stm32: add new stm32 target

New stm32 target introduces support for stm32mp1 based devices.
For now it includes an initial support of the STM32MP135F-DK device.
The specifications bellow only list supported features.

Specifications
--------------

SOC: STM32MP135FAF7
RAM: 512 MiB
Storage: SD Card
Ethernet: 2x 100 Mbps
Wireless: 2.4GHz Cypress CYW43455 (802.11b/g/n)
LEDs: Heartbeat (Blue)
Buttons: 1x Reset, 1x User (USER2)
USB: 4x 2.0 Type-A

Signed-off-by: Thomas Richard <[email protected]>
Link: openwrt#16716
Signed-off-by: Hauke Mehrtens <[email protected]>

target/linux/stm32/Makefile

@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Copyright (C) 2024 Bootlin
+#
+
+include $(TOPDIR)/rules.mk
+
+BOARD:=stm32
+BOARDNAME:=STMicroelectronics STM32
+FEATURES:=boot-part emmc ext4 gpio rtc usb
+SUBTARGETS:=stm32mp1
+CPU_TYPE:=
+
+KERNEL_PATCHVER:=6.6
+
+include $(INCLUDE_DIR)/target.mk
+
+DEFAULT_PACKAGES += blockdev kmod-gpio-button-hotplug
+
+define Target/Description
+	Build firmware image for STM32 devices
+endef
+
+$(eval $(call BuildTarget))

target/linux/stm32/base-files/etc/board.d/02_network

@@ -0,0 +1,18 @@
+
+. /lib/functions/uci-defaults.sh
+. /lib/functions.sh
+. /lib/functions/system.sh
+
+board_config_update
+
+board=$(board_name)
+
+case "$board" in
+st,stm32mp135f-dk)
+	ucidef_set_interfaces_lan_wan "eth0" "eth1"
+	;;
+esac
+
+board_config_flush
+
+exit 0

target/linux/stm32/base-files/lib/preinit/79_move_config

@@ -0,0 +1,15 @@
+
+move_config() {
+	. /lib/upgrade/common.sh
+	. /lib/upgrade/platform.sh
+
+	if export_bootdevice && export_partdevice partdev 4; then
+		mount -t ext4 -o rw,noatime "/dev/$partdev" /mnt
+		if [ -f "/mnt/$BACKUP_FILE" ]; then
+			mv -f "/mnt/$BACKUP_FILE" /
+		fi
+		umount /mnt
+	fi
+}
+
+boot_hook_add preinit_mount_root move_config

target/linux/stm32/base-files/lib/upgrade/platform.sh

@@ -0,0 +1,181 @@
+REQUIRE_IMAGE_METADATA=1
+
+UBOOT_ENV_PART=3
+BOOT_PART=4
+ROOTFS_PART=5
+
+RAMFS_COPY_BIN='blockdev'
+
+export_bootdevice() {
+	local cmdline uuid blockdev uevent line class
+	local MAJOR MINOR DEVNAME DEVTYPE
+	local rootpart="$(cmdline_get_var root)"
+
+	case "$rootpart" in
+		PARTUUID=????????-????-????-????-??????????0?/PARTNROFF=1 | \
+		PARTUUID=????????-????-????-????-??????????05)
+			uuid="${rootpart#PARTUUID=}"
+			uuid="${uuid%/PARTNROFF=1}"
+			uuid="${uuid%0?}00"
+			for disk in $(find /dev -type b); do
+				set -- $(dd if=$disk bs=1 skip=568 count=16 2>/dev/null | hexdump -v -e '8/1 "%02x "" "2/1 "%02x""-"6/1 "%02x"')
+				if [ "$4$3$2$1-$6$5-$8$7-$9" = "$uuid" ]; then
+					uevent="/sys/class/block/${disk##*/}/uevent"
+					break
+				fi
+			done
+		;;
+	esac
+
+	if [ -e "$uevent" ]; then
+		while read line; do
+			export -n "$line"
+		done < "$uevent"
+		export BOOTDEV_MAJOR=$MAJOR
+		export BOOTDEV_MINOR=$MINOR
+		return 0
+	fi
+
+	return 1
+}
+
+platform_check_image() {
+	local diskdev partdev diff
+
+        [ "$#" -gt 1 ] && return 1
+
+	export_bootdevice && export_partdevice diskdev 0 || {
+		v "platform_check_image: Unable to determine upgrade device"
+		return 1
+	}
+
+	get_partitions "/dev/$diskdev" bootdisk
+
+	v "Extract the boot sector from the image"
+	get_image_dd "$1" of=/tmp/image.bs count=63 bs=512b
+
+	get_partitions /tmp/image.bs image
+
+	#compare tables
+	diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
+
+	rm -f /tmp/image.bs /tmp/partmap.bootdisk /tmp/partmap.image
+
+	if [ -n "$diff" ]; then
+		echo "Partition layout has changed. Full image will be written."
+		ask_bool 0 "Abort" && exit 1
+		return 0
+	fi
+}
+
+platform_do_upgrade() {
+	local diskdev partdev diff partlabel
+
+	export_bootdevice && export_partdevice diskdev 0 || {
+		v "platform_do_upgrade: Unable to determine upgrade device"
+		return 1
+	}
+
+	sync
+
+	if [ "$UPGRADE_OPT_SAVE_PARTITIONS" = "1" ]; then
+		get_partitions "/dev/$diskdev" bootdisk
+
+		v "Extract boot sector from the image"
+		get_image_dd "$1" of=/tmp/image.bs count=63 bs=512b
+
+		get_partitions /tmp/image.bs image
+
+		#compare tables
+		diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
+	else
+		diff=1
+	fi
+
+	if [ -n "$diff" ]; then
+		rm -rf /tmp/ubootenv
+
+		if export_partdevice partdev $UBOOT_ENV_PART; then
+			v "Saving u-boot env (/dev/$partdev) before to write image"
+			get_image_dd "/dev/$partdev" of=/tmp/ubootenv
+		fi
+
+		v "Writing image to /dev/$diskdev..."
+		get_image_dd "$1" of="/dev/$diskdev" conv=fsync
+
+		blockdev --rereadpt "/dev/$diskdev"
+
+		[ -f /tmp/ubootenv ] && {
+			# iterate over each partition from the image to find the
+			# u-boot-env partition and restore u-boot env.
+			while read part start size; do
+				if export_partdevice partdev $part; then
+					while read line; do
+						eval "local l$line"
+					done < "/sys/class/block/$partdev/uevent"
+
+					[ "$lPARTNAME" = "u-boot-env" ] || continue
+
+					v "Writting u-boot env to /dev/$partdev"
+					get_image_dd /tmp/ubootenv of="/dev/$partdev" conv=fsync
+
+					return 0
+				fi
+			done < /tmp/partmap.image
+		}
+		return 0
+	fi
+
+	#iterate over each partition from the image and write it to the boot disk
+	while read part start size; do
+		if export_partdevice partdev $part; then
+			# do not erase u-boot env
+			[ "$part" = "$UBOOT_ENV_PART" ] && continue
+
+			v "Writing image to /dev/$partdev..."
+			v "Normal partition, doing DD"
+			get_image_dd "$1" of="/dev/$partdev" ibs=512 obs=1M skip="$start" \
+				count="$size" conv=fsync
+		else
+			v "Unable to find partition $part device, skipped."
+		fi
+	done < /tmp/partmap.image
+
+	if export_partdevice partdev "$BOOT_PART"; then
+		mount -t ext4 -o rw,noatime "/dev/$partdev" /mnt
+		local partuuid="$(cmdline_get_var root)"
+		v "Setting rootfs ${partuuid}"
+		sed -i "s/PARTUUID=[a-f0-9-]\+/${partuuid}/ig" \
+			/mnt/extlinux/extlinux.conf
+		umount /mnt
+	fi
+}
+
+platform_copy_config() {
+	local partdev
+
+	# Iterate over each partition from the image to find the boot partition
+	# and copy the config tarball.
+	# The partlabel is used to find the partition.
+	# An hardcoded partition number cannot be used, as it could be wrong if
+	# the partition table changed, and the full image was written.
+	while read part start size; do
+		# config is copied in the boot partition, as for squashfs image, the
+		# rootfs partition is not writable.
+		if export_partdevice partdev "$part"; then
+			while read line; do
+				eval "local l$line"
+			done < "/sys/class/block/$partdev/uevent"
+
+			[ "$lPARTNAME" = "boot" ] || continue
+
+			mount -t ext4 -o rw,noatime "/dev/$partdev" /mnt
+			cp -af "$UPGRADE_BACKUP" "/mnt/$BACKUP_FILE"
+			umount /mnt
+			return 0
+		else
+			v "ERROR: Unable to find partition to copy config data to"
+		fi
+	done < /tmp/partmap.image
+}
+

target/linux/stm32/image/Makefile

@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Copyright (C) 2024 Bootlin
+#
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/image.mk
+
+define Build/boot-img-ext4
+	rm -fR $@.boot
+	mkdir -p $@.boot
+	$(foreach dts,$(DEVICE_DTS), $(CP) $(KDIR)/image-$(dts).dtb $@.boot/$(dts).dtb;)
+	$(CP) $(IMAGE_KERNEL) $@.boot/$(KERNEL_IMG)
+	$(INSTALL_DIR) $@.boot/extlinux
+	$(CP) ./extlinux.conf $@.boot/extlinux/
+	$(SED) 's/@KERNEL@/$(KERNEL_IMG)/' $@.boot/extlinux/extlinux.conf
+	$(SED) 's/@DEVICE@/$(DEVICE_NAME)/' $@.boot/extlinux/extlinux.conf
+	$(SED) 's/@DTS@/$(DEVICE_DTS)/' $@.boot/extlinux/extlinux.conf
+	$(SED) 's/@ROOT@/PARTUUID=$(shell echo $(IMG_PART_DISKGUID) | sed 's/00$$/05/')/' $@.boot/extlinux/extlinux.conf
+
+	make_ext4fs -J -L kernel -l $(CONFIG_TARGET_KERNEL_PARTSIZE)M \
+		$(if $(SOURCE_DATE_EPOCH),-T $(SOURCE_DATE_EPOCH)) \
+		$@.bootimg $@.boot
+endef
+
+define Build/sdcard-img
+	GUID=$(IMG_PART_DISKGUID) ./gen_stm32_sdcard_img.sh \
+	     $@ $(STAGING_DIR_IMAGE)/tf-a-$(DEVICE_NAME).stm32 \
+	     $(STAGING_DIR_IMAGE)/fip-$(DEVICE_NAME).bin $@.bootimg $(IMAGE_ROOTFS) \
+	     $(ENV_SIZE) $(CONFIG_TARGET_KERNEL_PARTSIZE) $(CONFIG_TARGET_ROOTFS_PARTSIZE)
+endef
+
+define Device/Default
+  PROFILES := Default
+  DEVICE_VENDOR := STMicroelectronics
+  IMAGES := factory.img.gz sysupgrade.img.gz
+  IMAGE/factory.img.gz := boot-img-ext4 | sdcard-img | gzip
+  IMAGE/sysupgrade.img.gz := boot-img-ext4 | sdcard-img | gzip | append-metadata
+  KERNEL := kernel-bin
+  KERNEL_NAME := zImage
+  KERNEL_IMG := zImage
+  DEVICE_DTS_DIR := $(DTS_DIR)/st
+  ENV_SIZE := 0x200000
+  DEVICE_PACKAGES := kmod-brcmfmac \
+		     murata-firmware-43430-sdio \
+		     murata-nvram-43430-sdio \
+		     wpad-basic-mbedtls \
+		     kmod-phy-stm32-usbphyc \
+		     kmod-usb2 \
+		     kmod-usb-storage \
+		     kmod-usb-ledtrig-usbport \
+		     -mtd
+endef
+
+define Device/stm32mp135f-dk
+  DEVICE_MODEL := STM32MP135F-DK
+  DEVICE_DTS := stm32mp135f-dk
+  SUPPORTED_DEVICES := st,stm32mp135f-dk
+endef
+
+TARGET_DEVICES += stm32mp135f-dk
+
+$(eval $(call BuildImage))

target/linux/stm32/image/extlinux.conf

@@ -0,0 +1,4 @@
+label @DEVICE@-openwrt
+  kernel /@KERNEL@
+  devicetree /@[email protected]
+  append root=@ROOT@ rootwait

target/linux/stm32/image/gen_stm32_sdcard_img.sh

@@ -0,0 +1,35 @@
+#!/bin/sh
+# Copyright (C) 2024 Bootlin
+
+set -ex
+[ $# -eq 8 ] || {
+    echo "SYNTAX: $0 <file> <fsbl> <fip> <bootfs image> <rootfs image> <env size> <bootfs size> <rootfs size>"
+    exit 1
+}
+
+OUTPUT="${1}"
+FSBL="${2}"
+FIP="${3}"
+BOOTFS="${4}"
+ROOTFS="${5}"
+ENVSIZE="$((${6} / 1024))"
+BOOTFSSIZE="${7}"
+ROOTFSSIZE="${8}"
+
+set $(ptgen -o "${OUTPUT}" -g -a 4 -l 2048 -G ${GUID} -N fsbla -p 2M -N fip -p 3M -N u-boot-env -p "${ENVSIZE}" -N boot -p${BOOTFSSIZE}M -N rootfs -p ${ROOTFSSIZE}M)
+FSBLAOFFSET="$((${1} / 512))"
+FSBLASIZE="$((${2} / 512))"
+FIPOFFSET="$((${3} / 512))"
+FIPSIZE="$((${4} / 512))"
+ENVOFFSET="$((${5} / 512))"
+ENVSIZE="$((${6} / 512))"
+BOOTFSOFFSET="$((${7} / 512))"
+BOOTFSSIZE="$((${8} / 512))"
+ROOTFSOFFSET="$((${9} / 512))"
+ROOTFSSIZE="$((${10} / 512))"
+
+dd bs=512 if="${FSBL}" of="${OUTPUT}" seek="${FSBLAOFFSET}" conv=notrunc
+dd bs=512 if="${FIP}"  of="${OUTPUT}" seek="${FIPOFFSET}" conv=notrunc
+dd bs=512 if=/dev/zero of="${OUTPUT}" seek="${ENVOFFSET}" count="${ENVSIZE}" conv=notrunc
+dd bs=512 if="${BOOTFS}" of="${OUTPUT}" seek="${BOOTFSOFFSET}" conv=notrunc
+dd bs=512 if="${ROOTFS}" of="${OUTPUT}" seek="${ROOTFSOFFSET}" conv=notrunc