#!/bin/bash
#
# This file is part of the coreboot project.
#
# Copyright (C) 2008 Carl-Daniel Hailfinger
#
# 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; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
#
#
# This program checks whether a given list of files ($3+) has any writable
# and allocatable non-empty sections. If so, the name of the file, the name of
# the section and the symbols in that section are printed and an error is
# returned.
#
# This is extremely useful for stage1 and initram correctness because
# the .data* and .bss sections are silently dropped. All accesses there
# would wreak havoc (silent discard of writes or silent corruption of
# unspecified memory or cache).
#
# The string parsing used here heavily depends on the textual form of
# GNU objdump output and on the instruction architecture of the files.

LANG=C
OBJDUMP=$1
READELF=$2
shift 2
for a in $*; do
	# Look for sections which have WRITE and ALLOC flags set.
	$READELF -St $a|
		grep -B2 "WRITE.*ALLOC"|
		grep -B1 "^ \+[[:alnum:]]\+ \+[0-9a-f]\+ \+[0-9a-f]\+ \+0*[1-9a-f]"|
		grep "^ \+\[ *[0-9]\+"|
		cut -f 2 -d"]"|
		sed "s/^[[:blank:]]*//"|
		while read b; do
			echo -n "$a: section $b: "
			$OBJDUMP -t --section=$b $a|
				grep -i "^[0-9a-f]\{8\}"|
				grep -v "00000000 [^ ]\+$"|
				sed "s/.* //"|
				xargs echo
		done
done|
	grep ""

# Invert the result
test $? -ne 0