diff --git a/kern/libkern/limits.h b/kern/libkern/limits.h
new file mode 100644
index 0000000..de21df2
--- /dev/null
+++ b/kern/libkern/limits.h
@@ -0,0 +1,26 @@
+/* Support signed or unsigned plain-char */
+
+#if '\xff' > 0
+#define CHAR_MIN 0
+#define CHAR_MAX 255
+#else
+#define CHAR_MIN (-128)
+#define CHAR_MAX 127
+#endif
+
+#define CHAR_BIT   8
+#define SCHAR_MIN  (-128)
+#define SCHAR_MAX  127
+#define UCHAR_MAX  255
+#define SHRT_MIN   (-1 - 0x7fff)
+#define SHRT_MAX   0x7fff
+#define USHRT_MAX  0xffff
+#define INT_MIN    (-1 - 0x7fffffff)
+#define INT_MAX    0x7fffffff
+#define UINT_MAX   0xffffffffU
+#define LONG_MIN   (-LONG_MAX - 1)
+#define LONG_MAX   __LONG_MAX
+#define ULONG_MAX  (2UL * LONG_MAX + 1)
+#define LLONG_MIN  (-LLONG_MAX - 1)
+#define LLONG_MAX  0x7fffffffffffffffLL
+#define ULLONG_MAX (2ULL * LLONG_MAX + 1)