User guide

Atmel AVR2054: Serial Bootloader User Guide [APPLICATION NOTE]

8390D−WIRELESS−03/2015

4. Bootloader PC tool

The Bootloader PC tool is a PC application that is used to load a firmware image to a device programmed with the

embedded bootloader code. Connection to the MCU shall be enumerated as a COM or USB port depending on the

interface used. Source firmware images shall be in the Motorola S-record (SREC) format. Such images are created

during compilation further to .hex and .elf images. A device must be pre-programmed with an image of the embedded

bootloader application, which will receive data sent by the Bootloader PC tool and write it to the device’s flash.

Another use of the Bootloader PC tool is initiating Over-the-Air Upgrade. This document does not cover this usage of the

tool for this purpose. A complete guide to Over-the-Air Upgrade of ZigBee networks is given in [8].

4.1 Using the Bootloader PC tool

To install the Bootloader PC tool, launch the installation file from the \PC_Bootloader_Setup\ and proceed with

instructions. After setup is completed both GUI and console versions of the bootloader are extracted to the provided

installation path. The Bootloader PC tool is a Java application, and to launch it Java [14] must be installed on the host

PC.

As a firmware image the Bootloader PC tool requires a file in the Motorola S-record hexadecimal format, also known as

SREC or S19 format. Such file names have the .srec extension and can contain both flash memory and EEPROM

images.

4.1.1 Generating SREC images

4.1.1.1

Using GCC tools

An SREC image can be generated from initial binary image with the help of a special tool supplied with a tool chain.

• For Atmel AVR use avr-objcopy.exe tool provided in AVR toolchain for Atmel Studio 6

• For ARM use arm-elf-objcopy.exe tool, which is a part of the Yagarto GCC toolchain

For example, to generate an SREC image from a .hex image for AVR run a command in the following format from the

command line:

avr-objcopy.exe -O srec --srec-len 128 <srcFile> <destFile>

For ARM just replace the name of the AVR tool with

arm-elf-objcopy.exe. Note that this tool takes an image in the

.elf format as input.

4.1.1.2 Using IAR tools

If you use IAR toolchain to compile applications you may also specify a directive for the linker to create an SREC image:

• For command line compilation add -Omotorola-s28=<path>/<fileName>.srec to the linker flags

• For IAR Embedded Workbench

• Open configuration’s options and go to

Linker

• On the

Extra Output tab check the Generate extra output file box, specify the image name and

select

motorola-s28 as Output format

An image generated by the IAR compiler may be also converted to SREC format with the

avr-objcopy.exe or arm-

elf-objcopy.exe.