diff --git a/src/core/serial.c b/src/core/serial.c
index f6d0ecbb..a5b3f913 100644
--- a/src/core/serial.c
+++ b/src/core/serial.c
@@ -263,6 +263,6 @@ struct startup_fn serial_startup_fn __startup_fn ( STARTUP_NORMAL ) = {
  * early debug messages.  It is safe to call serial_init() multiple
  * times.
  */
-struct init_fn serial_init_fn __init_fn ( INIT_EARLY ) = {
+struct init_fn serial_init_fn __init_fn ( INIT_CONSOLE ) = {
 	.initialise = serial_init,
 };
diff --git a/src/core/timer.c b/src/core/timer.c
index e736f528..ef80c044 100644
--- a/src/core/timer.c
+++ b/src/core/timer.c
@@ -22,7 +22,6 @@
 #include <assert.h>
 #include <gpxe/init.h>
 #include <gpxe/timer.h>
-#include <stdio.h>
 
 static struct timer ts_table[0]
 	__table_start ( struct timer, timers );
@@ -53,48 +52,64 @@ static void timer_init(void)
 	struct timer *ts;
 
 	for (ts = ts_table; ts < ts_table_end; ts++) {
-		if (ts->init && ts->init() >= 0) {
+		if ( ts->init() == 0 ) {
 			used_ts = ts;
-			break;
+			return;
 		}
 	}
 
-	assert(used_ts);
+	/* No timer found; we cannot continue */
+	assert ( 0 );
+	while ( 1 ) {};
 }
 
 struct init_fn ts_init_fn __init_fn ( INIT_NORMAL ) = {
 	.initialise = timer_init,
 };
 
-/* Functions for public use. */
-
-tick_t currticks(void)
-{
+/**
+ * Read current time
+ *
+ * @ret ticks	Current time, in ticks
+ */
+tick_t currticks ( void ) {
 	tick_t ct;
 	assert(used_ts);
 
 	ct = used_ts->currticks();
-	DBG("currticks: %ld seconds and %06ld microseconds\n", ct/USECS_IN_SEC, ct%USECS_IN_SEC);
+	DBG ( "currticks: %ld.%06ld seconds\n",
+	      ct / USECS_IN_SEC, ct % USECS_IN_SEC );
 
 	return ct;
 }
 
-void udelay(unsigned int usecs)
-{
-	used_ts->udelay(usecs);
+/**
+ * Delay
+ *
+ * @v usecs	Time to delay, in microseconds
+ */
+void udelay ( unsigned int usecs ) {
+	assert(used_ts);
+	used_ts->udelay ( usecs );
 }
 
-void mdelay(unsigned int msecs)
-{
-	while(msecs--)
-		used_ts->udelay(USECS_IN_MSEC);
+/**
+ * Delay
+ *
+ * @v msecs	Time to delay, in milliseconds
+ */
+void mdelay ( unsigned int msecs ) {
+	while ( msecs-- )
+		udelay ( USECS_IN_MSEC );
 }
 
-unsigned int sleep(unsigned int secs)
-{
-	while (secs--)
-		mdelay(MSECS_IN_SEC);
-
+/**
+ * Delay
+ *
+ * @v secs	Time to delay, in seconds
+ */
+unsigned int sleep ( unsigned int secs ) {
+	while ( secs-- )
+		mdelay ( MSECS_IN_SEC );
 	return 0;
 }
-
diff --git a/src/include/gpxe/init.h b/src/include/gpxe/init.h
index a5caa3e0..d83aa5e5 100644
--- a/src/include/gpxe/init.h
+++ b/src/include/gpxe/init.h
@@ -22,7 +22,8 @@ struct init_fn {
  */
 
 #define INIT_EARLY	01	/**< Early initialisation */
-#define INIT_NORMAL	02	/**< Normal initialisation */
+#define	INIT_CONSOLE	02	/**< Console initialisation */
+#define INIT_NORMAL	03	/**< Normal initialisation */
 
 /** @} */
 
@@ -54,14 +55,6 @@ struct startup_fn {
 
 /** @} */
 
-/* Use double digits to avoid problems with "10" < "9" on alphabetic sort */
-#define	INIT_CONSOLE	02
-#define	INIT_GDBSYM	03
-#define	INIT_CPU	04
-#define	INIT_TIMERS	05
-#define	INIT_LOADBUF	08
-#define	INIT_PCMCIA	09
-
 extern void initialise ( void );
 extern void startup ( void );
 extern void shutdown ( void );
diff --git a/src/include/gpxe/timer.h b/src/include/gpxe/timer.h
index 4a4cf5b2..ecd30001 100644
--- a/src/include/gpxe/timer.h
+++ b/src/include/gpxe/timer.h
@@ -3,7 +3,7 @@
 
 #include <stddef.h>
 
-typedef uint32_t tick_t;
+typedef unsigned long tick_t;
 
 #define MSECS_IN_SEC (1000)
 #define USECS_IN_SEC (1000*1000)
@@ -11,22 +11,30 @@ typedef uint32_t tick_t;
 
 #define	TICKS_PER_SEC	USECS_IN_SEC
 
-tick_t currticks(void);
+extern tick_t currticks ( void );
 
-void generic_currticks_udelay(unsigned int usecs);
+extern void generic_currticks_udelay ( unsigned int usecs );
 
+/** A timer */
 struct timer {
-	/* Returns zero on successful initialisation. */
-	int (*init) (void);
-
-	/* Return the current time, int mictoseconds since the beginning. */
-	tick_t (*currticks) (void);
-
-	/* Sleep for a few useconds. */
-	void (*udelay) (unsigned int useconds);
+	/** Initialise timer
+	 *
+	 * @ret rc	Return status code
+	 */
+	int ( * init ) ( void );
+	/** Read current time
+	 *
+	 * @ret ticks	Current time, in ticks
+	 */
+	tick_t ( * currticks ) ( void );
+	/** Delay
+	 *
+	 * @v usecs	Time to delay, in microseconds
+	 */
+	void ( * udelay ) ( unsigned int usecs );
 };
 
-#define __timer(order) __table (struct timer, timers, order)
+#define __timer( order ) __table ( struct timer, timers, order )
 
 #endif	/* GPXE_TIMER_H */