openwrt/target/linux/apm821xx/image/mbl_gen_hdd_img.sh
Christian Lamparter aed4799d6d apm821xx: build squashfs-rootfs images for the MBL
This patch adds support for squashfs as the root filesystem.

advantages:
 - migrate from a existing -ext4 installation and back
   with the sysupgrade utility
 - existing partition layout will not be lost during switch
 - slightly smaller image size as compared to the -ext4 image.

disadvantages:
 - needs f2fs + tools. This is because fstools rootdisk.c decides based
   on the partition size (currently root partitions > 100 MiB) f2fs is
   used as the rootfs_data filesystem.
 - rootfs_data is placed into the rootfs partition after the squashfs.
   This makes it difficult for tools that expect a /dev/sda${X} device.
   It also makes it difficult for data recovery tools as they might not
   expect to find a embedded partition or will be slightly confused.
   ... or will not support f2fs.

For people with existing build configurations: make sure to include mkf2fs
and f2fsck packages into the image. Otherwise the new -squashfs image will
only boot from the ram-overlay.

Note:
All overlay data (configurations/all installed packages/...) will be
placed in inside the rootfs partition (i.e. /dev/sda2) just after the
squashfs image.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
2018-07-30 08:11:56 +02:00

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#!/usr/bin/env bash
set -x
[ $# -eq 5 ] || {
echo "SYNTAX: $0 <file> <bootfs image> <rootfs image> <bootfs size> <rootfs size>"
exit 1
}
OUTPUT="$1"
BOOTFS="$2"
ROOTFS="$3"
BOOTFSSIZE="$4"
ROOTFSSIZE="$5"
head=4
sect=63
set `ptgen -o $OUTPUT -h $head -s $sect -l 4096 -t 83 -p ${BOOTFSSIZE}M -t 83 -p ${ROOTFSSIZE}M`
BOOTOFFSET="$(($1 / 512))"
BOOTSIZE="$(($2 / 512))"
ROOTFSOFFSET="$(($3 / 512))"
ROOTFSSIZE="$(($4 / 512))"
dd bs=512 if="$BOOTFS" of="$OUTPUT" seek="$BOOTOFFSET" conv=notrunc
dd bs=512 if="$ROOTFS" of="$OUTPUT" seek="$ROOTFSOFFSET" conv=notrunc