atusb/fw: use the unique serial number of the ATmega8/16/32U2 for iSerialNumber

- usb/usb.h (USB_LANGID_ENGLISH_US): added USB LANGID for US-English
- board.h (board_sernum), board.c (board_sernum, hex, get_sernum,
  board_init): provide the board's serial number in "board_sernum"
  (UTF-encoded)
- sernum.h (sernum_get_descr), sernum.c (sernum_get_descr): return
  string descriptors for the serial number
- descr.c (device_descriptor), usb/dfu.c (device_descriptor):
  set iSerialNumber if serial number is available
- atusb.c (main), usb/dfu.c (my_descr): call sernum_get_descr for
  unknown descriptors
- Makefile (OBJS, BOOT_OBJS): added sernum.o

atusb/fw/Makefile

@@ -29,8 +29,8 @@ OBJCOPY = $(AVR_PREFIX)objcopy
 SIZE = $(AVR_PREFIX)size
 
 USB_OBJS  = usb.o atu2.o
-OBJS = atusb.o board.o spi.o descr.o ep0.o $(USB_OBJS)
-BOOT_OBJS = boot.o board.o spi.o flash.o dfu.o $(USB_OBJS)
+OBJS = atusb.o board.o sernum.o spi.o descr.o ep0.o $(USB_OBJS)
+BOOT_OBJS = boot.o board.o sernum.o spi.o flash.o dfu.o $(USB_OBJS)
 
 vpath %.c usb/
 

atusb/fw/atusb.c

@@ -18,6 +18,7 @@
 #include "usb.h"
 
 #include "board.h"
+#include "sernum.h"
 #include "spi.h"
 #include "atusb/ep0.h"
 
@@ -28,6 +29,8 @@ int main(void)
 	spi_init();
 	reset_rf();
 
+	user_get_descriptor = sernum_get_descr;
+
 	/* now we should be at 8 MHz */
 
 	usb_init();

atusb/fw/board.c

@@ -15,15 +15,20 @@
 
 #include <avr/io.h>
 #include <avr/interrupt.h>
+#include <avr/boot.h>
 
 #define F_CPU   8000000UL
 #include <util/delay.h>
 
+#include "usb.h"
 #include "at86rf230.h"
 #include "board.h"
 #include "spi.h"
 
 
+uint8_t board_sernum[42] = { 42, USB_DT_STRING };
+
+
 static void set_clkm(void)
 {
 	/* switch CLKM to 8 MHz */
@@ -94,6 +99,25 @@ void panic(void)
 }
 
 
+static char hex(uint8_t nibble)
+{
+	return nibble < 10 ? '0'+nibble : 'a'+nibble-10;
+}
+
+
+static void get_sernum(void)
+{
+	uint8_t sig;
+	int i;
+
+	for (i = 0; i != 10; i++) {
+		sig = boot_signature_byte_get(i+0xe);
+		board_sernum[(i << 2)+2] = hex(sig >> 4);
+		board_sernum[(i << 2)+4] = hex(sig & 0xf);
+	}
+}
+
+
 void board_init(void)
 {
 	/* Disable the watchdog timer */
@@ -111,6 +135,8 @@ void board_init(void)
 	/* set up all the outputs; default port value is 0 */
 
 	OUT(LED);
-	OUT(nRST_RF);   /* resets the transceiver */
+	OUT(nRST_RF);   /* this also resets the transceiver */
 	OUT(SLP_TR);
+
+	get_sernum();
 }

atusb/fw/board.h

@@ -62,6 +62,11 @@
 #define	DFU_USB_PRODUCT	USB_PRODUCT
 
 
+#define	HAS_BOARD_SERNUM
+
+extern uint8_t board_sernum[42];
+
+
 void reset_rf(void);
 void reset_cpu(void);
 uint8_t read_irq(void);

atusb/fw/descr.c

@@ -34,7 +34,11 @@ const uint8_t device_descriptor[18] = {
 	LE(0x0001),		/* bcdDevice */
 	0,			/* iManufacturer */
 	0,			/* iProduct */
+#ifdef HAS_BOARD_SERNUM
+	1,			/* iSerialNumber */
+#else
 	0,			/* iSerialNumber */
+#endif
 	1			/* bNumConfigurations */
 };
 

atusb/fw/sernum.c

@@ -0,0 +1,46 @@
+/*
+ * fw/sernum.c - ATUSB serial number
+ *
+ * Written 2008-2011 by Werner Almesberger
+ * Copyright 2008-2011 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#include <stdint.h>
+
+#include "usb.h"
+
+#include "board.h"
+#include "sernum.h"
+
+
+static const uint8_t string_descriptor_0[] = {
+	4,				/* blength */
+	USB_DT_STRING,			/* bDescriptorType */
+	LE(USB_LANGID_ENGLISH_US)	/* wLANGID[0]  */
+};
+
+
+int sernum_get_descr(uint8_t type, uint8_t index, const uint8_t **reply,
+    uint8_t *size)
+{
+	if (type != USB_DT_STRING)
+		return 0;
+	switch (index) {
+	case 0:
+		*reply = string_descriptor_0;
+		*size = sizeof(string_descriptor_0);
+		return 1;
+	case 1:
+		*reply = board_sernum;
+		*size = sizeof(board_sernum);
+		return 1;
+	default:
+		return 0;
+	}
+}

atusb/fw/sernum.h

@@ -0,0 +1,36 @@
+/*
+ * fw/sernum.h - ATUSB serial number
+ *
+ * Written 2011 by Werner Almesberger
+ * Copyright 2011 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef SERNUM_H
+#define	SERNUM_H
+
+#include <stdint.h>
+
+#include "board.h"
+
+
+#ifdef HAS_BOARD_SERNUM
+
+int sernum_get_descr(uint8_t type, uint8_t index, const uint8_t **reply,
+    uint8_t *size);
+
+#else /* HAS_BOARD_SERNUM */
+
+static inline int sernum_get_descr(uint8_t type, uint8_t index,
+    const uint8_t **reply, uint8_t *size)
+{
+	return 0;
+}
+
+#endif /* !HAS_BOARD_SERNUM */
+
+#endif /* !SERNUM_H */

atusb/fw/usb/dfu.c

@@ -31,6 +31,7 @@
 #include "dfu.h"
 
 #include "../board.h"
+#include "../sernum.h"
 
 
 #ifndef NULL
@@ -54,7 +55,11 @@ const uint8_t device_descriptor[] = {
 	LE(0x0001),		/* bcdDevice */
 	0,			/* iManufacturer */
 	0,			/* iProduct */
+#ifdef HAS_BOARD_SERNUM
+	1,			/* iSerialNumber */
+#else
 	0,			/* iSerialNumber */
+#endif
 	1			/* bNumConfigurations */
 };
 
@@ -262,7 +267,7 @@ static int my_descr(uint8_t type, uint8_t index, const uint8_t **reply,
     uint8_t *size)
 {
 	if (type != DFU_DT_FUNCTIONAL)
-		return 0;
+		return sernum_get_descr(type, index, reply, size);
 	*reply = functional_descriptor;
 	*size = sizeof(functional_descriptor);
 	return 1;

atusb/fw/usb/usb.h

@@ -1,8 +1,8 @@
 /*
  * fw/usb//usb.h - USB hardware setup and standard device requests
  *
- * Written 2008, 2009 by Werner Almesberger
- * Copyright 2008, 2009 Werner Almesberger
+ * Written 2008, 2009, 2011 by Werner Almesberger
+ * Copyright 2008, 2009, 2011 Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -74,6 +74,14 @@
 #define	SET_INTERFACE		0x0b
 #define	SYNCH_FRAME		0x0c
 
+/*
+ * USB Language ID codes
+ *
+ * http://www.usb.org/developers/docs/USB_LANGIDs.pdf
+ */
+
+#define	USB_LANGID_ENGLISH_US	0x409
+
 
 /*
  * Odd. sdcc seems to think "x" assumes the size of the destination, i.e.,