up_internal.h b/arch/z80/src/common/up_internal.h
index 7aff91968bd..746b4d32fa5 100644
--- a/arch/z80/src/common/up_internal.h
+++ b/arch/z80/src/common/up_internal.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/z80/src/common/up_internal.h
  *
- *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -174,7 +174,7 @@ void lowconsole_init(void);
 /* Defined in drivers/syslog_console.c */
 
 #ifdef defined(CONFIG_SYSLOG_CONSOLE)
-  syslog_console_init();
+void syslog_console_init();
 #else
 # define syslog_console_init()
 #endif
@@ -182,14 +182,14 @@ void lowconsole_init(void);
 /* Defined in drivers/ramlog.c */
 
 #ifdef CONFIG_RAMLOG_CONSOLE
-extern void ramlog_consoleinit(void);
+void ramlog_consoleinit(void);
 #else
 # define ramlog_consoleinit()
 #endif
 
 /* Low level string output */
 
-extern void up_puts(const char *str);
+void up_puts(const char *str);
 
 /* Defined in up_timerisr.c */
 
diff --git a/include/nuttx/sercomm/msgb.h b/include/nuttx/sercomm/msgb.h
index 64825c1eaaa..68005bbb46c 100644
--- a/include/nuttx/sercomm/msgb.h
+++ b/include/nuttx/sercomm/msgb.h
@@ -1,7 +1,5 @@
-#ifndef _MSGB_H
-#define _MSGB_H
-
-/* (C) 2008-2010 by Harald Welte <laforge@gnumonks.org>
+/**************************************************************************
+ * (C) 2008-2010 by Harald Welte <laforge@gnumonks.org>
  *
  * This source code is derivated from Osmocom-BB project and was
  * relicensed as BSD with permission from original authors.
@@ -35,142 +33,186 @@
  *
  **************************************************************************/
 
+#ifndef __INCLUDE_NUTTX_SERCOM_MSGB_H
+#define __INCLUDE_NUTTX_SERCOM_MSGB_H
+
+/**************************************************************************
+ * Included Files
+ **************************************************************************/
+
 #include <osmocom/core/linuxlist.h>
 #include <console.h>
 
-struct msgb {
-	struct llist_head list;
+/**************************************************************************
+ * Public Types
+ **************************************************************************/
 
-	/* the layer 1 header, if any */
-	unsigned char *l1h;
-	/* the A-bis layer 2 header: OML, RSL(RLL), NS */
-	unsigned char *l2h;
-	/* the layer 3 header. For OML: FOM; RSL: 04.08; GPRS: BSSGP */
-	unsigned char *l3h;
+struct msgb
+{
+  struct llist_head list;
 
-	uint16_t data_len;
-	uint16_t len;
+  /* the layer 1 header, if any */
 
-	unsigned char *head;	/* start of buffer */
-	unsigned char *tail;	/* end of message */
-	unsigned char *data;	/* start of message */
-	unsigned char _data[0];
+  unsigned char *l1h;
+
+  /* the A-bis layer 2 header: OML, RSL(RLL), NS */
+
+  unsigned char *l2h;
+
+  /* the layer 3 header. For OML: FOM; RSL: 04.08; GPRS: BSSGP */
+
+  unsigned char *l3h;
+
+  uint16_t data_len;
+  uint16_t len;
+
+  unsigned char *head;  /* start of buffer */
+  unsigned char *tail;  /* end of message */
+  unsigned char *data;  /* start of message */
+  unsigned char _data[0];
 };
 
-extern struct msgb *msgb_alloc(uint16_t size, const char *name);
-extern void msgb_free(struct msgb *m);
-extern void msgb_enqueue(struct llist_head *queue, struct msgb *msg);
-extern struct msgb *msgb_dequeue(struct llist_head *queue);
-extern void msgb_reset(struct msgb *m);
+/**************************************************************************
+ * Public Function Prototypes
+ **************************************************************************/
 
-#define msgb_l1(m)	((void *)(m->l1h))
-#define msgb_l2(m)	((void *)(m->l2h))
-#define msgb_l3(m)	((void *)(m->l3h))
+struct msgb *msgb_alloc(uint16_t size, const char *name);
+void msgb_free(struct msgb *m);
+void msgb_enqueue(struct llist_head *queue, struct msgb *msg);
+struct msgb *msgb_dequeue(struct llist_head *queue);
+void msgb_reset(struct msgb *m);
+
+/**************************************************************************
+ * Inline Functions
+ **************************************************************************/
+
+#define msgb_l1(m)  ((void *)(m->l1h))
+#define msgb_l2(m)  ((void *)(m->l2h))
+#define msgb_l3(m)  ((void *)(m->l3h))
 
 static inline unsigned int msgb_l1len(const struct msgb *msgb)
 {
-	return msgb->tail - (uint8_t *)msgb_l1(msgb);
+  return msgb->tail - (uint8_t *)msgb_l1(msgb);
 }
 
 static inline unsigned int msgb_l2len(const struct msgb *msgb)
 {
-	return msgb->tail - (uint8_t *)msgb_l2(msgb);
+  return msgb->tail - (uint8_t *)msgb_l2(msgb);
 }
 
 static inline unsigned int msgb_l3len(const struct msgb *msgb)
 {
-	return msgb->tail - (uint8_t *)msgb_l3(msgb);
+  return msgb->tail - (uint8_t *)msgb_l3(msgb);
 }
 
 static inline unsigned int msgb_headlen(const struct msgb *msgb)
 {
-	return msgb->len - msgb->data_len;
+  return msgb->len - msgb->data_len;
 }
+
 static inline int msgb_tailroom(const struct msgb *msgb)
 {
-	return (msgb->head + msgb->data_len) - msgb->tail;
+  return (msgb->head + msgb->data_len) - msgb->tail;
 }
+
 static inline unsigned char *msgb_put(struct msgb *msgb, unsigned int len)
 {
-	unsigned char *tmp = msgb->tail;
+  unsigned char *tmp = msgb->tail;
 
-	/* we intentionally call cons_puts() here to display an allocation
-	 * failure on the _other_ serial port (i.e. the one that doesn't
-	 * have the HDLC layer on it */
-	if (msgb_tailroom(msgb) < len)
-		cons_puts("msgb_tailroom insufficient!\n");
+  /* we intentionally call cons_puts() here to display an allocation
+   * failure on the _other_ serial port (i.e. the one that doesn't
+   * have the HDLC layer on it
+   */
 
-	msgb->tail += len;
-	msgb->len += len;
-	return tmp;
+  if (msgb_tailroom(msgb) < len)
+    {
+      cons_puts("msgb_tailroom insufficient!\n");
+    }
+
+  msgb->tail += len;
+  msgb->len += len;
+  return tmp;
 }
+
 static inline void msgb_put_u8(struct msgb *msgb, uint8_t word)
 {
-	uint8_t *space = msgb_put(msgb, 1);
-	space[0] = word & 0xFF;
+  uint8_t *space = msgb_put(msgb, 1);
+  space[0] = word & 0xFF;
 }
+
 static inline void msgb_put_u16(struct msgb *msgb, uint16_t word)
 {
-	uint8_t *space = msgb_put(msgb, 2);
-	space[0] = word >> 8 & 0xFF;
-	space[1] = word & 0xFF;
+  uint8_t *space = msgb_put(msgb, 2);
+  space[0] = word >> 8 & 0xFF;
+  space[1] = word & 0xFF;
 }
+
 static inline void msgb_put_u32(struct msgb *msgb, uint32_t word)
 {
-	uint8_t *space = msgb_put(msgb, 4);
-	space[0] = word >> 24 & 0xFF;
-	space[1] = word >> 16 & 0xFF;
-	space[2] = word >> 8 & 0xFF;
-	space[3] = word & 0xFF;
+  uint8_t *space = msgb_put(msgb, 4);
+  space[0] = word >> 24 & 0xFF;
+  space[1] = word >> 16 & 0xFF;
+  space[2] = word >> 8 & 0xFF;
+  space[3] = word & 0xFF;
 }
+
 static inline unsigned char *msgb_get(struct msgb *msgb, unsigned int len)
 {
-	unsigned char *tmp = msgb->data;
-	msgb->data += len;
-	msgb->len -= len;
-	return tmp;
+  unsigned char *tmp = msgb->data;
+  msgb->data += len;
+  msgb->len -= len;
+  return tmp;
 }
+
 static inline uint8_t msgb_get_u8(struct msgb *msgb)
 {
-	uint8_t *space = msgb_get(msgb, 1);
-	return space[0];
+  uint8_t *space = msgb_get(msgb, 1);
+  return space[0];
 }
+
 static inline uint16_t msgb_get_u16(struct msgb *msgb)
 {
-	uint8_t *space = msgb_get(msgb, 2);
-	return space[0] << 8 | space[1];
+  uint8_t *space = msgb_get(msgb, 2);
+  return space[0] << 8 | space[1];
 }
+
 static inline uint32_t msgb_get_u32(struct msgb *msgb)
 {
-	uint8_t *space = msgb_get(msgb, 4);
-	return space[0] << 24 | space[1] << 16 | space[2] << 8 | space[3];
+  uint8_t *space = msgb_get(msgb, 4);
+  return space[0] << 24 | space[1] << 16 | space[2] << 8 | space[3];
 }
+
 static inline unsigned char *msgb_push(struct msgb *msgb, unsigned int len)
 {
-	msgb->data -= len;
-	msgb->len += len;
-	return msgb->data;
+  msgb->data -= len;
+  msgb->len += len;
+  return msgb->data;
 }
+
 static inline unsigned char *msgb_pull(struct msgb *msgb, unsigned int len)
 {
-	msgb->len -= len;
-	return msgb->data += len;
+  msgb->len -= len;
+  return msgb->data += len;
 }
 
 /* increase the headroom of an empty msgb, reducing the tailroom */
+
 static inline void msgb_reserve(struct msgb *msg, int len)
 {
-	msg->data += len;
-	msg->tail += len;
+  msg->data += len;
+  msg->tail += len;
 }
 
 static inline struct msgb *msgb_alloc_headroom(int size, int headroom,
-						const char *name)
+            const char *name)
 {
-	struct msgb *msg = msgb_alloc(size, name);
-	if (msg)
-		msgb_reserve(msg, headroom);
-	return msg;
+  struct msgb *msg = msgb_alloc(size, name);
+  if (msg)
+    {
+      msgb_reserve(msg, headroom);
+    }
+
+  return msg;
 }
 
-#endif /* _MSGB_H */
+#endif /* __INCLUDE_NUTTX_SERCOM_MSGB_H */
diff --git a/include/nuttx/serial/uart_16550.h b/include/nuttx/serial/uart_16550.h
index 9486095b6f2..de37fb5502e 100644
--- a/include/nuttx/serial/uart_16550.h
+++ b/include/nuttx/serial/uart_16550.h
@@ -2,7 +2,7 @@
  * include/nuttx/serial/uart_16550.h
  * Serial driver for 16550 UART
  *
- *   Copyright (C) 2011-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011-2013, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -344,8 +344,8 @@ typedef uint32_t uart_addrwidth_t;
  *
  ************************************************************************************/
 
-extern uart_datawidth_t uart_getreg(uart_addrwidth_t base, unsigned int offset);
-extern void uart_putreg(uart_addrwidth_t base, unsigned int offset, uart_datawidth_t value);
+uart_datawidth_t uart_getreg(uart_addrwidth_t base, unsigned int offset);
+void uart_putreg(uart_addrwidth_t base, unsigned int offset, uart_datawidth_t value);
 
 #endif /* CONFIG_16550_UART */
 #endif /* __INCLUDE_NUTTX_SERIAL_UART_16550_H */