diff --git a/configs/eagle100/nxflat/defconfig b/configs/eagle100/nxflat/defconfig
index 930593ddfc3..af479ff4574 100644
--- a/configs/eagle100/nxflat/defconfig
+++ b/configs/eagle100/nxflat/defconfig
@@ -6,11 +6,13 @@ CONFIG_ARCH_CHIP_LM3S6918=y
 CONFIG_ARCH_STACKDUMP=y
 CONFIG_ARCH="arm"
 CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y
+CONFIG_BOARD_INITIALIZE=y
 CONFIG_BOARD_LOOPSPERMSEC=4531
 CONFIG_DEV_LOWCONSOLE=y
 CONFIG_DISABLE_ENVIRON=y
 CONFIG_DISABLE_POLL=y
 CONFIG_EXAMPLES_NXFLAT=y
+CONFIG_EXECFUNCS_SYMTAB="exports"
 CONFIG_FS_ROMFS=y
 CONFIG_HOST_WINDOWS=y
 CONFIG_MAX_TASKS=16
@@ -42,4 +44,5 @@ CONFIG_TIVA_SSI0=y
 CONFIG_TIVA_UART0=y
 CONFIG_UART0_SERIAL_CONSOLE=y
 CONFIG_USER_ENTRYPOINT="nxflat_main"
+CONFIG_USERMAIN_STACKSIZE=4096
 CONFIG_WDOG_INTRESERVE=0
diff --git a/configs/sama5d4-ek/elf/defconfig b/configs/sama5d4-ek/elf/defconfig
index b5e13a282d7..01f7ecd7843 100644
--- a/configs/sama5d4-ek/elf/defconfig
+++ b/configs/sama5d4-ek/elf/defconfig
@@ -2,6 +2,7 @@
 CONFIG_ARCH_ADDRENV=y
 CONFIG_ARCH_BOARD_SAMA5D4_EK=y
 CONFIG_ARCH_BOARD="sama5d4-ek"
+CONFIG_BOARD_INITIALIZE=y
 CONFIG_ARCH_BUTTONS=y
 CONFIG_ARCH_CHIP_ATSAMA5D44=y
 CONFIG_ARCH_CHIP_SAMA5=y
@@ -28,8 +29,10 @@ CONFIG_BOOT_RUNFROMSDRAM=y
 CONFIG_BUILTIN=y
 CONFIG_DEV_ZERO=y
 CONFIG_ELF=y
+CONFIG_ELF_STACKSIZE=4096
 CONFIG_EXAMPLES_ELF_SYSCALL=y
 CONFIG_EXAMPLES_ELF=y
+CONFIG_EXECFUNCS_SYMTAB="exports"
 CONFIG_EXPERIMENTAL=y
 CONFIG_FS_ROMFS=y
 CONFIG_GRAN_SINGLE=y
@@ -71,3 +74,4 @@ CONFIG_SYS_RESERVED=1
 CONFIG_SYSTEM_READLINE=y
 CONFIG_USART3_SERIAL_CONSOLE=y
 CONFIG_USER_ENTRYPOINT="elf_main"
+CONFIG_USERMAIN_STACKSIZE=4096
diff --git a/configs/stm32f4discovery/elf/defconfig b/configs/stm32f4discovery/elf/defconfig
index cb29ae8ee76..ca9f058bd29 100644
--- a/configs/stm32f4discovery/elf/defconfig
+++ b/configs/stm32f4discovery/elf/defconfig
@@ -9,10 +9,13 @@ CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y
 CONFIG_ARMV7M_USEBASEPRI=y
 CONFIG_BINFMT_CONSTRUCTORS=y
 CONFIG_BINFMT_EXEPATH=y
+CONFIG_BOARD_INITIALIZE=y
 CONFIG_BOARD_LOOPSPERMSEC=16717
 CONFIG_DEV_LOWCONSOLE=y
+CONFIG_ELF_STACKSIZE=4096
 CONFIG_ELF=y
 CONFIG_EXAMPLES_ELF=y
+CONFIG_EXECFUNCS_SYMTAB="exports"
 CONFIG_FS_ROMFS=y
 CONFIG_HAVE_CXX=y
 CONFIG_HOST_WINDOWS=y
@@ -37,8 +40,7 @@ CONFIG_START_YEAR=2012
 CONFIG_STM32_JTAG_SW_ENABLE=y
 CONFIG_STM32_USART2=y
 CONFIG_SYMTAB_ORDEREDBYNAME=y
-CONFIG_USART2_RXBUFSIZE=128
 CONFIG_USART2_SERIAL_CONSOLE=y
-CONFIG_USART2_TXBUFSIZE=128
 CONFIG_USER_ENTRYPOINT="elf_main"
+CONFIG_USERMAIN_STACKSIZE=4096
 CONFIG_WDOG_INTRESERVE=0