ipq806x: add support for OpenMesh A42

* QCA IPQ401x
* 256 MB of RAM
* 32 MB of SPI NOR flash (s25fl256s1)
  - 2x 15 MB available; but one of the 15 MB regions is the recovery image
* 2T2R 2.4 GHz
  - QCA4019 hw1.0 (SoC)
  - requires special BDF in QCA4019/hw1.0/board-2.bin with
    bus=ahb,bmi-chip-id=0,bmi-board-id=16,variant=OM-A42
* 2T2R 5 GHz
  - QCA4019 hw1.0 (SoC)
  - requires special BDF in QCA4019/hw1.0/board-2.bin with
    bus=ahb,bmi-chip-id=0,bmi-board-id=17,variant=OM-A42
* multi-color LED (controlled via red/green/blue GPIOs)
* 1x button (reset; kmod-input-gpio-keys compatible)
* external watchdog
  - triggered GPIO
* 1x USB (xHCI)
* TTL pins are on board (arrow points to VCC, then follows: GND, TX, RX)
* 2x gigabit ethernet
* powered only via POE
  - 802.3af POE on Ethernet 1
  - 18-24v passive POE (mode B) on Ethernet 2

The tool ap51-flash (https://github.com/ap51-flash/ap51-flash) should be
used to transfer the factory image to the u-boot when the device boots up.

Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>

2 files changed, 114 insertions, 0 deletions

diff --git a/target/linux/ipq806x/base-files/lib/upgrade/openmesh.sh b/target/linux/ipq806x/base-files/lib/upgrade/openmesh.sh
new file mode 100644
index 0000000000..a2c79d9e44
--- /dev/null
+++ b/target/linux/ipq806x/base-files/lib/upgrade/openmesh.sh
@@ -0,0 +1,110 @@
+# The U-Boot loader of the OpenMesh devices requires image sizes and
+# checksums to be provided in the U-Boot environment.
+# The OpenMesh devices come with 2 main partitions - while one is active
+# sysupgrade will flash the other. The boot order is changed to boot the
+# newly flashed partition. If the new partition can't be booted due to
+# upgrade failures the previously used partition is loaded.
+
+platform_do_upgrade_openmesh() {
+	local tar_file="$1"
+	local restore_backup
+	local primary_kernel_mtd
+
+	local setenv_script="/tmp/fw_env_upgrade"
+
+	local kernel_mtd="$(find_mtd_index $PART_NAME)"
+	local kernel_offset="$(cat /sys/class/mtd/mtd${kernel_mtd}/offset)"
+	local total_size="$(cat /sys/class/mtd/mtd${kernel_mtd}/size)"
+
+	# detect to which flash region the new image is written to.
+	#
+	# 1. check what is the mtd index for the first flash region on this
+	#    device
+	# 2. check if the target partition ("inactive") has the mtd index of
+	#    the first flash region
+	#
+	#    - when it is: the new bootseq will be 1,2 and the first region is
+	#      modified
+	#    - when it isnt: bootseq will be 2,1 and the second region is
+	#      modified
+	#
+	# The detection has to be done via the hardcoded mtd partition because
+	# the current boot might be done with the fallback region. Let us
+	# assume that the current bootseq is 1,2. The bootloader detected that
+	# the image in flash region 1 is corrupt and thus switches to flash
+	# region 2. The bootseq in the u-boot-env is now still the same and
+	# the sysupgrade code can now only rely on the actual mtd indexes and
+	# not the bootseq variable to detect the currently booted flash
+	# region/image.
+	#
+	# In the above example, an implementation which uses bootseq ("1,2") to
+	# detect the currently booted image would assume that region 1 is booted
+	# and then overwrite the variables for the wrong flash region (aka the
+	# one which isn't modified). This could result in a device which doesn't
+	# boot anymore to Linux until it was reflashed with ap51-flash.
+	local next_boot_part="1"
+	case "$(board_name)" in
+	openmesh,a42)
+		primary_kernel_mtd=8
+		;;
+	*)
+		echo "failed to detect primary kernel mtd partition for board"
+		return 1
+		;;
+	esac
+	[ "$kernel_mtd" = "$primary_kernel_mtd" ] || next_boot_part="2"
+
+	local board_dir=$(tar tf $tar_file | grep -m 1 '^sysupgrade-.*/$')
+	board_dir=${board_dir%/}
+
+	local kernel_length=$(tar xf $tar_file ${board_dir}/kernel -O | wc -c)
+	local rootfs_length=$(tar xf $tar_file ${board_dir}/root -O | wc -c)
+	# rootfs without EOF marker
+	rootfs_length=$((rootfs_length-4))
+
+	local kernel_md5=$(tar xf $tar_file ${board_dir}/kernel -O | md5sum); kernel_md5="${kernel_md5%% *}"
+	# md5 checksum of rootfs with EOF marker
+	local rootfs_md5=$(tar xf $tar_file ${board_dir}/root -O | dd bs=1 count=$rootfs_length | md5sum); rootfs_md5="${rootfs_md5%% *}"
+
+	#
+	# add tar support to get_image() to use default_do_upgrade() instead?
+	#
+
+	# take care of restoring a saved config
+	[ "$SAVE_CONFIG" -eq 1 ] && restore_backup="${MTD_CONFIG_ARGS} -j ${CONF_TAR}"
+
+	# write concatinated kernel + rootfs to flash
+	tar xf $tar_file ${board_dir}/kernel ${board_dir}/root -O | \
+		mtd $restore_backup write - $PART_NAME
+
+	# prepare new u-boot env
+	if [ "$next_boot_part" = "1" ]; then
+		echo "bootseq 1,2" > $setenv_script
+	else
+		echo "bootseq 2,1" > $setenv_script
+	fi
+
+	printf "kernel_size_%i 0x%08x\n" $next_boot_part $kernel_length >> $setenv_script
+	printf "vmlinux_start_addr 0x%08x\n" ${kernel_offset} >> $setenv_script
+	printf "vmlinux_size 0x%08x\n" ${kernel_length} >> $setenv_script
+	printf "vmlinux_checksum %s\n" ${kernel_md5} >> $setenv_script
+
+	printf "rootfs_size_%i 0x%08x\n" $next_boot_part $((total_size-kernel_length)) >> $setenv_script
+	printf "rootfs_start_addr 0x%08x\n" $((kernel_offset+kernel_length)) >> $setenv_script
+	printf "rootfs_size 0x%08x\n" ${rootfs_length} >> $setenv_script
+	printf "rootfs_checksum %s\n" ${rootfs_md5} >> $setenv_script
+
+	# store u-boot env changes
+	fw_setenv -s $setenv_script || {
+		echo "failed to update U-Boot environment"
+		return 1
+	}
+}
+
+# create /var/lock for the lock "fw_setenv.lock" of fw_setenv
+# the rest is copied using ipq806x's RAMFS_COPY_BIN and RAMFS_COPY_DATA
+platform_add_ramfs_ubootenv()
+{
+        mkdir -p $RAM_ROOT/var/lock
+}
+append sysupgrade_pre_upgrade platform_add_ramfs_ubootenv
diff --git a/target/linux/ipq806x/base-files/lib/upgrade/platform.sh b/target/linux/ipq806x/base-files/lib/upgrade/platform.sh
index f71ee37d99..5561dd538c 100644
--- a/target/linux/ipq806x/base-files/lib/upgrade/platform.sh
+++ b/target/linux/ipq806x/base-files/lib/upgrade/platform.sh
@@ -22,6 +22,10 @@ platform_do_upgrade() {
 	zyxel,nbg6817)
 		nand_do_upgrade "$ARGV"
 		;;
+	openmesh,a42)
+		PART_NAME="inactive"
+		platform_do_upgrade_openmesh "$ARGV"
+		;;
 	tplink,c2600)
 		PART_NAME="os-image:rootfs"
 		MTD_CONFIG_ARGS="-s 0x200000"