diff --git a/src/Makefile.am b/src/Makefile.am
index f0effa2..75a66bf 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -9,7 +9,8 @@
 
 libosmocore_la_SOURCES = timer.c select.c signal.c msgb.c rxlev_stat.c \
 			 tlv_parser.c bitvec.c comp128.c gsm_utils.c statistics.c \
-			 write_queue.c utils.c rsl.c gsm48.c gsm48_ie.c
+			 write_queue.c utils.c rsl.c gsm48.c gsm48_ie.c \
+			 debug.c
 
 if ENABLE_TALLOC
 libosmocore_la_SOURCES += talloc.c
diff --git a/src/debug.c b/src/debug.c
new file mode 100644
index 0000000..934f229
--- /dev/null
+++ b/src/debug.c
@@ -0,0 +1,347 @@
+/* Debugging/Logging support code */
+
+/* (C) 2008-2010 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2008 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * All Rights Reserved
+ *
+ * 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
+ * (at your option) 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <strings.h>
+#include <time.h>
+#include <errno.h>
+
+#include <osmocore/talloc.h>
+#include <osmocore/utils.h>
+#include <osmocore/debug.h>
+
+static const struct debug_info *debug_info;
+
+static struct debug_context debug_context;
+static void *tall_dbg_ctx = NULL;
+static LLIST_HEAD(target_list);
+
+static const struct value_string loglevel_strs[] = {
+	{ 0,		"EVERYTHING" },
+	{ LOGL_DEBUG,	"DEBUG" },
+	{ LOGL_INFO,	"INFO" },
+	{ LOGL_NOTICE,	"NOTICE" },
+	{ LOGL_ERROR,	"ERROR" },
+	{ LOGL_FATAL,	"FATAL" },
+	{ 0, NULL },
+};
+
+int debug_parse_level(const char *lvl)
+{
+	return get_string_value(loglevel_strs, lvl);
+}
+
+int debug_parse_category(const char *category)
+{
+	int i;
+
+	for (i = 0; i < debug_info->num_cat; ++i) {
+		if (!strcasecmp(debug_info->cat[i].name+1, category))
+			return debug_info->cat[i].number;
+	}
+
+	return -EINVAL;
+}
+
+/*
+ * Parse the category mask.
+ * The format can be this: category1:category2:category3
+ * or category1,2:category2,3:...
+ */
+void debug_parse_category_mask(struct debug_target* target, const char *_mask)
+{
+	int i = 0;
+	char *mask = strdup(_mask);
+	char *category_token = NULL;
+
+	/* Disable everything to enable it afterwards */
+	for (i = 0; i < ARRAY_SIZE(target->categories); ++i)
+		target->categories[i].enabled = 0;
+
+	category_token = strtok(mask, ":");
+	do {
+		for (i = 0; i < debug_info->num_cat; ++i) {
+			char* colon = strstr(category_token, ",");
+			int length = strlen(category_token);
+
+			if (colon)
+			    length = colon - category_token;
+
+			if (strncasecmp(debug_info->cat[i].name, category_token,
+					length) == 0) {
+				int number = debug_info->cat[i].number;
+				int level = 0;
+
+				if (colon)
+					level = atoi(colon+1);
+
+				target->categories[number].enabled = 1;
+				target->categories[number].loglevel = level;
+			}
+		}
+	} while ((category_token = strtok(NULL, ":")));
+
+	free(mask);
+}
+
+static const char* color(int subsys)
+{
+	int i = 0;
+
+	for (i = 0; i < debug_info->num_cat; ++i) {
+		if (debug_info->cat[i].number == subsys)
+			return debug_info->cat[i].color;
+	}
+
+	return "";
+}
+
+static void _output(struct debug_target *target, unsigned int subsys,
+		    char *file, int line, int cont, const char *format,
+		    va_list ap)
+{
+	char col[30];
+	char sub[30];
+	char tim[30];
+	char buf[4096];
+	char final[4096];
+
+	/* prepare the data */
+	col[0] = '\0';
+	sub[0] = '\0';
+	tim[0] = '\0';
+	buf[0] = '\0';
+
+	/* are we using color */
+	if (target->use_color) {
+		snprintf(col, sizeof(col), "%s", color(subsys));
+		col[sizeof(col)-1] = '\0';
+	}
+	vsnprintf(buf, sizeof(buf), format, ap);
+	buf[sizeof(buf)-1] = '\0';
+
+	if (!cont) {
+		if (target->print_timestamp) {
+			char *timestr;
+			time_t tm;
+			tm = time(NULL);
+			timestr = ctime(&tm);
+			timestr[strlen(timestr)-1] = '\0';
+			snprintf(tim, sizeof(tim), "%s ", timestr);
+			tim[sizeof(tim)-1] = '\0';
+		}
+		snprintf(sub, sizeof(sub), "<%4.4x> %s:%d ", subsys, file, line);
+		sub[sizeof(sub)-1] = '\0';
+	}
+
+	snprintf(final, sizeof(final), "%s%s%s%s\033[0;m", col, tim, sub, buf);
+	final[sizeof(final)-1] = '\0';
+	target->output(target, final);
+}
+
+
+static void _debugp(unsigned int subsys, int level, char *file, int line,
+		    int cont, const char *format, va_list ap)
+{
+	struct debug_target *tar;
+
+	llist_for_each_entry(tar, &target_list, entry) {
+		struct debug_category *category;
+		int output = 0;
+
+		category = &tar->categories[subsys];
+		/* subsystem is not supposed to be debugged */
+		if (!category->enabled)
+			continue;
+
+		/* Check the global log level */
+		if (tar->loglevel != 0 && level < tar->loglevel)
+			continue;
+
+		/* Check the category log level */
+		if (tar->loglevel == 0 && category->loglevel != 0 &&
+		    level < category->loglevel)
+			continue;
+
+		/* Apply filters here... if that becomes messy we will
+		 * need to put filters in a list and each filter will
+		 * say stop, continue, output */
+		if ((tar->filter_map & DEBUG_FILTER_ALL) != 0)
+			output = 1;
+		else if (debug_info->filter_fn)
+			output = debug_info->filter_fn(&debug_context,
+						       tar);
+
+		if (output) {
+			/* FIXME: copying the va_list is an ugly
+			 * workaround against a bug hidden somewhere in
+			 * _output.  If we do not copy here, the first
+			 * call to _output() will corrupt the va_list
+			 * contents, and any further _output() calls
+			 * with the same va_list will segfault */
+			va_list bp;
+			va_copy(bp, ap);
+			_output(tar, subsys, file, line, cont, format, bp);
+			va_end(bp);
+		}
+	}
+}
+
+void debugp(unsigned int subsys, char *file, int line, int cont,
+	    const char *format, ...)
+{
+	va_list ap;
+
+	va_start(ap, format);
+	_debugp(subsys, LOGL_DEBUG, file, line, cont, format, ap);
+	va_end(ap);
+}
+
+void debugp2(unsigned int subsys, unsigned int level, char *file, int line, int cont, const char *format, ...)
+{
+	va_list ap;
+
+	va_start(ap, format);
+	_debugp(subsys, level, file, line, cont, format, ap);
+	va_end(ap);
+}
+
+static char hexd_buff[4096];
+
+char *hexdump(const unsigned char *buf, int len)
+{
+	int i;
+	char *cur = hexd_buff;
+
+	hexd_buff[0] = 0;
+	for (i = 0; i < len; i++) {
+		int len_remain = sizeof(hexd_buff) - (cur - hexd_buff);
+		int rc = snprintf(cur, len_remain, "%02x ", buf[i]);
+		if (rc <= 0)
+			break;
+		cur += rc;
+	}
+	hexd_buff[sizeof(hexd_buff)-1] = 0;
+	return hexd_buff;
+}
+
+void debug_add_target(struct debug_target *target)
+{
+	llist_add_tail(&target->entry, &target_list);
+}
+
+void debug_del_target(struct debug_target *target)
+{
+	llist_del(&target->entry);
+}
+
+void debug_reset_context(void)
+{
+	memset(&debug_context, 0, sizeof(debug_context));
+}
+
+int debug_set_context(uint8_t ctx_nr, void *value)
+{
+	if (ctx_nr > DEBUG_MAX_CTX)
+		return -EINVAL;
+
+	debug_context.ctx[ctx_nr] = value;
+
+	return 0;
+}
+
+void debug_set_all_filter(struct debug_target *target, int all)
+{
+	if (all)
+		target->filter_map |= DEBUG_FILTER_ALL;
+	else
+		target->filter_map &= ~DEBUG_FILTER_ALL;
+}
+
+void debug_set_use_color(struct debug_target *target, int use_color)
+{
+	target->use_color = use_color;
+}
+
+void debug_set_print_timestamp(struct debug_target *target, int print_timestamp)
+{
+	target->print_timestamp = print_timestamp;
+}
+
+void debug_set_log_level(struct debug_target *target, int log_level)
+{
+	target->loglevel = log_level;
+}
+
+void debug_set_category_filter(struct debug_target *target, int category,
+			       int enable, int level)
+{
+	if (category >= debug_info->num_cat)
+		return;
+	target->categories[category].enabled = !!enable;
+	target->categories[category].loglevel = level;
+}
+
+static void _stderr_output(struct debug_target *target, const char *log)
+{
+	fprintf(target->tgt_stdout.out, "%s", log);
+	fflush(target->tgt_stdout.out);
+}
+
+struct debug_target *debug_target_create(void)
+{
+	struct debug_target *target;
+
+	target = talloc_zero(tall_dbg_ctx, struct debug_target);
+	if (!target)
+		return NULL;
+
+	INIT_LLIST_HEAD(&target->entry);
+	memcpy(target->categories, debug_info->cat,
+		sizeof(struct debug_category)*debug_info->num_cat);
+	target->use_color = 1;
+	target->print_timestamp = 0;
+	target->loglevel = 0;
+	return target;
+}
+
+struct debug_target *debug_target_create_stderr(void)
+{
+	struct debug_target *target;
+
+	target = debug_target_create();
+	if (!target)
+		return NULL;
+
+	target->tgt_stdout.out = stderr;
+	target->output = _stderr_output;
+	return target;
+}
+
+void debug_init(const struct debug_info *cat)
+{
+	tall_dbg_ctx = talloc_named_const(NULL, 1, "debug");
+	debug_info = cat;
+}