atusb/fw/: flash a boot loader instead of the application (in progress)

- boot.c: basic boot loader that runs DFU for 2 s, then starts the payload
- board.h (DFU_USB_VENDOR, DFU_USB_PRODUCT): added USB IDs for DFU
- flash.c: stubs for board-specific Flash functions
- Makefile: build boot.hex for the boot loader
- Makefile (prog): load the boot loader at its rightful place
- Makefile (prog): also set hfuse and the lock fuse

atusb/fw/Makefile

@@ -24,9 +24,11 @@ AVR_PREFIX = $(BIN_PATH) avr-
 CC = $(AVR_PREFIX)gcc
 OBJCOPY = $(AVR_PREFIX)objcopy
 #OBJDUMP = $(AVR_PREFIX)objdump
+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)
 
 vpath %.c usb/
 
@@ -56,20 +58,30 @@ endif
 
 .PHONY:		all clean upload prog version.c
 
-all:		$(NAME).bin
+all:		$(NAME).bin boot.hex
 
 $(NAME).elf:	$(OBJS)
 		$(MAKE) version.o
 		$(CC) $(CFLAGS) -mmcu=$(CHIP) -o $@ $(OBJS) version.o
 
+boot.elf:	$(BOOT_OBJS)
+		$(CC) $(CFLAGS) -mmcu=$(CHIP) -o $@ $(BOOT_OBJS) \
+		  -Wl,--section-start=.text=0x7000
+
 %.bin:		%.elf
 		$(BUILD) $(OBJCOPY) -j .text -j .data -O binary $< $@
 		@echo "build #`cat .version`, `ls -l $@`"
 
+%.hex:		%.elf
+		$(BUILD) $(OBJCOPY) -j .text -j .data -O ihex $< $@
+		$(SIZE) $@
+
 # ----- Cleanup ---------------------------------------------------------------
 
 clean:
-		rm -f $(NAME).bin $(NAME).elf $(OBJS) $(OBJS:.o=.d)
+		rm -f $(NAME).bin $(NAME).elf
+		rm -f $(OBJS) $(OBJS:.o=.d)
+		rm -f $(BOOT_OBJS) $(BOOT_OBJS:.o=.d)
 		rm -f version.c version.d version.o
 
 # ----- Build version ---------------------------------------------------------
@@ -102,13 +114,21 @@ version.c:
 
 # ----- Programming and device control ----------------------------------------
 
-upload:		$(NAME).bin
-		scp $(NAME).bin $(HOST):
+upload:		$(NAME).bin boot.hex
+		scp $(NAME).bin boot.hex $(HOST):
+
+# lfuse: external clock, slow start-up
+# hfuse: 4 kB boot loader, reset into boot loader
+# lock: allow everything but SPM to the boot loader
 
 prog:
 		ssh $(HOST) avrdude -F -p $(CHIP) -c nanonote_atusb -e \
-		  -U flash:w:$(NAME).bin:r \
-		  -U lfuse:w:0x60:m		# external clock, slow start-up
+		  -U flash:w:boot.hex:i \
+		  -U lfuse:w:0x60:m \
+		  -U hfuse:w:0xde:m \
+		  -U lock:w:0xef:m
+
+#		  -U flash:w:$(NAME).bin:r \
 
 on:
 		ssh $(HOST) poke 0x10010318 4

atusb/fw/board.h

@@ -58,11 +58,16 @@
 #define	USB_VENDOR	0x20b7	/* Qi Hardware */
 #define	USB_PRODUCT	0x1540	/* ben-wpan atusb */
 
+#define	DFU_USB_VENDOR	USB_VENDOR
+#define	DFU_USB_PRODUCT	USB_PRODUCT
+
 
 void reset_rf(void);
 uint8_t read_irq(void);
+
 void led(int on);
 void panic(void);
+
 void board_init(void);
 
 #endif /* !BOARD_H */

atusb/fw/boot.c

@@ -0,0 +1,63 @@
+/*
+ * fw/boot.c - DFU boot loader for ATUSB
+ *
+ * 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 <avr/io.h>
+
+#define F_CPU   8000000UL
+#include <util/delay.h>
+
+#include "usb.h"
+#include "dfu.h"
+
+#include "board.h"
+#include "spi.h"
+#include "atusb/ep0.h"
+
+
+#define	MS_TO_LOOPS(ms) ((uint32_t) (ms)*81)
+
+
+static void (*run_payload)(void) = 0;
+
+
+int main(void)
+{
+	uint32_t loop = 0;
+
+	board_init();
+	spi_init();
+	reset_rf();
+
+	/* now we should be at 8 MHz */
+
+	usb_init();
+	dfu_init();
+
+	led(1);
+
+	while (loop != MS_TO_LOOPS(2000)) {
+		usb_poll();
+		if (dfu.state == dfuIDLE)
+			loop++;
+		else
+			loop = 0;
+	}
+
+	led(0);
+
+	run_payload();
+
+	while (1);	/* not reached */
+}

atusb/fw/flash.c

@@ -0,0 +1,46 @@
+/*
+ * fw/flash.c - Board-specific flash functions
+ *
+ * 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.
+ */
+
+
+#include <stdint.h>
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+#define F_CPU   8000000UL
+#include <util/delay.h>
+
+#include "dfu.h"
+#include "board.h"
+
+
+
+void flash_start(void)
+{
+}
+
+
+int flash_can_write(uint16_t size)
+{
+	return 0;
+}
+
+
+void flash_write(const uint8_t *buf, uint16_t size)
+{
+}
+
+
+uint16_t flash_read(uint8_t *buf, uint16_t size)
+{
+	return 0;
+}