diff --git a/include/env/get.sh b/include/env/get.sh
index 0863615b..9cd88174 100644
--- a/include/env/get.sh
+++ b/include/env/get.sh
@@ -39,14 +39,12 @@ single_tree_fetch()
 			x_ "$mk" -f $d
 		done
 
-	clone_project
+	$if_single_tree \
+		clone_project; :
 }
 
 clone_project()
 {
-	singletree "$project" || \
-		return 0
-
 	loc="src/$project"
 	[ -d "$loc" ] && \
 		return 0
@@ -174,10 +172,8 @@ try_fetch_curl()
 		try_$2 "$cached" "$@" || \
 			return 1
 
-	[ -f "$5" ] && \
-		if bad_checksum "$6" "$5" 2>/dev/null; then
-			x_ cp "$cached" "$5"
-		fi
+	[ -f "$5" ] && bad_checksum "$6" "$5" 2>/dev/null && \
+		x_ cp "$cached" "$5"
 
 	if [ ! -f "$cached" ]; then
 		return 1
@@ -202,8 +198,7 @@ try_curl()
 	ua="Mozilla/5.0 (Windows NT 10.0; rv:91.0) Gecko/20100101 Firefox/91.0"
 
 	( x_ curl --location --retry 3 -A "$ua" "$2" -o "$1" ) \
-	    || ( x_ wget --tries 3 -U "$ua" "$2" -O "$1" ) \
-	    || return 1; :
+	    || ( x_ wget --tries 3 -U "$ua" "$2" -O "$1" ) || return 1; :
 }
 
 try_copy()
@@ -230,15 +225,9 @@ try_git()
 		x_ mv "$tmpgitcache" "$gitdest"
 	fi
 
-	if git -C "$gitdest" show "$7" 1>/dev/null 2>/dev/null && \
-	    [ "$forcepull" != "y" ]; then
-		# don't try to pull the latest changes if the given target
-		# revision already exists locally. this saves a lot of time
-		# during release builds, and reduces the chance that we will
-		# interact with grub.git or gnulib.git overall during runtime
-
-		return 0
-	fi
+	git -C "$gitdest" show "$7" 1>/dev/null 2>/dev/null && \
+	    [ "$forcepull" != "y" ] && \
+		return 0 # don't pull changes if target rev exists locally
 
 	if [ "$XBMK_CACHE_MIRROR" = "y" ]; then
 		( x_ git -C "$gitdest" fetch ) || :; :
@@ -250,9 +239,8 @@ try_git()
 
 bad_checksum()
 {
-	if e "$2" f missing; then
+	e "$2" f missing && \
 		return 0
-	fi
 
 	build_sbase
 	csum="$(x_ "$sha512sum" "$2" | awk '{print $1}')" || \
diff --git a/include/env/init.sh b/include/env/init.sh
index d17b5fb8..d04474e3 100644
--- a/include/env/init.sh
+++ b/include/env/init.sh
@@ -165,13 +165,11 @@ xbmk_parent_set_env()
 
 	x_ chmod -w "$xbmklock"
 
-	xbmk_parent_set_export
-	xbmk_set_version
+	forx 'xbmk_%s' parent_set_export set_version
 
 	remkdir "$xbtmp" "$xbtmp/xbmkpath"
 
-	xbmk_set_pyver
-	xbmk_set_mirror
+	forx 'xbmk_set_%s' pyver mirror
 }
 
 xbmk_parent_check_tmp()
diff --git a/include/fw/inject.sh b/include/fw/inject.sh
index adff3861..900d2a5d 100644
--- a/include/fw/inject.sh
+++ b/include/fw/inject.sh
@@ -18,8 +18,7 @@ inject()
 {
 	remkdir "$tmpromdel"
 
-	[ $# -lt 1 ] && \
-		err "No options specified" "inject" "$@"
+	[ $# -lt 1 ] && err "No options specified" "inject" "$@"
 
 	archive="$1";
 	new_mac="xx:xx:xx:xx:xx:xx"
@@ -58,9 +57,8 @@ check_release()
 {
 	[ -L "$archive" ] && \
 		err "'$archive' is a symlink" "check_release" "$@"
-	if e "$archive" f missing; then
+	e "$archive" f missing && \
 		err "'$archive' missing" "check_release" "$@"
-	fi
 
 	archivename="`basename "$archive" || err "Can't get '$archive' name"`" \
 	    || err "can't get '$archive' name" "check_release" "$@"
@@ -100,7 +98,6 @@ check_target()
 	x_ "$mk" -d coreboot "$tree"
 
 	ifdtool="elf/coreboot/$tree/ifdtool"
-
 	[ -n "$IFD_platform" ] && \
 		ifdprefix="-p $IFD_platform"; :
 }
@@ -125,8 +122,7 @@ patch_release()
 		fi
 	done
 
-	readkconfig || \
-		return 1
+	readkconfig || return 1
 
 	[ -n "$new_mac" ] && [ -n "$CONFIG_GBE_BIN_PATH" ] && \
 		modify_mac; :
@@ -137,15 +133,13 @@ readkconfig()
 	x_ rm -f "$xbtmp/cbcfg"
 	fx_ scankconfig x_ find "$boarddir/config" -type f
 
-	if e "$xbtmp/cbcfg" f missing; then
+	e "$xbtmp/cbcfg" f missing && \
 		return 1
-	fi
 
 	. "$xbtmp/cbcfg" || \
 	    err "Can't read '$xbtmp/cbcfg'" "readkconfig" "$@"
 
-	setvfile "$@" || \
-		return 1; :
+	setvfile "$@" || return 1; :
 }
 
 scankconfig()
@@ -173,10 +167,9 @@ modify_mac()
 
 newmac()
 {
-	if e "$1" f; then
-		xchanged="y"
-		x_ "$ifdtool" $ifdprefix -i GbE:"$xbtmp/gbe" "$1" -O "$1"
-	fi
+	e "$1" f || return 0
+	xchanged="y"
+	x_ "$ifdtool" $ifdprefix -i GbE:"$xbtmp/gbe" "$1" -O "$1"
 }
 
 remktar()
@@ -190,6 +183,5 @@ remktar()
 	) || err "Cannot re-generate '$archive'" "remktar" "$@"
 
 	mv "${tmpromdir%"/bin/$board"}/bin/${relname}_${board}.tar.xz" \
-	    "$archive" || \
-	    err "'$archive' -> Can't overwrite" "remktar" "$@"; :
+	    "$archive" || err "'$archive' -> Can't overwrite" "remktar" "$@"; :
 }
diff --git a/include/fw/vendor.sh b/include/fw/vendor.sh
index 41c51e09..05f8b226 100644
--- a/include/fw/vendor.sh
+++ b/include/fw/vendor.sh
@@ -51,14 +51,12 @@ eval "`newvar DL_hash DL_url DL_url_bkup E6400_VGA_bin_hash E6400_VGA_DL_hash \
 
 download()
 {
-	[ $# -lt 1 ] && \
-		err "No argument given" "download" "$@"
+	[ $# -lt 1 ] && err "No argument given" "download" "$@"
 
 	export PATH="$PATH:/sbin"
 	board="$1"
 
-	check_target || return 0
-	readkconfig download
+	check_target && readkconfig download; :
 }
 
 getfiles()
@@ -108,14 +106,12 @@ fetch()
 	dlop="$6"
 	binsum="$7"
 
-	[ -z "$binsum" ] && \
-		err "binsum is empty (no checksum)" "fetch" "$@"
+	[ -z "$binsum" ] && err "binsum is empty (no checksum)" "fetch" "$@"
 
 	_dl="$XBMK_CACHE/file/$dlsum" # internet file to extract from e.g. .exe
 	_dl_bin="$XBMK_CACHE/file/$binsum" # extracted file e.g. me.bin
 
-	[ "$5" = "/dev/null" ] && \
-		return 0
+	[ "$5" = "/dev/null" ] && return 0 # fetch/extract disabled
 
 	# an extracted vendor file will be placed in pre_dest first, for
 	# verifying its checksum. if it matches, it is later moved to _dest
@@ -160,32 +156,24 @@ fetch()
 		[ ! -f "$_dest" ] || \
 			return 0; :
 
-	[ -z "$binsum" ] && \
-		printf "WARNING: %s: checksum undefined\n" "$_dest" 1>&2
-
 	x_ rm -f "$_dest"
 
+	[ -z "$binsum" ] && printf "WARNING: %s: no checksum\n" "$_dest" 1>&2
 	err "Can't safely extract '$_dest', for board '$board'" "fetch" "$@"
 }
 
 mkdst()
 {
-	if bad_checksum "$1" "$2" 2>/dev/null; then
-		x_ rm -f "$2"
-	else
+	if ! bad_checksum "$1" "$2" 2>/dev/null; then
 		x_ mv "$2" "$_dl_bin"
 		x_ cp "$_dl_bin" "$_dest"
-
 		exit 1
 	fi
+	x_ rm -f "$2"
 }
 
 extract_intel_me()
 {
-	if e "$mecleaner" f missing; then
-		err "$cbdir: me_cleaner missing" "extract_intel_me" "$@"
-	fi
-
 	mfs=""
 	_7ztest="$xbtmp/metmp/a"
 	_metmp="$xbtmp/me.bin"
@@ -228,10 +216,8 @@ extract_intel_me()
 # must be called inside a subshell.
 find_me()
 {
-	[ -f "$_metmp" ] && \
-		exit 1 # me.bin found
-	[ -L "$1" ] && \
-		return 0 # symlinks disabled for security reasons
+	[ -f "$_metmp" ] && exit 1 # me.bin found
+	[ -L "$1" ] && return 0 # symlinks disabled for security reasons
 
 	_7ztest="${_7ztest}a"
 
@@ -268,8 +254,7 @@ find_me()
 		return 0 # can't extract, so try the next file
 	fi
 
-	[ -f "$_metmp" ] && \
-		exit 1 # me.bin found
+	[ -f "$_metmp" ] && exit 1 # me.bin found
 
 	( fx_ find_me x_ find "$_7ztest" -type f ) || exit 1; : # 1==me found
 }
@@ -318,8 +303,7 @@ extract_kbc1126ec_dump()
 	    unar -D 68*.CAB Rom.bin || \
 		err "!kbc1126 unar" "extract_kbc1126ec" "$@"
 
-	[ ! -f "ec.bin" ] && \
-		x_ mv Rom.bin ec.bin
+	[ -f "ec.bin" ] || x_ mv Rom.bin ec.bin
 
 	x_ e ec.bin f
 	x_ "$kbc1126_ec_dump" ec.bin
@@ -365,8 +349,7 @@ extract_sch5545ec()
 # https://pcsupport.lenovo.com/us/en/products/laptops-and-netbooks/thinkpad-t-series-laptops/thinkpad-t480-type-20l5-20l6/20l5/solutions/ht508988
 extract_tbfw()
 {
-	[ -z "$TBFW_size" ] && \
-		err "$board: TBFW_size unset" "extract_tbfw" "$@"
+	[ -z "$TBFW_size" ] && err "$board: TBFW_size unset" extract_tbfw "$@"
 
 	fx_ copytb x_ find "$appdir" -type f -name "TBT.bin"
 }
@@ -415,12 +398,8 @@ getvfile()
 	bootstrap
 
 	if [ $# -gt 0 ]; then
-		# download vendor files
-
-		getfiles
-	else
-		# inject vendor files
-
+		getfiles # ./mk download
+	else # ./mk inject
 		fx_ prep x_ find "$tmpromdir" -mindepth 1 -maxdepth 1 \
 		    -type f -name "*.rom"
 		( check_vendor_hashes ) || \
@@ -484,8 +463,7 @@ prep()
 		( mksha512 "$_xrom" "vendorhashes" ) || err; :
 	fi
 
-	add_vfiles "$_xrom" || \
-		return 1 # no need to insert files
+	add_vfiles "$_xrom" || return 1 # no need to insert files
 
 	if [ "$nuke" = "nuke" ]; then
 		pad_one_byte "$_xrom"
@@ -548,8 +526,7 @@ add_vfiles()
 
 vfile()
 {
-	[ "$2" = "/dev/null" ] && \
-		return 0
+	[ "$2" = "/dev/null" ] && return 0
 
 	cbfsname="$1"
 	_dest="${2##*../}"
diff --git a/include/lib.sh b/include/lib.sh
index 63a82084..03758982 100644
--- a/include/lib.sh
+++ b/include/lib.sh
@@ -80,8 +80,6 @@ e()
 	printf "%s %s\n" "$1" "$es2" 1>&2
 }
 
-# return 0 if project is single-tree, otherwise 1
-# e.g. coreboot is multi-tree, so 1
 singletree()
 {
 	( fx_ "eval exit 1 && err" find "config/$1/"*/ -type f \
@@ -116,8 +114,7 @@ unpad_one_byte()
 
 build_sbase()
 {
-	[ ! -f "$sha512sum" ] && \
-		x_ make -C "$xbmkpwd/util/sbase"; :
+	[ ! -f "$sha512sum" ] && x_ make -C "$xbmkpwd/util/sbase"; :
 }
 
 remkdir()
diff --git a/mk b/mk
index a6525310..0611231e 100755
--- a/mk
+++ b/mk
@@ -76,25 +76,17 @@ shift 1 2>/dev/null || :
 eval "$(printf "version release download inject\n" | awk '{ for (i=1; i<=NF; \
     i++) $i = "[ \""$i"\" = \"$_f\" ] && x_ "$i" \"$@\" && exit 0;"; print }')"
 
-# flag e.g. "$mk" -b <-- mkflag would be "b"
-flag=""
-
 # macros, overridden depending on the flag
-# : means false
-if_do_make=""
-if_not_do_make=":"
+if_not_do_make=":" # : means false
 if_make_config=":"
-if_not_make_config=""
 if_build=":" # can be false even if make is true
-if_not_build=""
 if_dry_build=":"
-if_not_dry_build=""
-
 if_single_tree=":"
+eval "`newvar if_do_make if_not_make_config if_not_build if_not_dry_build`"
 
 eval "`newvar configureargs autogenargs badhash badtghash bootstrapargs \
     build_depend buildtype cleanargs cmakedir cmd defconfig dest_dir elfdir \
-    forcepull listfile makeargs mdir mkhelper mkhelpercfg mode postmake \
+    flag forcepull listfile makeargs mdir mkhelper mkhelpercfg mode postmake \
     premake project release rev srcdir target target_dir tree xarch xgcctree \
     xlang`"
 
@@ -119,9 +111,8 @@ main()
 			if_not_dry_build=":"
 			;;
 		-f|-F) # download source code for a project
+			eval "`newvar if_not_do_make if_dry_build`"
 			if_do_make=":"
-			if_not_do_make=""
-			if_dry_build=""
 			if_not_dry_build=":"
 			[ "$flag" = "-F" ] && \
 				forcepull="y"; : # never skip git fetch/pull
@@ -180,10 +171,10 @@ main()
 	fi
 
 	if singletree "$project"; then
-		cmd="single_tree_build"
+		cmd="mk_single_tree"
 		if_single_tree=""
 	else
-		cmd="multi_tree_build"
+		cmd="mk_multi_tree"
 	fi
 
 	remkdir "${tmpgit%/*}"
@@ -193,27 +184,24 @@ main()
 	$cmd "$@"
 }
 
-single_tree_build()
+mk_single_tree()
 {
 	configure_project "$configdir" || \
 		return 0
 
-	[ ! -f "$listfile" ] || \
-		$if_not_dry_build elfcheck || \
-			return 0
+	[ ! -f "$listfile" ] || $if_not_dry_build \
+		elfcheck || return 0
 
-	run_make_command && \
-	    $if_build $if_not_dry_build \
+	run_make_command && $if_build $if_not_dry_build \
 		copy_elf; :
 }
 
-multi_tree_build()
+mk_multi_tree()
 {
-	[ ! -d "$configdir" ] && \
-		err "dir '$configdir' doesn't exist" multi_tree_build "$@"
-	[ $# -lt 1 ] && \
-		fx_ multi_tree_build find "$configdir" \
+	[ ! -d "$configdir" ] && err "missing '$configdir'" mk_multi_tree "$@"
+	[ $# -lt 1 ] && fx_ mk_multi_tree find "$configdir" \
 		    -mindepth 1 -maxdepth 1 -type d
+
 	[ $# -gt 0 ] && for x in "$@"
 	do
 		unset CROSS_COMPILE
@@ -245,8 +233,7 @@ handle_defconfig()
 	configure_project "$target_dir" || \
 		return 0
 
-	[ -z "$tree" ] && \
-		err "$configdir: 'tree' not set" "handle_defconfig" "$@"
+	[ -z "$tree" ] && err "$configdir: 'tree' unset" handle_defconfig "$@"
 
 	srcdir="src/$project/$tree"
 
@@ -256,18 +243,16 @@ handle_defconfig()
 			$if_not_dry_build \
 				continue
 
-		$if_not_dry_build \
-			eval defconfig="$y"
+		$if_not_dry_build eval \
+			defconfig="$y"
 
 		$if_build \
-			prep_multi_tree_build || \
-			    continue
+			prep_mk_multi_tree || continue
 
 		handle_makefile
 
-		$if_build \
-			$if_not_dry_build \
-				copy_elf; :
+		$if_build $if_not_dry_build \
+			copy_elf; :
 	done; :
 }
 
@@ -279,8 +264,7 @@ configure_project()
 	    build_depend buildtype cleanargs makeargs mkhelper postmake \
 	    premake release xarch xgcctree xlang`"
 
-	[ ! -f "$_tcfg" ] && \
-		buildtype="auto"
+	[ ! -f "$_tcfg" ] && buildtype="auto"
 
 	# globally initialise all variables for a source tree / target:
 	if e "$datadir/mkhelper.cfg" f; then
@@ -290,16 +274,15 @@ configure_project()
 	fi
 
 	# override target/tree specific variables from per-target config:
-	while e "$_tcfg" f || [ "$cmd" != "single_tree_build" ]
+	while e "$_tcfg" f || [ "$cmd" != "mk_single_tree" ]
 	do
 		printf "Loading %s config: %s\n" "$project" "$_tcfg"
 		eval "`newvar rev tree`"
 
-		. "$_tcfg" || \
-		    err "Can't read '$_tcfg'" "configure_project" "$@"
+		. "$_tcfg" || err "Can't read '$_tcfg'" configure_project "$@"
 
-		$if_dry_build \
-			eval build_depend=""
+		$if_dry_build eval \
+			build_depend=""
 
 		$if_single_tree \
 			break
@@ -313,22 +296,19 @@ configure_project()
 
 	[ "$XBMK_RELEASE" = "y" ] && [ "$release" = "n" ] && \
 		return 1
-	[ -n "$buildtype" ] && \
-		$if_make_config \
-			return 1
+	[ -n "$buildtype" ] && $if_make_config \
+		return 1
 
-	$if_build \
-		$if_not_dry_build \
-			build_dependencies
+	$if_build $if_not_dry_build \
+		build_dependencies
 
 	mdir="$xbmkpwd/config/submodule/$project"
-	[ -n "$tree" ] && \
-		mdir="$mdir/$tree"
+	[ -n "$tree" ] && mdir="$mdir/$tree"
 
 	if [ ! -f "CHANGELOG" ]; then
 		delete_old_project_files
 		$if_not_do_make \
-			${cmd%_build}_fetch
+			${cmd#mk_}_fetch
 	fi
 	$if_not_do_make \
 		return 1
@@ -434,7 +414,7 @@ project_up_to_date()
 	eval "[ \"\$$badhashvar\" = \"y\" ] && return 1"; :
 }
 
-prep_multi_tree_build()
+prep_mk_multi_tree()
 {
 	dest_dir="$elfdir/$tree/$target/${defconfig#"$target_dir/config/"}"
 
@@ -455,8 +435,7 @@ check_xgcc()
 	cbelfdir="elf${cbdir#src}"
 
 	xfix="${1%-*}"
-	[ "$xfix" = "x86_64" ] && \
-		xfix="x64"
+	[ "$xfix" = "x86_64" ] && xfix="x64"
 
 	xgccfile="$cbelfdir/xgcc_${xfix}_was_compiled"
 	xgccargs="crossgcc-$xfix UPDATED_SUBMODULES=1 CPUS=$XBMK_THREADS"
@@ -472,10 +451,8 @@ check_xgcc()
 	[ -n "$xlang" ] && \
 		export BUILD_LANGUAGES="$xlang"
 
-	[ -f "$xgccfile" ] && \
-		return 0 # build exists already, so skip building
+	[ -f "$xgccfile" ] && return 0 # skip (build already exists)
 
-	                           # it sometimes fails for like, no reason
 	make -C "$cbdir" $xgccargs || x_ make -C "$cbdir" $xgccargs
 
 	x_ touch "$xgccfile" # prevent unnecessary re-build operations
@@ -484,15 +461,13 @@ check_xgcc()
 elfcheck()
 {
 	# TODO: *STILL* very hacky check. do it properly (based on build.list)
-
 	( fx_ "eval exit 1 && err" find "$dest_dir" -type f ) || return 1; :
 }
 
 handle_makefile()
 {
-	check_makefile "$srcdir" && \
-		$if_not_dry_build \
-			x_ make -C "$srcdir" clean $cleanargs
+	check_makefile "$srcdir" && $if_not_dry_build \
+		x_ make -C "$srcdir" clean $cleanargs
 
 	[ -f "$defconfig" ] && \
 		x_ cp "$defconfig" "$srcdir/.config"
@@ -546,8 +521,7 @@ check_autoconf()
 check_makefile()
 {
 	[ ! -f "$1/Makefile" ] && [ ! -f "$1/makefile" ] && \
-	    [ ! -f "$1/GNUmakefile" ] && \
-		return 1; :
+	    [ ! -f "$1/GNUmakefile" ] && return 1; :
 }
 
 copy_elf()