build_library: Run dd with status=none

Avoid dumping dd statistics to stderr.

build_library/build_image_util.sh

@@ -504,7 +504,7 @@ EOF
     # Our modified GRUB extracts the hash and adds it to the cmdline.
     printf %s "$(cat ${BUILD_DIR}/${image_name%.bin}_verity.txt)" | \
         sudo dd of="${root_fs_dir}/boot/coreos/vmlinuz-a" conv=notrunc \
-        seek=${verity_offset} count=64 bs=1
+        seek=${verity_offset} count=64 bs=1 status=none
   fi
 
   # Sign the kernel after /usr is in a consistent state and verity is calculated

build_library/grub_install.sh

@@ -189,7 +189,7 @@ case "${FLAGS_target}" in
             --directory="${ESP_DIR}/${GRUB_DIR}" "${LOOP_DEV}"
         # boot.img gets manipulated by grub-bios-setup so it alone isn't
         # sufficient to restore the MBR boot code if it gets corrupted.
-        sudo dd bs=448 count=1 if="${LOOP_DEV}" \
+        sudo dd bs=448 count=1 status=none if="${LOOP_DEV}" \
             of="${ESP_DIR}/${GRUB_DIR}/mbr.bin"
         ;;
     x86_64-efi)

build_library/vm_image_util.sh

@@ -722,8 +722,10 @@ _write_qemu_uefi_conf() {
             emerge-${BOARD} --nodeps --select -qugKN sys-firmware/edk2-armvirt
             # this bit of magic comes from http://tech.donghao.org/2014/12/18/running-fedora-21-on-qemu-system-aarch64/
             cat "/build/${BOARD}/usr/share/edk2-armvirt/QEMU_EFI.fd" /dev/zero | \
-                dd iflag=fullblock bs=1M count=64 of="$(_dst_dir)/${flash_ro}"
-            dd if=/dev/zero bs=1M count=64 of="$(_dst_dir)/${flash_rw}"
+                dd iflag=fullblock bs=1M count=64 of="$(_dst_dir)/${flash_ro}" \
+                status=none
+            dd if=/dev/zero bs=1M count=64 of="$(_dst_dir)/${flash_rw}" \
+                status=none
             ;;
     esac