diff --git a/release/arm/CUBOX-HUMMINGBOARD.conf b/release/arm/CUBOX-HUMMINGBOARD.conf
index d69ca8eddbc2..258ebc46847d 100644
--- a/release/arm/CUBOX-HUMMINGBOARD.conf
+++ b/release/arm/CUBOX-HUMMINGBOARD.conf
@@ -9,7 +9,7 @@ EMBEDDED_TARGET_ARCH="armv6"
 EMBEDDEDPORTS="sysutils/u-boot-cubox-hummingboard"
 KERNEL="IMX6"
 WORLD_FLAGS="${WORLD_FLAGS} UBLDR_LOADADDR=0x12000000"
-IMAGE_SIZE="1G"
+IMAGE_SIZE="1536M"
 PART_SCHEME="MBR"
 FAT_SIZE="50m -b 16384"
 FAT_TYPE="16"
@@ -23,7 +23,7 @@ arm_install_uboot() {
 	FATMOUNT="${DESTDIR%${KERNEL}}/fat"
 	UFSMOUNT="${DESTDIR%${KERNEL}}/ufs"
 	chroot ${CHROOTDIR} dd if=${UBOOT_DIR}/${UBOOT_FILES} \
-		of=/dev/${mddev} bs=512 seek=2
+		of=/dev/${mddev} bs=512 seek=2 conv=sync
 	chroot ${CHROOTDIR} mkdir -p "${FATMOUNT}" "${UFSMOUNT}"
 	chroot ${CHROOTDIR} mount_msdosfs /dev/${mddev}s1 ${FATMOUNT}
 	chroot ${CHROOTDIR} mount /dev/${mddev}s2a ${UFSMOUNT}
diff --git a/release/arm/RPI2.conf b/release/arm/RPI2.conf
index 9d5a64235858..c2c0cf093e18 100644
--- a/release/arm/RPI2.conf
+++ b/release/arm/RPI2.conf
@@ -9,7 +9,7 @@ EMBEDDED_TARGET_ARCH="armv6"
 EMBEDDEDPORTS="sysutils/u-boot-rpi2"
 KERNEL="GENERIC"
 WORLD_FLAGS="${WORLD_FLAGS} UBLDR_LOADADDR=0x2000000"
-IMAGE_SIZE="1G"
+IMAGE_SIZE="1536M"
 PART_SCHEME="MBR"
 FAT_SIZE="50m"
 FAT_TYPE="16"
diff --git a/release/arm/WANDBOARD.conf b/release/arm/WANDBOARD.conf
index 1afdc720de2d..52fe2daa0136 100644
--- a/release/arm/WANDBOARD.conf
+++ b/release/arm/WANDBOARD.conf
@@ -9,7 +9,7 @@ EMBEDDED_TARGET_ARCH="armv6"
 EMBEDDEDPORTS="sysutils/u-boot-wandboard"
 KERNEL="IMX6"
 WORLD_FLAGS="${WORLD_FLAGS} UBLDR_LOADADDR=0x12000000"
-IMAGE_SIZE="1G"
+IMAGE_SIZE="1536M"
 PART_SCHEME="MBR"
 FAT_SIZE="50m -b 16384"
 FAT_TYPE="16"
@@ -23,7 +23,7 @@ arm_install_uboot() {
 	FATMOUNT="${DESTDIR%${KERNEL}}/fat"
 	UFSMOUNT="${DESTDIR%${KERNEL}}/ufs"
 	chroot ${CHROOTDIR} dd if=${UBOOT_DIR}/${UBOOT_FILES} \
-		of=/dev/${mddev} bs=512 seek=2
+		of=/dev/${mddev} bs=512 seek=2 conv=sync
 	chroot ${CHROOTDIR} mkdir -p "${FATMOUNT}" "${UFSMOUNT}"
 	chroot ${CHROOTDIR} mount_msdosfs /dev/${mddev}s1 ${FATMOUNT}
 	chroot ${CHROOTDIR} mount /dev/${mddev}s2a ${UFSMOUNT}