nanopi-m5: migrate to mainline U-Boot v2026.04

Switches from the u-boot-radxa-rk35xx legacy fork to mainline v2026.04
with BOOT_SCENARIO=vendor-spl-blobs. Adds SD/SPI/UFS install helpers,
rewrites BOOT_TARGETS to 'mmc0 scsi nvme pxe dhcp', and expands
KERNEL_TARGET to current,edge,vendor.

Author: SuperKali

config/boards/nanopi-m5.conf

@@ -1,17 +1,16 @@
-# Rockchip RK3576 SoC octa core 4-16GB RAM SoC 2xGbE UFS USB3 WIFI NvME
+# Rockchip RK3576 SoC octa core 4-16GB RAM SoC 2xGbE UFS USB3 WIFI NvMe
 BOARD_NAME="NanoPi M5"
 BOARD_VENDOR="friendlyelec"
 BOARDFAMILY="rk35xx"
+BOOT_SOC="rk3576"
 BOOTCONFIG="nanopi-m5-rk3576_defconfig"
-# WIP: current kernel (no comments on same line as KERNEL_TARGET)
-KERNEL_TARGET="vendor,edge"
+KERNEL_TARGET="current,edge,vendor"
+KERNEL_TEST_TARGET="vendor,current"
 FULL_DESKTOP="yes"
 ASOUND_STATE="asound.state.nanopi-m5"
 BOOT_LOGO="desktop"
 BOOT_FDT_FILE="rockchip/rk3576-nanopi-m5.dtb"
-BOOT_SCENARIO="spl-blobs"
-BOOT_SUPPORT_SPI="yes"
-BOOT_SPI_RKSPI_LOADER="yes"
+BOOT_SCENARIO="vendor-spl-blobs"
 IMAGE_PARTITION_TABLE="gpt"
 BOARD_MAINTAINER="SuperKali"
 INTRODUCED="2023"
@@ -25,3 +24,40 @@ function post_family_tweaks__nanopi-m5_naming_audios() {
 	echo 'SUBSYSTEM=="sound", ENV{ID_PATH}=="platform-rt5616-sound", ENV{SOUND_DESCRIPTION}="RT5616 Audio"' >> $SDCARD/etc/udev/rules.d/90-naming-audios.rules
 	return 0
 }
+
+function post_family_config__nanopi_m5_use_mainline_uboot() {
+	display_alert "$BOARD" "Mainline U-Boot v2026.04 + vendor SPL hybrid" "info"
+
+	declare -g BOOTDELAY=1
+	declare -g BOOTSOURCE="https://github.com/u-boot/u-boot.git"
+	declare -g BOOTBRANCH="tag:v2026.04"
+	declare -g BOOTPATCHDIR="v2026.04"
+	unset BOOT_FDT_FILE
+
+	unset write_uboot_platform write_uboot_platform_mtd
+
+	# Bootloader on SD/eMMC.
+	function write_uboot_platform() {
+		dd "if=$1/idbloader.img" "of=$2" seek=64 conv=notrunc status=none
+		dd "if=$1/u-boot.itb"    "of=$2" seek=16384 conv=notrunc status=none
+	}
+
+	# Bootloader on SPI NOR (mainline binman image).
+	function write_uboot_platform_mtd() {
+		flashcp -v -p "$1/u-boot-rockchip-spi.bin" /dev/mtd0
+	}
+
+	# Bootloader on UFS: idblock on Boot LUN A, u-boot.itb on General LUN.
+	function write_uboot_platform_ufs() {
+		dd "if=$1/idbloader.img" "of=$2" bs=4096 seek=8    conv=notrunc,fsync status=none
+		dd "if=$1/u-boot.itb"    "of=$3" bs=4096 seek=2048 conv=notrunc,fsync status=none
+	}
+}
+
+# Boot order: SD → UFS (scsi uclass) → NVMe → net.
+function pre_config_uboot_target__nanopi_m5_patch_rockchip_common_boot_order() {
+	declare -a rockchip_uboot_targets=("mmc0" "scsi" "nvme" "pxe" "dhcp")
+	display_alert "u-boot for ${BOARD}/${BRANCH}" "boot order '${rockchip_uboot_targets[*]}'" "info"
+	sed -i -e "s/#define BOOT_TARGETS.*/#define BOOT_TARGETS \"${rockchip_uboot_targets[*]}\"/" include/configs/rockchip-common.h
+	regular_git diff -u include/configs/rockchip-common.h || true
+}