diff --git a/src/Makefile.housekeeping b/src/Makefile.housekeeping
index 8ba7e441..7e7ad762 100644
--- a/src/Makefile.housekeeping
+++ b/src/Makefile.housekeeping
@@ -375,6 +375,35 @@ CFLAGS		+= -Werror
 ASFLAGS		+= --fatal-warnings
 endif
 
+# Function trace recorder state in the last build.  This is needed
+# in order to correctly rebuild whenever the function recorder is
+# enabled/disabled.
+#
+FNREC_STATE	:= $(BIN)/.fnrec.state
+ifeq ($(wildcard $(FNREC_STATE)),)
+FNREC_STATE_OLD := <invalid>
+else
+FNREC_STATE_OLD	:= $(shell cat $(FNREC_STATE))
+endif
+ifeq ($(FNREC_STATE_OLD),$(FNREC))
+$(FNREC_STATE) :
+else
+$(FNREC_STATE) : clean
+$(shell $(ECHO) "$(FNREC)" > $(FNREC_STATE))
+endif
+
+VERYCLEANUP	+= $(FNREC_STATE)
+MAKEDEPS	+= $(FNREC_STATE)
+
+ifeq ($(FNREC),1)
+# Enabling -finstrument-functions affects gcc's analysis and leads to spurious
+# warnings about use of uninitialised variables.
+#
+CFLAGS		+= -Wno-uninitialized
+CFLAGS		+= -finstrument-functions
+CFLAGS		+= -finstrument-functions-exclude-file-list=core/fnrec.c
+endif
+
 # compiler.h is needed for our linking and debugging system
 #
 CFLAGS		+= -include compiler.h
diff --git a/src/core/fnrec.c b/src/core/fnrec.c
new file mode 100644
index 00000000..c768c91d
--- /dev/null
+++ b/src/core/fnrec.c
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2010 Stefan Hajnoczi <stefanha@gmail.com>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <gpxe/init.h>
+#include <gpxe/uaccess.h>
+
+/** @file
+ *
+ * Function trace recorder for crash and hang debugging
+ *
+ */
+
+enum {
+	/** Constant for identifying valid trace buffers */
+	fnrec_magic = 'f' << 24 | 'n' << 16 | 'r' << 8 | 'e',
+
+	/** Trace buffer length */
+	fnrec_buffer_length = 4096 / sizeof ( unsigned long ),
+};
+
+/** A trace buffer */
+struct fnrec_buffer {
+	/** Constant for identifying valid trace buffers */
+	uint32_t magic;
+
+	/** Next trace buffer entry to fill */
+	uint32_t idx;
+
+	/** Function address trace buffer */
+	unsigned long data[fnrec_buffer_length];
+};
+
+/** The trace buffer */
+static struct fnrec_buffer *fnrec_buffer;
+
+/**
+ * Test whether the trace buffer is valid
+ *
+ * @ret is_valid	Buffer is valid
+ */
+static int fnrec_is_valid ( void ) {
+	return fnrec_buffer && fnrec_buffer->magic == fnrec_magic;
+}
+
+/**
+ * Reset the trace buffer and clear entries
+ */
+static void fnrec_reset ( void ) {
+	memset ( fnrec_buffer, 0, sizeof ( *fnrec_buffer ) );
+	fnrec_buffer->magic = fnrec_magic;
+}
+
+/**
+ * Write a value to the end of the buffer if it is not a repetition
+ *
+ * @v l			Value to append
+ */
+static void fnrec_append_unique ( unsigned long l ) {
+	static unsigned long lastval;
+	uint32_t idx = fnrec_buffer->idx;
+
+	/* Avoid recording the same value repeatedly */
+	if ( l == lastval )
+		return;
+
+	fnrec_buffer->data[idx] = l;
+	fnrec_buffer->idx = ( idx + 1 ) % fnrec_buffer_length;
+	lastval = l;
+}
+
+/**
+ * Print the contents of the trace buffer in chronological order
+ */
+static void fnrec_dump ( void ) {
+	size_t i;
+
+	if ( !fnrec_is_valid() ) {
+		printf ( "fnrec buffer not found\n" );
+		return;
+	}
+
+	printf ( "fnrec buffer dump:\n" );
+	for ( i = 0; i < fnrec_buffer_length; i++ ) {
+		unsigned long l = fnrec_buffer->data[
+			( fnrec_buffer->idx + i ) % fnrec_buffer_length];
+		printf ( "%08lx%c", l, i % 8 == 7 ? '\n' : ' ' );
+	}
+}
+
+/**
+ * Function tracer initialisation function
+ */
+static void fnrec_init ( void ) {
+	/* Hardcoded to 17 MB */
+	fnrec_buffer = phys_to_virt ( 17 * 1024 * 1024 );
+	fnrec_dump();
+	fnrec_reset();
+}
+
+struct init_fn fnrec_init_fn __init_fn ( INIT_NORMAL ) = {
+	.initialise = fnrec_init,
+};
+
+/*
+ * These functions are called from every C function.  The compiler inserts
+ * these calls when -finstrument-functions is used.
+ */
+void __cyg_profile_func_enter ( void *called_fn, void *call_site __unused ) {
+	if ( fnrec_is_valid() )
+		fnrec_append_unique ( ( unsigned long ) called_fn );
+}
+
+void __cyg_profile_func_exit ( void *called_fn __unused, void *call_site __unused ) {
+}
diff --git a/src/util/fnrec.sh b/src/util/fnrec.sh
new file mode 100755
index 00000000..00784ac5
--- /dev/null
+++ b/src/util/fnrec.sh
@@ -0,0 +1,32 @@
+#!/bin/bash
+#
+# Copyright (C) 2010 Stefan Hajnoczi <stefanha@gmail.com>.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of the
+# License, or any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+if [ $# != 2 ]
+then
+	cat >&2 <<EOF
+usage: $0 <elf-binary> <addresses-file>
+Look up symbol names in <elf-binary> for function addresses from
+<addresses-file>.
+
+Example:
+$0 bin/gpxe.hd.tmp fnrec.dat
+EOF
+	exit 1
+fi
+
+tr ' ' '\n' <"$2" | addr2line -fe "$1" | awk '(NR % 2) { print }'