rk35xx/rockchip-rk3588: add check for 0-byte-dtb u-boot.itb for Radxa u-boot (vendor)

- uses the new hook `check_uboot_produced_binary_file`
- runs dumpimage and greps for magic string `Data Size:    0 Bytes`
- if found, exits with error
- this is to clearly catch build-host related issue in #8227

Author: rpardini

config/sources/families/rk35xx.conf

@@ -45,7 +45,7 @@ esac
 
 prepare_boot_configuration
 
-pre_config_uboot_target__warn_modern_hosts() {
+function pre_config_uboot_target__warn_modern_hosts() {
 	# Check if building Radxa U-Boot on a host other than Ubuntu Jammy
 	if [[ "${BOOTSOURCE}" == "https://github.com/radxa/u-boot.git" ]]; then
 		if [[ "${HOSTRELEASE}" != "jammy" ]]; then
@@ -54,6 +54,23 @@ pre_config_uboot_target__warn_modern_hosts() {
 	fi
 }
 
+function check_uboot_produced_binary_file__check_vendor_uboot_for_0_byte_dtb() {
+	# this hook is called with those two variables
+	: "${base_binfile:?base_binfile is not set}"
+	: "${binfile:?binfile is not set}"
+
+	[[ "${BOOTSOURCE}" != "https://github.com/radxa/u-boot.git" ]] && return 0 # Check if building Radxa U-Boot
+	[[ "${base_binfile}" != "u-boot.itb" ]] && return 0                        # Only check 'u-boot.itb' file
+	display_alert "u-boot for ${BOARD}::${BRANCH} built on ${HOSTRELEASE}" "Checking for 0-byte DTB: ${base_binfile}" "info"
+
+	# Run dumpimage -l, grep it for string 'Data Size:    0 Bytes', if found, exit_with_error
+	if dumpimage -l "${binfile}" | grep -q "Data Size:    0 Bytes"; then
+		exit_with_error "u-boot for ${BOARD}::${BRANCH}::${base_binfile}: Error: The produced u-boot.itb file contains a 0-byte DTB; built on ${HOSTRELEASE}"
+	fi
+
+	return 0
+}
+
 family_tweaks_bsp() {
 	:
 }

config/sources/families/rockchip-rk3588.conf

@@ -43,7 +43,7 @@ esac
 
 prepare_boot_configuration
 
-pre_config_uboot_target__warn_modern_hosts() {
+function pre_config_uboot_target__warn_modern_hosts() {
 	# Check if building Radxa U-Boot on a host other than Ubuntu Jammy
 	if [[ "${BOOTSOURCE}" == "https://github.com/radxa/u-boot.git" ]]; then
 		if [[ "${HOSTRELEASE}" != "jammy" ]]; then
@@ -52,6 +52,23 @@ pre_config_uboot_target__warn_modern_hosts() {
 	fi
 }
 
+function check_uboot_produced_binary_file__check_vendor_uboot_for_0_byte_dtb() {
+	# this hook is called with those two variables
+	: "${base_binfile:?base_binfile is not set}"
+	: "${binfile:?binfile is not set}"
+
+	[[ "${BOOTSOURCE}" != "https://github.com/radxa/u-boot.git" ]] && return 0 # Check if building Radxa U-Boot
+	[[ "${base_binfile}" != "u-boot.itb" ]] && return 0                        # Only check 'u-boot.itb' file
+	display_alert "u-boot for ${BOARD}::${BRANCH} built on ${HOSTRELEASE}" "Checking for 0-byte DTB: ${base_binfile}" "info"
+
+	# Run dumpimage -l, grep it for string 'Data Size:    0 Bytes', if found, exit_with_error
+	if dumpimage -l "${binfile}" | grep -q "Data Size:    0 Bytes"; then
+		exit_with_error "u-boot for ${BOARD}::${BRANCH}::${base_binfile}: Error: The produced u-boot.itb file contains a 0-byte DTB; built on ${HOSTRELEASE}"
+	fi
+
+	return 0
+}
+
 family_tweaks_bsp() {
 	:
 }