diff --git a/arch/arm/include/asm/bootm.h b/arch/arm/include/asm/bootm.h
index a2131ca..27f183b 100644
--- a/arch/arm/include/asm/bootm.h
+++ b/arch/arm/include/asm/bootm.h
@@ -41,9 +41,12 @@
 struct tag_serialnr;
 #ifdef CONFIG_SERIAL_TAG
  #define BOOTM_ENABLE_SERIAL_TAG	1
-void get_board_serial(struct tag_serialnr *serialnr);
 #else
  #define BOOTM_ENABLE_SERIAL_TAG	0
+#endif
+#if defined(CONFIG_SERIAL_TAG) || defined(CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG)
+void get_board_serial(struct tag_serialnr *serialnr);
+#else
 static inline void get_board_serial(struct tag_serialnr *serialnr)
 {
 }
diff --git a/arch/arm/mach-imx/imx8/cpu.c b/arch/arm/mach-imx/imx8/cpu.c
index 02db322..ee5cc47 100644
--- a/arch/arm/mach-imx/imx8/cpu.c
+++ b/arch/arm/mach-imx/imx8/cpu.c
@@ -172,7 +172,7 @@
 	return boot_dev;
 }
 
-#ifdef CONFIG_SERIAL_TAG
+#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
 #define FUSE_UNIQUE_ID_WORD0 16
 #define FUSE_UNIQUE_ID_WORD1 17
 void get_board_serial(struct tag_serialnr *serialnr)
@@ -201,7 +201,7 @@
 	serialnr->low = val1;
 	serialnr->high = val2;
 }
-#endif /*CONFIG_SERIAL_TAG*/
+#endif /*CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG*/
 
 #ifdef CONFIG_ENV_IS_IN_MMC
 __weak int board_mmc_get_env_dev(int devno)
diff --git a/arch/arm/mach-imx/imx8ulp/soc.c b/arch/arm/mach-imx/imx8ulp/soc.c
index 1c33acc..bba6323 100644
--- a/arch/arm/mach-imx/imx8ulp/soc.c
+++ b/arch/arm/mach-imx/imx8ulp/soc.c
@@ -405,7 +405,7 @@
 	return 0;
 }
 
-#ifdef CONFIG_SERIAL_TAG
+#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
 void get_board_serial(struct tag_serialnr *serialnr)
 {
 	u32 uid[4];
diff --git a/arch/arm/mach-imx/mx7/soc.c b/arch/arm/mach-imx/mx7/soc.c
index 6f9a30b..9c7d5f1 100644
--- a/arch/arm/mach-imx/mx7/soc.c
+++ b/arch/arm/mach-imx/mx7/soc.c
@@ -15,6 +15,7 @@
 #include <asm/arch/imx-rdc.h>
 #include <asm/mach-imx/boot_mode.h>
 #include <asm/arch/crm_regs.h>
+#include <asm/bootm.h>
 #include <dm.h>
 #include <env.h>
 #include <imx_thermal.h>
@@ -337,10 +338,19 @@
 int arch_misc_init(void)
 {
 #ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
+	struct tag_serialnr serialnr;
+	char serial_string[0x20];
+
 	if (is_mx7d())
 		env_set("soc", "imx7d");
 	else
 		env_set("soc", "imx7s");
+
+	/* Set serial# standard environment variable based on OTP settings */
+	get_board_serial(&serialnr);
+	snprintf(serial_string, sizeof(serial_string), "0x%08x%08x",
+		 serialnr.low, serialnr.high);
+	env_set("serial#", serial_string);
 #endif
 
 #ifdef CONFIG_FSL_CAAM
@@ -351,7 +361,7 @@
 }
 #endif
 
-#ifdef CONFIG_SERIAL_TAG
+#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
 /*
  * OCOTP_TESTER
  * i.MX 7Solo Applications Processor Reference Manual, Rev. 0.1, 08/2016
diff --git a/board/warp7/warp7.c b/board/warp7/warp7.c
index 0f20224..c5c5433 100644
--- a/board/warp7/warp7.c
+++ b/board/warp7/warp7.c
@@ -134,7 +134,7 @@
 int board_late_init(void)
 {
 	struct wdog_regs *wdog = (struct wdog_regs *)WDOG1_BASE_ADDR;
-#ifdef CONFIG_SERIAL_TAG
+#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
 	struct tag_serialnr serialnr;
 	char serial_string[0x20];
 #endif
@@ -156,7 +156,7 @@
 	env_set_ulong(HAB_ENABLED_ENVNAME, 0);
 #endif
 
-#ifdef CONFIG_SERIAL_TAG
+#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
 	/* Set serial# standard environment variable based on OTP settings */
 	get_board_serial(&serialnr);
 	snprintf(serial_string, sizeof(serial_string), "WaRP7-0x%08x%08x",
diff --git a/configs/gwventana_emmc_defconfig b/configs/gwventana_emmc_defconfig
index d107432..000bdb5 100644
--- a/configs/gwventana_emmc_defconfig
+++ b/configs/gwventana_emmc_defconfig
@@ -79,6 +79,7 @@
 CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_SYS_MMC_ENV_PART=1
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_NETCONSOLE=y
 CONFIG_DM=y
 CONFIG_BOUNCE_BUFFER=y
diff --git a/configs/gwventana_gw5904_defconfig b/configs/gwventana_gw5904_defconfig
index f579d0f..87851f3 100644
--- a/configs/gwventana_gw5904_defconfig
+++ b/configs/gwventana_gw5904_defconfig
@@ -79,6 +79,7 @@
 CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_SYS_MMC_ENV_PART=1
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_NETCONSOLE=y
 CONFIG_DM=y
 CONFIG_BOUNCE_BUFFER=y
diff --git a/configs/gwventana_nand_defconfig b/configs/gwventana_nand_defconfig
index b587ade..ff5001e 100644
--- a/configs/gwventana_nand_defconfig
+++ b/configs/gwventana_nand_defconfig
@@ -81,6 +81,7 @@
 CONFIG_ENV_IS_IN_NAND=y
 CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_NETCONSOLE=y
 CONFIG_DM=y
 CONFIG_BOUNCE_BUFFER=y
diff --git a/configs/imx8ulp_evk_defconfig b/configs/imx8ulp_evk_defconfig
index 1c6288d..f156100 100644
--- a/configs/imx8ulp_evk_defconfig
+++ b/configs/imx8ulp_evk_defconfig
@@ -40,6 +40,7 @@
 CONFIG_CMD_EXT4_WRITE=y
 CONFIG_SPL_OF_CONTROL=y
 CONFIG_ENV_IS_IN_MMC=y
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_SPL_DM=y
 CONFIG_IMX_RGPIO2P=y
diff --git a/configs/puma-rk3399_defconfig b/configs/puma-rk3399_defconfig
index a0a3059..afc54fe 100644
--- a/configs/puma-rk3399_defconfig
+++ b/configs/puma-rk3399_defconfig
@@ -46,6 +46,7 @@
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_SYS_MMC_ENV_DEV=1
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_SPL_DM_SEQ_ALIAS=y
 CONFIG_ROCKCHIP_GPIO=y
 CONFIG_SYS_I2C_ROCKCHIP=y
diff --git a/configs/warp7_bl33_defconfig b/configs/warp7_bl33_defconfig
index e260bbe..d127a4f 100644
--- a/configs/warp7_bl33_defconfig
+++ b/configs/warp7_bl33_defconfig
@@ -32,6 +32,7 @@
 CONFIG_OF_CONTROL=y
 CONFIG_ENV_OVERWRITE=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_BOUNCE_BUFFER=y
 CONFIG_DFU_MMC=y
diff --git a/configs/warp7_defconfig b/configs/warp7_defconfig
index 1b77528..4b339b4 100644
--- a/configs/warp7_defconfig
+++ b/configs/warp7_defconfig
@@ -38,6 +38,7 @@
 CONFIG_OF_CONTROL=y
 CONFIG_ENV_OVERWRITE=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_BOUNCE_BUFFER=y
 CONFIG_DFU_MMC=y
diff --git a/include/configs/apalis_imx6.h b/include/configs/apalis_imx6.h
index 839af48..de6e205 100644
--- a/include/configs/apalis_imx6.h
+++ b/include/configs/apalis_imx6.h
@@ -27,7 +27,6 @@
 #define CONFIG_SETUP_MEMORY_TAGS
 #define CONFIG_INITRD_TAG
 #define CONFIG_REVISION_TAG
-#define CONFIG_SERIAL_TAG
 
 #define CONFIG_MXC_UART_BASE		UART1_BASE
 
diff --git a/include/configs/cm_fx6.h b/include/configs/cm_fx6.h
index 2e7d343..7092def 100644
--- a/include/configs/cm_fx6.h
+++ b/include/configs/cm_fx6.h
@@ -173,7 +173,6 @@
 
 /* Boot */
 #define CONFIG_SYS_BOOTMAPSZ	        (8 << 20)
-#define CONFIG_SERIAL_TAG
 
 /* misc */
 
diff --git a/include/configs/colibri_imx6.h b/include/configs/colibri_imx6.h
index be0ed45..8d628e7 100644
--- a/include/configs/colibri_imx6.h
+++ b/include/configs/colibri_imx6.h
@@ -25,7 +25,6 @@
 #define CONFIG_SETUP_MEMORY_TAGS
 #define CONFIG_INITRD_TAG
 #define CONFIG_REVISION_TAG
-#define CONFIG_SERIAL_TAG
 
 #define CONFIG_MXC_UART_BASE		UART1_BASE
 
diff --git a/include/configs/gw_ventana.h b/include/configs/gw_ventana.h
index 012c9b6..ed8e508 100644
--- a/include/configs/gw_ventana.h
+++ b/include/configs/gw_ventana.h
@@ -26,9 +26,6 @@
 
 #define CONFIG_MACH_TYPE	4520   /* Gateworks Ventana Platform */
 
-/* Serial ATAG */
-#define CONFIG_SERIAL_TAG
-
 /* Serial */
 #define CONFIG_MXC_UART_BASE	       UART2_BASE
 
diff --git a/include/configs/imx8ulp_evk.h b/include/configs/imx8ulp_evk.h
index 1621b04..8e9a159 100644
--- a/include/configs/imx8ulp_evk.h
+++ b/include/configs/imx8ulp_evk.h
@@ -33,8 +33,6 @@
 
 #endif
 
-#define CONFIG_SERIAL_TAG
-
 #define CONFIG_REMAKE_ELF
 
 #define CONFIG_BOARD_EARLY_INIT_F
diff --git a/include/configs/puma_rk3399.h b/include/configs/puma_rk3399.h
index f52ea01..23de326 100644
--- a/include/configs/puma_rk3399.h
+++ b/include/configs/puma_rk3399.h
@@ -10,6 +10,4 @@
 
 #define SDRAM_BANK_SIZE			(2UL << 30)
 
-#define CONFIG_SERIAL_TAG
-
 #endif
diff --git a/include/configs/warp7.h b/include/configs/warp7.h
index bb9ba37..0822eaf 100644
--- a/include/configs/warp7.h
+++ b/include/configs/warp7.h
@@ -18,9 +18,6 @@
 #define CONFIG_SYS_FSL_ESDHC_HAS_DDR_MODE
 #define CONFIG_SYS_MMC_IMG_LOAD_PART	1
 
-/* Switch on SERIAL_TAG */
-#define CONFIG_SERIAL_TAG
-
 #define CONFIG_DFU_ENV_SETTINGS \
 	"dfu_alt_info=boot raw 0x2 0x1000 mmcpart 1\0" \