test -n "${BOOT_ORDER}" || setenv BOOT_ORDER "A B"
test -n "${BOOT_A_LEFT}" || setenv BOOT_A_LEFT 3
test -n "${BOOT_B_LEFT}" || setenv BOOT_B_LEFT 3
test -n "${bootargs_default}" || setenv bootargs_default coherent_pool=1M vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000 rootwait console=tty1 console=ttyAMA0,115200
test -n "${DTB_FILE}" || setenv DTB_FILE bcm2711-rpi-cm4.dtb

# RPi firmware uses a dynamic fdt_addr, but U-Boot does not use the fw
# provided address if fdt_addr is already defined in the environment!
# Copy fdt_addr to a local variable and delete the environment variable
# so it never gets accidentally saved:
fdt_addr=${fdt_addr}
env delete fdt_addr

# To boot from the rescue partition, tie GPIO4 (pin 7) to GND (pin 9)
# The gpio input command will return an exit status of 0 (true)
# If the pin is high (pulled up by default) the exit status is 1 (false)
if gpio input gpio4 ; then
	# GPIO4 is shorted to ground so boot in rescue mode
	echo "Booting from rescue partition"
	setenv load_uenv "load mmc 0:2 ${kernel_addr_r} /boot/uEnv.txt"
	setenv load_fdt "load mmc 0:2 ${fdt_addr_r} /boot/${DTB_FILE}"
	setenv load_kernel "load mmc 0:2 ${kernel_addr_r} /boot/Image"
	raucargs="root=/dev/mmcblk0p2"
	rescue=true
else
	raucargs=unset
	for BOOT_SLOT in "${BOOT_ORDER}"; do
		if test "x${raucargs}" != "xunset"; then
			# skip remaining slots
		elif test "x${BOOT_SLOT}" = "xA"; then
			if test ${BOOT_A_LEFT} -gt 0; then
				echo "Found valid slot A, ${BOOT_A_LEFT} attempts remaining"
				setexpr BOOT_A_LEFT ${BOOT_A_LEFT} - 1
				setenv load_uenv "load mmc 0:5 ${kernel_addr_r} /boot/uEnv.txt"
				setenv load_fdt "load mmc 0:5 ${fdt_addr_r} /boot/${DTB_FILE}"
				setenv load_kernel "load mmc 0:5 ${kernel_addr_r} /boot/Image"
				raucargs="root=/dev/mmcblk0p5 rauc.slot=A"
			fi
		elif test "x${BOOT_SLOT}" = "xB"; then
			if test ${BOOT_B_LEFT} -gt 0; then
				echo "Found valid slot B, ${BOOT_B_LEFT} attempts remaining"
				setexpr BOOT_B_LEFT ${BOOT_B_LEFT} - 1
				setenv load_uenv "load mmc 0:6 ${kernel_addr_r} /boot/uEnv.txt"
				setenv load_fdt "load mmc 0:6 ${fdt_addr_r} /boot/${DTB_FILE}"
				setenv load_kernel "load mmc 0:6 ${kernel_addr_r} /boot/Image"
				raucargs="root=/dev/mmcblk0p6 rauc.slot=B"
			fi
		fi
	done
fi

if test "x${raucargs}" = "xunset"; then
	echo "No valid slot found, resetting tries to 3"
	setenv BOOT_A_LEFT 3
	setenv BOOT_B_LEFT 3
	saveenv
	reset
fi

# Examine the fdt loaded by the firmware
# Pass fw_dtb to use the dtb loaded by the firmware
fdt_live=unset
fdt addr ${fdt_addr}
fdt get value bootargs_fw /chosen bootargs
for arg in ${bootargs_fw} ; do
	if test "x${arg}" = "xfw_dtb" ; then
		fdt_live=${fdt_addr}
	fi
done

# Save bootargs_fw in a local variable for later use
bootargs_fw=${bootargs_fw}
env del bootargs_fw

if test "x${rescue}" = "xtrue" -o "x${fdt_live}" = "xunset"; then
	# Using device-tree from rootfs
	# Check to see if we have any customizations in a uEnv.txt file
	env del bootargs_force bootargs_extra
	echo "Checking for /boot/uEnv.txt"
	if run load_uenv ; then
		echo "Importing uEnv.txt"
		env import -t -r ${fileaddr} ${filesize}
	fi

	# Load our actual device-tree file
	echo "Loading device-tree"
	run load_fdt

	# Point to run-time device-tree
	fdt_live=${fdt_addr_r}

	# Setup kernel parameters
	if test -n "${bootargs_force}" ; then
		setenv bootargs "${bootargs_force} ${raucargs}"
	else
		setenv bootargs "${bootargs_default} ${bootargs_extra} ${raucargs}"
	fi
else
	# Using FW provided device-tree
	# Append rauc boot arguments to FW generated command line
	# This setting will override /chosen/bootargs in the device-tree
	echo "Using firmware device-tree"
	setenv bootargs "${bootargs_fw} ${raucargs}"
fi

# Store updated boot state...
# ...above code should have modified BOOT_(AB)_LEFT and bootargs
saveenv

echo "Loading kernel"
run load_kernel

echo "Starting kernel"
booti ${kernel_addr_r} - ${fdt_live}