diff --git a/os/hal/include/pal.h b/os/hal/include/pal.h
index 7ffa5fc69..dc96f6e60 100644
--- a/os/hal/include/pal.h
+++ b/os/hal/include/pal.h
@@ -1,6 +1,6 @@
 /*
     ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
-                 2011,2012 Giovanni Di Sirio.
+                 2011,2012,2013 Giovanni Di Sirio.
 
     This file is part of ChibiOS/RT.
 
@@ -58,7 +58,7 @@
  * @brief   Safe state for <b>unconnected</b> pads.
  * @details The state itself is not specified and is architecture dependent,
  *          it may be mapped on @p PAL_MODE_INPUT_PULLUP,
- *          @p PAL_MODE_INPUT_PULLDOWN or @p PAL_MODE_OUTPUT_PUSHPULL as
+ *          @p PAL_MODE_INPUT_PULLDOWN or @p PAL_MODE_OUTPUT_PUSHPULL for
  *          example.
  */
 #define PAL_MODE_UNCONNECTED            1
@@ -101,12 +101,12 @@
 /**
  * @brief   Logical low state.
  */
-#define PAL_LOW 0
+#define PAL_LOW                         0
 
 /**
  * @brief   Logical high state.
  */
-#define PAL_HIGH 1
+#define PAL_HIGH                        1
 /** @} */
 
 /*===========================================================================*/
@@ -158,7 +158,9 @@ typedef struct {
  * @param[in] n         bit position within the port
  * @return              The bit mask.
  */
+#if !defined(PAL_PORT_BIT) || defined(__DOXYGEN__)
 #define PAL_PORT_BIT(n) ((ioportmask_t)(1 << (n)))
+#endif
 
 /**
  * @brief   Bits group mask helper.
@@ -167,7 +169,9 @@ typedef struct {
  * @param[in] width         group width
  * @return                  The group mask.
  */
+#if !defined(PAL_GROUP_MASK) || defined(__DOXYGEN__)
 #define PAL_GROUP_MASK(width) ((ioportmask_t)(1 << (width)) - 1)
+#endif
 
 /**
  * @brief   Data part of a static I/O bus initializer.
@@ -179,7 +183,7 @@ typedef struct {
  * @param[in] width     bus width in bits
  * @param[in] offset     bus bit offset within the port
  */
-#define _IOBUS_DATA(name, port, width, offset)                          \
+#define _IOBUS_DATA(name, port, width, offset)                              \
   {port, PAL_GROUP_MASK(width), offset}
 
 /**
@@ -190,7 +194,7 @@ typedef struct {
  * @param[in] width     bus width in bits
  * @param[in] offset    bus bit offset within the port
  */
-#define IOBUS_DECL(name, port, width, offset)                           \
+#define IOBUS_DECL(name, port, width, offset)                               \
   IOBus name = _IOBUS_DATA(name, port, width, offset)
 
 /**
@@ -214,11 +218,12 @@ typedef struct {
  * @brief   Reads the physical I/O port states.
  * @note    The default implementation always return zero and computes the
  *          parameter eventual side effects.
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @return              The port logical states.
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_readport) || defined(__DOXYGEN__)
 #define palReadPort(port) ((void)(port), 0)
@@ -232,11 +237,12 @@ typedef struct {
  *          value.
  * @note    The default implementation always return zero and computes the
  *          parameter eventual side effects.
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @return              The latched logical states.
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_readlatch) || defined(__DOXYGEN__)
 #define palReadLatch(port) ((void)(port), 0)
@@ -248,11 +254,12 @@ typedef struct {
  * @brief   Writes a bits mask on a I/O port.
  * @note    The default implementation does nothing except computing the
  *          parameters eventual side effects.
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] bits      bits to be written on the specified port
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_writeport) || defined(__DOXYGEN__)
 #define palWritePort(port, bits) ((void)(port), (void)(bits))
@@ -269,14 +276,15 @@ typedef struct {
  * @note    The default implementation is non atomic and not necessarily
  *          optimal. Low level drivers may  optimize the function by using
  *          specific hardware or coding.
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] bits      bits to be ORed on the specified port
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_setport) || defined(__DOXYGEN__)
-#define palSetPort(port, bits)                                          \
+#define palSetPort(port, bits)                                              \
   palWritePort(port, palReadLatch(port) | (bits))
 #else
 #define palSetPort(port, bits) pal_lld_setport(port, bits)
@@ -291,14 +299,15 @@ typedef struct {
  * @note    The default implementation is non atomic and not necessarily
  *          optimal. Low level drivers may  optimize the function by using
  *          specific hardware or coding.
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] bits      bits to be cleared on the specified port
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_clearport) || defined(__DOXYGEN__)
-#define palClearPort(port, bits)                                        \
+#define palClearPort(port, bits)                                            \
   palWritePort(port, palReadLatch(port) & ~(bits))
 #else
 #define palClearPort(port, bits) pal_lld_clearport(port, bits)
@@ -313,14 +322,15 @@ typedef struct {
  * @note    The default implementation is non atomic and not necessarily
  *          optimal. Low level drivers may  optimize the function by using
  *          specific hardware or coding.
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] bits      bits to be XORed on the specified port
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_toggleport) || defined(__DOXYGEN__)
-#define palTogglePort(port, bits)                                       \
+#define palTogglePort(port, bits)                                           \
   palWritePort(port, palReadLatch(port) ^ (bits))
 #else
 #define palTogglePort(port, bits) pal_lld_toggleport(port, bits)
@@ -328,6 +338,7 @@ typedef struct {
 
 /**
  * @brief   Reads a group of bits.
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] mask      group mask, a logical AND is performed on the input
@@ -335,10 +346,10 @@ typedef struct {
  * @param[in] offset    group bit offset within the port
  * @return              The group logical states.
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_readgroup) || defined(__DOXYGEN__)
-#define palReadGroup(port, mask, offset)                               \
+#define palReadGroup(port, mask, offset)                                    \
   ((palReadPort(port) >> (offset)) & (mask))
 #else
 #define palReadGroup(port, mask, offset) pal_lld_readgroup(port, mask, offset)
@@ -346,6 +357,7 @@ typedef struct {
 
 /**
  * @brief   Writes a group of bits.
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] mask      group mask, a logical AND is performed on the
@@ -354,14 +366,14 @@ typedef struct {
  * @param[in] bits      bits to be written. Values exceeding the group
  *                      width are masked.
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_writegroup) || defined(__DOXYGEN__)
-#define palWriteGroup(port, mask, offset, bits)                         \
-  palWritePort(port, (palReadLatch(port) & ~((mask) << (offset))) |     \
+#define palWriteGroup(port, mask, offset, bits)                             \
+  palWritePort(port, (palReadLatch(port) & ~((mask) << (offset))) |         \
                      (((bits) & (mask)) << (offset)))
 #else
-#define palWriteGroup(port, mask, offset, bits)                         \
+#define palWriteGroup(port, mask, offset, bits)                             \
   pal_lld_writegroup(port, mask, offset, bits)
 #endif
 
@@ -371,13 +383,14 @@ typedef struct {
  * @details This function programs a pads group belonging to the same port
  *          with the specified mode.
  * @note    Programming an unknown or unsupported mode is silently ignored.
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] mask      group mask
  * @param[in] offset    group bit offset within the port
  * @param[in] mode      group mode
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_setgroupmode) || defined(__DOXYGEN__)
 #define palSetGroupMode(port, mask, offset, mode)
@@ -392,6 +405,7 @@ typedef struct {
  *          drivers may  optimize the function by using specific hardware
  *          or coding.
  * @note    The default implementation internally uses the @p palReadPort().
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] pad       pad number within the port
@@ -399,7 +413,7 @@ typedef struct {
  * @retval PAL_LOW      low logical state.
  * @retval PAL_HIGH     high logical state.
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_readpad) || defined(__DOXYGEN__)
 #define palReadPad(port, pad) ((palReadPort(port) >> (pad)) & 1)
@@ -418,17 +432,18 @@ typedef struct {
  *          specific hardware or coding.
  * @note    The default implementation internally uses the @p palReadLatch()
  *          and @p palWritePort().
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] pad       pad number within the port
  * @param[in] bit       logical value, the value must be @p PAL_LOW or
  *                      @p PAL_HIGH
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_writepad) || defined(__DOXYGEN__)
-#define palWritePad(port, pad, bit)                                     \
-  palWritePort(port, (palReadLatch(port) & ~PAL_PORT_BIT(pad)) |        \
+#define palWritePad(port, pad, bit)                                         \
+  palWritePort(port, (palReadLatch(port) & ~PAL_PORT_BIT(pad)) |            \
                      (((bit) & 1) << pad))
 #else
 #define palWritePad(port, pad, bit) pal_lld_writepad(port, pad, bit)
@@ -444,11 +459,12 @@ typedef struct {
  *          optimal. Low level drivers may  optimize the function by using
  *          specific hardware or coding.
  * @note    The default implementation internally uses the @p palSetPort().
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] pad       pad number within the port
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_setpad) || defined(__DOXYGEN__)
 #define palSetPad(port, pad) palSetPort(port, PAL_PORT_BIT(pad))
@@ -466,11 +482,12 @@ typedef struct {
  *          optimal. Low level drivers may  optimize the function by using
  *          specific hardware or coding.
  * @note    The default implementation internally uses the @p palClearPort().
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] pad       pad number within the port
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_clearpad) || defined(__DOXYGEN__)
 #define palClearPad(port, pad) palClearPort(port, PAL_PORT_BIT(pad))
@@ -488,11 +505,12 @@ typedef struct {
  *          optimal. Low level drivers may  optimize the function by using
  *          specific hardware or coding.
  * @note    The default implementation internally uses the @p palTogglePort().
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] pad       pad number within the port
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_togglepad) || defined(__DOXYGEN__)
 #define palTogglePad(port, pad) palTogglePort(port, PAL_PORT_BIT(pad))
@@ -500,7 +518,6 @@ typedef struct {
 #define palTogglePad(port, pad) pal_lld_togglepad(port, pad)
 #endif
 
-
 /**
  * @brief   Pad mode setup.
  * @details This function programs a pad with the specified mode.
@@ -508,15 +525,16 @@ typedef struct {
  *          drivers may  optimize the function by using specific hardware
  *          or coding.
  * @note    Programming an unknown or unsupported mode is silently ignored.
+ * @note    The function can be called from any context.
  *
  * @param[in] port      port identifier
  * @param[in] pad       pad number within the port
  * @param[in] mode      pad mode
  *
- * @api
+ * @special
  */
 #if !defined(pal_lld_setpadmode) || defined(__DOXYGEN__)
-#define palSetPadMode(port, pad, mode)                                  \
+#define palSetPadMode(port, pad, mode)                                      \
   palSetGroupMode(port, PAL_PORT_BIT(pad), 0, mode)
 #else
 #define palSetPadMode(port, pad, mode) pal_lld_setpadmode(port, pad, mode)
diff --git a/os/hal/src/pal.c b/os/hal/src/pal.c
index 3f8c91f60..3481ba6f0 100644
--- a/os/hal/src/pal.c
+++ b/os/hal/src/pal.c
@@ -1,6 +1,6 @@
 /*
     ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
-                 2011,2012 Giovanni Di Sirio.
+                 2011,2012,2013 Giovanni Di Sirio.
 
     This file is part of ChibiOS/RT.
 
@@ -47,7 +47,7 @@
 /*===========================================================================*/
 
 /*===========================================================================*/
-/* Driver local variables.                                                   */
+/* Driver local variables and types.                                         */
 /*===========================================================================*/
 
 /*===========================================================================*/
@@ -67,16 +67,16 @@
  * @note    The function internally uses the @p palReadGroup() macro. The use
  *          of this function is preferred when you value code size, readability
  *          and error checking over speed.
+ * @note    The function can be called from any context.
  *
  * @param[in] bus       the I/O bus, pointer to a @p IOBus structure
  * @return              The bus logical states.
  *
- * @api
+ * @special
  */
 ioportmask_t palReadBus(IOBus *bus) {
 
-  chDbgCheck((bus != NULL) &&
-             (bus->offset < PAL_IOPORTS_WIDTH), "palReadBus");
+  osalDbgCheck((bus != NULL) && (bus->offset < PAL_IOPORTS_WIDTH));
 
   return palReadGroup(bus->portid, bus->mask, bus->offset);
 }
@@ -90,18 +90,18 @@ ioportmask_t palReadBus(IOBus *bus) {
  * @note    The default implementation is non atomic and not necessarily
  *          optimal. Low level drivers may  optimize the function by using
  *          specific hardware or coding.
+ * @note    The function can be called from any context.
  *
  * @param[in] bus       the I/O bus, pointer to a @p IOBus structure
  * @param[in] bits      the bits to be written on the I/O bus. Values exceeding
  *                      the bus width are masked so most significant bits are
  *                      lost.
  *
- * @api
+ * @special
  */
 void palWriteBus(IOBus *bus, ioportmask_t bits) {
 
-  chDbgCheck((bus != NULL) &&
-             (bus->offset < PAL_IOPORTS_WIDTH), "palWriteBus");
+  osalDbgCheck((bus != NULL) && (bus->offset < PAL_IOPORTS_WIDTH));
 
   palWriteGroup(bus->portid, bus->mask, bus->offset, bits);
 }
@@ -115,16 +115,16 @@ void palWriteBus(IOBus *bus, ioportmask_t bits) {
  * @note    The default implementation is non atomic and not necessarily
  *          optimal. Low level drivers may  optimize the function by using
  *          specific hardware or coding.
+ * @note    The function can be called from any context.
  *
  * @param[in] bus       the I/O bus, pointer to a @p IOBus structure
  * @param[in] mode      the mode
  *
- * @api
+ * @special
  */
 void palSetBusMode(IOBus *bus, iomode_t mode) {
 
-  chDbgCheck((bus != NULL) &&
-             (bus->offset < PAL_IOPORTS_WIDTH), "palSetBusMode");
+  osalDbgCheck((bus != NULL) && (bus->offset < PAL_IOPORTS_WIDTH));
 
   palSetGroupMode(bus->portid, bus->mask, bus->offset, mode);
 }
diff --git a/readme.txt b/readme.txt
index 3d03eef72..368fe2261 100644
--- a/readme.txt
+++ b/readme.txt
@@ -79,6 +79,7 @@
 *****************************************************************************
 
 *** 2.4.5 ***
+- FIX: Fixed PAL driver documentation error (bug #427).
 - FIX: Fixed wrong RTC macro names in STM32L1xx HAL (bug #422).
 
 *** 2.4.4 ***