extractfuses.sh

#!/bin/sh
# Copyright 2010 Stefan Reinhold <development@ithron.de>. All rights reserved.
#
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#
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#       of conditions and the following disclaimer in the documentation and/or other materials
#       provided with the distribution.
# 
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# FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL STEFAN REINHOLD OR
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FUSECMD="avr-objdump -s -j .fuse $2"

function help_message
{
	echo "Usage: $0 [a|l|h|e|avrdude] elf-file"
}

function objdump_error
{
	if ($FUSECMD 2>&1 | grep -q "section.*not found")
	then
		cat<<EOF 1>&2
Error: The .fuse section was not found.

In avr-libc 1.8 the FUSES helper macro does not add the attribute "used". As a
result the section can be dropped due to linker optimizations.  This appears to
be fixed in avr-libc as of at least svn r2297.

As a workaround, use
__fuse_t __fuse __attribute__((section (".fuse"), used)) = 
{
    .low = LFUSE_DEFAULT,
    .high = HFUSE_DEFAULT,
    .extended = EFUSE_DEFAULT
};

rather than

FUSES =
{
    .low = LFUSE_DEFAULT,
    .high = HFUSE_DEFAULT,
    .extended = EFUSE_DEFAULT
};
EOF
	fi
	exit 1
}

if [ $# -ne 2 ]
then
	help_message
	exit 0
fi

fuses=`$FUSECMD | tail -n 1 | sed 's/^ *[0-9a-f]\{6,6\}[ \t][ \t]*\([0-9a-f]\{6,6\}\).*/\1/'`

if [ "$fuses"x == x ]
then
	objdump_error
fi

low=`echo $fuses | sed 's/\([0-9a-f]\{2,2\}\)[0-9a-f]\{4,4\}/\1/'`
high=`echo $fuses | sed 's/[0-9a-f]\{2,2\}\([0-9a-f]\{2,2\}\)[0-9a-f]\{2,2\}/\1/'`
extended=`echo $fuses | sed 's/[0-9a-f]\{4,4\}\([0-9a-f]\{2,2\}\)/\1/'`

case $1 in
	"a") echo $fuses ;;
	"l") echo $low ;;
	"h") echo $high ;;
	"e") echo $extended ;;
	"avrdude") echo "-U lfuse:w:0x$low:m -U hfuse:w:0x$high:m -U efuse:w:0x$extended:m" ;;
	*) help_message
esac