Index: uspace/drv/isa/isa.c
===================================================================
--- uspace/drv/isa/isa.c	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/drv/isa/isa.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -53,4 +53,5 @@
 
 #include <ddf/driver.h>
+#include <ddf/log.h>
 #include <ops/hw_res.h>
 
@@ -134,5 +135,5 @@
 	fd = open(conf_path, O_RDONLY);
 	if (fd < 0) {
-		printf(NAME ": unable to open %s\n", conf_path);
+		ddf_msg(LVL_ERROR, "Unable to open %s\n", conf_path);
 		goto cleanup;
 	}
@@ -141,8 +142,8 @@
 
 	len = lseek(fd, 0, SEEK_END);
-	lseek(fd, 0, SEEK_SET);	
+	lseek(fd, 0, SEEK_SET);
 	if (len == 0) {
-		printf(NAME ": fun_conf_read error: configuration file '%s' "
-		    "is empty.\n", conf_path);
+		ddf_msg(LVL_ERROR, "Configuration file '%s' is empty.\n",
+		    conf_path);
 		goto cleanup;
 	}
@@ -150,11 +151,10 @@
 	buf = malloc(len + 1);
 	if (buf == NULL) {
-		printf(NAME ": fun_conf_read error: memory allocation failed.\n");
+		ddf_msg(LVL_ERROR, "Memory allocation failed.\n");
 		goto cleanup;
 	}
 
 	if (0 >= read(fd, buf, len)) {
-		printf(NAME ": fun_conf_read error: unable to read file '%s'.\n",
-		    conf_path);
+		ddf_msg(LVL_ERROR, "Unable to read file '%s'.\n", conf_path);
 		goto cleanup;
 	}
@@ -252,5 +252,5 @@
 		fun->hw_resources.count++;
 
-		printf(NAME ": added irq 0x%x to function %s\n", irq,
+		ddf_msg(LVL_NOTE, "Added irq 0x%x to function %s\n", irq,
 		    fun->fnode->name);
 	}
@@ -270,5 +270,5 @@
 		fun->hw_resources.count++;
 
-		printf(NAME ": added io range (addr=0x%x, size=0x%x) to "
+		ddf_msg(LVL_NOTE, "Added io range (addr=0x%x, size=0x%x) to "
 		    "function %s\n", (unsigned int) addr, (unsigned int) len,
 		    fun->fnode->name);
@@ -331,6 +331,6 @@
 	score = (int)strtol(val, &end, 10);
 	if (val == end) {
-		printf(NAME " : error - could not read match score for "
-		    "function %s.\n", fun->fnode->name);
+		ddf_msg(LVL_ERROR, "Cannot read match score for function "
+		    "%s.\n", fun->fnode->name);
 		return;
 	}
@@ -339,15 +339,17 @@
 	get_match_id(&id, val);
 	if (id == NULL) {
-		printf(NAME " : error - could not read match id for "
-		    "function %s.\n", fun->fnode->name);
+		ddf_msg(LVL_ERROR, "Cannot read match ID for function %s.\n",
+		    fun->fnode->name);
 		return;
 	}
 
-	printf(NAME ": adding match id '%s' with score %d to function %s\n", id,
-	    score, fun->fnode->name);
+	ddf_msg(LVL_DEBUG, "Adding match id '%s' with score %d to "
+	    "function %s\n", id, score, fun->fnode->name);
 
 	rc = ddf_fun_add_match_id(fun->fnode, id, score);
-	if (rc != EOK)
-		printf(NAME ": error adding match ID: %s\n", str_error(rc));
+	if (rc != EOK) {
+		ddf_msg(LVL_ERROR, "Failed adding match ID: %s\n",
+		    str_error(rc));
+	}
 }
 
@@ -375,8 +377,8 @@
 	if (!prop_parse(fun, line, "io_range", &fun_parse_io_range) &&
 	    !prop_parse(fun, line, "irq", &fun_parse_irq) &&
-	    !prop_parse(fun, line, "match", &fun_parse_match_id))
-	{
-	    printf(NAME " error undefined device property at line '%s'\n",
-		line);
+	    !prop_parse(fun, line, "match", &fun_parse_match_id)) {
+
+		ddf_msg(LVL_ERROR, "Undefined device property at line '%s'\n",
+		    line);
 	}
 }
@@ -439,5 +441,5 @@
 	fun->fnode->ops = &isa_fun_ops;
 
-	printf(NAME ": Binding function %s.\n", fun->fnode->name);
+	ddf_msg(LVL_DEBUG, "Binding function %s.\n", fun->fnode->name);
 
 	/* XXX Handle error */
@@ -467,18 +469,18 @@
 static int isa_add_device(ddf_dev_t *dev)
 {
-	printf(NAME ": isa_add_device, device handle = %d\n",
+	ddf_msg(LVL_DEBUG, "isa_add_device, device handle = %d\n",
 	    (int) dev->handle);
 
 	/* Make the bus device more visible. Does not do anything. */
-	printf(NAME ": adding a 'ctl' function\n");
+	ddf_msg(LVL_DEBUG, "Adding a 'ctl' function\n");
 
 	ddf_fun_t *ctl = ddf_fun_create(dev, fun_exposed, "ctl");
 	if (ctl == NULL) {
-		printf(NAME ": Error creating control function.\n");
+		ddf_msg(LVL_ERROR, "Failed creating control function.\n");
 		return EXDEV;
 	}
 
 	if (ddf_fun_bind(ctl) != EOK) {
-		printf(NAME ": Error binding control function.\n");
+		ddf_msg(LVL_ERROR, "Failed binding control function.\n");
 		return EXDEV;
 	}
@@ -486,5 +488,5 @@
 	/* Add functions as specified in the configuration file. */
 	isa_functions_add(dev);
-	printf(NAME ": finished the enumeration of legacy functions\n");
+	ddf_msg(LVL_NOTE, "Finished enumerating legacy functions\n");
 
 	return EOK;
@@ -493,4 +495,5 @@
 static void isa_init() 
 {
+	ddf_log_init(NAME, LVL_ERROR);
 	isa_fun_ops.interfaces[HW_RES_DEV_IFACE] = &isa_fun_hw_res_ops;
 }
Index: uspace/drv/ns8250/ns8250.c
===================================================================
--- uspace/drv/ns8250/ns8250.c	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/drv/ns8250/ns8250.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -55,4 +55,5 @@
 #include <ddf/driver.h>
 #include <ddf/interrupt.h>
+#include <ddf/log.h>
 #include <ops/char_dev.h>
 
@@ -275,11 +276,11 @@
 static bool ns8250_pio_enable(ns8250_t *ns)
 {
-	printf(NAME ": ns8250_pio_enable %s\n", ns->dev->name);
+	ddf_msg(LVL_DEBUG, "ns8250_pio_enable %s\n", ns->dev->name);
 	
 	/* Gain control over port's registers. */
 	if (pio_enable((void *)(uintptr_t) ns->io_addr, REG_COUNT,
 	    (void **) &ns->port)) {
-		printf(NAME ": error - cannot gain the port %#" PRIx32 " for device "
-		    "%s.\n", ns->io_addr, ns->dev->name);
+		ddf_msg(LVL_ERROR, "Cannot map the port %#" PRIx32
+		    " for device %s.\n", ns->io_addr, ns->dev->name);
 		return false;
 	}
@@ -295,5 +296,5 @@
 static bool ns8250_dev_probe(ns8250_t *ns)
 {
-	printf(NAME ": ns8250_dev_probe %s\n", ns->dev->name);
+	ddf_msg(LVL_DEBUG, "ns8250_dev_probe %s\n", ns->dev->name);
 	
 	ioport8_t *port_addr = ns->port;
@@ -313,6 +314,8 @@
 	pio_write_8(port_addr + 4, olddata);
 	
-	if (!res)
-		printf(NAME ": device %s is not present.\n", ns->dev->name);
+	if (!res) {
+		ddf_msg(LVL_DEBUG, "Device %s is not present.\n",
+		    ns->dev->name);
+	}
 	
 	return res;
@@ -326,5 +329,5 @@
 static int ns8250_dev_initialize(ns8250_t *ns)
 {
-	printf(NAME ": ns8250_dev_initialize %s\n", ns->dev->name);
+	ddf_msg(LVL_DEBUG, "ns8250_dev_initialize %s\n", ns->dev->name);
 	
 	int ret = EOK;
@@ -337,5 +340,5 @@
 	    IPC_FLAG_BLOCKING);
 	if (ns->dev->parent_phone < 0) {
-		printf(NAME ": failed to connect to the parent driver of the "
+		ddf_msg(LVL_ERROR, "Failed to connect to parent driver of "
 		    "device %s.\n", ns->dev->name);
 		ret = ns->dev->parent_phone;
@@ -346,5 +349,5 @@
 	ret = hw_res_get_resource_list(ns->dev->parent_phone, &hw_resources);
 	if (ret != EOK) {
-		printf(NAME ": failed to get hw resources for the device "
+		ddf_msg(LVL_ERROR, "Failed to get HW resources for device "
 		    "%s.\n", ns->dev->name);
 		goto failed;
@@ -362,5 +365,5 @@
 			ns->irq = res->res.interrupt.irq;
 			irq = true;
-			printf(NAME ": the %s device was asigned irq = 0x%x.\n",
+			ddf_msg(LVL_NOTE, "Device %s was asigned irq = 0x%x.\n",
 			    ns->dev->name, ns->irq);
 			break;
@@ -369,11 +372,11 @@
 			ns->io_addr = res->res.io_range.address;
 			if (res->res.io_range.size < REG_COUNT) {
-				printf(NAME ": i/o range assigned to the device "
-				    "%s is too small.\n", ns->dev->name);
+				ddf_msg(LVL_ERROR, "I/O range assigned to "
+				    "device %s is too small.\n", ns->dev->name);
 				ret = ELIMIT;
 				goto failed;
 			}
 			ioport = true;
-			printf(NAME ": the %s device was asigned i/o address = "
+			ddf_msg(LVL_NOTE, "Device %s was asigned I/O address = "
 			    "0x%x.\n", ns->dev->name, ns->io_addr);
 			break;
@@ -385,5 +388,5 @@
 	
 	if (!irq || !ioport) {
-		printf(NAME ": missing hw resource(s) for the device %s.\n",
+		ddf_msg(LVL_ERROR, "Missing HW resource(s) for device %s.\n",
 		    ns->dev->name);
 		ret = ENOENT;
@@ -470,6 +473,6 @@
 	
 	if (baud_rate < 50 || MAX_BAUD_RATE % baud_rate != 0) {
-		printf(NAME ": error - somebody tried to set invalid baud rate "
-		    "%d\n", baud_rate);
+		ddf_msg(LVL_ERROR, "Invalid baud rate %d requested.\n",
+		    baud_rate);
 		return EINVAL;
 	}
@@ -654,8 +657,8 @@
 			if (ns->client_connected) {
 				if (!buf_push_back(&ns->input_buffer, val)) {
-					printf(NAME ": buffer overflow on "
+					ddf_msg(LVL_WARN, "Buffer overflow on "
 					    "%s.\n", ns->dev->name);
 				} else {
-					printf(NAME ": the character %c saved "
+					ddf_msg(LVL_DEBUG2, "Character %c saved "
 					    "to the buffer of %s.\n",
 					    val, ns->dev->name);
@@ -714,5 +717,5 @@
 	int rc;
 	
-	printf(NAME ": ns8250_add_device %s (handle = %d)\n",
+	ddf_msg(LVL_DEBUG, "ns8250_add_device %s (handle = %d)\n",
 	    dev->name, (int) dev->handle);
 	
@@ -749,5 +752,5 @@
 	/* Register interrupt handler. */
 	if (ns8250_register_interrupt_handler(ns) != EOK) {
-		printf(NAME ": failed to register interrupt handler.\n");
+		ddf_msg(LVL_ERROR, "Failed to register interrupt handler.\n");
 		rc = EADDRNOTAVAIL;
 		goto fail;
@@ -757,5 +760,5 @@
 	rc = ns8250_interrupt_enable(ns);
 	if (rc != EOK) {
-		printf(NAME ": failed to enable the interrupt. Error code = "
+		ddf_msg(LVL_ERROR, "Failed to enable the interrupt. Error code = "
 		    "%d.\n", rc);
 		goto fail;
@@ -764,5 +767,5 @@
 	fun = ddf_fun_create(dev, fun_exposed, "a");
 	if (fun == NULL) {
-		printf(NAME ": error creating function.\n");
+		ddf_msg(LVL_ERROR, "Failed creating function.\n");
 		goto fail;
 	}
@@ -772,5 +775,5 @@
 	rc = ddf_fun_bind(fun);
 	if (rc != EOK) {
-		printf(NAME ": error binding function.\n");
+		ddf_msg(LVL_ERROR, "Failed binding function.\n");
 		goto fail;
 	}
@@ -780,5 +783,5 @@
 	ddf_fun_add_to_class(fun, "serial");
 	
-	printf(NAME ": the %s device has been successfully initialized.\n",
+	ddf_msg(LVL_NOTE, "Device %s successfully initialized.\n",
 	    dev->name);
 	
@@ -862,5 +865,5 @@
 	fibril_mutex_unlock(&data->mutex);
 	
-	printf(NAME ": ns8250_get_props: baud rate %d, parity 0x%x, word "
+	ddf_msg(LVL_DEBUG, "ns8250_get_props: baud rate %d, parity 0x%x, word "
 	    "length %d, stop bits %d\n", *baud_rate, *parity, *word_length,
 	    *stop_bits);
@@ -879,5 +882,5 @@
     unsigned int parity, unsigned int word_length, unsigned int stop_bits)
 {
-	printf(NAME ": ns8250_set_props: baud rate %d, parity 0x%x, word "
+	ddf_msg(LVL_DEBUG, "ns8250_set_props: baud rate %d, parity 0x%x, word "
 	    "length %d, stop bits %d\n", baud_rate, parity, word_length,
 	    stop_bits);
@@ -940,4 +943,6 @@
 static void ns8250_init(void)
 {
+	ddf_log_init(NAME, LVL_ERROR);
+	
 	ns8250_dev_ops.open = &ns8250_open;
 	ns8250_dev_ops.close = &ns8250_close;
Index: uspace/drv/pciintel/pci.c
===================================================================
--- uspace/drv/pciintel/pci.c	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/drv/pciintel/pci.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -48,4 +48,5 @@
 
 #include <ddf/driver.h>
+#include <ddf/log.h>
 #include <devman.h>
 #include <ipc/devman.h>
@@ -225,5 +226,5 @@
 
 	if (match_id_str == NULL) {
-		printf(NAME ": out of memory creating match ID.\n");
+		ddf_msg(LVL_ERROR, "Out of memory creating match ID.\n");
 		return;
 	}
@@ -231,5 +232,5 @@
 	rc = ddf_fun_add_match_id(fun->fnode, match_id_str, 90);
 	if (rc != EOK) {
-		printf(NAME ": error adding match ID: %s\n",
+		ddf_msg(LVL_ERROR, "Failed adding match ID: %s\n",
 		    str_error(rc));
 	}
@@ -323,7 +324,7 @@
 	
 	if (range_addr != 0) {
-		printf(NAME ": function %s : ", fun->fnode->name);
-		printf("address = %" PRIx64, range_addr);
-		printf(", size = %x\n", (unsigned int) range_size);
+		ddf_msg(LVL_DEBUG, "Function %s : address = %" PRIx64
+		    ", size = %x\n", fun->fnode->name, range_addr,
+		    (unsigned int) range_size);
 	}
 	
@@ -350,5 +351,5 @@
 	hw_res_list->count++;
 	
-	printf(NAME ": function %s uses irq %x.\n", fun->fnode->name, irq);
+	ddf_msg(LVL_NOTE, "Function %s uses irq %x.\n", fun->fnode->name, irq);
 }
 
@@ -406,5 +407,5 @@
 			char *fun_name = pci_fun_create_name(fun);
 			if (fun_name == NULL) {
-				printf(NAME ": out of memory.\n");
+				ddf_msg(LVL_ERROR, "Out of memory.\n");
 				return;
 			}
@@ -412,5 +413,5 @@
 			fnode = ddf_fun_create(bus->dnode, fun_inner, fun_name);
 			if (fnode == NULL) {
-				printf(NAME ": error creating function.\n");
+				ddf_msg(LVL_ERROR, "Failed creating function.\n");
 				return;
 			}
@@ -426,5 +427,5 @@
 			fnode->driver_data = fun;
 			
-			printf(NAME ": adding new function %s.\n",
+			ddf_msg(LVL_DEBUG, "Adding new function %s.\n",
 			    fnode->name);
 			
@@ -443,6 +444,7 @@
 				child_bus = pci_conf_read_8(fun,
 				    PCI_BRIDGE_SEC_BUS_NUM);
-				printf(NAME ": device is pci-to-pci bridge, "
-				    "secondary bus number = %d.\n", bus_num);
+				ddf_msg(LVL_DEBUG, "Device is pci-to-pci "
+				    "bridge, secondary bus number = %d.\n",
+				    bus_num);
 				if (child_bus > bus_num)
 					pci_bus_scan(bus, child_bus);
@@ -466,10 +468,10 @@
 	int rc;
 	
-	printf(NAME ": pci_add_device\n");
+	ddf_msg(LVL_DEBUG, "pci_add_device\n");
 	dnode->parent_phone = -1;
 	
 	bus = pci_bus_new();
 	if (bus == NULL) {
-		printf(NAME ": pci_add_device allocation failed.\n");
+		ddf_msg(LVL_ERROR, "pci_add_device allocation failed.\n");
 		rc = ENOMEM;
 		goto fail;
@@ -481,5 +483,5 @@
 	    IPC_FLAG_BLOCKING);
 	if (dnode->parent_phone < 0) {
-		printf(NAME ": pci_add_device failed to connect to the "
+		ddf_msg(LVL_ERROR, "pci_add_device failed to connect to the "
 		    "parent's driver.\n");
 		rc = dnode->parent_phone;
@@ -491,11 +493,11 @@
 	rc = hw_res_get_resource_list(dnode->parent_phone, &hw_resources);
 	if (rc != EOK) {
-		printf(NAME ": pci_add_device failed to get hw resources for "
-		    "the device.\n");
+		ddf_msg(LVL_ERROR, "pci_add_device failed to get hw resources "
+		    "for the device.\n");
 		goto fail;
 	}
 	got_res = true;
 	
-	printf(NAME ": conf_addr = %" PRIx64 ".\n",
+	ddf_msg(LVL_DEBUG, "conf_addr = %" PRIx64 ".\n",
 	    hw_resources.resources[0].res.io_range.address);
 	
@@ -509,5 +511,5 @@
 	if (pio_enable((void *)(uintptr_t)bus->conf_io_addr, 8,
 	    &bus->conf_addr_port)) {
-		printf(NAME ": failed to enable configuration ports.\n");
+		ddf_msg(LVL_ERROR, "Failed to enable configuration ports.\n");
 		rc = EADDRNOTAVAIL;
 		goto fail;
@@ -516,5 +518,5 @@
 	
 	/* Make the bus device more visible. It has no use yet. */
-	printf(NAME ": adding a 'ctl' function\n");
+	ddf_msg(LVL_DEBUG, "Adding a 'ctl' function\n");
 	
 	ctl = ddf_fun_create(bus->dnode, fun_exposed, "ctl");
@@ -532,5 +534,5 @@
 	
 	/* Enumerate functions. */
-	printf(NAME ": scanning the bus\n");
+	ddf_msg(LVL_DEBUG, "Scanning the bus\n");
 	pci_bus_scan(bus, 0);
 	
@@ -554,4 +556,5 @@
 static void pciintel_init(void)
 {
+	ddf_log_init(NAME, LVL_ERROR);
 	pci_fun_ops.interfaces[HW_RES_DEV_IFACE] = &pciintel_hw_res_ops;
 }
Index: uspace/drv/root/root.c
===================================================================
--- uspace/drv/root/root.c	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/drv/root/root.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -52,4 +52,5 @@
 
 #include <ddf/driver.h>
+#include <ddf/log.h>
 #include <devman.h>
 #include <ipc/devman.h>
@@ -89,11 +90,11 @@
 	int rc;
 
-	printf(NAME ": adding new function for virtual devices.\n");
-	printf(NAME ":   function node is `%s' (%d %s)\n", name,
+	ddf_msg(LVL_DEBUG, "Adding new function for virtual devices. "
+	    "Function node is `%s' (%d %s)\n", name,
 	    VIRTUAL_FUN_MATCH_SCORE, VIRTUAL_FUN_MATCH_ID);
 
 	fun = ddf_fun_create(dev, fun_inner, name);
 	if (fun == NULL) {
-		printf(NAME ": error creating function %s\n", name);
+		ddf_msg(LVL_ERROR, "Failed creating function %s\n", name);
 		return ENOMEM;
 	}
@@ -102,5 +103,5 @@
 	    VIRTUAL_FUN_MATCH_SCORE);
 	if (rc != EOK) {
-		printf(NAME ": error adding match IDs to function %s\n", name);
+		ddf_msg(LVL_ERROR, "Failed adding match IDs to function %s\n", name);
 		ddf_fun_destroy(fun);
 		return rc;
@@ -109,5 +110,5 @@
 	rc = ddf_fun_bind(fun);
 	if (rc != EOK) {
-		printf(NAME ": error binding function %s: %s\n", name,
+		ddf_msg(LVL_ERROR, "Failed binding function %s: %s\n", name,
 		    str_error(rc));
 		ddf_fun_destroy(fun);
@@ -136,5 +137,5 @@
 	platform = sysinfo_get_data("platform", &platform_size);
 	if (platform == NULL) {
-		printf(NAME ": Failed to obtain platform name.\n");
+		ddf_msg(LVL_ERROR, "Failed to obtain platform name.\n");
 		return ENOENT;
 	}
@@ -143,5 +144,5 @@
 	platform = realloc(platform, platform_size + 1);
 	if (platform == NULL) {
-		printf(NAME ": Memory allocation failed.\n");
+		ddf_msg(LVL_ERROR, "Memory allocation failed.\n");
 		return ENOMEM;
 	}
@@ -151,16 +152,16 @@
 	/* Construct match ID. */
 	if (asprintf(&match_id, PLATFORM_FUN_MATCH_ID_FMT, platform) == -1) {
-		printf(NAME ": Memory allocation failed.\n");
+		ddf_msg(LVL_ERROR, "Memory allocation failed.\n");
 		return ENOMEM;
 	}
 
 	/* Add function. */
-	printf(NAME ": adding platform function\n");
-	printf(NAME ":   function node is `%s' (%d %s)\n", PLATFORM_FUN_NAME,
-	    PLATFORM_FUN_MATCH_SCORE, match_id);
+	ddf_msg(LVL_DEBUG, "Adding platform function. Function node is `%s' "
+	    " (%d %s)\n", PLATFORM_FUN_NAME, PLATFORM_FUN_MATCH_SCORE,
+	    match_id);
 
 	fun = ddf_fun_create(dev, fun_inner, name);
 	if (fun == NULL) {
-		printf(NAME ": error creating function %s\n", name);
+		ddf_msg(LVL_ERROR, "Error creating function %s\n", name);
 		return ENOMEM;
 	}
@@ -168,5 +169,6 @@
 	rc = ddf_fun_add_match_id(fun, match_id, PLATFORM_FUN_MATCH_SCORE);
 	if (rc != EOK) {
-		printf(NAME ": error adding match IDs to function %s\n", name);
+		ddf_msg(LVL_ERROR, "Failed adding match IDs to function %s\n",
+		    name);
 		ddf_fun_destroy(fun);
 		return rc;
@@ -175,5 +177,5 @@
 	rc = ddf_fun_bind(fun);
 	if (rc != EOK) {
-		printf(NAME ": error binding function %s: %s\n", name,
+		ddf_msg(LVL_ERROR, "Failed binding function %s: %s\n", name,
 		    str_error(rc));
 		ddf_fun_destroy(fun);
@@ -191,5 +193,5 @@
 static int root_add_device(ddf_dev_t *dev)
 {
-	printf(NAME ": root_add_device, device handle=%" PRIun "\n",
+	ddf_msg(LVL_DEBUG, "root_add_device, device handle=%" PRIun "\n",
 	    dev->handle);
 
@@ -204,5 +206,5 @@
 	int res = add_platform_fun(dev);
 	if (EOK != res)
-		printf(NAME ": failed to add child device for platform.\n");
+		ddf_msg(LVL_ERROR, "Failed adding child device for platform.\n");
 
 	return res;
@@ -212,4 +214,6 @@
 {
 	printf(NAME ": HelenOS root device driver\n");
+
+	ddf_log_init(NAME, LVL_ERROR);
 	return ddf_driver_main(&root_driver);
 }
Index: uspace/drv/rootpc/rootpc.c
===================================================================
--- uspace/drv/rootpc/rootpc.c	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/drv/rootpc/rootpc.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -47,4 +47,5 @@
 
 #include <ddf/driver.h>
+#include <ddf/log.h>
 #include <devman.h>
 #include <ipc/devman.h>
@@ -119,5 +120,5 @@
     rootpc_fun_t *fun)
 {
-	printf(NAME ": adding new function '%s'.\n", name);
+	ddf_msg(LVL_DEBUG, "Adding new function '%s'.\n", name);
 	
 	ddf_fun_t *fnode = NULL;
@@ -145,5 +146,5 @@
 	/* Register function. */
 	if (ddf_fun_bind(fnode) != EOK) {
-		printf(NAME ": error binding function %s.\n", name);
+		ddf_msg(LVL_ERROR, "Failed binding function %s.\n", name);
 		goto failure;
 	}
@@ -158,5 +159,5 @@
 		ddf_fun_destroy(fnode);
 	
-	printf(NAME ": failed to add function '%s'.\n", name);
+	ddf_msg(LVL_ERROR, "Failed adding function '%s'.\n", name);
 	
 	return false;
@@ -176,10 +177,10 @@
 static int rootpc_add_device(ddf_dev_t *dev)
 {
-	printf(NAME ": rootpc_add_device, device handle = %d\n",
+	ddf_msg(LVL_DEBUG, "rootpc_add_device, device handle = %d\n",
 	    (int)dev->handle);
 	
 	/* Register functions. */
 	if (!rootpc_add_functions(dev)) {
-		printf(NAME ": failed to add functions for PC platform.\n");
+		ddf_msg(LVL_ERROR, "Failed to add functions for PC platform.\n");
 	}
 	
@@ -189,4 +190,5 @@
 static void root_pc_init(void)
 {
+	ddf_log_init(NAME, LVL_ERROR);
 	rootpc_fun_ops.interfaces[HW_RES_DEV_IFACE] = &fun_hw_res_ops;
 }
Index: uspace/drv/rootvirt/rootvirt.c
===================================================================
--- uspace/drv/rootvirt/rootvirt.c	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/drv/rootvirt/rootvirt.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -40,4 +40,5 @@
 #include <str_error.h>
 #include <ddf/driver.h>
+#include <ddf/log.h>
 
 #define NAME "rootvirt"
@@ -83,10 +84,10 @@
 	int rc;
 
-	printf(NAME ": registering function `%s' (match \"%s\")\n",
+	ddf_msg(LVL_DEBUG, "Registering function `%s' (match \"%s\")\n",
 	    vfun->name, vfun->match_id);
 
 	fun = ddf_fun_create(vdev, fun_inner, vfun->name);
 	if (fun == NULL) {
-		printf(NAME ": error creating function %s\n", vfun->name);
+		ddf_msg(LVL_ERROR, "Failed creating function %s\n", vfun->name);
 		return ENOMEM;
 	}
@@ -94,5 +95,5 @@
 	rc = ddf_fun_add_match_id(fun, vfun->match_id, 10);
 	if (rc != EOK) {
-		printf(NAME ": error adding match IDs to function %s\n",
+		ddf_msg(LVL_ERROR, "Failed adding match IDs to function %s\n",
 		    vfun->name);
 		ddf_fun_destroy(fun);
@@ -102,5 +103,5 @@
 	rc = ddf_fun_bind(fun);
 	if (rc != EOK) {
-		printf(NAME ": error binding function %s: %s\n", vfun->name,
+		ddf_msg(LVL_ERROR, "Failed binding function %s: %s\n", vfun->name,
 		    str_error(rc));
 		ddf_fun_destroy(fun);
@@ -108,5 +109,5 @@
 	}
 
-	printf(NAME ": registered child device `%s'\n", vfun->name);
+	ddf_msg(LVL_NOTE, "Registered child device `%s'\n", vfun->name);
 	return EOK;
 }
@@ -124,5 +125,5 @@
 	}
 
-	printf(NAME ": add_device(handle=%d)\n", (int)dev->handle);
+	ddf_msg(LVL_DEBUG, "add_device(handle=%d)\n", (int)dev->handle);
 
 	/*
@@ -142,4 +143,6 @@
 {
 	printf(NAME ": HelenOS virtual devices root driver\n");
+
+	ddf_log_init(NAME, LVL_ERROR);
 	return ddf_driver_main(&rootvirt_driver);
 }
Index: uspace/drv/test1/test1.c
===================================================================
--- uspace/drv/test1/test1.c	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/drv/test1/test1.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -35,4 +35,5 @@
 #include <str_error.h>
 #include <ddf/driver.h>
+#include <ddf/log.h>
 
 #include "test1.h"
@@ -63,9 +64,9 @@
 	int rc;
 
-	printf(NAME ": registering function `%s': %s.\n", name, message);
+	ddf_msg(LVL_DEBUG, "Registering function `%s': %s.\n", name, message);
 
 	fun = ddf_fun_create(parent, fun_inner, name);
 	if (fun == NULL) {
-		printf(NAME ": error creating function %s\n", name);
+		ddf_msg(LVL_ERROR, "Failed creating function %s\n", name);
 		return ENOMEM;
 	}
@@ -73,5 +74,6 @@
 	rc = ddf_fun_add_match_id(fun, match_id, match_score);
 	if (rc != EOK) {
-		printf(NAME ": error adding match IDs to function %s\n", name);
+		ddf_msg(LVL_ERROR, "Failed adding match IDs to function %s\n",
+		    name);
 		ddf_fun_destroy(fun);
 		return rc;
@@ -80,5 +82,5 @@
 	rc = ddf_fun_bind(fun);
 	if (rc != EOK) {
-		printf(NAME ": error binding function %s: %s\n", name,
+		ddf_msg(LVL_ERROR, "Failed binding function %s: %s\n", name,
 		    str_error(rc));
 		ddf_fun_destroy(fun);
@@ -86,5 +88,5 @@
 	}
 
-	printf(NAME ": registered child device `%s'\n", name);
+	ddf_msg(LVL_NOTE, "Registered child device `%s'\n", name);
 	return EOK;
 }
@@ -112,10 +114,10 @@
 	int rc;
 
-	printf(NAME ": add_device(name=\"%s\", handle=%d)\n",
+	ddf_msg(LVL_DEBUG, "add_device(name=\"%s\", handle=%d)\n",
 	    dev->name, (int) dev->handle);
 
 	fun_a = ddf_fun_create(dev, fun_exposed, "a");
 	if (fun_a == NULL) {
-		printf(NAME ": error creating function 'a'.\n");
+		ddf_msg(LVL_ERROR, "Failed creating function 'a'.\n");
 		return ENOMEM;
 	}
@@ -123,5 +125,5 @@
 	rc = ddf_fun_bind(fun_a);
 	if (rc != EOK) {
-		printf(NAME ": error binding function 'a'.\n");
+		ddf_msg(LVL_ERROR, "Failed binding function 'a'.\n");
 		return rc;
 	}
@@ -140,5 +142,5 @@
 	}
 
-	printf(NAME ": device `%s' accepted.\n", dev->name);
+	ddf_msg(LVL_DEBUG, "Device `%s' accepted.\n", dev->name);
 
 	return EOK;
@@ -148,4 +150,5 @@
 {
 	printf(NAME ": HelenOS test1 virtual device driver\n");
+	ddf_log_init(NAME, LVL_ERROR);
 	return ddf_driver_main(&test1_driver);
 }
Index: uspace/drv/test2/test2.c
===================================================================
--- uspace/drv/test2/test2.c	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/drv/test2/test2.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -36,4 +36,5 @@
 #include <str_error.h>
 #include <ddf/driver.h>
+#include <ddf/log.h>
 
 #define NAME "test2"
@@ -64,9 +65,9 @@
 	int rc;
 
-	printf(NAME ": registering function `%s': %s.\n", name, message);
+	ddf_msg(LVL_DEBUG, "Registering function `%s': %s.\n", name, message);
 
 	fun = ddf_fun_create(parent, fun_inner, name);
 	if (fun == NULL) {
-		printf(NAME ": error creating function %s\n", name);
+		ddf_msg(LVL_ERROR, "Failed creating function %s\n", name);
 		return ENOMEM;
 	}
@@ -74,5 +75,6 @@
 	rc = ddf_fun_add_match_id(fun, match_id, match_score);
 	if (rc != EOK) {
-		printf(NAME ": error adding match IDs to function %s\n", name);
+		ddf_msg(LVL_ERROR, "Failed adding match IDs to function %s\n",
+		    name);
 		ddf_fun_destroy(fun);
 		return rc;
@@ -81,5 +83,5 @@
 	rc = ddf_fun_bind(fun);
 	if (rc != EOK) {
-		printf(NAME ": error binding function %s: %s\n", name,
+		ddf_msg(LVL_ERROR, "Failed binding function %s: %s\n", name,
 		    str_error(rc));
 		ddf_fun_destroy(fun);
@@ -87,5 +89,5 @@
 	}
 
-	printf(NAME ": registered child device `%s'\n", name);
+	ddf_msg(LVL_NOTE, "Registered child device `%s'\n", name);
 	return EOK;
 }
@@ -111,5 +113,5 @@
 	fun_a = ddf_fun_create(dev, fun_exposed, "a");
 	if (fun_a == NULL) {
-		printf(NAME ": error creating function 'a'.\n");
+		ddf_msg(LVL_ERROR, "Failed creating function 'a'.\n");
 		return ENOMEM;
 	}
@@ -117,5 +119,5 @@
 	rc = ddf_fun_bind(fun_a);
 	if (rc != EOK) {
-		printf(NAME ": error binding function 'a'.\n");
+		ddf_msg(LVL_ERROR, "Failed binding function 'a'.\n");
 		return rc;
 	}
@@ -128,5 +130,5 @@
 static int test2_add_device(ddf_dev_t *dev)
 {
-	printf(NAME ": test2_add_device(name=\"%s\", handle=%d)\n",
+	ddf_msg(LVL_DEBUG, "test2_add_device(name=\"%s\", handle=%d)\n",
 	    dev->name, (int) dev->handle);
 
@@ -134,5 +136,5 @@
 		fid_t postpone = fibril_create(postponed_birth, dev);
 		if (postpone == 0) {
-			printf(NAME ": fibril_create() error\n");
+			ddf_msg(LVL_ERROR, "fibril_create() failed.\n");
 			return ENOMEM;
 		}
@@ -149,4 +151,5 @@
 {
 	printf(NAME ": HelenOS test2 virtual device driver\n");
+	ddf_log_init(NAME, LVL_ERROR);
 	return ddf_driver_main(&test2_driver);
 }
Index: uspace/lib/c/generic/io/log.c
===================================================================
--- uspace/lib/c/generic/io/log.c	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/lib/c/generic/io/log.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -35,4 +35,5 @@
 #include <errno.h>
 #include <fibril_synch.h>
+#include <stdarg.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -89,12 +90,25 @@
 	va_list args;
 
+	va_start(args, fmt);
+	log_msgv(level, fmt, args);
+	va_end(args);
+}
+
+/** Write an entry to the log (va_list variant).
+ *
+ * @param level		Message verbosity level. Message is only printed
+ *			if verbosity is less than or equal to current
+ *			reporting level.
+ * @param fmt		Format string
+ */
+void log_msgv(log_level_t level, const char *fmt, va_list args)
+{
 	assert(level < LVL_LIMIT);
 
 	/* Higher number means higher verbosity. */
 	if (level <= log_level) {
-		va_start(args, fmt);
 		fibril_mutex_lock(&log_serializer);
 
-		fprintf(log_stream, "%s: %s", log_prog_name,
+		fprintf(log_stream, "%s: %s: ", log_prog_name,
 		    log_level_names[level]);
 		vfprintf(log_stream, fmt, args);
@@ -102,5 +116,4 @@
 
 		fibril_mutex_unlock(&log_serializer);
-		va_end(args);
 	}
 }
Index: uspace/lib/c/include/io/log.h
===================================================================
--- uspace/lib/c/include/io/log.h	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/lib/c/include/io/log.h	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -35,4 +35,6 @@
 #define LIBC_IO_LOG_H_
 
+#include <stdarg.h>
+
 typedef enum {
 	LVL_FATAL,
@@ -49,4 +51,5 @@
 extern int log_init(const char *, log_level_t);
 extern void log_msg(log_level_t, const char *, ...);
+extern void log_msgv(log_level_t, const char *, va_list);
 
 #endif
Index: uspace/lib/drv/Makefile
===================================================================
--- uspace/lib/drv/Makefile	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/lib/drv/Makefile	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -35,4 +35,5 @@
 	generic/driver.c \
 	generic/dev_iface.c \
+	generic/log.c \
 	generic/remote_hw_res.c \
 	generic/remote_char_dev.c
Index: uspace/lib/drv/generic/driver.c
===================================================================
--- uspace/lib/drv/generic/driver.c	(revision 9b415c96f2f29f61f5d4f5f7ea3fd3b1ef1ea27a)
+++ uspace/lib/drv/generic/driver.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -273,12 +273,6 @@
 	
 	res = driver->driver_ops->add_device(dev);
-	if (res == EOK) {
-		printf("%s: new device with handle=%" PRIun " was added.\n",
-		    driver->name, dev_handle);
-	} else {
-		printf("%s: failed to add a new device with handle = %" PRIun ".\n",
-		    driver->name, dev_handle);
+	if (res != EOK)
 		delete_device(dev);
-	}
 	
 	async_answer_0(iid, res);
Index: uspace/lib/drv/generic/log.c
===================================================================
--- uspace/lib/drv/generic/log.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
+++ uspace/lib/drv/generic/log.c	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2011 Jiri Svoboda
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libdrv
+ * @{
+ */
+
+#include <io/log.h>
+#include <stdarg.h>
+
+#include <ddf/log.h>
+
+/** Initialize the logging system.
+ *
+ * @param drv_name	Driver name, will be printed as part of message
+ * @param level		Minimum message level to print
+ */
+int ddf_log_init(const char *drv_name, log_level_t level)
+{
+	return log_init(drv_name, level);
+}
+
+/** Log a driver message.
+ *
+ * @param level		Message verbosity level. Message is only printed
+ *			if verbosity is less than or equal to current
+ *			reporting level.
+ * @param fmt		Format string
+ */
+void ddf_msg(log_level_t level, const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	log_msgv(level, fmt, args);
+	va_end(args);
+}
+
+/** @}
+ */
Index: uspace/lib/drv/include/ddf/log.h
===================================================================
--- uspace/lib/drv/include/ddf/log.h	(revision fc51296af4f45da426f5626f3573adee6b0babda)
+++ uspace/lib/drv/include/ddf/log.h	(revision fc51296af4f45da426f5626f3573adee6b0babda)
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2011 Jiri Svoboda
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup libdrv
+ * @{
+ */
+
+#ifndef DDF_LOG_H_
+#define DDF_LOG_H_
+
+#include <io/log.h>
+
+extern int ddf_log_init(const char *, log_level_t);
+extern void ddf_msg(log_level_t, const char *, ...);
+
+#endif
+
+/** @}
+ */