diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 7c5012ac..d6b0cea 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -181,6 +181,25 @@
 	  the hosted environment to call out to the emulator to
 	  retrieve files from the host machine.
 
+config SYS_THUMB_BUILD
+	bool "Build U-Boot using the Thumb instruction set"
+	depends on !ARM64
+	help
+	   Use this flag to build U-Boot using the Thumb instruction set for
+	   ARM architectures. Thumb instruction set provides better code
+	   density. For ARM architectures that support Thumb2 this flag will
+	   result in Thumb2 code generated by GCC.
+
+config SPL_SYS_THUMB_BUILD
+	bool "Build SPL using the Thumb instruction set"
+	default y if SYS_THUMB_BUILD
+	depends on !ARM64
+	help
+	   Use this flag to build SPL using the Thumb instruction set for
+	   ARM architectures. Thumb instruction set provides better code
+	   density. For ARM architectures that support Thumb2 this flag will
+	   result in Thumb2 code generated by GCC.
+
 config SYS_L2CACHE_OFF
 	bool "L2cache off"
 	help
@@ -571,6 +590,7 @@
 	bool "TI Keystone"
 	select CPU_V7
 	select SUPPORT_SPL
+	select SYS_THUMB_BUILD
 	select CMD_POWEROFF
 
 config ARCH_MESON
@@ -595,6 +615,7 @@
 	select SYS_FSL_HAS_SEC if SECURE_BOOT
 	select SYS_FSL_SEC_COMPAT_4
 	select SYS_FSL_SEC_LE
+	select SYS_THUMB_BUILD if SPL
 
 config ARCH_MX5
 	bool "Freescale MX5"
@@ -654,6 +675,7 @@
 	imply SPL_NAND_SUPPORT
 	imply SPL_POWER_SUPPORT
 	imply SPL_SERIAL_SUPPORT
+	imply SYS_THUMB_BUILD
 
 config OMAP44XX
 	bool "OMAP44XX SoC"
@@ -671,11 +693,13 @@
 	imply SPL_NAND_SUPPORT
 	imply SPL_POWER_SUPPORT
 	imply SPL_SERIAL_SUPPORT
+	imply SYS_THUMB_BUILD
 
 config OMAP54XX
 	bool "OMAP54XX SoC"
 	select ARCH_OMAP2
 	select ARM_ERRATA_798870
+	select SYS_THUMB_BUILD
 	imply SPL_DISPLAY_PRINT
 	imply SPL_ENV_SUPPORT
 	imply SPL_EXT_SUPPORT
@@ -693,6 +717,7 @@
 config AM43XX
 	bool "AM43XX SoC"
 	select ARCH_OMAP2
+	imply SYS_THUMB_BUILD
 	help
 	  Support for AM43xx SOC from Texas Instruments.
 	  The AM43xx high performance SOC features a Cortex-A9
@@ -703,6 +728,7 @@
 config AM33XX
 	bool "AM33XX SoC"
 	select ARCH_OMAP2
+	imply SYS_THUMB_BUILD
 	help
 	  Support for AM335x SOC from Texas Instruments.
 	  The AM335x high performance SOC features a Cortex-A8
@@ -715,6 +741,7 @@
 	select DM
 	select DM_SERIAL
 	select BOARD_EARLY_INIT_F
+	imply SYS_THUMB_BUILD
 
 config TARGET_S32V234EVB
 	bool "Support s32v234evb"
@@ -744,6 +771,7 @@
 	select ARCH_EARLY_INIT_R
 	select ARCH_MISC_INIT
 	select SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION
+	select SYS_THUMB_BUILD
 
 config TARGET_CM_T43
 	bool "Support cm_t43"
@@ -766,6 +794,7 @@
 	select SPL_STACK_R if SUPPORT_SPL
 	select SPL_SYS_MALLOC_SIMPLE if SUPPORT_SPL
 	select SYS_NS16550
+	select SPL_SYS_THUMB_BUILD if !ARM64
 	select USB if DISTRO_DEFAULTS
 	select USB_STORAGE if DISTRO_DEFAULTS
 	select USB_KEYBOARD if DISTRO_DEFAULTS
@@ -1095,6 +1124,7 @@
 	select CPU_V7M
 	select DM
 	select DM_SERIAL
+	select SYS_THUMB_BUILD
 
 config ARCH_STI
 	bool "Support STMicrolectronics SoCs"
@@ -1114,6 +1144,7 @@
 	select DM
 	select SPL_DM if SPL
 	select SYS_MALLOC_F
+	select SYS_THUMB_BUILD if !ARM64
 	select SPL_SYS_MALLOC_SIMPLE if SPL
 	select DM_GPIO
 	select DM_I2C
diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index 3a81f13..08d7d1b 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -31,7 +31,7 @@
 PLATFORM_CPPFLAGS += -D__ARM__
 
 # Choose between ARM/Thumb instruction sets
-ifeq ($(CONFIG_SYS_THUMB_BUILD),y)
+ifeq ($(CONFIG_$(SPL_)SYS_THUMB_BUILD),y)
 AFLAGS_IMPLICIT_IT	:= $(call as-option,-Wa$(comma)-mimplicit-it=always)
 PF_CPPFLAGS_ARM		:= $(AFLAGS_IMPLICIT_IT) \
 			$(call cc-option, -mthumb -mthumb-interwork,\
@@ -44,8 +44,7 @@
 endif
 
 # Only test once
-ifneq ($(CONFIG_SPL_BUILD),y)
-ifeq ($(CONFIG_SYS_THUMB_BUILD),y)
+ifeq ($(CONFIG_$(SPL_)SYS_THUMB_BUILD),y)
 archprepare: checkthumb
 
 checkthumb:
@@ -57,7 +56,6 @@
 		false; \
 	fi
 endif
-endif
 
 # Try if EABI is supported, else fall back to old API,
 # i. e. for example:
@@ -99,7 +97,7 @@
 #
 # http://sourceware.org/bugzilla/show_bug.cgi?id=12532
 #
-ifeq ($(CONFIG_SYS_THUMB_BUILD),y)
+ifeq ($(CONFIG_$(SPL_)SYS_THUMB_BUILD),y)
 ifeq ($(GAS_BUG_12532),)
 export GAS_BUG_12532:=$(shell if [ $(call binutils-version) -lt 0222 ] ; \
 	then echo y; else echo n; fi)
diff --git a/arch/arm/cpu/arm920t/Makefile b/arch/arm/cpu/arm920t/Makefile
index 1832b9d..7aa432a 100644
--- a/arch/arm/cpu/arm920t/Makefile
+++ b/arch/arm/cpu/arm920t/Makefile
@@ -16,6 +16,6 @@
 
 # some files can only build in ARM mode
 
-ifdef CONFIG_SYS_THUMB_BUILD
+ifdef CONFIG_$(SPL_)SYS_THUMB_BUILD
 CFLAGS_cpu.o := -marm
 endif
diff --git a/arch/arm/cpu/arm926ejs/Makefile b/arch/arm/cpu/arm926ejs/Makefile
index fe78922..0f73011 100644
--- a/arch/arm/cpu/arm926ejs/Makefile
+++ b/arch/arm/cpu/arm926ejs/Makefile
@@ -23,7 +23,7 @@
 
 # some files can only build in ARM or THUMB2, not THUMB1
 
-ifdef CONFIG_SYS_THUMB_BUILD
+ifdef CONFIG_$(SPL_)SYS_THUMB_BUILD
 ifndef CONFIG_HAS_THUMB2
 
 CFLAGS_cpu.o := -marm
diff --git a/arch/arm/cpu/arm926ejs/cache.c b/arch/arm/cpu/arm926ejs/cache.c
index 02cb24c..d56e594 100644
--- a/arch/arm/cpu/arm926ejs/cache.c
+++ b/arch/arm/cpu/arm926ejs/cache.c
@@ -63,6 +63,6 @@
 
 __weak void l2_cache_disable(void) {}
 
-#if defined CONFIG_SYS_THUMB_BUILD
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD)
 __weak void invalidate_l2_cache(void) {}
 #endif
diff --git a/arch/arm/cpu/armv7/cache_v7_asm.S b/arch/arm/cpu/armv7/cache_v7_asm.S
index a433628..bd27ab2 100644
--- a/arch/arm/cpu/armv7/cache_v7_asm.S
+++ b/arch/arm/cpu/armv7/cache_v7_asm.S
@@ -7,7 +7,7 @@
 #include <linux/sizes.h>
 #include <asm/system.h>
 
-#ifdef CONFIG_SYS_THUMB_BUILD
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD)
 #define ARM(x...)
 #define THUMB(x...)	x
 #else
diff --git a/arch/arm/cpu/pxa/cache.c b/arch/arm/cpu/pxa/cache.c
index d26354e..30e1e34 100644
--- a/arch/arm/cpu/pxa/cache.c
+++ b/arch/arm/cpu/pxa/cache.c
@@ -52,6 +52,6 @@
 
 __weak void l2_cache_disable(void) {}
 
-#if defined CONFIG_SYS_THUMB_BUILD
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD)
 __weak void invalidate_l2_cache(void) {}
 #endif
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index d24be2d..b146918 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -77,7 +77,7 @@
  * We disable it especially for Thumb builds since those instructions
  * are not made in a Thumb ready way...
  */
-#ifdef CONFIG_SYS_THUMB_BUILD
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD)
 #define CALGN(code...)
 #else
 #define CALGN(code...) code
diff --git a/arch/arm/include/asm/cache.h b/arch/arm/include/asm/cache.h
index 5400cbe..fac65d8 100644
--- a/arch/arm/include/asm/cache.h
+++ b/arch/arm/include/asm/cache.h
@@ -16,7 +16,7 @@
 /*
  * Invalidate L2 Cache using co-proc instruction
  */
-#ifdef CONFIG_SYS_THUMB_BUILD
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD)
 void invalidate_l2_cache(void);
 #else
 static inline void invalidate_l2_cache(void)
diff --git a/arch/arm/include/asm/setjmp.h b/arch/arm/include/asm/setjmp.h
index df9934b..c3399a7 100644
--- a/arch/arm/include/asm/setjmp.h
+++ b/arch/arm/include/asm/setjmp.h
@@ -39,7 +39,7 @@
 		  "x30", "cc", "memory");
 #else
 	asm volatile(
-#ifdef CONFIG_SYS_THUMB_BUILD
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD)
 		".align 2\n"
 		"adr r0, jmp_target\n"
 		"add r0, r0, $1\n"
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 166fa9e..b95e105 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -71,7 +71,7 @@
 
 # some files can only build in ARM or THUMB2, not THUMB1
 
-ifdef CONFIG_SYS_THUMB_BUILD
+ifdef CONFIG_$(SPL_)SYS_THUMB_BUILD
 asflags-$(CONFIG_HAS_THUMB2) += -DCONFIG_THUMB2_KERNEL
 ifndef CONFIG_HAS_THUMB2
 
diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c
index 4f72f89..7683386 100644
--- a/arch/arm/lib/cache.c
+++ b/arch/arm/lib/cache.c
@@ -107,7 +107,7 @@
 }
 #endif /* CONFIG_SYS_NONCACHED_MEMORY */
 
-#if defined(CONFIG_SYS_THUMB_BUILD)
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD)
 void invalidate_l2_cache(void)
 {
 	unsigned int val = 0;
diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S
index 2c4867a..fa81317 100644
--- a/arch/arm/lib/crt0.S
+++ b/arch/arm/lib/crt0.S
@@ -156,7 +156,7 @@
 	mov     r0, r9                  /* gd_t */
 	ldr	r1, [r9, #GD_RELOCADDR]	/* dest_addr */
 	/* call board_init_r */
-#if defined(CONFIG_SYS_THUMB_BUILD)
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD)
 	ldr	lr, =board_init_r	/* this is auto-relocated! */
 	bx	lr
 #else
diff --git a/arch/arm/lib/lib1funcs.S b/arch/arm/lib/lib1funcs.S
index 76968ce..6e29cbf 100644
--- a/arch/arm/lib/lib1funcs.S
+++ b/arch/arm/lib/lib1funcs.S
@@ -368,7 +368,7 @@
 .popsection
 
 /* Thumb-1 specialities */
-#if defined(CONFIG_SYS_THUMB_BUILD) && !defined(CONFIG_HAS_THUMB2)
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD) && !defined(CONFIG_HAS_THUMB2)
 .pushsection .text.__gnu_thumb1_case_sqi, "ax"
 ENTRY(__gnu_thumb1_case_sqi)
 	push	{r1}
diff --git a/arch/arm/lib/memcpy.S b/arch/arm/lib/memcpy.S
index 00602e9..588b3f8 100644
--- a/arch/arm/lib/memcpy.S
+++ b/arch/arm/lib/memcpy.S
@@ -56,7 +56,7 @@
 
 /* Prototype: void *memcpy(void *dest, const void *src, size_t n); */
 	.syntax unified
-#if defined(CONFIG_SYS_THUMB_BUILD) && !defined(MEMCPY_NO_THUMB_BUILD)
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD) && !defined(MEMCPY_NO_THUMB_BUILD)
 	.thumb
 	.thumb_func
 #endif
diff --git a/arch/arm/lib/memset.S b/arch/arm/lib/memset.S
index df053a3..cc4cc44 100644
--- a/arch/arm/lib/memset.S
+++ b/arch/arm/lib/memset.S
@@ -16,7 +16,7 @@
 	.align	5
 
 	.syntax unified
-#if defined(CONFIG_SYS_THUMB_BUILD) && !defined(MEMSET_NO_THUMB_BUILD)
+#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD) && !defined(MEMSET_NO_THUMB_BUILD)
 	.thumb
 	.thumb_func
 #endif
diff --git a/arch/arm/mach-at91/arm926ejs/Makefile b/arch/arm/mach-at91/arm926ejs/Makefile
index d36e15a..624ccd7 100644
--- a/arch/arm/mach-at91/arm926ejs/Makefile
+++ b/arch/arm/mach-at91/arm926ejs/Makefile
@@ -27,3 +27,11 @@
 ifndef CONFIG_SKIP_LOWLEVEL_INIT
 obj-y	+= lowlevel_init.o
 endif
+
+ifdef CONFIG_$(SPL_)SYS_THUMB_BUILD
+ifndef CONFIG_HAS_THUMB2
+
+CFLAGS_cache.o := -marm
+
+endif
+endif
diff --git a/arch/arm/mach-orion5x/Makefile b/arch/arm/mach-orion5x/Makefile
index 33dcad4..5249aa8 100644
--- a/arch/arm/mach-orion5x/Makefile
+++ b/arch/arm/mach-orion5x/Makefile
@@ -19,7 +19,7 @@
 
 # some files can only build in ARM or THUMB2, not THUMB1
 
-ifdef CONFIG_SYS_THUMB_BUILD
+ifdef CONFIG_$(SPL_)SYS_THUMB_BUILD
 ifndef CONFIG_HAS_THUMB2
 
 CFLAGS_cpu.o := -marm