bcm4908: sysupgrade: add pkgtb format support

BCM4908 devices with U-Boot use pkgtb firmware format. It's based on
U-Boot's FIT: DTB with configurations, images & embedded data.

This format contains bootfs, rootfs and optionally a first stage U-Boot
loader. Contained images need to be extracted & flashed.

Broadcom used two sets of firmwares: main & backup. It uses UBI volumes
"metadata1" & "metadata2" for storing U-Boot env variables with info
about flashed images.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

target/linux/bcm4908/base-files/lib/upgrade/platform.sh

@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
 
-RAMFS_COPY_BIN="bcm4908img expr"
+RAMFS_COPY_BIN="bcm4908img expr egrep fdtget fw_printenv fw_setenv tr"
 
 PART_NAME=firmware
 
@@ -15,6 +15,12 @@ get_content() {
 	dd if="$1" skip=$2 bs=1 count=$3 2>/dev/null
 }
 
+# $(1): file to read from
+# $(2): offset in bytes
+get_hex_u32_le() {
+	dd if="$1" skip=$2 bs=1 count=4 2>/dev/null | hexdump -v -e '1/4 "%02x"'
+}
+
 # $(1): file to read from
 # $(2): offset in bytes
 get_hex_u32_be() {
@@ -37,13 +43,23 @@ platform_identify() {
 
 	magic=$(get_hex_u32_be "$1" 0)
 	case "$magic" in
+		d00dfeed)
+			BCM4908_FW_FORMAT="pkgtb"
+			return
+			;;
 		2a23245e)
 			local header_len=$((0x$(get_hex_u32_be "$1" 4)))
 			local board_id_len=$(($header_len - 40))
 
 			BCM4908_FW_FORMAT="chk"
 			BCM4908_FW_BOARD_ID=$(dd if="$1" skip=40 bs=1 count=$board_id_len 2>/dev/null | hexdump -v -e '1/1 "%c"')
-			BCM4908_FW_INT_IMG_FORMAT="bcm4908img"
+			magic=$(get_hex_u32_be "$1" "$header_len")
+			[ "$magic" = "d00dfeed" ] && {
+				BCM4908_FW_INT_IMG_FORMAT="pkgtb"
+			} || {
+				BCM4908_FW_INT_IMG_FORMAT="bcm4908img"
+			}
+			BCM4908_FW_INT_IMG_EXTRACT_CMD="dd skip=$header_len iflag=skip_bytes"
 			return
 		;;
 	esac
@@ -71,6 +87,117 @@ platform_identify() {
 	}
 }
 
+#
+# pkgtb helpers
+#
+
+platform_pkgtb_get_image_name() {
+	local configuration=$($2 < $1 | fdtget - /configurations default)
+	[ -z "$configuration" ] && {
+		echo "Failed to read default configuration from pkgtb" >&2
+		return
+	}
+
+	local image_name=$($2 < $1 | fdtget - /configurations/$configuration $3)
+	[ -z "$image_name" ] && {
+		echo "Failed to read $3 from pkgtb configuration \"$configuration\"" >&2
+		return
+	}
+
+	echo "$image_name"
+}
+
+platform_pkgtb_get_image() {
+	local cmd="${2:-cat}"
+
+	local image_name=$(platform_pkgtb_get_image_name "$1" "$cmd" "$3")
+
+	$cmd < $1 | fdtget -p - /images/$image_name | egrep -q "^data$" && {
+		$cmd < $1 | fdtget -t r - /images/$image_name data
+		return
+	}
+
+	$cmd < $1 | fdtget -p - /images/$image_name | egrep -q "^data-position$" && {
+		local data_position=$($cmd < $1 | fdtget - /images/$image_name data-position)
+		local data_size=$($cmd < $1 | fdtget - /images/$image_name data-size)
+		$cmd < $1 2>/dev/null | dd skip=$data_position count=$data_size iflag=skip_bytes,count_bytes
+		return
+	}
+
+	$cmd < $1 | fdtget -p - /images/$image_name | egrep -q "^data-offset" && {
+		local data_offset=$($cmd < $1 | fdtget - /images/$image_name data-offset)
+		local totalsize=$(get_hex_u32_be "$1" 4)
+		local data_position=$(((0x$totalsize + data_offset + 3) & ~3))
+		local data_size=$($cmd < $1 | fdtget - /images/$image_name data-size)
+		$cmd < $1 2>/dev/null | dd skip=$data_position count=$data_size iflag=skip_bytes,count_bytes
+		return
+	}
+}
+
+platform_pkgtb_setup_env_config() {
+	local size=$((0x$(get_hex_u32_le /dev/ubi0_1 4)))
+
+	dd if=/dev/ubi0_1 of=/tmp/env.head count=8 iflag=count_bytes
+	dd if=/dev/ubi0_1 of=/tmp/env.body skip=8 iflag=skip_bytes
+	printf "%s\t0x%x\t0x%x\t0x%x" "/tmp/env.body" 0x0 $size $size > /tmp/env.config
+}
+
+platform_pkgtb_get_upgrade_index() {
+	platform_pkgtb_setup_env_config
+
+	case "$(fw_printenv -l /tmp -n -c /tmp/env.config COMMITTED)" in
+		1) echo 2;;
+		2) echo 1;;
+		*) echo 1;;
+	esac
+}
+
+platform_pkgtb_commit() {
+	local size=$((0x$(get_hex_u32_le /dev/ubi0_1 4)))
+	local valid1=0
+	local valid2=0
+	local seq1
+	local seq2
+	local tmp
+
+	platform_pkgtb_setup_env_config
+
+	# Read current values
+	for valid in $(fw_printenv -l /tmp -n -c /tmp/env.config VALID | tr ',' ' '); do
+		case "$valid" in
+			1) valid0=1;;
+			2) valid1=2;;
+		esac
+	done
+	seq0=$(fw_printenv -l /tmp -n -c /tmp/env.config SEQ | cut -d ',' -f 1)
+	seq1=$(fw_printenv -l /tmp -n -c /tmp/env.config SEQ | cut -d ',' -f 2)
+
+	# Calculate values
+	case "$1" in
+		1) valid0=1; seq0=$(((seq1 + 1) % 1000));;
+		2) valid1=2; seq1=$(((seq0 + 1) % 1000));;
+	esac
+
+	# Update variables
+	fw_setenv -l /tmp -c /tmp/env.config COMMITTED "$1"
+	fw_setenv -l /tmp -c /tmp/env.config VALID "$valid0,$valid1"
+	fw_setenv -l /tmp -c /tmp/env.config SEQ "$seq0,$seq1"
+
+	# Write
+	tmp=$(cat /tmp/env.head /tmp/env.body | wc -c)
+	cat /tmp/env.head /tmp/env.body | ubiupdatevol /dev/ubi0_1 -s $tmp -
+}
+
+#
+# check
+#
+
+platform_check_pkgtb() {
+	local cmd="${2:-cat}"
+
+	[ -n "$(platform_pkgtb_get_image_name "$1" "$cmd" "bootfs")" -a -n "$(platform_pkgtb_get_image_name "$1" "$cmd" "rootfs")" ]
+}
+
 platform_check_image() {
 	[ "$#" -gt 1 ] && return 1
 
@@ -105,6 +232,13 @@ platform_check_image() {
 				notify_firmware_no_backup
 			}
 			;;
+		"pkgtb")
+			platform_check_pkgtb "$1" || {
+				echo "Failed to validate pkgtb firmware" >&2
+				notify_firmware_broken
+				return 1
+			}
+			;;
 		*)
 			case "$BCM4908_FW_INT_IMG_FORMAT" in
 				"bcm4908img")
@@ -120,6 +254,13 @@ platform_check_image() {
 						notify_firmware_no_backup
 					}
 					;;
+				"pkgtb")
+					platform_check_pkgtb "$1" "$BCM4908_FW_INT_IMG_EXTRACT_CMD" || {
+						echo "Failed to validate pkgtb firmware" >&2
+						notify_firmware_broken
+						return 1
+					}
+					;;
 			esac
 			;;
 	esac
@@ -127,6 +268,36 @@ platform_check_image() {
 	return $error
 }
 
+#
+# upgrade
+#
+
+platform_do_upgrade_pkgtb() {
+	local cmd="${2:-cat}"
+	local size
+	local idx bootfs_id rootfs_id
+
+	idx=$(platform_pkgtb_get_upgrade_index)
+	case "$idx" in
+		1) bootfs_id=3; rootfs_id=4;;
+		2) bootfs_id=5; rootfs_id=6;;
+	esac
+
+	size=$(platform_pkgtb_get_image "$1" "$cmd" "bootfs" | wc -c)
+	ubirmvol /dev/ubi0 -N bootfs$idx
+	ubimkvol /dev/ubi0 -n $bootfs_id -N bootfs$idx -t static -s $size
+	platform_pkgtb_get_image "$1" "$cmd" "bootfs" | ubiupdatevol /dev/ubi0_$bootfs_id -s $size -
+
+	size=$(platform_pkgtb_get_image "$1" "$cmd" "rootfs" | wc -c)
+	ubirmvol /dev/ubi0 -N rootfs$idx
+	ubimkvol /dev/ubi0 -n $rootfs_id -N rootfs$idx -t dynamic -s $size
+	platform_pkgtb_get_image "$1" "$cmd" "rootfs" | ubiupdatevol /dev/ubi0_$rootfs_id -s $size -
+
+	platform_pkgtb_commit $idx
+
+	nand_do_upgrade_success
+}
+
 # $1: cferam index increment value
 platform_calc_new_cferam() {
 	local inc="$1"
@@ -223,11 +394,17 @@ platform_do_upgrade() {
 		"bcm4908img")
 			bcm4908img bootfs -i "$1" ls | grep -q "1-openwrt" && platform_do_upgrade_ubi "$1"
 			;;
+		"pkgtb")
+			platform_do_upgrade_pkgtb "$1"
+			;;
 		*)
 			case "$BCM4908_FW_INT_IMG_FORMAT" in
 				"bcm4908img")
 					bcm4908img bootfs -i "$1" ls | grep -q "1-openwrt" && platform_do_upgrade_ubi "$1"
 					;;
+				"pkgtb")
+					platform_do_upgrade_pkgtb "$1" "$BCM4908_FW_INT_IMG_EXTRACT_CMD"
+					;;
 				*)
 					echo "NAND aware sysupgrade is unsupported for $BCM4908_FW_FORMAT format"
 					;;
@@ -237,6 +414,10 @@ platform_do_upgrade() {
 
 	# Above calls exit on success.
 	# If we got here it isn't OpenWrt image or something went wrong.
+	[ "$BCM4908_FW_FORMAT" = "pkgtb" -o "$BCM4908_FW_INT_IMG_FORMAT" = "pkgtb" ] && {
+		echo "Failed to upgrade pkgtb. Fallback to raw flashing is impossible for this format." >&2
+		exit 1
+	}
 	echo "Writing whole image to NAND flash. All erase counters will be lost."
 
 	# Find cferam name for new firmware