diff --git a/kernel/Makefile b/kernel/Makefile
index ab1e072..2d34e68 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -12,6 +12,7 @@ export CPPFLAGS := -I$(HOS_TOPLEVEL) -I$(HOS_TOPLEVEL)/include
 export CFLAGS   := -Wall -O2
 export CXXFLAGS := -Wall -O2 -fno-rtti -fno-exceptions
 export LDFLAGS  := -T $(LDSCRIPT) -Map $(KERNEL).map
+export LDLIBS   := `$(CC) -print-libgcc-file-name`
 
 SUBDIRS         := boot mm lang
 SUBDIRS_clean   := $(SUBDIRS:%=%.clean)
@@ -23,7 +24,7 @@ $(KERNEL).gz: $(KERNEL)
 	gzip -c $< > $@
 
 $(KERNEL): $(SUBDIRS)
-	$(LD) $(LDFLAGS) -o $@ $(foreach subdir,$(SUBDIRS),$(subdir)/$(subdir)_all.o)
+	$(LD) $(LDFLAGS) -o $@ $(foreach subdir,$(SUBDIRS),$(subdir)/$(subdir)_all.o) $(LDLIBS)
 
 .PHONY: $(SUBDIRS)
 $(SUBDIRS):
diff --git a/kernel/lang/kio.cc b/kernel/lang/kio.cc
index 227d76c..d30a9e6 100644
--- a/kernel/lang/kio.cc
+++ b/kernel/lang/kio.cc
@@ -2,6 +2,7 @@
 #include "kio.h"
 #include "string.h"
 
+#include <limits.h>
 #include <stdarg.h>                 /* va_*() */
 
 static void fmt_d2a(char * buf, int val);
@@ -95,7 +96,7 @@ void kputs(char * s)
 
 static void fmt_d2a(char * buf, int val)
 {
-    if (val == 0x7FFFFFFF)
+    if (val == INT_MIN)
     {
         strcpy(buf, "-2147483648");
     }
@@ -112,14 +113,55 @@ static void fmt_d2a(char * buf, int val)
 
 static void fmt_u2a(char * buf, unsigned int val)
 {
+    bool printing = false;
+    for (unsigned int div = 1000000000; div >= 1; div /= 10)
+    {
+        unsigned int n = val / div;
+        if (n)
+        {
+            printing = true;
+        }
+        if (printing)
+        {
+            *buf++ = '0' + (val % div);
+        }
+        val -= n * div;
+    }
 }
 
 static void fmt_ll2a(char * buf, long long val)
 {
+    if (val == LONG_LONG_MIN)
+    {
+        strcpy(buf, "-9223372036854775808");
+    }
+    else
+    {
+        if (val < 0)
+        {
+            *buf++ = '-';
+            val = -val;
+        }
+        fmt_ull2a(buf, (unsigned long long) val);
+    }
 }
 
 static void fmt_ull2a(char * buf, unsigned long long val)
 {
+    bool printing = false;
+    for (unsigned long long div = 10000000000000000000ull; div >= 1; div /= 10)
+    {
+        unsigned long long n = val / div;
+        if (n)
+        {
+            printing = true;
+        }
+        if (printing)
+        {
+            *buf++ = '0' + (val % div);
+        }
+        val -= n * div;
+    }
 }
 
 static void fmt_x2a(char * buf, unsigned int val)