openwrt/scripts/gen_image_generic.sh
Daniel Golle 4d289ae7e6
scripts/gen_image_generic.sh: fix order of files in EFI bootfs
mtools recursive copy (mcopy -s ...) is using READDIR(3) to iterate
over the directory entries, hence they end up in the FAT filesystem in
traversal order which breaks reproducibility (rather than being added
to the FAT filesystem in a reproducible order). Implement recursive
copy in gen_image_generic.sh in Shell code instead, as in that way we
can force files to be copied in reproducible order.

Fixes: aece8f5ae8 ("scripts/gen_image_generic.sh: generate reproducible EFI filesystem")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2022-04-15 01:17:04 +01:00

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#!/bin/sh
# Copyright (C) 2006-2012 OpenWrt.org
set -e -x
if [ $# -ne 5 ] && [ $# -ne 6 ]; then
echo "SYNTAX: $0 <file> <kernel size> <kernel directory> <rootfs size> <rootfs image> [<align>]"
exit 1
fi
OUTPUT="$1"
KERNELSIZE="$2"
KERNELDIR="$3"
ROOTFSSIZE="$4"
ROOTFSIMAGE="$5"
ALIGN="$6"
rm -f "$OUTPUT"
head=16
sect=63
# create partition table
set $(ptgen -o "$OUTPUT" -h $head -s $sect ${GUID:+-g} -p "${KERNELSIZE}m" -p "${ROOTFSSIZE}m" ${ALIGN:+-l $ALIGN} ${SIGNATURE:+-S 0x$SIGNATURE} ${GUID:+-G $GUID})
KERNELOFFSET="$(($1 / 512))"
KERNELSIZE="$2"
ROOTFSOFFSET="$(($3 / 512))"
ROOTFSSIZE="$(($4 / 512))"
# Using mcopy -s ... is using READDIR(3) to iterate through the directory
# entries, hence they end up in the FAT filesystem in traversal order which
# breaks reproducibility.
# Implement recursive copy with reproducible order.
dos_dircopy() {
local entry
local baseentry
for entry in "$1"/* ; do
if [ -f "$entry" ]; then
mcopy -i "$OUTPUT.kernel" "$entry" ::"$2"
elif [ -d "$entry" ]; then
baseentry="$(basename "$entry")"
mmd -i "$OUTPUT.kernel" ::"$2""$baseentry"
dos_dircopy "$entry" "$2""$baseentry"/
fi
done
}
[ -n "$PADDING" ] && dd if=/dev/zero of="$OUTPUT" bs=512 seek="$ROOTFSOFFSET" conv=notrunc count="$ROOTFSSIZE"
dd if="$ROOTFSIMAGE" of="$OUTPUT" bs=512 seek="$ROOTFSOFFSET" conv=notrunc
if [ -n "$GUID" ]; then
[ -n "$PADDING" ] && dd if=/dev/zero of="$OUTPUT" bs=512 seek="$((ROOTFSOFFSET + ROOTFSSIZE))" conv=notrunc count="$sect"
mkfs.fat --invariant -n kernel -C "$OUTPUT.kernel" -S 512 "$((KERNELSIZE / 1024))"
LC_ALL=C dos_dircopy "$KERNELDIR" /
else
make_ext4fs -J -L kernel -l "$KERNELSIZE" ${SOURCE_DATE_EPOCH:+-T ${SOURCE_DATE_EPOCH}} "$OUTPUT.kernel" "$KERNELDIR"
fi
dd if="$OUTPUT.kernel" of="$OUTPUT" bs=512 seek="$KERNELOFFSET" conv=notrunc
rm -f "$OUTPUT.kernel"