+
+extern const char hex_asc[];
+#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
+#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
+
+static inline char *pack_hex_byte(char *buf, u8 byte)
+{
+ *buf++ = hex_asc_hi(byte);
+ *buf++ = hex_asc_lo(byte);
+ return buf;
+}