image: add support for building FIT image with filesystem

Allow for single (external-data) FIT image to hold kernel, dtb and
squashfs. In that way, the bootloader verifies the system integrity
including the rootfs, because what's the point of checking that the
hash of the kernel is correct if it won't boot in case of squashfs
being corrupted? Better allow bootloader to check everything needed
to make it at least up to failsafe mode. As a positive side effect
this change also makes the sysupgrade process on nand potentially
much easier as it is now.
In short: mkimage has a parameter '-E' which allows generating FIT
images with 'external' data rather than embedding the data into the
device-tree blob itself. In this way, the FIT structure itself remains
small and can be parsed easily (rather than having to page around
megabytes of image content). This patch makes use of that and adds
support for adding sub-images of type 'filesystem' which are used to
store the squashfs. Now U-Boot can verify the whole OS and the new
partition parsers added in the Linux kernel can detect the filesystem
sub-images, create partitions for them, and select the active rootfs
volume based on the configuration in FIT (passing configuration via
device tree could be implemented easily at a later stage).

This new FIT partition parser works for NOR flash (on top of mtdblock),
NAND flash (on top of ubiblock) as well as classic block devices
(ie. eMMC, SDcard, SATA, NVME, ...).
It could even be used to mount such FIT images via `losetup -P` on a
user PC if this patch gets included in Linux upstream one day ;)

Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>

1 files changed, 63 insertions, 37 deletions

diff --git a/package/base-files/files/lib/upgrade/nand.sh b/package/base-files/files/lib/upgrade/nand.sh
index e6f58df4f5..7cf95c0139 100644
--- a/package/base-files/files/lib/upgrade/nand.sh
+++ b/package/base-files/files/lib/upgrade/nand.sh
@@ -3,13 +3,13 @@
 
 . /lib/functions.sh
 
-# 'kernel' partition on NAND contains the kernel
+# 'kernel' partition or UBI volume on NAND contains the kernel
 CI_KERNPART="${CI_KERNPART:-kernel}"
 
 # 'ubi' partition on NAND contains UBI
 CI_UBIPART="${CI_UBIPART:-ubi}"
 
-# 'rootfs' partition on NAND contains the rootfs
+# 'rootfs' UBI volume on NAND contains the rootfs
 CI_ROOTPART="${CI_ROOTPART:-rootfs}"
 
 ubi_mknod() {
@@ -117,9 +117,11 @@ nand_restore_config() {
 nand_upgrade_prepare_ubi() {
 	local rootfs_length="$1"
 	local rootfs_type="$2"
-	local has_kernel="${3:-0}"
+	local kernel_length="$3"
 	local has_env="${4:-0}"
 
+	[ -n "$rootfs_length" -o -n "$kernel_length" ] || return 1
+
 	local mtdnum="$( find_mtd_index "$CI_UBIPART" )"
 	if [ ! "$mtdnum" ]; then
 		echo "cannot find ubi mtd partition $CI_UBIPART"
@@ -148,23 +150,24 @@ nand_upgrade_prepare_ubi() {
 	local root_ubivol="$( nand_find_volume $ubidev $CI_ROOTPART )"
 	local data_ubivol="$( nand_find_volume $ubidev rootfs_data )"
 
-	# remove ubiblock device of rootfs
-	local root_ubiblk="ubiblock${root_ubivol:3}"
-	if [ "$root_ubivol" -a -e "/dev/$root_ubiblk" ]; then
-		echo "removing $root_ubiblk"
-		if ! ubiblock -r /dev/$root_ubivol; then
-			echo "cannot remove $root_ubiblk"
-			return 1;
+	local ubiblk ubiblkvol
+	for ubiblk in /dev/ubiblock*_? ; do
+		[ -e "$ubiblk" ] || continue
+		echo "removing ubiblock${ubiblk:13}"
+		ubiblkvol=ubi${ubiblk:13}
+		if ! ubiblock -r /dev/$ubiblkvol; then
+			echo "cannot remove $ubiblk"
+			return 1
 		fi
-	fi
+	done
 
 	# kill volumes
 	[ "$kern_ubivol" ] && ubirmvol /dev/$ubidev -N $CI_KERNPART || true
-	[ "$root_ubivol" ] && ubirmvol /dev/$ubidev -N $CI_ROOTPART || true
+	[ "$root_ubivol" -a "$root_ubivol" != "$kern_ubivol" ] && ubirmvol /dev/$ubidev -N $CI_ROOTPART || true
 	[ "$data_ubivol" ] && ubirmvol /dev/$ubidev -N rootfs_data || true
 
 	# update kernel
-	if [ "$has_kernel" = "1" ]; then
+	if [ -n "$kernel_length" ]; then
 		if ! ubimkvol /dev/$ubidev -N $CI_KERNPART -s $kernel_length; then
 			echo "cannot create kernel volume"
 			return 1;
@@ -172,15 +175,17 @@ nand_upgrade_prepare_ubi() {
 	fi
 
 	# update rootfs
-	local root_size_param
-	if [ "$rootfs_type" = "ubifs" ]; then
-		root_size_param="-m"
-	else
-		root_size_param="-s $rootfs_length"
-	fi
-	if ! ubimkvol /dev/$ubidev -N $CI_ROOTPART $root_size_param; then
-		echo "cannot create rootfs volume"
-		return 1;
+	if [ -n "$rootfs_length" ]; then
+		local root_size_param
+		if [ "$rootfs_type" = "ubifs" ]; then
+			root_size_param="-m"
+		else
+			root_size_param="-s $rootfs_length"
+		fi
+		if ! ubimkvol /dev/$ubidev -N $CI_ROOTPART $rootfs_size_param; then
+			echo "cannot create rootfs volume"
+			return 1;
+		fi
 	fi
 
 	# create rootfs_data for non-ubifs rootfs
@@ -232,7 +237,7 @@ nand_upgrade_ubinized() {
 nand_upgrade_ubifs() {
 	local rootfs_length=$( (cat $1 | wc -c) 2> /dev/null)
 
-	nand_upgrade_prepare_ubi "$rootfs_length" "ubifs" "0" "0"
+	nand_upgrade_prepare_ubi "$rootfs_length" "ubifs" "" ""
 
 	local ubidev="$( nand_find_ubi "$CI_UBIPART" )"
 	local root_ubivol="$(nand_find_volume $ubidev $CI_ROOTPART)"
@@ -241,39 +246,59 @@ nand_upgrade_ubifs() {
 	nand_do_upgrade_success
 }
 
+nand_upgrade_fit() {
+	local fit_file="$1"
+	local fit_length="$(wc -c < "$fit_file")"
+
+	nand_upgrade_prepare_ubi "" "" "$fit_length" "1"
+
+	local fit_ubidev="$(nand_find_ubi "$CI_UBIPART")"
+	local fit_ubivol="$(nand_find_volume $fit_ubidev "$CI_KERNPART")"
+	ubiupdatevol /dev/$fit_ubivol -s $fit_length $fit_file
+
+	nand_do_upgrade_success
+}
+
 nand_upgrade_tar() {
 	local tar_file="$1"
 	local kernel_mtd="$(find_mtd_index $CI_KERNPART)"
 
-	local board_dir=$(tar tf $tar_file | grep -m 1 '^sysupgrade-.*/$')
+	local board_dir=$(tar tf "$tar_file" | grep -m 1 '^sysupgrade-.*/$')
 	board_dir=${board_dir%/}
 
-	local kernel_length=$( (tar xf $tar_file ${board_dir}/kernel -O | wc -c) 2> /dev/null)
-	local rootfs_length=$( (tar xf $tar_file ${board_dir}/root -O | wc -c) 2> /dev/null)
+	kernel_length=$( (tar xf "$tar_file" ${board_dir}/kernel -O | wc -c) 2> /dev/null)
+	local has_rootfs=0
+	local rootfs_length
+	local rootfs_type
 
-	local rootfs_type="$(identify_tar "$tar_file" ${board_dir}/root)"
+	tar tf "$tar_file" ${board_dir}/root 1>/dev/null 2>/dev/null && has_rootfs=1
+	[ "$has_rootfs" = "1" ] && {
+		rootfs_length=$( (tar xf "$tar_file" ${board_dir}/root -O | wc -c) 2> /dev/null)
+		rootfs_type="$(identify_tar "$tar_file" ${board_dir}/root)"
+	}
 
 	local has_kernel=1
 	local has_env=0
 
 	[ "$kernel_length" != 0 -a -n "$kernel_mtd" ] && {
-		tar xf $tar_file ${board_dir}/kernel -O | mtd write - $CI_KERNPART
+		tar xf "$tar_file" ${board_dir}/kernel -O | mtd write - $CI_KERNPART
 	}
-	[ "$kernel_length" = 0 -o ! -z "$kernel_mtd" ] && has_kernel=0
+	[ "$kernel_length" = 0 -o ! -z "$kernel_mtd" ] && has_kernel=
 
-	nand_upgrade_prepare_ubi "$rootfs_length" "$rootfs_type" "$has_kernel" "$has_env"
+	nand_upgrade_prepare_ubi "$rootfs_length" "$rootfs_type" "${has_kernel:+$kernel_length}" "$has_env"
 
 	local ubidev="$( nand_find_ubi "$CI_UBIPART" )"
 	[ "$has_kernel" = "1" ] && {
-		local kern_ubivol="$(nand_find_volume $ubidev $CI_KERNPART)"
-		tar xf $tar_file ${board_dir}/kernel -O | \
+		local kern_ubivol="$( nand_find_volume $ubidev $CI_KERNPART )"
+		tar xf "$tar_file" ${board_dir}/kernel -O | \
 			ubiupdatevol /dev/$kern_ubivol -s $kernel_length -
 	}
 
-	local root_ubivol="$(nand_find_volume $ubidev $CI_ROOTPART)"
-	tar xf $tar_file ${board_dir}/root -O | \
-		ubiupdatevol /dev/$root_ubivol -s $rootfs_length -
-
+	[ "$has_rootfs" = "1" ] && {
+		local root_ubivol="$( nand_find_volume $ubidev $CI_ROOTPART )"
+		tar xf "$tar_file" ${board_dir}/root -O | \
+			ubiupdatevol /dev/$root_ubivol -s $rootfs_length -
+	}
 	nand_do_upgrade_success
 }
 
@@ -284,6 +309,7 @@ nand_do_upgrade() {
 	[ ! "$(find_mtd_index "$CI_UBIPART")" ] && CI_UBIPART="rootfs"
 
 	case "$file_type" in
+		"fit")		nand_upgrade_fit $1;;
 		"ubi")		nand_upgrade_ubinized $1;;
 		"ubifs")	nand_upgrade_ubifs $1;;
 		*)		nand_upgrade_tar $1;;
@@ -309,7 +335,7 @@ nand_do_platform_check() {
 	local control_length=$( (tar xf $tar_file sysupgrade-$board_name/CONTROL -O | wc -c) 2> /dev/null)
 	local file_type="$(identify $2)"
 
-	[ "$control_length" = 0 -a "$file_type" != "ubi" -a "$file_type" != "ubifs" ] && {
+	[ "$control_length" = 0 -a "$file_type" != "ubi" -a "$file_type" != "ubifs" -a "$file_type" != "fit" ] && {
 		echo "Invalid sysupgrade file."
 		return 1
 	}