diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index c044ad4..85fddd2 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -132,6 +132,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_DUMMY
 	bool "Dummy target"
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index cee3126..1c7cf7f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -64,6 +64,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config ARCH_AT91
 	bool "Atmel AT91"
diff --git a/arch/arm/cpu/armv7/exynos/Kconfig b/arch/arm/cpu/armv7/exynos/Kconfig
index f6084ac..c614425 100644
--- a/arch/arm/cpu/armv7/exynos/Kconfig
+++ b/arch/arm/cpu/armv7/exynos/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "EXYNOS board select"
+	optional
 
 config TARGET_SMDKV310
 	select SUPPORT_SPL
diff --git a/arch/arm/cpu/armv7/mx5/Kconfig b/arch/arm/cpu/armv7/mx5/Kconfig
index 2d6c0ce..9f250c6 100644
--- a/arch/arm/cpu/armv7/mx5/Kconfig
+++ b/arch/arm/cpu/armv7/mx5/Kconfig
@@ -12,6 +12,7 @@
 
 choice
 	prompt "MX5 board select"
+	optional
 
 config TARGET_USBARMORY
 	bool "Support USB armory"
diff --git a/arch/arm/cpu/armv7/mx6/Kconfig b/arch/arm/cpu/armv7/mx6/Kconfig
index 076ba52..1282be3 100644
--- a/arch/arm/cpu/armv7/mx6/Kconfig
+++ b/arch/arm/cpu/armv7/mx6/Kconfig
@@ -27,6 +27,7 @@
 
 choice
 	prompt "MX6 board select"
+	optional
 
 config TARGET_SECOMX6
 	bool "Support secomx6 boards"
diff --git a/arch/arm/cpu/armv7/omap3/Kconfig b/arch/arm/cpu/armv7/omap3/Kconfig
index cc82c50..b32a6b0 100644
--- a/arch/arm/cpu/armv7/omap3/Kconfig
+++ b/arch/arm/cpu/armv7/omap3/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "OMAP3 board select"
+	optional
 
 config TARGET_AM3517_EVM
 	bool "AM3517 EVM"
diff --git a/arch/arm/cpu/armv7/omap4/Kconfig b/arch/arm/cpu/armv7/omap4/Kconfig
index eccf897..df27ea1 100644
--- a/arch/arm/cpu/armv7/omap4/Kconfig
+++ b/arch/arm/cpu/armv7/omap4/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "OMAP4 board select"
+	optional
 
 config TARGET_DUOVERO
 	bool "OMAP4430 Gumstix Duovero"
diff --git a/arch/arm/cpu/armv7/omap5/Kconfig b/arch/arm/cpu/armv7/omap5/Kconfig
index aca862d..20c3bd9 100644
--- a/arch/arm/cpu/armv7/omap5/Kconfig
+++ b/arch/arm/cpu/armv7/omap5/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "OMAP5 board select"
+	optional
 
 config TARGET_CM_T54
 	bool "CompuLab CM-T54"
diff --git a/arch/arm/cpu/armv7/rmobile/Kconfig b/arch/arm/cpu/armv7/rmobile/Kconfig
index 57dccec..ae23078 100644
--- a/arch/arm/cpu/armv7/rmobile/Kconfig
+++ b/arch/arm/cpu/armv7/rmobile/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Renesus ARM SoCs board select"
+	optional
 
 config TARGET_ARMADILLO_800EVA
 	bool "armadillo 800 eva board"
diff --git a/arch/arm/cpu/armv7/s5pc1xx/Kconfig b/arch/arm/cpu/armv7/s5pc1xx/Kconfig
index bc73813..04acdaa 100644
--- a/arch/arm/cpu/armv7/s5pc1xx/Kconfig
+++ b/arch/arm/cpu/armv7/s5pc1xx/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "S5PC1XX board select"
+	optional
 
 config TARGET_S5P_GONI
 	bool "S5P Goni board"
diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index b660a5b..7dfa520 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Atmel AT91 board select"
+	optional
 
 config TARGET_AT91RM9200EK
 	bool "Atmel AT91RM9200 evaluation kit"
diff --git a/arch/arm/mach-bcm283x/Kconfig b/arch/arm/mach-bcm283x/Kconfig
index c740180..99779df 100644
--- a/arch/arm/mach-bcm283x/Kconfig
+++ b/arch/arm/mach-bcm283x/Kconfig
@@ -3,6 +3,7 @@
 
 choice
 	prompt "Broadcom BCM283X board select"
+	optional
 
 config TARGET_RPI
 	bool "Raspberry Pi"
diff --git a/arch/arm/mach-davinci/Kconfig b/arch/arm/mach-davinci/Kconfig
index 3ef55d3..e6cb390 100644
--- a/arch/arm/mach-davinci/Kconfig
+++ b/arch/arm/mach-davinci/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "DaVinci board select"
+	optional
 
 config TARGET_ENBW_CMC
 	bool "EnBW CMC board"
diff --git a/arch/arm/mach-integrator/Kconfig b/arch/arm/mach-integrator/Kconfig
index 8ffc544..c54d69d 100644
--- a/arch/arm/mach-integrator/Kconfig
+++ b/arch/arm/mach-integrator/Kconfig
@@ -3,6 +3,7 @@
 
 choice
 	prompt "Integrator platform select"
+	optional
 
 config ARCH_INTEGRATOR_AP
 	bool "Support Integrator/AP platform"
@@ -18,6 +19,7 @@
 
 choice
 	prompt "Integrator core module select"
+	optional
 
 config CM720T
 	bool "Core Module for ARM720T"
diff --git a/arch/arm/mach-keystone/Kconfig b/arch/arm/mach-keystone/Kconfig
index 134ae87..67f1a33 100644
--- a/arch/arm/mach-keystone/Kconfig
+++ b/arch/arm/mach-keystone/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "TI Keystone board select"
+	optional
 
 config TARGET_K2HK_EVM
 	bool "TI Keystone 2 Kepler/Hawking EVM"
diff --git a/arch/arm/mach-kirkwood/Kconfig b/arch/arm/mach-kirkwood/Kconfig
index 45c6687..1261885 100644
--- a/arch/arm/mach-kirkwood/Kconfig
+++ b/arch/arm/mach-kirkwood/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Marvell Kirkwood board select"
+	optional
 
 config TARGET_OPENRD
 	bool "Marvell OpenRD Board"
diff --git a/arch/arm/mach-nomadik/Kconfig b/arch/arm/mach-nomadik/Kconfig
index 265f336..ba72a41 100644
--- a/arch/arm/mach-nomadik/Kconfig
+++ b/arch/arm/mach-nomadik/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Nomadik board select"
+	optional
 
 config NOMADIK_NHK8815
 	bool "ST 8815 Nomadik Hardware Kit"
diff --git a/arch/arm/mach-orion5x/Kconfig b/arch/arm/mach-orion5x/Kconfig
index 291c511..7644b8d 100644
--- a/arch/arm/mach-orion5x/Kconfig
+++ b/arch/arm/mach-orion5x/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Marvell Orion board select"
+	optional
 
 config TARGET_EDMINIV2
 	bool "LaCie Ethernet Disk mini V2"
diff --git a/arch/arm/mach-socfpga/Kconfig b/arch/arm/mach-socfpga/Kconfig
index 204efca..e46c348 100644
--- a/arch/arm/mach-socfpga/Kconfig
+++ b/arch/arm/mach-socfpga/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Altera SOCFPGA board select"
+	optional
 
 config TARGET_SOCFPGA_ARRIA5
 	bool "Altera SOCFPGA Arria V"
diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
index 8bab594..9b42871 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Tegra SoC select"
+	optional
 
 config TEGRA20
 	bool "Tegra20 family"
diff --git a/arch/arm/mach-tegra/tegra114/Kconfig b/arch/arm/mach-tegra/tegra114/Kconfig
index 31012bc..1047b92 100644
--- a/arch/arm/mach-tegra/tegra114/Kconfig
+++ b/arch/arm/mach-tegra/tegra114/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Tegra114 board select"
+	optional
 
 config TARGET_DALMORE
 	bool "NVIDIA Tegra114 Dalmore evaluation board"
diff --git a/arch/arm/mach-tegra/tegra124/Kconfig b/arch/arm/mach-tegra/tegra124/Kconfig
index 88f627c..36bb636 100644
--- a/arch/arm/mach-tegra/tegra124/Kconfig
+++ b/arch/arm/mach-tegra/tegra124/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Tegra124 board select"
+	optional
 
 config TARGET_JETSON_TK1
 	bool "NVIDIA Tegra124 Jetson TK1 board"
diff --git a/arch/arm/mach-tegra/tegra20/Kconfig b/arch/arm/mach-tegra/tegra20/Kconfig
index 7f09f81..1bb8dff 100644
--- a/arch/arm/mach-tegra/tegra20/Kconfig
+++ b/arch/arm/mach-tegra/tegra20/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Tegra20 board select"
+	optional
 
 config TARGET_HARMONY
 	bool "NVIDIA Tegra20 Harmony evaluation board"
diff --git a/arch/arm/mach-tegra/tegra30/Kconfig b/arch/arm/mach-tegra/tegra30/Kconfig
index 3abdc7b..e78331e 100644
--- a/arch/arm/mach-tegra/tegra30/Kconfig
+++ b/arch/arm/mach-tegra/tegra30/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Tegra30 board select"
+	optional
 
 config TARGET_APALIS_T30
 	bool "Toradex Apalis T30 board"
diff --git a/arch/arm/mach-uniphier/Kconfig b/arch/arm/mach-uniphier/Kconfig
index 288e6ab..2d27c49 100644
--- a/arch/arm/mach-uniphier/Kconfig
+++ b/arch/arm/mach-uniphier/Kconfig
@@ -9,6 +9,7 @@
 
 choice
 	prompt "UniPhier SoC select"
+	optional
 
 config MACH_PH1_PRO4
 	bool "PH1-Pro4"
diff --git a/arch/arm/mach-zynq/Kconfig b/arch/arm/mach-zynq/Kconfig
index 1046ece..483c3a0 100644
--- a/arch/arm/mach-zynq/Kconfig
+++ b/arch/arm/mach-zynq/Kconfig
@@ -2,6 +2,7 @@
 
 choice
 	prompt "Xilinx Zynq board select"
+	optional
 
 config TARGET_ZYNQ_ZED
 	bool "Zynq ZedBoard"
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index 66de2ad..c69654c 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_ATNGW100
 	bool "Support atngw100"
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 31913fe..0a2fb4d 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_BCT_BRETTL2
 	bool "Support bct-brettl2"
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 69cb0f7..26509b7 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -114,6 +114,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_M52277EVB
 	bool "Support M52277EVB"
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 6f419f0..077b2a7 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_MICROBLAZE_GENERIC
 	bool "Support microblaze-generic"
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index b0a8a43..feb2f68 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -13,6 +13,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_QEMU_MIPS
 	bool "Support qemu-mips"
diff --git a/arch/nds32/Kconfig b/arch/nds32/Kconfig
index 81b0a01..98b0282 100644
--- a/arch/nds32/Kconfig
+++ b/arch/nds32/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_ADP_AG101
 	bool "Support adp-ag101"
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index b3be7b5..8ae7f6e 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_NIOS2_GENERIC
 	bool "Support nios2-generic"
diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 4d62b4c..11014d1 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_OPENRISC_GENERIC
 	bool "Support openrisc-generic"
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 8e5a3e2..3b3f446 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "CPU select"
+	optional
 
 config MPC512X
 	bool "MPC512X"
diff --git a/arch/powerpc/cpu/mpc512x/Kconfig b/arch/powerpc/cpu/mpc512x/Kconfig
index a0f0ede..53450ae 100644
--- a/arch/powerpc/cpu/mpc512x/Kconfig
+++ b/arch/powerpc/cpu/mpc512x/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_PDM360NG
 	bool "Support pdm360ng"
diff --git a/arch/powerpc/cpu/mpc5xx/Kconfig b/arch/powerpc/cpu/mpc5xx/Kconfig
index aad4a7c..5275447 100644
--- a/arch/powerpc/cpu/mpc5xx/Kconfig
+++ b/arch/powerpc/cpu/mpc5xx/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_CMI_MPC5XX
 	bool "Support cmi_mpc5xx"
diff --git a/arch/powerpc/cpu/mpc5xxx/Kconfig b/arch/powerpc/cpu/mpc5xxx/Kconfig
index eec9d7d..5d49228 100644
--- a/arch/powerpc/cpu/mpc5xxx/Kconfig
+++ b/arch/powerpc/cpu/mpc5xxx/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_A3M071
 	bool "Support a3m071"
diff --git a/arch/powerpc/cpu/mpc8260/Kconfig b/arch/powerpc/cpu/mpc8260/Kconfig
index 55941c8..e93732d 100644
--- a/arch/powerpc/cpu/mpc8260/Kconfig
+++ b/arch/powerpc/cpu/mpc8260/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_KM82XX
 	bool "Support km82xx"
diff --git a/arch/powerpc/cpu/mpc83xx/Kconfig b/arch/powerpc/cpu/mpc83xx/Kconfig
index 88a3bd6..3fb901f 100644
--- a/arch/powerpc/cpu/mpc83xx/Kconfig
+++ b/arch/powerpc/cpu/mpc83xx/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_MPC8308_P1M
 	bool "Support mpc8308_p1m"
diff --git a/arch/powerpc/cpu/mpc85xx/Kconfig b/arch/powerpc/cpu/mpc85xx/Kconfig
index aff5fdb..3e8d0b1 100644
--- a/arch/powerpc/cpu/mpc85xx/Kconfig
+++ b/arch/powerpc/cpu/mpc85xx/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_SBC8548
 	bool "Support sbc8548"
diff --git a/arch/powerpc/cpu/mpc86xx/Kconfig b/arch/powerpc/cpu/mpc86xx/Kconfig
index 14e8b1a..fe1859d 100644
--- a/arch/powerpc/cpu/mpc86xx/Kconfig
+++ b/arch/powerpc/cpu/mpc86xx/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_SBC8641D
 	bool "Support sbc8641d"
diff --git a/arch/powerpc/cpu/mpc8xx/Kconfig b/arch/powerpc/cpu/mpc8xx/Kconfig
index e8bcbe9..79cee35 100644
--- a/arch/powerpc/cpu/mpc8xx/Kconfig
+++ b/arch/powerpc/cpu/mpc8xx/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_TQM823L
 	bool "Support TQM823L"
diff --git a/arch/powerpc/cpu/ppc4xx/Kconfig b/arch/powerpc/cpu/ppc4xx/Kconfig
index 4d5954a..10b86e0 100644
--- a/arch/powerpc/cpu/ppc4xx/Kconfig
+++ b/arch/powerpc/cpu/ppc4xx/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_CSB272
 	bool "Support csb272"
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 2128f23..2f7a2fe 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -29,6 +29,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_RSK7203
 	bool "RSK+ 7203"
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 2df09b2..04dc08f 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -14,6 +14,7 @@
 
 choice
 	prompt "Board select"
+	optional
 
 config TARGET_GRSIM_LEON2
 	bool "GRSIM simulating a LEON2 board"