Some versions of doxygen seem to object to "@ret None" or similar.

src/arch/i386/prefix/int19exit.c

@@ -15,8 +15,8 @@
  * Exit via INT19
  *
  * @v ix86		i386 register values to be loaded on exit
- * @ret Never
+ * @ret Never		-
- * @err None
+ * @err None		-
  *
  * Exit back to the BIOS by switching to real mode, reloading the
  * registers as they were before Etherboot started, and executing INT

src/core/buffer.c

@@ -48,8 +48,8 @@
  * Initialise a buffer.
  *
  * @v buffer		The buffer to be initialised
- * @ret None
+ * @ret None		-
- * @err None
+ * @err None		-
  *
  * Set @c buffer->start and @c buffer->end before calling init_buffer().
  * init_buffer() will initialise the buffer to the state of being
@@ -72,8 +72,8 @@ void init_buffer ( struct buffer *buffer ) {
  * @v desc		A descriptor for the free block
  * @v block		Start address of the block
  * @v split		Address at which to split the block
- * @ret None
+ * @ret None		-
- * @err None
+ * @err None		-
  *
  * Split a free block into two separate free blocks.  If the split
  * point lies outside the block, no action is taken; this is not an
@@ -120,8 +120,8 @@ static void split_free_block ( struct buffer_free_block *desc,
  * @v buffer		The buffer containing the block
  * @v desc		A descriptor for the free block
  * @v prev_block	Address of the previous block
- * @ret None
+ * @ret None		-
- * @err None
+ * @err None		-
  *
  * Marks a free block as used, i.e. removes it from the free list.
  *

src/core/console.c

@@ -12,8 +12,8 @@ static struct console_driver console_drivers_end[0] __table_end ( console );
  * Write a single character to each console device.
  *
  * @v character		Character to be written
- * @ret None
+ * @ret None		-
- * @err None
+ * @err None		-
  *
  * The character is written out to all enabled console devices, using
  * each device's console_driver::putchar() method.
@@ -36,10 +36,10 @@ void putchar ( int character ) {
 /**
  * Check to see if any input is available on any console.
  *
- * @v None
+ * @v None		-
  * @ret console		Console device that has input available, if any.
  * @ret NULL		No console device has input available.
- * @err None
+ * @err None		-
  *
  * All enabled console devices are checked once for available input
  * using each device's console_driver::iskey() method.  The first
@@ -62,9 +62,9 @@ static struct console_driver * has_input ( void ) {
 /**
  * Read a single character from any console.
  *
- * @v None
+ * @v None		-
  * @ret character	Character read from a console.
- * @err None
+ * @err None		-
  *
  * A character will be read from the first enabled console device that
  * has input available using that console's console_driver::getchar()
@@ -112,10 +112,10 @@ int getchar ( void ) {
 
 /** Check for available input on any console.
  *
- * @v None
+ * @v None		-
  * @ret True		Input is available on a console
  * @ret False		Input is not available on any console
- * @err None
+ * @err None		-
  *
  * All enabled console devices are checked once for available input
  * using each device's console_driver::iskey() method.  If any console

src/core/vsprintf.c

@@ -20,7 +20,7 @@
  * @v args		Arguments corresponding to the format string
  * @ret len		Length of string written to buffer (if buf != NULL)
  * @ret	0		(if buf == NULL)
- * @err None
+ * @err None		-
  *
  * If #buf==NULL, then the string will be written to the console
  * directly using putchar().
@@ -157,7 +157,7 @@ static int vsprintf(char *buf, const char *fmt, va_list args)
  * @v ...		Arguments corresponding to the format string
  * @ret len		Length of string written to buffer (if buf != NULL)
  * @ret	0		(if buf == NULL)
- * @err None
+ * @err None		-
  *
  * If #buf==NULL, then the string will be written to the console
  * directly using putchar().
@@ -178,8 +178,8 @@ int sprintf(char *buf, const char *fmt, ...)
  *
  * @v fmt		Format string
  * @v ...		Arguments corresponding to the format string
- * @ret	None
+ * @ret	None		-
- * @err None
+ * @err None		-
  *
  */
 void printf(const char *fmt, ...)

src/drivers/bus/isapnp.c

@@ -172,8 +172,8 @@ static inline void isapnp_reset_csn ( void ) {
  * Place a specified card into the Config state.
  *
  * @v csn		Card Select Number
- * @ret None
+ * @ret None		-
- * @err None
+ * @err None		-
  *
  * Only cards currently in the Sleep, Isolation, or Config states will
  * respond to this command.  The card that has the specified CSN will
@@ -196,8 +196,8 @@ static inline uint8_t isapnp_read_status ( void ) {
  * Assign a Card Select Number to a card, and enter the Config state.
  *
  * @v csn		Card Select Number
- * @ret None
+ * @ret None		-
- * @err None
+ * @err None		-
  *
  * Only cards in the Isolation state will respond to this command.
  * The isolation protocol is designed so that only one card will
@@ -241,7 +241,7 @@ static void isapnp_delay ( void ) {
  * @v lfsr		Current value of the LFSR
  * @v input_bit		Current input bit to the LFSR
  * @ret lfsr		Next value of the LFSR
- * @err None
+ * @err None		-
  *
  * This routine implements the linear feedback shift register as
  * described in Appendix B of the PnP ISA spec.  The hardware
@@ -286,7 +286,7 @@ static void isapnp_send_key ( void ) {
  *
  * @v identifier		ISAPnP identifier
  * @ret checksum		Expected checksum value
- * @err None
+ * @err None			-
  *
  */
 static uint8_t isapnp_checksum ( struct isapnp_identifier *identifier ) {
@@ -329,8 +329,8 @@ static inline uint8_t isapnp_peek_byte ( void ) {
  *
  * @v buf		Buffer in which to store data, or NULL
  * @v bytes		Number of bytes to read
- * @ret None
+ * @ret None		-
- * @err None
+ * @err None		-
  *
  * Resource data is read from the current location.  If #buf is NULL,
  * the data is discarded.
@@ -355,7 +355,7 @@ static void isapnp_peek ( uint8_t *buf, size_t bytes ) {
  * @v buf		Buffer in which to store the tag's contents
  * @ret True		Tag was found
  * @ret False		Tag was not found
- * @err None
+ * @err None		-
  *
  * Scan through the resource data until we find a particular tag, and
  * read its contents into a buffer.  It is the caller's responsibility
@@ -396,7 +396,7 @@ static int isapnp_find_tag ( uint8_t wanted_tag, uint8_t *buf ) {
  * @ret \>0		Number of ISAPnP cards found
  * @ret 0		There are no ISAPnP cards in the system
  * @ret \<0		A conflict was detected; try a new read port
- * @err None
+ * @err None		-
  *
  * The state diagram on page 18 (PDF page 24) of the PnP ISA spec
  * gives the best overview of what happens here.
@@ -550,7 +550,7 @@ static void isapnp_isolate ( void ) {
  * @v bus_loc		Bus location
  * @ret True		#bus_loc contains a valid ISAPnP location
  * @ret False		There are no more valid ISAPnP locations
- * @err None
+ * @err None		-
  *
  * If there are no more valid locations, the #bus_loc structure will
  * be zeroed.
@@ -578,7 +578,7 @@ static int isapnp_next_location ( struct bus_loc *bus_loc ) {
  * @v bus_loc		Bus location as filled in by isapnp_next_location()
  * @ret True		A device is present at this location
  * @ret False		No device is present at this location
- * @err None
+ * @err None		-
  *
  */
 static int isapnp_fill_device ( struct bus_dev *bus_dev,
@@ -677,7 +677,7 @@ static int isapnp_fill_device ( struct bus_dev *bus_dev,
  * @v device_driver	Device driver
  * @ret True		Driver is capable of driving this device
  * @ret False		Driver is not capable of driving this device
- * @err None
+ * @err None		-
  *
  */
 static int isapnp_check_driver ( struct bus_dev *bus_dev,
@@ -713,7 +713,7 @@ static int isapnp_check_driver ( struct bus_dev *bus_dev,
  *
  * @v bus_dev		Bus device as filled in by isapnp_fill_device()
  * @ret string		Printable string describing the device
- * @err None
+ * @err None		-
  *
  * The string returned by isapnp_describe_device() is valid only until
  * the next call to isapnp_describe_device().
@@ -733,7 +733,7 @@ static char * isapnp_describe_device ( struct bus_dev *bus_dev ) {
  *
  * @v bus_dev		Bus device as filled in by isapnp_fill_device()
  * @ret string		Printable string naming the device
- * @err None
+ * @err None		-
  *
  * The string returned by isapnp_name_device() is valid only until the
  * next call to isapnp_name_device().
@@ -763,8 +763,8 @@ struct bus_driver isapnp_driver __bus_driver = {
  *
  * @v isapnp		ISAPnP device
  * @v activation	True to enable, False to disable the device
- * @ret None
+ * @ret None		-
- * @err None
+ * @err None		-
  *
  * This routine simply activates the device in its current
  * configuration, or deactivates the device.  It does not attempt any
@@ -796,8 +796,8 @@ void isapnp_device_activation ( struct isapnp_device *isapnp,
  *
  * @v nic		NIC structure to be filled in
  * @v isapnp		ISAPnP device
- * @ret None
+ * @ret None		-
- * @err None
+ * @err None		-
  *
  * This fills in generic NIC parameters (e.g. I/O address and IRQ
  * number) that can be determined directly from the ISAPnP device,

src/include/console.h

@@ -43,17 +43,17 @@ struct console_driver {
 	/** Write a character to the console.
 	 *
 	 * @v character		Character to be written
-	 * @ret None
+	 * @ret None		-
-	 * @err None
+	 * @err None		-
 	 *
 	 */
 	void ( *putchar ) ( int character );
 
 	/** Read a character from the console.
 	 *
-	 * @v None
+	 * @v None		-
 	 * @ret character	Character read
-	 * @err None
+	 * @err None		-
 	 *
 	 * If no character is available to be read, this method will
 	 * block.  The character read should not be echoed back to the
@@ -64,10 +64,10 @@ struct console_driver {
 
 	/** Check for available input.
 	 *
-	 * @v None
+	 * @v None		-
 	 * @ret True		Input is available
 	 * @ret False		Input is not available
-	 * @err None
+	 * @err None		-
 	 *
 	 * This should return True if a subsequent call to getchar()
 	 * will not block.

src/interface/pxe/pxe_preboot.c

@@ -29,7 +29,7 @@
 /**
  * UNLOAD BASE CODE STACK
  *
- * @v None
+ * @v None				-
  * @ret ...
  *
  */

src/interface/pxe/pxe_udp.c

@@ -83,7 +83,7 @@ PXENV_EXIT_t pxenv_udp_open ( struct s_PXENV_UDP_OPEN *udp_open ) {
  * @v udp_close				Pointer to a struct s_PXENV_UDP_CLOSE
  * @ret #PXENV_EXIT_SUCCESS		Always
  * @ret s_PXENV_UDP_CLOSE::Status	PXE status code
- * @err None
+ * @err None				-
  *
  * Closes a UDP "connection" opened with pxenv_udp_open().  Since UDP
  * is a connectionless protocol, this is a no-op.