Index: kernel/generic/src/console/console.c
===================================================================
--- kernel/generic/src/console/console.c	(revision 7ba289acbe98d97ccfefd3124fa914845c001281)
+++ kernel/generic/src/console/console.c	(revision 82b71ef11d249b753e957080f4ee91adb9dc570d)
@@ -36,7 +36,12 @@
 #include <console/console.h>
 #include <console/chardev.h>
+#include <sysinfo/sysinfo.h>
 #include <synch/waitq.h>
 #include <synch/spinlock.h>
 #include <arch/types.h>
+#include <ddi/device.h>
+#include <ddi/irq.h>
+#include <ddi/ddi.h>
+#include <ipc/irq.h>
 #include <arch.h>
 #include <func.h>
@@ -44,9 +49,11 @@
 #include <atomic.h>
 
-#define KLOG_SIZE 4096
+#define KLOG_SIZE PAGE_SIZE
 
 /**< Kernel log cyclic buffer */
-static char klog[KLOG_SIZE];
-
+static char klog[KLOG_SIZE] __attribute__ ((aligned (PAGE_SIZE)));
+
+/**< Kernel log initialized */
+static bool klog_inited = false;
 /**< First kernel log characters */
 static index_t klog_start = 0;
@@ -55,4 +62,21 @@
 /**< Number of stored (not printed) kernel log characters */
 static size_t klog_stored = 0;
+/**< Number of stored kernel log characters for uspace */
+static size_t klog_uspace = 0;
+
+/**< Kernel log spinlock */
+SPINLOCK_INITIALIZE(klog_lock);
+
+/** Physical memory area used for klog buffer */
+static parea_t klog_parea;
+	
+/*
+ * For now, we use 0 as INR.
+ * However, it is therefore desirable to have architecture specific
+ * definition of KLOG_VIRT_INR in the future.
+ */
+#define KLOG_VIRT_INR	0
+
+static irq_t klog_irq;
 
 static chardev_operations_t null_stdout_ops = {
@@ -68,7 +92,55 @@
 };
 
-/** Standard input character device. */
+/** Allways refuse IRQ ownership.
+ *
+ * This is not a real IRQ, so we always decline.
+ *
+ * @return Always returns IRQ_DECLINE.
+ */
+static irq_ownership_t klog_claim(void)
+{
+	return IRQ_DECLINE;
+}
+
+/** Standard input character device */
 chardev_t *stdin = NULL;
 chardev_t *stdout = &null_stdout;
+
+/** Initialize kernel logging facility
+ *
+ * The shared area contains kernel cyclic buffer. Userspace application may
+ * be notified on new data with indication of position and size
+ * of the data within the circular buffer.
+ */
+void klog_init(void)
+{
+	void *faddr = (void *) KA2PA(klog);
+	
+	ASSERT((uintptr_t) faddr % FRAME_SIZE == 0);
+	ASSERT(KLOG_SIZE % FRAME_SIZE == 0);
+
+	devno_t devno = device_assign_devno();
+	
+	klog_parea.pbase = (uintptr_t) faddr;
+	klog_parea.vbase = (uintptr_t) klog;
+	klog_parea.frames = SIZE2FRAMES(KLOG_SIZE);
+	klog_parea.cacheable = true;
+	ddi_parea_register(&klog_parea);
+
+	sysinfo_set_item_val("klog.faddr", NULL, (unative_t) faddr);
+	sysinfo_set_item_val("klog.pages", NULL, SIZE2FRAMES(KLOG_SIZE));
+	sysinfo_set_item_val("klog.devno", NULL, devno);
+	sysinfo_set_item_val("klog.inr", NULL, KLOG_VIRT_INR);
+
+	irq_initialize(&klog_irq);
+	klog_irq.devno = devno;
+	klog_irq.inr = KLOG_VIRT_INR;
+	klog_irq.claim = klog_claim;
+	irq_register(&klog_irq);
+	
+	spinlock_lock(&klog_lock);
+	klog_inited = true;
+	spinlock_unlock(&klog_lock);
+}
 
 /** Get character from character device. Do not echo character.
@@ -161,6 +233,20 @@
 }
 
+void klog_update(void)
+{
+	spinlock_lock(&klog_lock);
+	
+	if ((klog_inited) && (klog_irq.notif_cfg.notify) && (klog_uspace > 0)) {
+		ipc_irq_send_msg_3(&klog_irq, klog_start, klog_len, klog_uspace);
+		klog_uspace = 0;
+	}
+	
+	spinlock_unlock(&klog_lock);
+}
+
 void putchar(char c)
 {
+	spinlock_lock(&klog_lock);
+	
 	if ((klog_stored > 0) && (stdout->op->write)) {
 		/* Print charaters stored in kernel log */
@@ -185,4 +271,12 @@
 			klog_stored++;
 	}
+	
+	/* The character is stored for uspace */
+	if (klog_uspace < klog_len)
+		klog_uspace++;
+	
+	spinlock_unlock(&klog_lock);
+	
+	klog_update();
 }
 
Index: kernel/generic/src/main/main.c
===================================================================
--- kernel/generic/src/main/main.c	(revision 7ba289acbe98d97ccfefd3124fa914845c001281)
+++ kernel/generic/src/main/main.c	(revision 82b71ef11d249b753e957080f4ee91adb9dc570d)
@@ -81,4 +81,5 @@
 #include <smp/smp.h>
 #include <ddi/ddi.h>
+#include <console/console.h>
 
 /** Global configuration structure. */
@@ -257,4 +258,5 @@
 	
 	LOG_EXEC(ipc_init());
+	LOG_EXEC(klog_init());
 
 	/*
Index: kernel/generic/src/syscall/syscall.c
===================================================================
--- kernel/generic/src/syscall/syscall.c	(revision 7ba289acbe98d97ccfefd3124fa914845c001281)
+++ kernel/generic/src/syscall/syscall.c	(revision 82b71ef11d249b753e957080f4ee91adb9dc570d)
@@ -64,23 +64,23 @@
 	int rc;
 
-	if (count == 0)
-		return 0;
-
 	if (count > PAGE_SIZE)
 		return ELIMIT;
-
-	data = (char *) malloc(count, 0);
-	if (!data)
-		return ENOMEM;
 	
-	rc = copy_from_uspace(data, buf, count);
-	if (rc) {
+	if (count > 0) {
+		data = (char *) malloc(count, 0);
+		if (!data)
+			return ENOMEM;
+		
+		rc = copy_from_uspace(data, buf, count);
+		if (rc) {
+			free(data);
+			return rc;
+		}
+	
+		for (i = 0; i < count; i++)
+			putchar(data[i]);
 		free(data);
-		return rc;
-	}
-
-	for (i = 0; i < count; i++)
-		putchar(data[i]);
-	free(data);
+	} else
+		klog_update();
 	
 	return count;