Index: include/userspace.h
===================================================================
--- include/userspace.h	(revision 70527f178e75c4d7b241a68de96deb60887233de)
+++ include/userspace.h	(revision 673104e55052fd9a0ddb2b6c2cc8b47a15e3f204)
@@ -30,5 +30,5 @@
 #define __USERSPACE_H__
 
-extern void userspace(void) __attribute__ ((noreturn));
+extern void userspace(void) __attribute__ ((noreturn)); /**< Switch to user-space (CPU user priviledge level) */
 
 #endif
Index: src/Makefile.config
===================================================================
--- src/Makefile.config	(revision 70527f178e75c4d7b241a68de96deb60887233de)
+++ src/Makefile.config	(revision 673104e55052fd9a0ddb2b6c2cc8b47a15e3f204)
@@ -10,4 +10,7 @@
 # Improved support for hyperthreading
 HT=__HT__
+
+# General debuging and assert checking disable
+#NDEBUG=__NDEBUG__
 
 # Deadlock detection support for spinlocks.
Index: src/cpu/cpu.c
===================================================================
--- src/cpu/cpu.c	(revision 70527f178e75c4d7b241a68de96deb60887233de)
+++ src/cpu/cpu.c	(revision 673104e55052fd9a0ddb2b6c2cc8b47a15e3f204)
@@ -44,4 +44,10 @@
 cpu_t *cpus;
 
+
+/** Initialize CPUs
+ *
+ * Initialize kernel CPUs support.
+ *
+ */
 void cpu_init(void) {
 	int i, j;
Index: src/main/main.c
===================================================================
--- src/main/main.c	(revision 70527f178e75c4d7b241a68de96deb60887233de)
+++ src/main/main.c	(revision 673104e55052fd9a0ddb2b6c2cc8b47a15e3f204)
@@ -85,6 +85,11 @@
 static void main_ap_separated_stack(void);
 
-/*
- * Executed by the bootstrap processor. cpu_priority_high()'d
+
+/** Bootstrap CPU main kernel routine
+ *
+ * Initializes the kernel by bootstrap CPU.
+ *
+ * Assuming cpu_priority_high().
+ *
  */
 void main_bsp(void)
@@ -103,4 +108,10 @@
 }
 
+
+/** Bootstrap CPU main kernel routine stack wrapper
+ *
+ * Second part of main_bsp().
+ *
+ */
 void main_bsp_separated_stack(void) {
 	vm_t *m;
@@ -162,8 +173,13 @@
 }
 
+
 #ifdef __SMP__
-/*
- * Executed by application processors. cpu_priority_high()'d
- * Temporary stack is at ctx.sp which was set during BP boot.
+/** Application CPUs main kernel routine
+ *
+ * Executed by application processors, temporary stack
+ * is at ctx.sp which was set during BP boot.
+ *
+ * Assuming  cpu_priority_high().
+ *
  */
 void main_ap(void)
@@ -199,4 +215,10 @@
 }
 
+
+/** Application CPUs main kernel routine stack wrapper
+ *
+ * Second part of main_ap().
+ *
+ */
 void main_ap_separated_stack(void)
 {