diff --git a/build.sh b/build.sh
index 16af358..0a25562 100755
--- a/build.sh
+++ b/build.sh
@@ -2,8 +2,8 @@
 #
 # Shell script for building Phoenix-RTOS ports
 #
-# Copyright 2019 Phoenix Systems
-# Author: Pawel Pisarczyk
+# Copyright 2019, 2024 Phoenix Systems
+# Author: Pawel Pisarczyk, Daniel Sawka
 #
 
 set -e
@@ -29,6 +29,7 @@ LDFLAGS="$EXPORT_LDFLAGS"
 STRIP="$EXPORT_STRIP"
 export CFLAGS LDFLAGS STRIP
 
+export PORTS_MIRROR_BASEURL="https://files.phoesys.com/ports/"
 
 if [ -n "$PORTS_INSTALL_STRIPPED" ] && [ "$PORTS_INSTALL_STRIPPED" = "n" ]; then
 	export PREFIX_PORTS_INSTALL="$PREFIX_PROG"
@@ -36,46 +37,44 @@ else
 	export PREFIX_PORTS_INSTALL="$PREFIX_PROG_STRIPPED"
 fi
 
-[ "${PORTS_MBEDTLS}" = "y" ] && ./phoenix-rtos-ports/mbedtls/build.sh
-
-[ "${PORTS_BUSYBOX}" = "y" ] && ./phoenix-rtos-ports/busybox/build.sh
-
-[ "${PORTS_PCRE}" = "y" ] && ./phoenix-rtos-ports/pcre/build.sh
-
-[ "${PORTS_OPENSSL}" = "y" ] && ./phoenix-rtos-ports/openssl/build.sh
-
-[ "${PORTS_ZLIB}" = "y" ] && ./phoenix-rtos-ports/zlib/build.sh
-
-[ "${PORTS_LIGHTTPD}" = "y" ] && ./phoenix-rtos-ports/lighttpd/build.sh
-
-[ "${PORTS_DROPBEAR}" = "y" ] && ./phoenix-rtos-ports/dropbear/build.sh
-
-[ "${PORTS_LUA}" = "y" ] && ./phoenix-rtos-ports/lua/build.sh
-
-[ "${PORTS_LZO}" = "y" ] && ./phoenix-rtos-ports/lzo/build.sh
-
-[ "${PORTS_OPENVPN}" = "y" ] && ./phoenix-rtos-ports/openvpn/build.sh
-
-[ "${PORTS_CURL}" = "y" ] && ./phoenix-rtos-ports/curl/build.sh
-
-[ "${PORTS_JANSSON}" = "y" ] && ./phoenix-rtos-ports/jansson/build.sh
-
-[ "${PORTS_MICROPYTHON}" = "y" ] && ./phoenix-rtos-ports/micropython/build.sh
-
-[ "${PORTS_SSCEP}" = "y" ] && ./phoenix-rtos-ports/sscep/build.sh
-
-[ "${PORTS_WPA_SUPPLICANT}" = "y" ] && ./phoenix-rtos-ports/wpa_supplicant/build.sh
-
-[ "${PORTS_LIBEVENT}" = "y" ] && ./phoenix-rtos-ports/libevent/build.sh
-
-[ "${PORTS_OPENIKED}" = "y" ] && ./phoenix-rtos-ports/openiked/build.sh
-
-[ "${PORTS_AZURE_SDK}" = "y" ] && ./phoenix-rtos-ports/azure_sdk/build.sh
-
-[ "${PORTS_PICOCOM}" = "y" ] && ./phoenix-rtos-ports/picocom/build.sh
-
-[ "${PORTS_FS_MARK}" = "y" ] && ./phoenix-rtos-ports/fs_mark/build.sh
-
-[ "${PORTS_COREMARK}" = "y" ] && ./phoenix-rtos-ports/coremark/build.sh
+# List of directories with ports. Built in this order
+ports=(
+	"mbedtls"
+	"busybox"
+	"pcre"
+	"openssl"
+	"zlib"
+	"lighttpd"
+	"dropbear"
+	"lua"
+	"lzo"
+	"openvpn"
+	"curl"
+	"jansson"
+	"micropython"
+	"sscep"
+	"wpa_supplicant"
+	"libevent"
+	"openiked"
+	"azure_sdk"
+	"picocom"
+	"fs_mark"
+	"coremark"
+)
+
+source "${PREFIX_PROJECT}/phoenix-rtos-ports/build.subr"
+
+for port in "${ports[@]}"; do
+	export PREFIX_PORT="${PREFIX_PROJECT}/phoenix-rtos-ports/${port}"
+	# TODO: Maybe "${PREFIX_BUILD}/ports/${port}" to avoid any potential name clashes?
+	export PREFIX_PORT_BUILD="${PREFIX_BUILD}/${port}"
+
+	port_env_name="PORTS_${port^^}"
+	if [ "${!port_env_name}" = "y" ]; then
+		b_log "Building ${port}"
+		mkdir -p "${PREFIX_PORT_BUILD}"
+		./phoenix-rtos-ports/"${port}"/build.sh
+	fi
+done
 
 exit 0
diff --git a/build.subr b/build.subr
new file mode 100644
index 0000000..72e53d7
--- /dev/null
+++ b/build.subr
@@ -0,0 +1,67 @@
+#!/usr/bin/env bash
+#
+# Shell script for building Phoenix-RTOS ports
+#
+# Common functions
+#
+# Copyright 2024 Phoenix Systems
+# Author: Daniel Sawka
+#
+
+# b_port_download(baseurl, filename, [url_filename])
+b_port_download() {
+	local baseurl="$1"
+	local filename="$2"
+	local url_filename="${3:-$filename}"
+
+	if [ ! -f "${PREFIX_PORT}/${filename}" ]; then
+		if ! wget "${baseurl}${url_filename}" -O "${PREFIX_PORT}/${filename}.part" --no-check-certificate; then
+			wget "${PORTS_MIRROR_BASEURL}${filename}" -O "${PREFIX_PORT}/${filename}.part" --no-check-certificate
+		fi
+
+		if [ -f "${PREFIX_PORT}/checksums" ]; then
+			local cksum_pattern='^(\S+)\s*\(([^\)]+)\)\s*\=\s*(\S+)\s*$'
+			# Verify checksums one after another. `cksum -c` it too limited
+			while read -r line; do
+				if [[ "$line" =~ $cksum_pattern ]] && [ "${BASH_REMATCH[2]}" = "${filename}" ]; then
+					local expected_checksum="${BASH_REMATCH[3]}"
+					local actual_checksum=$(cksum --untagged -a "${BASH_REMATCH[1],,}" "${PREFIX_PORT}/${BASH_REMATCH[2]}.part" | cut -d' ' -f1)
+
+					if [ "${expected_checksum}" = "${actual_checksum}" ]; then
+						echo "Checksum OK for \"${filename}\""
+					else
+						b_die "Checksum INVALID for \"${filename}\": expected \"${expected_checksum}\", got \"${actual_checksum}\""
+					fi
+				fi
+			done < "${PREFIX_PORT}/checksums"
+		fi
+
+		mv -f "${PREFIX_PORT}/${filename}.part" "${PREFIX_PORT}/${filename}"
+	fi
+}
+
+# b_port_apply_patches(srcdir, [patch_subdir])
+b_port_apply_patches() {
+	local srcdir="$1"
+	local patch_subdir="${2:-.}"
+
+	local patch_dir="${PREFIX_PORT}/patches/${patch_subdir}"
+	local marker_dir="${PREFIX_PORT_BUILD}/markers/${patch_subdir}"
+	if [ -d "${patch_dir}" ]; then
+		mkdir -p "${marker_dir}"
+	fi
+
+	# Restores the initial value of nullglob option upon function return
+	trap "$(shopt -p nullglob)" RETURN
+	shopt -s nullglob
+
+	for patchfile in "${patch_dir}"/*.patch; do
+		if [ ! -f "${marker_dir}/$(basename "${patchfile}").applied" ]; then
+			echo "applying patch: ${patchfile}"
+			patch -d "${srcdir}" -p1 < "${patchfile}"
+			touch "${marker_dir}/$(basename "${patchfile}").applied"
+		fi
+	done
+}
+
+export -f b_port_download b_port_apply_patches