diff --git a/lib/configuration.sh b/lib/configuration.sh
index 4e2b1414bd..c7246fc880 100644
--- a/lib/configuration.sh
+++ b/lib/configuration.sh
@@ -43,11 +43,12 @@ fi
 [[ $ROOTFS_TYPE == nfs ]] && FIXED_IMAGE_SIZE=64
 
 # used by multiple sources - reduce code duplication
-if [[ $USE_MAINLINE_GOOGLE_MIRROR == yes ]]; then
-	MAINLINE_KERNEL_SOURCE='https://kernel.googlesource.com/pub/scm/linux/kernel/git/stable/linux-stable'
-else
-	MAINLINE_KERNEL_SOURCE='git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git'
-fi
+[[ $USE_MAINLINE_GOOGLE_MIRROR == yes ]] && MAINLINE_MIRROR=google
+case $MAINLINE_MIRROR in
+	google) MAINLINE_KERNEL_SOURCE='https://kernel.googlesource.com/pub/scm/linux/kernel/git/stable/linux-stable' ;;
+	tuna) MAINLINE_KERNEL_SOURCE='https://mirrors.tuna.tsinghua.edu.cn/git/linux-stable.git' ;;
+	*) MAINLINE_KERNEL_SOURCE='git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git' ;;
+esac
 MAINLINE_KERNEL_DIR='linux-mainline'
 
 if [[ $USE_GITHUB_UBOOT_MIRROR == yes ]]; then
@@ -226,6 +227,11 @@ esac
 DEBIAN_MIRROR='httpredir.debian.org/debian'
 UBUNTU_MIRROR='ports.ubuntu.com/'
 
+if [[ $DOWNLOAD_MIRROR == china ]] ; then
+	DEBIAN_MIRROR='mirrors.tuna.tsinghua.edu.cn/debian'
+	UBUNTU_MIRROR='mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/'
+fi
+
 # For user override
 if [[ -f $SRC/userpatches/lib.config ]]; then
 	display_alert "Using user configuration override" "userpatches/lib.config" "info"
diff --git a/lib/debootstrap-ng.sh b/lib/debootstrap-ng.sh
index acf8e783c3..3a08808d94 100644
--- a/lib/debootstrap-ng.sh
+++ b/lib/debootstrap-ng.sh
@@ -375,7 +375,7 @@ prepare_partitions()
 
 	# stage: create blank image
 	display_alert "Creating blank image for rootfs" "$sdsize MiB" "info"
-	dd if=/dev/zero bs=1M status=none count=$sdsize | pv -p -b -r -s $(( $sdsize * 1024 * 1024 )) | dd status=none of=${SDCARD}.raw
+	truncate --size=${sdsize}M ${SDCARD}.raw
 
 	# stage: calculate boot partition size
 	local bootstart=$(($OFFSET * 2048))
diff --git a/lib/general.sh b/lib/general.sh
index a3cd0f184b..c90e0f24e7 100644
--- a/lib/general.sh
+++ b/lib/general.sh
@@ -624,7 +624,7 @@ prepare_host()
 	# sync clock
 	if [[ $SYNC_CLOCK != no ]]; then
 		display_alert "Syncing clock" "host" "info"
-		ntpdate -s ${NTP_SERVER:- time.ijs.si}
+		ntpdate -s ${NTP_SERVER:- pool.ntp.org}
 	fi
 
 	if [[ $(dpkg-query -W -f='${db:Status-Abbrev}\n' 'zlib1g:i386' 2>/dev/null) != *ii* ]]; then
@@ -658,6 +658,9 @@ prepare_host()
 	# Use backup server by default to balance the load
 
 	ARMBIANSERVER=dl.armbian.com
+	if [[ $DOWNLOAD_MIRROR == 'china' ]]; then
+		ARMBIANSERVER='mirrors.tuna.tsinghua.edu.cn/armbian-releases'
+	fi
 
 	local toolchains=(
 		"https://${ARMBIANSERVER}/_toolchains/gcc-linaro-aarch64-none-elf-4.8-2013.11_linux.tar.xz"
@@ -671,7 +674,6 @@ prepare_host()
 		"https://${ARMBIANSERVER}/_toolchains/gcc-linaro-5.5.0-2017.10-x86_64_arm-linux-gnueabihf.tar.xz"
 		"https://${ARMBIANSERVER}/_toolchains/gcc-linaro-6.4.1-2017.11-x86_64_arm-linux-gnueabihf.tar.xz"
 		"https://${ARMBIANSERVER}/_toolchains/gcc-linaro-6.4.1-2017.11-x86_64_aarch64-linux-gnu.tar.xz"
-		"https://${ARMBIANSERVER}/_toolchains/gcc-linaro-7.4.1-2019.02-x86_64_aarch64-linux-gnu.tar.xz"
 		"https://${ARMBIANSERVER}/_toolchains/gcc-linaro-7.4.1-2019.02-x86_64_arm-linux-gnueabihf.tar.xz"
 		"https://${ARMBIANSERVER}/_toolchains/gcc-linaro-7.4.1-2019.02-x86_64_arm-eabi.tar.xz"
 		"https://${ARMBIANSERVER}/_toolchains/gcc-linaro-7.4.1-2019.02-x86_64_arm-linux-gnueabi.tar.xz"
diff --git a/packages/extras/firmware.sh b/packages/extras/firmware.sh
index 43de2c0655..874faa4bdd 100644
--- a/packages/extras/firmware.sh
+++ b/packages/extras/firmware.sh
@@ -14,14 +14,17 @@ build_firmware()
 	local plugin_repo="https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git"
 	local plugin_dir="armbian-firmware${FULL}"
 	[[ -d $SRC/cache/sources/$plugin_dir ]] && rm -rf $SRC/cache/sources/$plugin_dir
+	mkdir -p $SRC/cache/sources/$plugin_dir/lib/firmware
 
 	fetch_from_repo "https://github.com/armbian/firmware" "armbian-firmware-git" "branch:master"
 	if [[ -n $FULL ]]; then
-		fetch_from_repo "$plugin_repo" "$plugin_dir/lib/firmware" "branch:master"
+		fetch_from_repo "$plugin_repo" "linux-firmware-git" "branch:master"
+		# cp : create hardlinks
+		cp -alf $SRC/cache/sources/linux-firmware-git/* $SRC/cache/sources/$plugin_dir/lib/firmware/
 	fi
-	mkdir -p $SRC/cache/sources/$plugin_dir/lib/firmware
 	# overlay our firmware
-	cp -R $SRC/cache/sources/armbian-firmware-git/* $SRC/cache/sources/$plugin_dir/lib/firmware
+	# cp : create hardlinks
+	cp -alf $SRC/cache/sources/armbian-firmware-git/* $SRC/cache/sources/$plugin_dir/lib/firmware/
 
 	# cleanup what's not needed for sure
 	rm -rf $SRC/cache/sources/$plugin_dir/lib/firmware/{amdgpu,amd-ucode,radeon,nvidia,matrox,.git}