start to add doxygen documentation to libosmocore headers
diff --git a/include/osmocom/core/bits.h b/include/osmocom/core/bits.h
index eb22d07..9f8e1fb 100644
--- a/include/osmocom/core/bits.h
+++ b/include/osmocom/core/bits.h
@@ -3,9 +3,13 @@
 
 #include <stdint.h>
 
-typedef int8_t  sbit_t;		/* soft bit (-127...127) */
-typedef uint8_t ubit_t;		/* unpacked bit (0 or 1) */
-typedef uint8_t pbit_t;		/* packed bis (8 bits in a byte) */
+/*! \file bits.h
+ *  \brief Osmocom bit level support code
+ */
+
+typedef int8_t  sbit_t;		/*!< \brief soft bit (-127...127) */
+typedef uint8_t ubit_t;		/*!< \brief unpacked bit (0 or 1) */
+typedef uint8_t pbit_t;		/*!< \brief packed bis (8 bits in a byte) */
 
 /*
    NOTE on the endianess of pbit_t:
@@ -13,7 +17,9 @@
    Bit i in a pbit_t array is array[i/8] & (1<<(7-i%8))
 */
 
-/* determine how many bytes we would need for 'num_bits' packed bits */
+/*! \brief determine how many bytes we would need for \a num_bits packed bits
+ *  \param[in] num_bits Number of packed bits
+ */
 static inline unsigned int osmo_pbit_bytesize(unsigned int num_bits)
 {
 	unsigned int pbit_bytesize = num_bits / 8;
@@ -24,20 +30,42 @@
 	return pbit_bytesize;
 }
 
-/* convert unpacked bits to packed bits, return length in bytes */
+/*! \brief convert unpacked bits to packed bits, return length in bytes
+ *  \param[out] out output buffer of packed bits
+ *  \param[in] in input buffer of unpacked bits
+ *  \param[in] num_bits number of bits
+ */
 int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned int num_bits);
 
-/* convert packed bits to unpacked bits, return length in bytes */
+/*! \brief convert packed bits to unpacked bits, return length in bytes
+ *  \param[out] out output buffer of unpacked bits
+ *  \param[in] in input buffer of packed bits
+ *  \param[in] num_bits number of bits
+ */
 int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits);
 
-/* convert unpacked bits to packed bits (extended options but slower),
- * return length in bytes (max written ofs of output buffer + 1) */
+/*! \brief convert unpacked bits to packed bits (extended options)
+ *  \param[out] out output buffer of packed bits
+ *  \param[in] out_ofs offset into output buffer
+ *  \param[in] in input buffer of unpacked bits
+ *  \param[in] in_ofs offset into input buffer
+ *  \param[in] num_bits number of bits
+ *  \param[in] lsb_mode Encode bits in LSB orde instead of MSB
+ *  \returns length in bytes (max written offset of output buffer + 1)
+ */
 int osmo_ubit2pbit_ext(pbit_t *out, unsigned int out_ofs,
                        const ubit_t *in, unsigned int in_ofs,
                        unsigned int num_bits, int lsb_mode);
 
-/* convert packed bits to unpacked bits (extended options but slower),
- * return length in bytes (max written ofs of output buffer + 1) */
+/*! \brief convert packed bits to unpacked bits (extended options)
+ *  \param[out] out output buffer of unpacked bits
+ *  \param[in] out_ofs offset into output buffer
+ *  \param[in] in input buffer of packed bits
+ *  \param[in] in_ofs offset into input buffer
+ *  \param[in] num_bits number of bits
+ *  \param[in] lsb_mode Encode bits in LSB orde instead of MSB
+ *  \returns length in bytes (max written offset of output buffer + 1)
+ */
 int osmo_pbit2ubit_ext(ubit_t *out, unsigned int out_ofs,
                        const pbit_t *in, unsigned int in_ofs,
                        unsigned int num_bits, int lsb_mode);
diff --git a/include/osmocom/core/logging.h b/include/osmocom/core/logging.h
index 154ee19..537dc60 100644
--- a/include/osmocom/core/logging.h
+++ b/include/osmocom/core/logging.h
@@ -1,11 +1,17 @@
 #ifndef _OSMOCORE_LOGGING_H
 #define _OSMOCORE_LOGGING_H
 
+/*! \file logging.h
+ *  \brief Osmocom logging framework
+ */
+
 #include <stdio.h>
 #include <stdint.h>
 #include <osmocom/core/linuxlist.h>
 
+/*! \brief Maximum number of logging contexts */
 #define LOG_MAX_CTX		8
+/*! \brief Maximum number of logging filters */
 #define LOG_MAX_FILTERS	8
 
 #define DEBUG
@@ -21,9 +27,21 @@
 
 void logp(int subsys, char *file, int line, int cont, const char *format, ...) __attribute__ ((format (printf, 5, 6)));
 
-/* new logging interface */
+/*! \brief Log a new message through the Osmocom logging framework
+ *  \param[in] ss logging subsystem (e.g. \ref DLGLOBAL)
+ *  \param[in] level logging level (e.g. \ref LOGL_NOTICE)
+ *  \param[in] fmt format string
+ *  \param[in] args variable argument list
+ */
 #define LOGP(ss, level, fmt, args...) \
 	logp2(ss, level, __FILE__, __LINE__, 0, fmt, ##args)
+
+/*! \brief Continue a log message through the Osmocom logging framework
+ *  \param[in] ss logging subsystem (e.g. \ref DLGLOBAL)
+ *  \param[in] level logging level (e.g. \ref LOGL_NOTICE)
+ *  \param[in] fmt format string
+ *  \param[in] args variable argument list
+ */
 #define LOGPC(ss, level, fmt, args...) \
 	logp2(ss, level, __FILE__, __LINE__, 1, fmt, ##args)
 
@@ -151,7 +169,12 @@
 					    int facility);
 int log_target_file_reopen(struct log_target *tgt);
 
+/*! \brief Add a new logging target
+ */
 void log_add_target(struct log_target *target);
+
+/*! \brief Deelete an existing logging target
+ */
 void log_del_target(struct log_target *target);
 
 /* Generate command string for VTY use */
diff --git a/include/osmocom/core/msgb.h b/include/osmocom/core/msgb.h
index 915c4a0..c579b8a 100644
--- a/include/osmocom/core/msgb.h
+++ b/include/osmocom/core/msgb.h
@@ -24,45 +24,85 @@
 #include <osmocom/core/linuxlist.h>
 #include <osmocom/core/utils.h>
 
+/*! \file msgb.h
+ *  \brief Osmocom message buffers
+ * The Osmocom message buffers are modelled after the 'struct skb'
+ * inside the Linux kernel network stack.  As they exist in userspace,
+ * they are much simplified.  However, terminology such as headroom,
+ * tailroom, push/pull/put etc. remains the same.
+ */
+
 #define MSGB_DEBUG
 
+/*! \brief Osmocom message buffer */
 struct msgb {
-	struct llist_head list;
+	struct llist_head list; /*!< \brief linked list header */
 
 
 	/* Part of which TRX logical channel we were received / transmitted */
 	/* FIXME: move them into the control buffer */
 	union {
-		void *dst;
+		void *dst; /*!< \brief reference of origin/destination */
 		struct gsm_bts_trx *trx;
 	};
-	struct gsm_lchan *lchan;
+	struct gsm_lchan *lchan; /*!< \brief logical channel */
 
-	/* the Layer1 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;
-	/* the layer 4 header */
-	unsigned char *l4h;
+	unsigned char *l1h; /*!< \brief pointer to Layer1 header (if any) */
+	unsigned char *l2h; /*!< \brief pointer to A-bis layer 2 header: OML, RSL(RLL), NS */
+	unsigned char *l3h; /*!< \brief pointer to Layer 3 header. For OML: FOM; RSL: 04.08; GPRS: BSSGP */
+	unsigned char *l4h; /*!< \brief pointer to layer 4 header */
 
-	/* the 'control buffer', large enough to contain 5 pointers */
-	unsigned long cb[5];
+	unsigned long cb[5]; /*!< \brief control buffer */
 
-	uint16_t data_len;
-	uint16_t len;
+	uint16_t data_len;   /*!< \brief length of underlying data array */
+	uint16_t len;	     /*!< \brief length of bytes used in msgb */
 
-	unsigned char *head;
-	unsigned char *tail;
-	unsigned char *data;
-	unsigned char _data[0];
+	unsigned char *head;	/*!< \brief start of underlying memory buffer */
+	unsigned char *tail;	/*!< \brief end of message in buffer */
+	unsigned char *data;	/*!< \brief start of message in buffer */
+	unsigned char _data[0]; /*!< \brief optional immediate data array */
 };
 
+/*! \brief Allocate a new message buffer
+ * \param[in] size Length in octets, including headroom
+ * \param[in] name Human-readable name to be associated with msgb
+ *
+ * This function allocates a 'struct msgb' as well as the underlying
+ * memory buffer for the actual message data (size specified by \a size)
+ * using the talloc memory context previously set by \ref msgb_set_talloc_ctx
+ */
 extern struct msgb *msgb_alloc(uint16_t size, const char *name);
+
+/*! \brief Release given message buffer
+ * \param[in] m Message buffer to be free'd
+ */
 extern void msgb_free(struct msgb *m);
+
+/*! \brief Enqueue message buffer to tail of a queue
+ * \param[in] queue linked list header of queue
+ * \param[in] msgb message buffer to be added to the queue
+ *
+ * The function will append the specified message buffer \a msg to the
+ * queue implemented by \ref llist_head \a queue
+ */
 extern void msgb_enqueue(struct llist_head *queue, struct msgb *msg);
+
+/*! \brief Dequeue message buffer from head of queue
+ * \param[in] queue linked list header of queue
+ * \returns message buffer (if any) or NULL if queue empty
+ *
+ * The function will remove the first message buffer from the queue
+ * implemented by 'ref llist_head \a queue.
+ */
 extern struct msgb *msgb_dequeue(struct llist_head *queue);
+
+/*! \brief Re-set all message buffer pointers
+ *  \param[in] m message buffer that is to be resetted
+ *
+ * This will re-set the various internal pointers into the underlying
+ * message buffer, i.e. remvoe all headroom and treat the msgb as
+ * completely empty.  It also initializes the control buffer to zero.
+ */
 extern void msgb_reset(struct msgb *m);
 
 #ifdef MSGB_DEBUG
@@ -74,41 +114,99 @@
 #define MSGB_ABORT(msg, fmt, args ...)
 #endif
 
+/*! \brief obtain L1 header of msgb */
 #define msgb_l1(m)	((void *)(m->l1h))
+/*! \brief obtain L2 header of msgb */
 #define msgb_l2(m)	((void *)(m->l2h))
+/*! \brief obtain L3 header of msgb */
 #define msgb_l3(m)	((void *)(m->l3h))
+/*! \brief obtain SMS header of msgb */
 #define msgb_sms(m)	((void *)(m->l4h))
 
+/*! \brief determine length of L1 message
+ *  \param[in] msgb message buffer
+ *  \returns size of L1 message in bytes
+ *
+ * This function computes the number of bytes between the tail of the
+ * message and the layer 1 header.
+ */
 static inline unsigned int msgb_l1len(const struct msgb *msgb)
 {
 	return msgb->tail - (uint8_t *)msgb_l1(msgb);
 }
 
+/*! \brief determine length of L2 message
+ *  \param[in] msgb message buffer
+ *  \returns size of L2 message in bytes
+ *
+ * This function computes the number of bytes between the tail of the
+ * message and the layer 2 header.
+ */
 static inline unsigned int msgb_l2len(const struct msgb *msgb)
 {
 	return msgb->tail - (uint8_t *)msgb_l2(msgb);
 }
 
+/*! \brief determine length of L3 message
+ *  \param[in] msgb message buffer
+ *  \returns size of L3 message in bytes
+ *
+ * This function computes the number of bytes between the tail of the
+ * message and the layer 3 header.
+ */
 static inline unsigned int msgb_l3len(const struct msgb *msgb)
 {
 	return msgb->tail - (uint8_t *)msgb_l3(msgb);
 }
 
+/*! \brief determine the length of the header
+ *  \param[in] msgb message buffer
+ *  \returns number of bytes between start of buffer and start of msg
+ *
+ * This function computes the length difference between the underlying
+ * data buffer and the used section of the \a msgb.
+ */
 static inline unsigned int msgb_headlen(const struct msgb *msgb)
 {
 	return msgb->len - msgb->data_len;
 }
 
+/*! \brief determine how much tail room is left in msgb
+ *  \param[in] msgb message buffer
+ *  \returns number of bytes remaining at end of msgb
+ *
+ * This function computes the amount of octets left in the underlying
+ * data buffer after the end of the message.
+ */
 static inline int msgb_tailroom(const struct msgb *msgb)
 {
 	return (msgb->head + msgb->data_len) - msgb->tail;
 }
 
+/*! \brief determine the amount of headroom in msgb
+ *  \param[in] msgb message buffer
+ *  \returns number of bytes left ahead of message start in msgb
+ *
+ * This function computes the amount of bytes left in the underlying
+ * data buffer before the start of the actual message.
+ */
 static inline int msgb_headroom(const struct msgb *msgb)
 {
 	return (msgb->data - msgb->head);
 }
 
+/*! \brief append data to end of message buffer
+ *  \param[in] msgb message buffer
+ *  \param[in] len number of bytes to append to message
+ *  \returns pointer to start of newly-appended data
+ *
+ * This function will move the \a tail pointer of the message buffer \a
+ * len bytes further, thus enlarging the message by \a len bytes.
+ *
+ * The return value is a pointer to start of the newly added section at
+ * the end of the message and can be used for actually filling/copying
+ * data into it.
+ */
 static inline unsigned char *msgb_put(struct msgb *msgb, unsigned int len)
 {
 	unsigned char *tmp = msgb->tail;
@@ -119,17 +217,32 @@
 	msgb->len += len;
 	return tmp;
 }
+
+/*! \brief append a uint8 value to the end of the message
+ *  \param[in] msgb message buffer
+ *  \param[in] word unsigned 8bit byte to be appended
+ */
 static inline void msgb_put_u8(struct msgb *msgb, uint8_t word)
 {
 	uint8_t *space = msgb_put(msgb, 1);
 	space[0] = word & 0xFF;
 }
+
+/*! \brief append a uint16 value to the end of the message
+ *  \param[in] msgb message buffer
+ *  \param[in] word unsigned 16bit byte to be appended
+ */
 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;
 }
+
+/*! \brief append a uint32 value to the end of the message
+ *  \param[in] msgb message buffer
+ *  \param[in] word unsigned 32bit byte to be appended
+ */
 static inline void msgb_put_u32(struct msgb *msgb, uint32_t word)
 {
 	uint8_t *space = msgb_put(msgb, 4);
@@ -138,6 +251,11 @@
 	space[2] = word >> 8 & 0xFF;
 	space[3] = word & 0xFF;
 }
+
+/*! \brief remove data from end of message
+ *  \param[in] msgb message buffer
+ *  \param[in] len number of bytes to remove from end
+ */
 static inline unsigned char *msgb_get(struct msgb *msgb, unsigned int len)
 {
 	unsigned char *tmp = msgb->data;
@@ -145,21 +263,46 @@
 	msgb->len -= len;
 	return tmp;
 }
+/*! \brief remove uint8 from end of message
+ *  \param[in] msgb message buffer
+ *  \returns 8bit value taken from end of msgb
+ */
 static inline uint8_t msgb_get_u8(struct msgb *msgb)
 {
 	uint8_t *space = msgb_get(msgb, 1);
 	return space[0];
 }
+/*! \brief remove uint16 from end of message
+ *  \param[in] msgb message buffer
+ *  \returns 16bit value taken from end of msgb
+ */
 static inline uint16_t msgb_get_u16(struct msgb *msgb)
 {
 	uint8_t *space = msgb_get(msgb, 2);
 	return space[0] << 8 | space[1];
 }
+/*! \brief remove uint32 from end of message
+ *  \param[in] msgb message buffer
+ *  \returns 32bit value taken from end of msgb
+ */
 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];
 }
+
+/*! \brief prepend (push) some data to start of message
+ *  \param[in] msgb message buffer
+ *  \param[in] len number of bytes to pre-pend
+ *  \returns pointer to newly added portion at start of \a msgb
+ *
+ * This function moves the \a data pointer of the \ref msgb further
+ * to the front (by \a len bytes), thereby enlarging the message by \a
+ * len bytes.
+ *
+ * The return value is a pointer to the newly added section in the
+ * beginning of the message.  It can be used to fill/copy data into it.
+ */
 static inline unsigned char *msgb_push(struct msgb *msgb, unsigned int len)
 {
 	if (msgb_headroom(msgb) < (int) len)
@@ -169,19 +312,48 @@
 	msgb->len += len;
 	return msgb->data;
 }
+/*! \brief remove (pull) a header from the front of the message buffer
+ *  \param[in] msgb message buffer
+ *  \param[in] len number of octets to be pulled
+ *  \returns pointer to new start of msgb
+ *
+ * This function moves the \a data pointer of the \ref msgb further back
+ * in the message, thereby shrinking the size of the message by \a len
+ * bytes.
+ */
 static inline unsigned char *msgb_pull(struct msgb *msgb, unsigned int len)
 {
 	msgb->len -= len;
 	return msgb->data += len;
 }
 
-/* increase the headroom of an empty msgb, reducing the tailroom */
+/*! \brief Increase headroom of empty msgb, reducing the tailroom
+ *  \param[in] msg message buffer
+ *  \param[in] len amount of extra octets to be reserved as headroom
+ *
+ * This function reserves some memory at the beginning of the underlying
+ * data buffer.  The idea is to reserve space in case further headers
+ * have to be pushed to the \ref msgb during further processing.
+ *
+ * Calling this function leads to undefined reusults if it is called on
+ * a non-empty \ref msgb.
+ */
 static inline void msgb_reserve(struct msgb *msg, int len)
 {
 	msg->data += len;
 	msg->tail += len;
 }
 
+/*! \brief Allocate message buffer with specified headroom
+ *  \param[in] size size in bytes, including headroom
+ *  \param[in] headroom headroom in bytes
+ *  \param[in] name human-readable name
+ *  \returns allocated message buffer with specified headroom
+ *
+ * This function is a convenience wrapper around \ref msgb_alloc
+ * followed by \ref msgb_reserve in order to create a new \ref msgb with
+ * user-specified amount of headroom.
+ */
 static inline struct msgb *msgb_alloc_headroom(int size, int headroom,
 						const char *name)
 {
@@ -194,10 +366,22 @@
 }
 
 /* non inline functions to ease binding */
+
+/*! \brief get pointer to data section of message buffer
+ *  \param[in] msg message buffer
+ *  \returns pointer to data section of message buffer
+ */
 uint8_t *msgb_data(const struct msgb *msg);
+
+/*! \brief get length of message buffer
+ *  \param[in] msg message buffer
+ *  \returns length of data section in message buffer
+ */
 uint16_t msgb_length(const struct msgb *msg);
 
-/* set the talloc context for msgb_alloc[_headroom] */
+/*! \brief Set the talloc context for \ref msgb_alloc
+ *  \param[in] ctx talloc context to be used as root for msgb allocations
+ */
 void msgb_set_talloc_ctx(void *ctx);
 
 #endif /* _MSGB_H */
diff --git a/include/osmocom/core/select.h b/include/osmocom/core/select.h
index 476c564..b1b8267 100644
--- a/include/osmocom/core/select.h
+++ b/include/osmocom/core/select.h
@@ -3,20 +3,48 @@
 
 #include <osmocom/core/linuxlist.h>
 
+/*! \file select.h
+ *  \brief select loop abstraction
+ */
+
+/*! \brief Indicate interest in reading from the file descriptor */
 #define BSC_FD_READ	0x0001
+/*! \brief Indicate interest in writing to the file descriptor */
 #define BSC_FD_WRITE	0x0002
+/*! \brief Indicate interest in exceptions from the file descriptor */
 #define BSC_FD_EXCEPT	0x0004
 
+/*! \brief Structure representing a file dsecriptor */
 struct osmo_fd {
-	struct llist_head list;
+	/*! linked list for internal management */
+	struct llist_head list;	
+	/*! actual operating-system level file decriptor */
 	int fd;
+	/*! bit-mask or of \ref BSC_FD_READ, \ref BSC_FD_WRITE and/or
+	 * \ref BSC_FD_EXCEPT */
 	unsigned int when;
+	/*! call-back function to be called once file descriptor becomes
+	 * available */
 	int (*cb)(struct osmo_fd *fd, unsigned int what);
+	/*! data pointer passed through to call-back function */
 	void *data;
+	/*! private number, extending \a data */
 	unsigned int priv_nr;
 };
 
+/*! \brief Register a new file descriptor with select loop abstraction
+ *  \param[in] fd osmocom file descriptor to be registered
+ */
 int osmo_fd_register(struct osmo_fd *fd);
+
+/*! \brief Unregister a file descriptor from select loop abstraction
+ *  \param[in] fd osmocom file descriptor to be unregistered
+ */
 void osmo_fd_unregister(struct osmo_fd *fd);
+
+/*! \brief select main loop integration
+ *  \param[in] polling should we pollonly (1) or block on select (0)
+ */
 int osmo_select_main(int polling);
+
 #endif /* _BSC_SELECT_H */
diff --git a/include/osmocom/core/socket.h b/include/osmocom/core/socket.h
index 612b12c..e915f78 100644
--- a/include/osmocom/core/socket.h
+++ b/include/osmocom/core/socket.h
@@ -1,6 +1,10 @@
 #ifndef _OSMOCORE_SOCKET_H
 #define _OSMOCORE_SOCKET_H
 
+/*! \file socket.h
+ *  \brief Osmocom socket convenience functions
+ */
+
 #include <stdint.h>
 
 struct sockaddr;
@@ -10,16 +14,53 @@
 #define OSMO_SOCK_F_BIND	(1 << 1)
 #define OSMO_SOCK_F_NONBLOCK	(1 << 2)
 
+/*! \brief Initialize a socket (including bind/connect)
+ *  \param[in] family Address Family like AF_INET, AF_INET6, AF_UNSPEC
+ *  \param[in] type Socket type like SOCK_DGRAM, SOCK_STREAM
+ *  \param[in] proto Protocol like IPPROTO_TCP, IPPROTO_UDP
+ *  \param[in] host remote host name or IP address in string form
+ *  \param[in] port remote port number in host byte order
+ *  \param[in] flags flags like \ref OSMO_SOCK_F_CONNECT
+ *
+ * This function creates a new socket of the designated \a family, \a
+ * type and \a proto and optionally binds or connects it, depending on
+ * the value of \a flags parameter.
+ */
 int osmo_sock_init(uint16_t family, uint16_t type, uint8_t proto,
 		   const char *host, uint16_t port, unsigned int flags);
 
+/*! \brief Initialize a socket and fill \ref osmo_fd
+ *  \param[out] osmocom file descriptor (will be filled in)
+ *  \param[in] family Address Family like AF_INET, AF_INET6, AF_UNSPEC
+ *  \param[in] type Socket type like SOCK_DGRAM, SOCK_STREAM
+ *  \param[in] proto Protocol like IPPROTO_TCP, IPPROTO_UDP
+ *  \param[in] host remote host name or IP address in string form
+ *  \param[in] port remote port number in host byte order
+ *  \param[in] flags flags like \ref OSMO_SOCK_F_CONNECT
+ *
+ * This function creates (and optionall binds/connects) a socket using
+ * \ref osmo_sock_init, but also fills the \a ofd structure.
+ */
 int osmo_sock_init_ofd(struct osmo_fd *ofd, int family, int type, int proto,
 			const char *host, uint16_t port, unsigned int flags);
 
+/*! \brief Initialize a socket and fill \ref sockaddr
+ *  \param[out] ss socket address (will be filled in)
+ *  \param[in] type Socket type like SOCK_DGRAM, SOCK_STREAM
+ *  \param[in] proto Protocol like IPPROTO_TCP, IPPROTO_UDP
+ *  \param[in] flags flags like \ref OSMO_SOCK_F_CONNECT
+ *
+ * This function creates (and optionall binds/connects) a socket using
+ * \ref osmo_sock_init, but also fills the \a ss structure.
+ */
 int osmo_sock_init_sa(struct sockaddr *ss, uint16_t type,
 		      uint8_t proto, unsigned int flags);
 
-/* determine if the given address is a local address */
+/*! \brief Determine if the given address is a local address
+ *  \param[in] addr Socket Address
+ *  \param[in] addrlen Length of socket address in bytes
+ *  \returns 1 if address is local, 0 otherwise.
+ */
 int osmo_sockaddr_is_local(struct sockaddr *addr, unsigned int addrlen);
 
 #endif /* _OSMOCORE_SOCKET_H */
diff --git a/include/osmocom/core/statistics.h b/include/osmocom/core/statistics.h
index 1849327..04816c1 100644
--- a/include/osmocom/core/statistics.h
+++ b/include/osmocom/core/statistics.h
@@ -1,33 +1,53 @@
 #ifndef _STATISTICS_H
 #define _STATISTICS_H
 
+/*! \file statistics.h
+ *  \brief Common routines regarding statistics */
+
+/*! structure representing a single counter */
 struct osmo_counter {
-	struct llist_head list;
-	const char *name;
-	const char *description;
-	unsigned long value;
+	struct llist_head list;		/*!< \brief internal list head */
+	const char *name;		/*!< \brief human-readable name */
+	const char *description;	/*!< \brief humn-readable description */
+	unsigned long value;		/*!< \brief current value */
 };
 
+/*! \brief Increment counter */
 static inline void osmo_counter_inc(struct osmo_counter *ctr)
 {
 	ctr->value++;
 }
 
+/*! \brief Get current value of counter */
 static inline unsigned long osmo_counter_get(struct osmo_counter *ctr)
 {
 	return ctr->value;
 }
 
+/*! \brief Reset current value of counter to 0 */
 static inline void osmo_counter_reset(struct osmo_counter *ctr)
 {
 	ctr->value = 0;
 }
 
+/*! \brief Allocate a new counter */
 struct osmo_counter *osmo_counter_alloc(const char *name);
+
+/*! \brief Free the specified counter
+ *  \param[ctr] Counter
+ */
 void osmo_counter_free(struct osmo_counter *ctr);
 
+/*! \brief Iteate over all counters
+ *  \param[in] handle_counter Call-back function
+ *  \param[in] data Private dtata handed through to \a handle_counter
+ */
 int osmo_counters_for_each(int (*handle_counter)(struct osmo_counter *, void *), void *data);
 
+/*! \brief Resolve counter by human-readable name
+ *  \param[in] name human-readable name of counter
+ *  \returns pointer to counter (\ref osmo_counter) or NULL otherwise
+ */
 struct osmo_counter *osmo_counter_get_by_name(const char *name);
 
 #endif /* _STATISTICS_H */
diff --git a/include/osmocom/core/timer.h b/include/osmocom/core/timer.h
index 6c2e8c5..326a0c8 100644
--- a/include/osmocom/core/timer.h
+++ b/include/osmocom/core/timer.h
@@ -18,6 +18,10 @@
  *
  */
 
+/*! \file timer.h
+ *  \brief Osmocom timer handling routines
+ */
+
 #ifndef TIMER_H
 #define TIMER_H
 
@@ -41,27 +45,58 @@
  *        the timers.
  *
  */
+/*! \brief A structure representing a single instance of a timer */
 struct osmo_timer_list {
-	struct llist_head entry;
-	struct timeval timeout;
-	unsigned int active  : 1;
-	unsigned int handled : 1;
-	unsigned int in_list : 1;
+	struct llist_head entry;  /*!< \brief linked list header */
+	struct timeval timeout;   /*!< \brief expiration time */
+	unsigned int active  : 1; /*!< \brief is it active? */
+	unsigned int handled : 1; /*!< \brief did we already handle it */
+	unsigned int in_list : 1; /*!< \brief is it in the global list? */
 
-	void (*cb)(void*);
-	void *data;
+	void (*cb)(void*);	  /*!< \brief call-back called at timeout */
+	void *data;		  /*!< \brief user data for callback */
 };
 
 /**
  * timer management
  */
+
+/*! \brief add a new timer to the timer management
+ *  \param[in] timer the timer that should be added
+ */
 void osmo_timer_add(struct osmo_timer_list *timer);
+
+/*! \brief schedule a timer at a given future relative time
+ *  \param[in] timer the to-be-added timer
+ *  \param[in] seconds number of seconds from now
+ *  \param[in] microseconds number of microseconds from now
+ *
+ * This function can be used to (re-)schedule a given timer at a
+ * specified number of seconds+microseconds in the future.  It will
+ * internally add it to the timer management data structures, thus
+ * osmo_timer_add() is automatically called.
+ */
 void osmo_timer_schedule(struct osmo_timer_list *timer, int seconds, int microseconds);
+
+/*! \brief delete a timer from timer management
+ *  \param[in] timer the to-be-deleted timer
+ *
+ * This function can be used to delete a previously added/scheduled
+ * timer from the timer management code.
+ */
 void osmo_timer_del(struct osmo_timer_list *timer);
+
+/*! \brief check if given timer is still pending
+ *  \param[in] timer the to-be-checked timer
+ *  \return 1 if pending, 0 otherwise
+ *
+ * This function can be used to determine whether a given timer
+ * has alredy expired (returns 0) or is still pending (returns 1)
+ */
 int osmo_timer_pending(struct osmo_timer_list *timer);
 
 
-/**
+/*
  * internal timer list management
  */
 struct timeval *osmo_timers_nearest(void);
diff --git a/include/osmocom/core/utils.h b/include/osmocom/core/utils.h
index a1a18e3..1e5fab7 100644
--- a/include/osmocom/core/utils.h
+++ b/include/osmocom/core/utils.h
@@ -1,32 +1,93 @@
 #ifndef OSMOCORE_UTIL_H
 #define OSMOCORE_UTIL_H
 
+/*! \file utils.h
+ *  \brief General-purpose utilities in the Osmocom core library
+ */
+
+/*! \brief Determine number of elements in an array of static size */
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+/*! \brief Return the maximum of two specified values */
 #define OSMO_MAX(a, b) (a) >= (b) ? (a) : (b)
+/*! \brief Return the minimum of two specified values */
 #define OSMO_MIN(a, b) (a) >= (b) ? (b) : (a)
 
 #include <stdint.h>
 
+/*! \brief A mapping between human-readable string and numeric value */
 struct value_string {
-	unsigned int value;
-	const char *str;
+	unsigned int value;	/*!< \brief numeric value */
+	const char *str;	/*!< \brief human-readable string */
 };
 
+/*! \fn get_value_string(const struct value_string *vs, uint32_t val)
+ * \brief get human-readable string for given value
+ * \param[in] vs Array of value_string tuples
+ * \param[in] val Value to be converted
+ * \returns pointer to human-readable string
+ */
 const char *get_value_string(const struct value_string *vs, uint32_t val);
+
+/*! \fn get_string_value(const struct value_string *vs, const char *str)
+ * \brief get numeric value for given human-readable string
+ * \param[in] vs Array of value_string tuples
+ * \param[in] str human-readable string
+ * \returns numeric value (>0) or negative numer in case of error
+ */
 int get_string_value(const struct value_string *vs, const char *str);
 
+/*! \fn osmo_bcd2char(uint8_t bcd)
+ * \brief Convert BCD-encoded digit into printable character
+ * \param[in] bcd A single BCD-encoded digit
+ * \returns single printable character
+ */
 char osmo_bcd2char(uint8_t bcd);
 /* only works for numbers in ascci */
 uint8_t osmo_char2bcd(char c);
 
 int osmo_hexparse(const char *str, uint8_t *b, int max_len);
+
+/*! \fn osmo_hexdump(const unsigned char *buf, int len)
+ * \brief Convert binary sequence to hexadecimal ASCII string
+ * This function will print a sequence of bytes as hexadecimal numbers,
+ * adding one space character between each byte (e.g. "1a ef d9")
+ * \param[in] buf pointer to sequence of bytes
+ * \param[in] len length of buf in number of bytes
+ * \returns pointer to zero-terminated string
+ */
 char *osmo_hexdump(const unsigned char *buf, int len);
+
+/*! \fn osmo_hexdump_nospc(const unsigned char *buf, int len)
+ * \brief Convert binary sequence to hexadecimal ASCII string
+ * This function will print a sequence of bytes as hexadecimal numbers,
+ * without any space character between each byte (e.g. "1aefd9")
+ * \param[in] buf pointer to sequence of bytes
+ * \param[in] len length of buf in number of bytes
+ * \returns pointer to zero-terminated string
+ */
 char *osmo_osmo_hexdump_nospc(const unsigned char *buf, int len);
+
+/*! \fn osmo_ubit_dump(const uint8_t *bits, unsigned int len)
+ * \brief Convert a sequence of unpacked bits to ASCII string
+ * \param[in] bits A sequence of unpacked bits
+ * \param[in] len Length of bits
+ */
 char *osmo_ubit_dump(const uint8_t *bits, unsigned int len);
 
 #define osmo_static_assert(exp, name) typedef int dummy##name [(exp) ? 1 : -1];
 
+/*! \fn osmo_str2lower(char *out, const char *in)
+ * \brief Convert an entire string to lower case
+ * \param[out] out output string, caller-allocated
+ * \param[in] in input string
+ */
 void osmo_str2lower(char *out, const char *in);
+
+/*! \fn osmo_str2upper(char *out, const char *in)
+ * \brief Convert an entire string to upper case
+ * \param[out] out output string, caller-allocated
+ * \param[in] in input string
+ */
 void osmo_str2upper(char *out, const char *in);
 
 #define OSMO_SNPRINTF_RET(ret, rem, offset, len)		\
diff --git a/include/osmocom/core/write_queue.h b/include/osmocom/core/write_queue.h
index 41748d7..373b64f 100644
--- a/include/osmocom/core/write_queue.h
+++ b/include/osmocom/core/write_queue.h
@@ -23,24 +23,59 @@
 #ifndef OSMO_WQUEUE_H
 #define OSMO_WQUEUE_H
 
+/*! \file write_queue.h
+ *  \brief Osmocom write queues
+ */
+
 #include <osmocom/core/select.h>
 #include <osmocom/core/msgb.h>
 
+/*! write queue instance */
 struct osmo_wqueue {
+	/*! \brief osmocom file descriptor */
 	struct osmo_fd bfd;
+	/*! \brief maximum length of write queue */
 	unsigned int max_length;
+	/*! \brief current length of write queue */
 	unsigned int current_length;
 
+	/*! \brief actual linked list implementing the queue */
 	struct llist_head msg_queue;
 
+	/*! \brief call-back in case qeueue is readable */
 	int (*read_cb)(struct osmo_fd *fd);
+	/*! \brief call-back in case qeueue is writable */
 	int (*write_cb)(struct osmo_fd *fd, struct msgb *msg);
+	/*! \brief call-back in case qeueue has exceptions */
 	int (*except_cb)(struct osmo_fd *fd);
 };
 
+/*! \brief Initialize a \ref osmo_wqueue structure
+ *  \param[in] queue Write queue to operate on
+ *  \param[in] max_length Maximum length of write queue
+ */
 void osmo_wqueue_init(struct osmo_wqueue *queue, int max_length);
+
+/*! \brief Clear a \ref osmo_wqueue
+ *  \param[in] queue Write queue to be cleared
+ *
+ *  This function will clear (remove/release) all messages in it.
+ */
 void osmo_wqueue_clear(struct osmo_wqueue *queue);
+
+/*! \brief Enqueue a new \ref msgb into a write queue
+ *  \param[in] queue Write queue to be used
+ *  \param[in] data to-be-enqueued message buffer
+ */
 int osmo_wqueue_enqueue(struct osmo_wqueue *queue, struct msgb *data);
+
+/*! \brief Select loop function for write queue handling
+ *  \param[in] fd osmocom file descriptor
+ *  \param[in] what bit-mask of events that have happened
+ *
+ * This function is provided so that it can be registered with the
+ * select loop abstraction code (\ref osmo_fd::cb).
+ */
 int osmo_wqueue_bfd_cb(struct osmo_fd *fd, unsigned int what);
 
 #endif