diff --git a/boot/mbr/mbr.asm b/boot/mbr/mbr.asm
index 42f0dbd..f94c713 100644
--- a/boot/mbr/mbr.asm
+++ b/boot/mbr/mbr.asm
@@ -123,6 +123,7 @@ load_root:
     mov di, BUFFER_OFF                          ; Set es:di to the disk buffer
     mov cx, word [rootDirEntries]               ; Search through all of the root dir entries
     xor ax, ax                                  ; Clear ax for the file entry offset
+
 search_root:
     xchg cx, dx                                 ; Save cx because it's a loop counter
     mov si, filename                            ; Load the filename
diff --git a/boot/mbr/mbr.inc b/boot/mbr/mbr.inc
index dc11db1..a5f396d 100644
--- a/boot/mbr/mbr.inc
+++ b/boot/mbr/mbr.inc
@@ -101,7 +101,7 @@ read_sectors:
     shl ah, 1
     or cl, ah                                   ; Now cx is set with respective track and sector numbers
     mov dl, byte [Bootdrv]                      ; Set correct Bootdrv for int 13h
-    mov di, 21                                  ; Try five times to read the sector because i love 21
+    mov di, 21                                  ; Try five times to read the sector because I love 21
   .attempt_read:
     mov ax, 0x0201                              ; Read Sectors func of int 13h, read one sector
     int 0x13                                    ; Call int 13h (BIOS disk I/O)
diff --git a/kaleid/common/itoa.c b/kaleid/common/itoa.c
index e24a41a..a5e3383 100644
--- a/kaleid/common/itoa.c
+++ b/kaleid/common/itoa.c
@@ -10,59 +10,89 @@
 #include <kaleid.h>
 
 //
-// Digits table for bases <=36
+// Digits table for bases <=36 (unused)
 //
 static const char digits[] =
         "0123456789abcdefghijklmnopqrstuvwxyz";
+
 //
 // Integer to string in any base between 2 and 36 (included)
 //
+
 #if defined(_NEED_ITOA)
+
 char *itoa(int i, char *str, int base)
+#define _IL_MIN INT_MIN
+#define _IL_MIN_STRING "-2147483648"
+
 #elif defined(_NEED_LTOA)
+
 char *ltoa(long i, char *str, int base)
+#define _IL_MIN LONG_MIN
+#define _IL_MIN_STRING "-9223372036854775808"
+
 #elif defined(_NEED_UTOA)
+
 char *utoa(uint i, char *str, int base)
+
 #elif defined(_NEED_ULTOA)
+
 char *ultoa(ulong i, char *str, int base)
+
 #else
 #error "What am I supposed to declare?"
 #endif
+
 {
-#if defined(_NEED_ITOA) || defined(_NEED_LTOA)
-    int neg = 0;
-#endif
-
     char *orig = str;
 
-    //
-    // Only handle base 2 -> 36
-    //
-    if (base < 2 || base > 36)
-        return NULL;
-
 #if defined(_NEED_ITOA) || defined(_NEED_LTOA)
     //
     // Deal with negatives
     //
-    if (i < 0) {
-        neg = 1;
-        i = -i;
+    int neg = 0;
+    if (i < 0 && base == 10) {
+        //
+        // Handle INT_MIN and LONG_MIN...
+        //
+        if (__builtin_expect(i == _IL_MIN, 0)) {
+            strcpy(orig, _IL_MIN_STRING);
+            goto leave;
+        }
+
+        else {
+            neg = 1;
+            i = -i;
+        }
     }
 #endif
 
+    //
+    // Only handle base 2 -> 36
+    //
+    if (base < 2 || base > 36) {
+        __set_errno(EINVAL);
+        *orig = '\0;
+        goto leave;
+    }
+
     //
     // Deal with zero separately
     //
     if (i == 0) {
         *str++ = '0';
+        *str = '\0';
+        goto leave;
     }
 
     //
     // Compute digits... in reverse order
     //
     while (i > 0) {
-        *str++ = digits[i % base];
+        rem = i % base;
+        *str++ = (rem > 9)
+               ? (rem - 10) + 'a'
+               :  rem       + '0';
         i /= base;
     }
 
@@ -75,7 +105,13 @@ char *ultoa(ulong i, char *str, int base)
     //
     // Reverse the string
     //
-    return strrev2(orig);
+    orig = strrev2(orig);
+
+    //
+    // End of conversion
+    //
+leave:
+    return orig;
 }
 
 
diff --git a/kaleid/common/memory.c b/kaleid/common/memory.c
index 3497a38..20a9dd2 100644
--- a/kaleid/common/memory.c
+++ b/kaleid/common/memory.c
@@ -58,7 +58,7 @@ void *memset(void *ptr, int val, size_t bytes)
 }
 
 //
-//  Set "words"-many words starting from ptr to val
+// Set "words"-many words starting from ptr to val
 //
 void *memsetw(void *ptr, int val, size_t words)
 {
@@ -99,8 +99,8 @@ void *memsetw(void *ptr, int val, size_t words)
 }
 
 //
-//  Set "dwords"-many dwords starting from ptr to val
-//  XXX unimplemented
+// Set "dwords"-many dwords starting from ptr to val
+// XXX unimplemented
 //
 void *memsetd(void *ptr, int val, size_t dwords)
 {
@@ -111,7 +111,7 @@ void *memsetd(void *ptr, int val, size_t dwords)
 }
 
 //
-//  Set "qwords"-many qwords starting from ptr to val
+// Set "qwords"-many qwords starting from ptr to val
 //
 void *memsetq(void *ptr, long val, size_t qwords)
 {
@@ -130,7 +130,7 @@ void *memsetq(void *ptr, long val, size_t qwords)
 //------------------------------------------//
 
 //
-//  Set "bytes"-many bytes starting from ptr to 0
+// Set "bytes"-many bytes starting from ptr to 0
 //
 void *memzero(void *ptr, size_t bytes)
 {
@@ -138,8 +138,8 @@ void *memzero(void *ptr, size_t bytes)
 }
 
 //
-//  Copy "bytes"-many bytes of src to dst
-//  Does not deal with overlapping blocks (memmove's job)
+// Copy "bytes"-many bytes of src to dst
+// Does not deal with overlapping blocks (memmove's job)
 //
 void *memcpy(void *restrict dst, const void *restrict src, size_t bytes)
 {
@@ -203,7 +203,7 @@ void *memcpy(void *restrict dst, const void *restrict src, size_t bytes)
 }
 
 //
-//  Move memory from src to dest, even if they overlap
+// Move memory from src to dest, even if they overlap
 //
 void *memmove(void *dst, const void *src, size_t bytes)
 {
@@ -228,7 +228,7 @@ void *memmove(void *dst, const void *src, size_t bytes)
 }
 
 //
-//  Compare memory areas
+// Compare memory areas
 //
 int memcmp(const void *ptr1, const void *ptr2, size_t bytes)
 {
diff --git a/kaleid/common/string.c b/kaleid/common/string.c
index fafaf89..d7c391d 100644
--- a/kaleid/common/string.c
+++ b/kaleid/common/string.c
@@ -235,7 +235,7 @@ char *strncpy(char *restrict dest, const char *restrict src, size_t n)
 // Returns TRUE if dest would have been null-terminated
 // by ordinary strncpy(), and FALSE otherwise
 //
-int xstrncpy(char *restrict dest, const char *restrict src, size_t n)
+int strnzcpy(char *restrict dest, const char *restrict src, size_t n)
 {
     size_t it;
 
@@ -243,9 +243,7 @@ int xstrncpy(char *restrict dest, const char *restrict src, size_t n)
         dest[it] = src[it];
     }
 
-    //
     // Was the copy complete?
-    //
     if (it == n) {
         if (dest[n] == 0) {
             return TRUE;
@@ -261,11 +259,63 @@ int xstrncpy(char *restrict dest, const char *restrict src, size_t n)
 }
 
 //
-// XXX strcat family
+// Appends a copy of src at the end of dest
 //
-char   *strcat  (char *restrict, const char *restrict);
-char   *strncat (char *restrict, const char *restrict, size_t);
-int    *xstrncat(char *restrict, const char *restrict, size_t);
+char *strcat(char *restrict dest, const char *restrict src)
+{
+    char *base = dest;
+    while (*dest) dest++;
+    while ((*dest++ = *src++));
+    return base;
+}
+
+//
+// Appends a copy of at most n bytes of src at the end of dest
+//
+char *strncat(char *restrict dest, const char *restrict src, size_t n)
+{
+    size_t it, off = 0;
+
+    while (dest[off]) off++;
+
+    for (it = 0; it < n && src[it]; it++) {
+        dest[it+off] = src[it];
+    }
+
+    while (it++ < n) dest[it+off] = 0;
+
+    return dest;
+}
+
+//
+// Appends a copy of at most n bytes of src at the end of dest
+// Always null-terminates, and returne TRUE or FALSE depending on whether
+// regular strcat() would have null-terminated this string, or not
+//
+int *strnzcat(char *restrict dest, const char *restrict src, size_t n)
+{
+    size_t it, off = 0;
+
+    while (dest[off]) off++;
+
+    for (it = 0; it < n - 1 && src[it]; it++) {
+        dest[it+off] = src[it];
+    }
+
+    // Was the copy complete?
+    if (it == n) {
+        if (dest[n+off] == 0) {
+            return TRUE;
+        }
+
+        dest[n+off] = 0;
+        return FALSE;
+    }
+
+    while (it++ < n) dest[it+off] = 0;
+
+    return TRUE;
+}
 
 //
 // Reverses the string src, putting the result into dest
diff --git a/kaleid/include/common/kalcrt.h b/kaleid/include/common/kalcrt.h
index 167ab52..165ba90 100644
--- a/kaleid/include/common/kalcrt.h
+++ b/kaleid/include/common/kalcrt.h
@@ -143,11 +143,11 @@ char   *strtok_r(char *restrict, const char *restrict, char **restrict);
 
 char   *strcpy  (char *restrict, const char *restrict);
 char   *strncpy (char *restrict, const char *restrict, size_t);
-int     xstrncpy(char *restrict, const char *restrict, size_t);
+int     strnzcpy(char *restrict, const char *restrict, size_t);
 
 char   *strcat  (char *restrict, const char *restrict);
 char   *strncat (char *restrict, const char *restrict, size_t);
-int    *xstrncat(char *restrict, const char *restrict, size_t);
+int    *strnzcat(char *restrict, const char *restrict, size_t);
 
 char   *strrev(char *restrict, const char *restrict);
 char   *strrev2(char *);
diff --git a/kaleid/include/common/kaldefs.h b/kaleid/include/common/kaldefs.h
index 9dbf1be..cc43ee9 100644
--- a/kaleid/include/common/kaldefs.h
+++ b/kaleid/include/common/kaldefs.h
@@ -23,11 +23,7 @@
 #endif
 
 #ifndef NULL
-#define NULL ((void *)0)
-#endif
-
-#ifndef INITOK
-#define INITOK ((unsigned int)0xCAFEBABE)
+#define NULL 0L
 #endif
 
 //------------------------------------------//
@@ -61,8 +57,8 @@
 //           Attributes and macros          //
 //------------------------------------------//
 
-#ifndef PACKED
-#define PACKED __attribute__((__packed__))
+#ifndef _PACKED
+#define _PACKED __attribute__((__packed__))
 #endif
 
 #ifndef noreturn
@@ -77,6 +73,14 @@
 #define unlikely(x) (__builtin_expect((x), 0))
 #endif
 
+#ifndef _STR
+#define _STR(x) #x
+#endif
+
+#ifndef _XSTR
+#define _XSTR(x) _STR(x)
+#endif
+
 //------------------------------------------//
 //           API specific macros            //
 //------------------------------------------//
diff --git a/kaleid/include/common/kalerror.h b/kaleid/include/common/kalerror.h
index ce8b2c4..b29c660 100644
--- a/kaleid/include/common/kalerror.h
+++ b/kaleid/include/common/kalerror.h
@@ -11,7 +11,7 @@
 #define _KALERROR_H
 
 //------------------------------------------//
-//          Preprocessor constants          //
+//              "errno" values              //
 //------------------------------------------//
 
 // Everything went fine
diff --git a/kaleid/include/common/kallist.h b/kaleid/include/common/kallist.h
index 96c5f9d..8257b64 100644
--- a/kaleid/include/common/kallist.h
+++ b/kaleid/include/common/kallist.h
@@ -204,7 +204,7 @@ static inline ListHead_t
 }
 
 //
-// Remove node of list
+// Remove node of list (and frees it)
 //
 static inline ListHead_t
 *RemoveNode(ListHead_t *head, ListNode_t *node)
diff --git a/kaleid/include/common/kalmask.h b/kaleid/include/common/kalmask.h
index 0295bd0..c185354 100644
--- a/kaleid/include/common/kalmask.h
+++ b/kaleid/include/common/kalmask.h
@@ -51,11 +51,11 @@
 
 #define strcpy      _osk_strcpy
 #define strncpy     _osk_strncpy
-#define xstrncpy    _osk_xstrncpy
+#define strnzcpy    _osk_strnzcpy
 
 #define strcat      _osk_strcat
 #define strncat     _osk_strncat
-#define xstrncat    _osk_xstrncat
+#define strnzcat    _osk_strnzcat
 
 #define strrev      _osk_strrev
 #define strrev2     _osk_strrev2
@@ -105,7 +105,7 @@
 
 //------------------------------------------//
 
-#define strerror _osk_strerror
+#define strerror    _osk_strerror
 
 //------------------------------------------//
 //              End of header               //
diff --git a/kaleid/include/kernel/kernbase.h b/kaleid/include/kernel/kernbase.h
index baf8e95..54307c7 100644
--- a/kaleid/include/kernel/kernbase.h
+++ b/kaleid/include/kernel/kernbase.h
@@ -59,6 +59,11 @@ typedef enum {
 //            Multiprocessor misc.          //
 //------------------------------------------//
 
+
+#ifndef INITOK
+#define INITOK ((unsigned int)0xCAFEBABE)
+#endif
+
 #ifndef NCPU
 #define NCPU 4
 #endif
@@ -108,12 +113,6 @@ DECLARE_PER_CPU(CurThread,   Thread_t *);
 //             global constants             //
 //------------------------------------------//
 
-#define SetPanicStr(str)                    \
-    do {                                    \
-        SetKernState(KSTATE_PANIC);         \
-        _SetPanicStr(str);                  \
-    } while (0)
-
 #define SetKernState(x)                     \
     do {                                    \
         _SetKernState(x);                   \
@@ -184,7 +183,6 @@ void WriteByteOnPort(port_t port, port_t val)
 static inline
 uchar ReadByteFromPort(port_t port)
 {
-
     KalAssert(FALSE && ENOSYS);
     (void)port;
     return 0;
diff --git a/kaleid/include/kernel/kernlocks.h b/kaleid/include/kernel/kernlocks.h
index f3dd7e2..6d32224 100644
--- a/kaleid/include/kernel/kernlocks.h
+++ b/kaleid/include/kernel/kernlocks.h
@@ -70,11 +70,15 @@ typedef struct sLock_t {
 //------------------------------------------//
 
 //
-// Linux syscall...
+// Linux syscall vs unimplemented syscall...
 //
 #ifndef _KALEID_KERNEL
+#ifdef _OSK_SOURCE
+int KalYieldCPU(void),
+#else
 int sched_yield(void);
 #endif
+#endif
 
 //
 // Initialize a lock
@@ -127,7 +131,11 @@ void AquireLock(Lock_t *lock)
         StartPanic("AquireLock on an already locked object");
 #else
         if likely (lock->type == KLOCK_SPINLOCK) continue;
+#ifdef _OSK_SOURCE
+        else KalYieldCPU();
+#else
         else sched_yield();
+#endif
 #endif
     }
     __sync_synchronize();
diff --git a/kaleid/include/kernel/kernsched.h b/kaleid/include/kernel/kernsched.h
index 1026d53..d99f8de 100644
--- a/kaleid/include/kernel/kernsched.h
+++ b/kaleid/include/kernel/kernsched.h
@@ -30,9 +30,10 @@
 //               Preprocessor               //
 //------------------------------------------//
 
+//
+// Debug stuff
+//
 #define printdbg printf
-#define _STR(x) #x
-#define _XSTR(x) _STR(x)
 
 //
 // States for a process
@@ -56,6 +57,8 @@ DECLARE_PER_CPU(ReglPrioProcs, ListHead_t *);
 DECLARE_PER_CPU(ServPrioProcs, ListHead_t *);
 DECLARE_PER_CPU(TimeCritProcs, ListHead_t *);
 
+extern const char *PrioClassesNames[];
+
 //------------------------------------------//
 //               Data types                 //
 //------------------------------------------//
@@ -63,7 +66,7 @@ DECLARE_PER_CPU(TimeCritProcs, ListHead_t *);
 //
 // A process
 //
-typedef struct sProcess_t{
+typedef struct sProcess_t {
 
     // Identifier
     int         pid;
@@ -94,6 +97,16 @@ typedef struct sProcess_t{
 
 } Process_t;
 
+//------------------------------------------//
+//                Functions                 //
+//------------------------------------------//
+
+void SchedInit(void);
+void SchedFini(void);
+
+void SchedThisProc(Process_t *);
+void SchedOnTick(void);
+
 //------------------------------------------//
 //              End of header               //
 //------------------------------------------//
diff --git a/kaleid/kernel/ke/panic.c b/kaleid/kernel/ke/panic.c
index 72fe089..79c9a89 100644
--- a/kaleid/kernel/ke/panic.c
+++ b/kaleid/kernel/ke/panic.c
@@ -34,6 +34,7 @@ noreturn void StartPanic(const char *str)
 {
     DisableIRQs();
 
+    // This should be made atomic
     SetKernState(KSTATE_PANIC);
 
     if (GetCurProc()) __CurProc[GetCurCPU()] = NULL;
@@ -46,11 +47,11 @@ noreturn void StartPanic(const char *str)
     }
 
     if (GetPanicStr()) {
-        GetStdOut()->PrintOnTermUnlocked(GetStdOut(), "double panic!\n");
+        GetStdOut()->PrintOnTermUnlocked(GetStdOut(), "\nDouble panic!\n");
         HaltCPU();
     }
 
-    SetPanicStr(str);
+    _SetPanicStr(str);
 
     GetStdOut()->PrintOnTermUnlocked(GetStdOut(), "PANIC! - ");
     GetStdOut()->PrintOnTermUnlocked(GetStdOut(), str);
diff --git a/kaleid/kernel/proc/sched.c b/kaleid/kernel/proc/sched.c
index b81ec45..ad040b1 100644
--- a/kaleid/kernel/proc/sched.c
+++ b/kaleid/kernel/proc/sched.c
@@ -66,12 +66,13 @@ void SchedUnlock(void) {
 //
 // The four priority classes of OS/2
 //
+
 CREATE_PER_CPU(IdlePrioProcs, ListHead_t *);
 CREATE_PER_CPU(ReglPrioProcs, ListHead_t *);
 CREATE_PER_CPU(ServPrioProcs, ListHead_t *);
 CREATE_PER_CPU(TimeCritProcs, ListHead_t *);
 
-char *PrioClassesNames[] = {
+const char *PrioClassesNames[] = {
             "Idle priority class",
             "Regular priority class",
             "Server priority class",
@@ -203,47 +204,55 @@ void BlockCurProc(void)
     SetCurProc(SelectSchedNext());
 }
 
+static inline
+void ReSchedCurProc(void)
+{
+    KalAssert(GetCurProc() && GetCurProc()->procState == STATE_RUNNING);
+
+    // Restore default attributes, cancelling boosts
+    GetCurProc()->prioClass = GetCurProc()->defPrioClass;
+    GetCurProc()->prioLevel = GetCurProc()->defPrioLevel;
+    GetCurProc()->timeSlice = GetCurProc()->defTimeSlice;
+    GetCurProc()->procState = STATE_RUNNABLE;
+
+    // Remove from list
+    RemoveNode(GetCurProc()->schedNode->head, GetCurProc()->schedNode);
+    GetCurProc()->schedNode = NULL;
+
+    // Schedule again, with default attributes now
+    SchedThisProcUnlocked(GetCurProc());
+}
+
 //
 // Should we schedule another process?
 // Called at each tick
 //
 void SchedOnTick(void)
 {
-    Process_t *procNext;
-    Process_t *winner;
-
     SchedLock();
 
+    Process_t *procNext, *winner, *previous = GetCurProc();
+
     //
     // We're either idle or running something
     //
     KalAssert(GetCurProc() == NULL || GetCurProc()->procState == STATE_RUNNING);
 
     //
-    // Has current process spent his timeslice?
+    // Have the current process spent its timeslice?
     // (To be handled in CPU decisions function)
     //
     if (GetCurProc() != NULL) {
         if (GetCurProc()->timeSlice <= 1) {
+            // Re-schedule
+            ReSchedCurProc();
 
-            // Restore default attributes, cancelling boosts
-            GetCurProc()->prioClass = GetCurProc()->defPrioClass;
-            GetCurProc()->prioLevel = GetCurProc()->defPrioLevel;
-            GetCurProc()->timeSlice = GetCurProc()->defTimeSlice;
-            GetCurProc()->procState = STATE_RUNNABLE;
-
-            // Remove from list
-            RemoveNode(GetCurProc()->schedNode->head, GetCurProc()->schedNode);
-
-            // Schedule again, with default attributes now
-            SchedThisProcUnlocked(GetCurProc());
-
-            // Mark as idle
-            SetCurProc(NULL);
+            // See next 'if' statement
+            _SetCurProc(NULL);
         }
 
         //
-        // Otherwise, make him lose a tick
+        // Otherwise, make it lose a tick
         //
         else {
             GetCurProc()->timeSlice--;
@@ -268,8 +277,10 @@ void SchedOnTick(void)
     // Yes, procNext should preempt current process
     //
     if (winner == procNext) {
-        GetCurProc()->procState = STATE_RUNNABLE;
-        SchedThisProcUnlocked(GetCurProc());
+        // Re-schedule
+        ReSchedCurProc();
+
+        // Switch to procNext
         SetCurProc(procNext);
     }
 
@@ -278,32 +289,10 @@ void SchedOnTick(void)
     //
 leave:
     SchedUnlock();
-}
 
-#define PrintProc(proc) printdbg("{ %d, '%s', %d , %d}\n", (proc)->pid, \
-                                 PrioClassesNames[(proc)->prioClass], (proc)->prioLevel, (proc)->timeSlice);
-
-//
-// Print out process list
-//
-void PrintList(ListHead_t *head)
-{
-    KalAssert(head);
-
-    Process_t *proc;
-    ListNode_t *node = head->first;
-
-    printdbg("len: %d\n", head->length);
-
-    while (node) {
-        proc = GetNodeData(node, Process_t *);
-
-        PrintProc(proc);
-
-        node = node->next;
+    if (GetCurProc() != NULL && GetCurProc() != previous) {
+        // XXX context switch
     }
-
-    puts("");
 }
 
 //
@@ -355,6 +344,33 @@ void FiniSched(void)
 }
 
 #ifndef _KALEID_KERNEL
+
+#define PrintProc(proc) printdbg("{ %d, '%s', %d , %d}\n", (proc)->pid, \
+                                 PrioClassesNames[(proc)->prioClass], (proc)->prioLevel, (proc)->timeSlice);
+
+//
+// Print out process list
+//
+void PrintList(ListHead_t *head)
+{
+    KalAssert(head);
+
+    Process_t *proc;
+    ListNode_t *node = head->first;
+
+    printdbg("len: %d\n", head->length);
+
+    while (node) {
+        proc = GetNodeData(node, Process_t *);
+
+        PrintProc(proc);
+
+        node = node->next;
+    }
+
+    puts("");
+}
+
 int main(void)
 {
     InitSched();
@@ -379,7 +395,17 @@ int main(void)
 
     int tick = 0;
 
-    while (tick < 20) {
+    while (tick < 120) {
+        if (tick > 0 && tick != 50 && tick % 10 == 0) {
+            puts("Blocking current process");
+            BlockCurProc();
+        }
+
+        if (tick == 50) {
+            procs[2].procState = STATE_RUNNABLE;
+            SchedThisProc(&procs[2]);
+        }
+
         printf("Tick %d - Running: ", tick);
 
         if (GetCurProc() == NULL) {
@@ -390,14 +416,8 @@ int main(void)
             PrintProc(GetCurProc());
         }
 
-        if (tick == 9 || tick == 14) {
-            puts("Blocking current process");
-            BlockCurProc();
-        }
-
         SchedOnTick();
 
-        //puts("\n---------------");
         tick++;
     }
 
@@ -405,5 +425,6 @@ int main(void)
 
     return 0;
 }
+
 #endif