diff --git a/meta-lmp-bsp/conf/machine/include/lmp-machine-custom.inc b/meta-lmp-bsp/conf/machine/include/lmp-machine-custom.inc
index c965437237..ce42727666 100644
--- a/meta-lmp-bsp/conf/machine/include/lmp-machine-custom.inc
+++ b/meta-lmp-bsp/conf/machine/include/lmp-machine-custom.inc
@@ -152,7 +152,7 @@ OSTREE_KERNEL_ARGS:mx7d-generic-bsp ?= "console=tty1 console=ttymxc0,115200 ${OS
 OSTREE_KERNEL_ARGS:mx7ulp-generic-bsp ?= "console=tty1 console=ttyLP0,115200 ${OSTREE_KERNEL_ARGS_COMMON}"
 
 # Embedded Artists i.MX7ULP COM
-UBOOT_SIGN_ENABLE:sota:imx7ulpea-ucom = "1"
+UBOOT_SIGN_ENABLE:sota:imx7ulpea-ucom ?= "1"
 PREFERRED_PROVIDER_u-boot-default-script:imx7ulpea-ucom = "u-boot-base-scr"
 PREFERRED_PROVIDER_u-boot-default-script:sota:imx7ulpea-ucom = "u-boot-ostree-scr-fit"
 LMP_BOOT_FIRMWARE:imx7ulpea-ucom = "SPL u-boot.itb"
@@ -168,7 +168,7 @@ UBOOT_MACHINE:imx7ulpea-ucom = "mx7ulp_com_defconfig"
 UBOOT_CONFIG:imx7ulpea-ucom = ""
 
 # iMX6UL
-UBOOT_SIGN_ENABLE:sota:mx6ul-generic-bsp = "1"
+UBOOT_SIGN_ENABLE:sota:mx6ul-generic-bsp ??= "1"
 PREFERRED_PROVIDER_virtual/kernel:mx6ul-nxp-bsp ?= "linux-lmp-fslc-imx"
 IMX_DEFAULT_BOOTLOADER:mx6ul-generic-bsp ?= "u-boot-fio"
 WKS_FILE_DEPENDS:append:mx6ul-generic-bsp = " u-boot-default-script"
@@ -189,13 +189,14 @@ KERNEL_IMAGETYPE:sota:mx6ul-generic-bsp = "fitImage"
 KERNEL_CLASSES:sota:mx6ul-generic-bsp = " kernel-lmp-fitimage "
 WKS_FILE:mx6ul-generic-bsp:sota = "sdimage-imx6-spl-fit-sota.wks"
 # iMX6UL EVK
+UBOOT_SIGN_ENABLE:sota:mx6ulevk ?= "1"
 SOTA_CLIENT_FEATURES:append:imx6ulevk = " ubootenv"
 UBOOT_MACHINE:imx6ulevk = "mx6ul_14x14_evk_defconfig"
 KERNEL_DEVICETREE:imx6ulevk = "imx6ul-14x14-evk.dtb"
 BOOTSCR_LOAD_ADDR:imx6ulevk = "0x85000000"
 
 # iMX6ULL
-UBOOT_SIGN_ENABLE:sota:mx6ull-generic-bsp = "1"
+UBOOT_SIGN_ENABLE:sota:mx6ull-generic-bsp ??= "1"
 PREFERRED_PROVIDER_virtual/kernel:mx6ull-nxp-bsp ?= "linux-lmp-fslc-imx"
 IMX_DEFAULT_BOOTLOADER:mx6ull-generic-bsp ?= "u-boot-fio"
 WKS_FILE_DEPENDS:append:mx6ull-generic-bsp = " u-boot-default-script"
@@ -216,6 +217,7 @@ KERNEL_IMAGETYPE:sota:mx6ull-generic-bsp = "fitImage"
 KERNEL_CLASSES:sota:mx6ull-generic-bsp = " kernel-lmp-fitimage "
 WKS_FILE:mx6ull-generic-bsp:sota = "sdimage-imx6-spl-fit-sota.wks"
 # iMX6ULL EVK
+UBOOT_SIGN_ENABLE:sota:mx6ullevk ?= "1"
 SOTA_CLIENT_FEATURES:append:imx6ullevk = " ubootenv"
 UBOOT_MACHINE:imx6ullevk = "mx6ull_14x14_evk_defconfig"
 KERNEL_DEVICETREE:imx6ullevk = "imx6ull-14x14-evk.dtb"
@@ -242,8 +244,9 @@ EXTRA_IMAGEDEPENDS:append:mx8qm-generic-bsp = "virtual/trusted-firmware-a"
 UBOOT_ENTRYPOINT:mx8qm-generic-bsp = "0x80280000"
 UBOOT_LOADADDRESS:mx8qm-generic-bsp = "0x80280000"
 UBOOT_DTB_LOADADDRESS:mx8qm-generic-bsp = "0x83000000"
-UBOOT_SIGN_ENABLE:sota:mx8qm-generic-bsp = "1"
+UBOOT_SIGN_ENABLE:sota:mx8qm-generic-bsp ??= "1"
 ## iMX8QM MEK
+UBOOT_SIGN_ENABLE:sota:mx8qm-mek ?= "1"
 OSTREE_KERNEL_ARGS:imx8qm-mek ?= "pci=nomsi console=ttyLP0,115200 earlycon ${OSTREE_KERNEL_ARGS_COMMON}"
 PREFERRED_PROVIDER_virtual/kernel:imx8qm-mek ?= "linux-lmp-fslc-imx"
 KERNEL_DANGLING_FEATURES_WARN_ONLY:imx8qm-mek ?= "1"
@@ -253,7 +256,7 @@ UBOOT_MACHINE:imx8qm-mek = "imx8qm_mek_defconfig"
 UBOOT_DTB_NAME:imx8qm-mek ?= "fsl-imx8qm-mek.dtb"
 
 # iMX8ULP
-UBOOT_SIGN_ENABLE:sota:mx8ulp-generic-bsp = "1"
+UBOOT_SIGN_ENABLE:sota:mx8ulp-generic-bsp ??= "1"
 IMX_DEFAULT_BOOTLOADER:mx8ulp-generic-bsp ?= "u-boot-fio"
 UBOOT_ENTRYPOINT:mx8ulp-generic-bsp = "0x80400000"
 UBOOT_LOADADDRESS:mx8ulp-generic-bsp = "0x80400000"
@@ -277,6 +280,7 @@ PREFERRED_VERSION_optee-os-fio:mx8ulp-nxp-bsp = "3.20.0-imx"
 PREFERRED_VERSION_optee-os-fio-mfgtool:mx8ulp-nxp-bsp = "3.20.0-imx"
 PREFERRED_VERSION_optee-os-tadevkit:mx8ulp-nxp-bsp = "3.20.0-imx"
 ## iMX8ULP LPDDR4 EVK
+UBOOT_SIGN_ENABLE:sota:imx8ulp-lpddr4-evk ?= "1"
 OSTREE_KERNEL_ARGS:imx8ulp-lpddr4-evk ?= "console=tty1 console=ttyLP1,115200 earlycon rootfstype=ext4"
 PREFERRED_PROVIDER_virtual/kernel:imx8ulp-lpddr4-evk ?= "linux-lmp-fslc-imx"
 BOOTSCR_LOAD_ADDR:imx8ulp-lpddr4-evk = "0x83500000"
@@ -289,7 +293,7 @@ UBOOT_DTB_NAME:imx8ulp-lpddr4-evk ?= "imx8ulp-evk.dtb"
 SOTA_CLIENT_FEATURES:remove:sota:imx8qm-mek-sec = "ubootenv"
 
 # iMX8MQ
-UBOOT_SIGN_ENABLE:sota:mx8mq-generic-bsp = "1"
+UBOOT_SIGN_ENABLE:sota:mx8mq-generic-bsp ??= "1"
 IMX_DEFAULT_BOOTLOADER:mx8mq-generic-bsp ?= "u-boot-fio"
 UBOOT_ENTRYPOINT:mx8mq-generic-bsp = "0x40400000"
 UBOOT_DTB_LOADADDRESS:mx8mq-generic-bsp = "0x43000000"
@@ -311,6 +315,7 @@ PREFERRED_PROVIDER_virtual/kernel:mx8mq-nxp-bsp ?= "linux-lmp-fslc-imx"
 WKS_FILE:sota:mx8mq-nxp-bsp = "sdimage-imx8-spl-sota.wks.in"
 IMXBOOT_TARGETS:mx8mq-nxp-bsp = "flash_evk_spl"
 ## iMX8MQ EVK
+UBOOT_SIGN_ENABLE:sota:imx8mq-evk ?= "1"
 KMACHINE:imx8mq-evk = "imx8mqevk"
 OSTREE_KERNEL_ARGS:imx8mq-evk ?= "console=tty1 console=ttymxc0,115200 earlycon=ec_imx6q,0x30860000,115200 rootfstype=ext4"
 SOTA_CLIENT_FEATURES:append:imx8mq-evk = " ubootenv"
@@ -321,7 +326,7 @@ BOOTSCR_LOAD_ADDR:imx8mq-evk = "0x44800000"
 MACHINE_EXTRA_RRECOMMENDS:append:imx8mq-evk = " bluetooth-attach"
 MACHINE_FIRMWARE:append:imx8mq-evk = " linux-firmware-bcm4356-pcie"
 ## iMX8MQ EVK with EBBR / SystemReady
-UBOOT_SIGN_ENABLE:sota:imx8mq-evk-ebbr = ""
+UBOOT_SIGN_ENABLE:sota:imx8mq-evk-ebbr ?= ""
 KERNEL_IMAGETYPE:sota:imx8mq-evk-ebbr ?= "Image"
 KERNEL_CLASSES:sota:imx8mq-evk-ebbr ?= ""
 EFI_PROVIDER:imx8mq-evk-ebbr ?= "grub-efi"
@@ -331,7 +336,7 @@ IMAGE_EFI_BOOT_FILES:sota:imx8mq-evk-ebbr ?= "${@make_efi_dtb_boot_files(d)}"
 WKS_FILE:sota:imx8mq-evk-ebbr ?= "efidisk-sota.wks.in"
 
 # iMX8MM
-UBOOT_SIGN_ENABLE:sota:mx8mm-generic-bsp = "1"
+UBOOT_SIGN_ENABLE:sota:mx8mm-generic-bsp ??= "1"
 IMX_DEFAULT_BOOTLOADER:mx8mm-generic-bsp ?= "u-boot-fio"
 UBOOT_ENTRYPOINT:mx8mm-generic-bsp = "0x40400000"
 UBOOT_DTB_LOADADDRESS:mx8mm-generic-bsp = "0x43000000"
@@ -356,6 +361,7 @@ OSTREE_SPLIT_BOOT:mx8mm-nxp-bsp = "${@bb.utils.contains('DISTRO_FEATURES', 'luks
 OSTREE_DEPLOY_USR_OSTREE_BOOT:mx8mm-nxp-bsp = "${@bb.utils.contains('DISTRO_FEATURES', 'luks', '1', '0', d)}"
 WKS_FILE:sota:mx8mm-nxp-bsp = "${@bb.utils.contains('DISTRO_FEATURES', 'luks', 'sdimage-imx8-spl-split-boot-sota.wks.in', 'sdimage-imx8-spl-sota.wks.in', d)}"
 ## iMX8MM EVK
+UBOOT_SIGN_ENABLE:sota:imx8mm-lpddr4-evk ?= "1"
 MACHINE_FIRMWARE:append:imx8mm-lpddr4-evk = " linux-firmware-qca"
 KERNEL_DEVICETREE:append:imx8mm-lpddr4-evk = " freescale/imx8mm-evkb.dtb"
 KMACHINE:imx8mm-lpddr4-evk = "imx8mmevk"
@@ -367,7 +373,7 @@ BOOTSCR_LOAD_ADDR:imx8mm-lpddr4-evk = "0x44800000"
 ## iMX8MM EVK with secure boot support
 SOTA_CLIENT_FEATURES:remove:sota:imx8mm-lpddr4-evk-sec = "ubootenv"
 ## iMX8MM EVK with EBBR / SystemReady
-UBOOT_SIGN_ENABLE:sota:imx8mm-lpddr4-evk-ebbr = ""
+UBOOT_SIGN_ENABLE:sota:imx8mm-lpddr4-evk-ebbr ?= ""
 KERNEL_IMAGETYPE:sota:imx8mm-lpddr4-evk-ebbr ?= "Image"
 KERNEL_CLASSES:sota:imx8mm-lpddr4-evk-ebbr ?= ""
 EFI_PROVIDER:imx8mm-lpddr4-evk-ebbr ?= "grub-efi"
@@ -379,7 +385,7 @@ WKS_FILE:sota:imx8mm-lpddr4-evk-ebbr ?= "efidisk-sota.wks.in"
 MACHINE_FEATURES:append:imx8mm-lpddr4-evk = " mxm-mwifiex-load"
 
 # iMX8MP
-UBOOT_SIGN_ENABLE:sota:mx8mp-generic-bsp = "1"
+UBOOT_SIGN_ENABLE:sota:mx8mp-generic-bsp ??= "1"
 IMX_DEFAULT_BOOTLOADER:mx8mp-generic-bsp ?= "u-boot-fio"
 UBOOT_ENTRYPOINT:mx8mp-generic-bsp = "0x40400000"
 UBOOT_DTB_LOADADDRESS:mx8mp-generic-bsp = "0x43000000"
@@ -401,14 +407,16 @@ PREFERRED_PROVIDER_virtual/kernel:mx8mp-nxp-bsp ?= "linux-lmp-fslc-imx"
 WKS_FILE:sota:mx8mp-nxp-bsp = "sdimage-imx8-spl-sota.wks.in"
 IMXBOOT_TARGETS:mx8mp-nxp-bsp = "flash_evk_spl"
 ## iMX8MP EVK
+UBOOT_SIGN_ENABLE:sota:imx8mp-lpddr4-evk ?= "1"
 OSTREE_KERNEL_ARGS:imx8mp-lpddr4-evk ?= "console=tty1 console=ttymxc1,115200 earlycon=ec_imx6q,0x30890000,115200 rootfstype=ext4"
 SOTA_CLIENT_FEATURES:append:imx8mp-lpddr4-evk = " ubootenv"
 UBOOT_MACHINE:imx8mp-lpddr4-evk = "imx8mp_evk_config"
 BOOTSCR_LOAD_ADDR:imx8mp-lpddr4-evk = "0x44800000"
 ## iMX8MP EVK with secure boot support
+UBOOT_SIGN_ENABLE:sota:imx8mp-lpddr4-evk-sec ?= "1"
 SOTA_CLIENT_FEATURES:remove:sota:imx8mp-lpddr4-evk-sec = "ubootenv"
 ## iMX8MP EVK with EBBR / SystemReady
-UBOOT_SIGN_ENABLE:sota:imx8mp-lpddr4-evk-ebbr = ""
+UBOOT_SIGN_ENABLE:sota:imx8mp-lpddr4-evk-ebbr ?= ""
 KERNEL_IMAGETYPE:sota:imx8mp-lpddr4-evk-ebbr ?= "Image"
 KERNEL_CLASSES:sota:imx8mp-lpddr4-evk-ebbr ?= ""
 EFI_PROVIDER:imx8mp-lpddr4-evk-ebbr ?= "grub-efi"
@@ -420,7 +428,7 @@ WKS_FILE:sota:imx8mp-lpddr4-evk-ebbr ?= "efidisk-sota.wks.in"
 MACHINE_FEATURES:append:imx8mp-lpddr4-evk = " mxm-mwifiex-load"
 
 # iMX8MN
-UBOOT_SIGN_ENABLE:sota:mx8mn-generic-bsp = "1"
+UBOOT_SIGN_ENABLE:sota:mx8mn-generic-bsp ??= "1"
 IMX_DEFAULT_BOOTLOADER:mx8mn-generic-bsp ?= "u-boot-fio"
 UBOOT_ENTRYPOINT:mx8mn-generic-bsp = "0x40400000"
 UBOOT_DTB_LOADADDRESS:mx8mn-generic-bsp = "0x43000000"
@@ -441,6 +449,7 @@ KERNEL_CLASSES:sota:mx8mn-generic-bsp = " kernel-lmp-fitimage "
 PREFERRED_PROVIDER_virtual/kernel:mx8mn-generic-bsp ?= "linux-lmp-fslc-imx"
 WKS_FILE:sota:mx8mn-generic-bsp = "sdimage-imx8-spl-sota.wks.in"
 # iMX8MN DDR4 EVK
+UBOOT_SIGN_ENABLE:sota:imx8mn-ddr4-evk ?= "1"
 KMACHINE:imx8mn-ddr4-evk = "imx8mn-evk"
 OSTREE_KERNEL_ARGS:imx8mn-ddr4-evk ?= "console=tty1 console=ttymxc1,115200 earlycon=ec_imx6q,0x30890000,115200 rootfstype=ext4"
 SOTA_CLIENT_FEATURES:append:imx8mn-ddr4-evk = " ubootenv"
@@ -451,6 +460,7 @@ IMXBOOT_TARGETS:imx8mn-ddr4-evk ?= "flash_evk_spl_ddr4"
 ## iMX8MN DDR4 EVK with secure boot support
 SOTA_CLIENT_FEATURES:remove:sota:imx8mn-ddr4-evk-sec = "ubootenv"
 # iMX8MN LPDDR4 EVK
+UBOOT_SIGN_ENABLE:sota:imx8mn-lpddr4-evk ?= "1"
 KMACHINE:imx8mn-lpddr4-evk = "imx8mn-evk"
 OSTREE_KERNEL_ARGS:imx8mn-lpddr4-evk ?= "console=tty1 console=ttymxc1,115200 earlycon=ec_imx6q,0x30890000,115200 rootfstype=ext4"
 SOTA_CLIENT_FEATURES:append:imx8mn-lpddr4-evk = " ubootenv"
@@ -463,7 +473,7 @@ MACHINE_FEATURES:append:imx8mn-lpddr4-evk = " mxm-mwifiex-load"
 SOTA_CLIENT_FEATURES:remove:sota:imx8mn-lpddr4-evk-sec = "ubootenv"
 
 # iMX93
-UBOOT_SIGN_ENABLE:sota:mx93-generic-bsp = "1"
+UBOOT_SIGN_ENABLE:sota:mx93-generic-bsp ??= "1"
 IMX_DEFAULT_BOOTLOADER:mx93-generic-bsp ?= "u-boot-fio"
 UBOOT_ENTRYPOINT:mx93-generic-bsp = "0x80400000"
 UBOOT_LOADADDRESS:mx93-generic-bsp = "0x80400000"
@@ -488,6 +498,7 @@ PREFERRED_VERSION_optee-os-fio-mfgtool:mx93-nxp-bsp = "3.20.0-imx"
 PREFERRED_VERSION_optee-os-tadevkit:mx93-nxp-bsp = "3.20.0-imx"
 PREFERRED_PROVIDER_virtual/kernel:mx93-nxp-bsp ?= "linux-lmp-fslc-imx"
 ## iMX93 DDR4 EVK
+UBOOT_SIGN_ENABLE:sota:imx93-11x11-lpddr4x-evk ?= "1"
 OSTREE_KERNEL_ARGS:imx93-11x11-lpddr4x-evk ?= "console=tty1 console=ttyLP0,115200 earlycon rootfstype=ext4"
 BOOTSCR_LOAD_ADDR:imx93-11x11-lpddr4x-evk = "0x83500000"
 UBOOT_CONFIG:imx93-11x11-lpddr4x-evk = ""