diff --git a/.circleci/config.yml b/.circleci/config.yml
index 47e6dff76c..3d69fa3e96 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -67,18 +67,11 @@ jobs:
           name: Ensure that every template builds for a variety of options.
           command: |
             go build .
-            goruncmd="./u-root -stats-output-path=/tmp/stats.json"
+            goruncmd="./u-root"
             $goruncmd minimal
             $goruncmd core
             $goruncmd coreboot-app
             $goruncmd all
             $goruncmd world
-            # Fails because of dups. Is this supposed to work?
-            #$goruncmd all core
-            #$goruncmd all core
+            $goruncmd all core
             GOOS=plan9 $goruncmd -defaultsh=/bbin/rush plan9
-            cat /tmp/stats.json
-      - store_artifacts:
-          name: Store build stats
-          path: /tmp/stats.json
-          destination: stats.json
diff --git a/templates.go b/templates.go
deleted file mode 100644
index a517e67097..0000000000
--- a/templates.go
+++ /dev/null
@@ -1,310 +0,0 @@
-// Copyright 2015-2020 the u-root Authors. All rights reserved
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package main
-
-// TODO: make templates able to include other templates.
-// e.g. "all" below should just say "core" and "boot". Use it to replace
-// the old 'systemboot' template.
-// Or just call it a day, now that we have the new directory structure, and dump the templates
-// completely; that may be our best bet.
-var templates = map[string][]string{
-	"all": {
-		"github.com/u-root/u-root/cmds/core/*",
-		"github.com/u-root/u-root/cmds/boot/*boot*",
-	},
-	"boot": {
-		"github.com/u-root/u-root/cmds/boot/*boot*",
-	},
-	// Absolutely everything, including experimental commands.
-	"world": {
-		"github.com/u-root/u-root/cmds/*/*",
-	},
-	// Core should be things you don't want to live without.
-	"core": {
-		"github.com/u-root/u-root/cmds/core/*",
-	},
-	// Minimal should be things you can't live without.
-	"minimal": {
-		"github.com/u-root/u-root/cmds/core/blkid",
-		"github.com/u-root/u-root/cmds/core/cat",
-		"github.com/u-root/u-root/cmds/core/chmod",
-		"github.com/u-root/u-root/cmds/core/cmp",
-		"github.com/u-root/u-root/cmds/core/cp",
-		"github.com/u-root/u-root/cmds/core/date",
-		"github.com/u-root/u-root/cmds/core/dd",
-		"github.com/u-root/u-root/cmds/core/df",
-		"github.com/u-root/u-root/cmds/core/dhclient",
-		"github.com/u-root/u-root/cmds/core/dmesg",
-		"github.com/u-root/u-root/cmds/core/echo",
-		"github.com/u-root/u-root/cmds/core/find",
-		"github.com/u-root/u-root/cmds/core/free",
-		"github.com/u-root/u-root/cmds/core/gosh",
-		"github.com/u-root/u-root/cmds/core/gpgv",
-		"github.com/u-root/u-root/cmds/core/grep",
-		"github.com/u-root/u-root/cmds/core/gzip",
-		"github.com/u-root/u-root/cmds/core/hostname",
-		"github.com/u-root/u-root/cmds/core/id",
-		"github.com/u-root/u-root/cmds/core/init",
-		"github.com/u-root/u-root/cmds/core/insmod",
-		"github.com/u-root/u-root/cmds/core/io",
-		"github.com/u-root/u-root/cmds/core/ip",
-		"github.com/u-root/u-root/cmds/core/kexec",
-		"github.com/u-root/u-root/cmds/core/kill",
-		"github.com/u-root/u-root/cmds/core/ln",
-		"github.com/u-root/u-root/cmds/core/losetup",
-		"github.com/u-root/u-root/cmds/core/ls",
-		"github.com/u-root/u-root/cmds/core/lsmod",
-		"github.com/u-root/u-root/cmds/core/mkdir",
-		"github.com/u-root/u-root/cmds/core/mknod",
-		"github.com/u-root/u-root/cmds/core/mount",
-		"github.com/u-root/u-root/cmds/core/msr",
-		"github.com/u-root/u-root/cmds/core/mv",
-		"github.com/u-root/u-root/cmds/core/pci",
-		"github.com/u-root/u-root/cmds/core/ping",
-		"github.com/u-root/u-root/cmds/core/printenv",
-		"github.com/u-root/u-root/cmds/core/ps",
-		"github.com/u-root/u-root/cmds/core/pwd",
-		"github.com/u-root/u-root/cmds/core/readlink",
-		"github.com/u-root/u-root/cmds/core/rm",
-		"github.com/u-root/u-root/cmds/core/rmmod",
-		"github.com/u-root/u-root/cmds/core/seq",
-		"github.com/u-root/u-root/cmds/core/shutdown",
-		"github.com/u-root/u-root/cmds/core/sleep",
-		"github.com/u-root/u-root/cmds/core/sync",
-		"github.com/u-root/u-root/cmds/core/tail",
-		"github.com/u-root/u-root/cmds/core/tee",
-		"github.com/u-root/u-root/cmds/core/truncate",
-		"github.com/u-root/u-root/cmds/core/umount",
-		"github.com/u-root/u-root/cmds/core/uname",
-		"github.com/u-root/u-root/cmds/core/unshare",
-		"github.com/u-root/u-root/cmds/core/wc",
-		"github.com/u-root/u-root/cmds/core/wget",
-		"github.com/u-root/u-root/cmds/core/which",
-	},
-	// embedded systems, like ARM based gadgets and SBCs
-	"embedded": {
-		"github.com/u-root/u-root/cmds/core/cat",
-		"github.com/u-root/u-root/cmds/core/cp",
-		"github.com/u-root/u-root/cmds/core/dd",
-		"github.com/u-root/u-root/cmds/core/dhclient",
-		"github.com/u-root/u-root/cmds/core/dmesg",
-		"github.com/u-root/u-root/cmds/core/echo",
-		"github.com/u-root/u-root/cmds/core/free",
-		"github.com/u-root/u-root/cmds/core/gosh",
-		"github.com/u-root/u-root/cmds/core/grep",
-		"github.com/u-root/u-root/cmds/core/init",
-		"github.com/u-root/u-root/cmds/core/insmod",
-		"github.com/u-root/u-root/cmds/core/ip",
-		"github.com/u-root/u-root/cmds/core/kexec",
-		"github.com/u-root/u-root/cmds/core/ln",
-		"github.com/u-root/u-root/cmds/core/ls",
-		"github.com/u-root/u-root/cmds/core/mkdir",
-		"github.com/u-root/u-root/cmds/core/mount",
-		"github.com/u-root/u-root/cmds/core/netcat",
-		"github.com/u-root/u-root/cmds/core/ping",
-		"github.com/u-root/u-root/cmds/core/rm",
-		"github.com/u-root/u-root/cmds/core/rmmod",
-		"github.com/u-root/u-root/cmds/core/shutdown",
-		"github.com/u-root/u-root/cmds/core/tail",
-		"github.com/u-root/u-root/cmds/core/tee",
-		"github.com/u-root/u-root/cmds/core/uname",
-		"github.com/u-root/u-root/cmds/core/wget",
-	},
-	// coreboot-app minimal environment
-	"coreboot-app": {
-		"github.com/u-root/u-root/cmds/core/cat",
-		"github.com/u-root/u-root/cmds/exp/cbmem",
-		"github.com/u-root/u-root/cmds/core/chroot",
-		"github.com/u-root/u-root/cmds/core/cp",
-		"github.com/u-root/u-root/cmds/core/dd",
-		"github.com/u-root/u-root/cmds/core/dhclient",
-		"github.com/u-root/u-root/cmds/core/dmesg",
-		"github.com/u-root/u-root/cmds/core/find",
-		"github.com/u-root/u-root/cmds/core/gosh",
-		"github.com/u-root/u-root/cmds/core/grep",
-		"github.com/u-root/u-root/cmds/core/id",
-		"github.com/u-root/u-root/cmds/core/init",
-		"github.com/u-root/u-root/cmds/core/insmod",
-		"github.com/u-root/u-root/cmds/core/ip",
-		"github.com/u-root/u-root/cmds/core/kill",
-		"github.com/u-root/u-root/cmds/core/ls",
-		"github.com/u-root/u-root/cmds/core/mount",
-		"github.com/u-root/u-root/cmds/core/pci",
-		"github.com/u-root/u-root/cmds/core/ping",
-		"github.com/u-root/u-root/cmds/core/ps",
-		"github.com/u-root/u-root/cmds/core/pwd",
-		"github.com/u-root/u-root/cmds/core/rm",
-		"github.com/u-root/u-root/cmds/core/rmmod",
-		"github.com/u-root/u-root/cmds/core/shutdown",
-		"github.com/u-root/u-root/cmds/core/sshd",
-		"github.com/u-root/u-root/cmds/core/switch_root",
-		"github.com/u-root/u-root/cmds/core/tail",
-		"github.com/u-root/u-root/cmds/core/tee",
-		"github.com/u-root/u-root/cmds/core/uname",
-		"github.com/u-root/u-root/cmds/core/wget",
-	},
-	"plan9": {
-		"github.com/u-root/u-root/cmds/core/*",
-	},
-	// For a command to be uncommented,
-	// tinygo test should work on linux and darwin.
-	"tinygo": {
-		"github.com/u-root/u-root/cmds/core/backoff",
-		"github.com/u-root/u-root/cmds/core/base64",
-		"github.com/u-root/u-root/cmds/core/basename",
-		////"github.com/u-root/u-root/cmds/core/bind",
-		//"github.com/u-root/u-root/cmds/core/blkid",
-		"github.com/u-root/u-root/cmds/core/cat",
-		"github.com/u-root/u-root/cmds/core/chmod",
-		//"github.com/u-root/u-root/cmds/core/chroot", credentials problem
-		"github.com/u-root/u-root/cmds/core/cmp",
-		"github.com/u-root/u-root/cmds/core/comm",
-		"github.com/u-root/u-root/cmds/core/cp",
-		//////"github.com/u-root/u-root/cmds/core/cpio", build constraints problem
-		"github.com/u-root/u-root/cmds/core/date",
-		"github.com/u-root/u-root/cmds/core/dd",
-		//////"github.com/u-root/u-root/cmds/core/df",
-		//////"github.com/u-root/u-root/cmds/core/dhclient",
-		"github.com/u-root/u-root/cmds/core/dirname",
-		//////"github.com/u-root/u-root/cmds/core/dmesg",
-		"github.com/u-root/u-root/cmds/core/echo",
-		//////"github.com/u-root/u-root/cmds/core/elvish",
-		"github.com/u-root/u-root/cmds/core/false",
-		//"github.com/u-root/u-root/cmds/core/find",
-		"github.com/u-root/u-root/cmds/core/free",
-		//"github.com/u-root/u-root/cmds/core/fusermount",
-		//////"github.com/u-root/u-root/cmds/core/gosh",
-		//"github.com/u-root/u-root/cmds/core/gpgv",
-		"github.com/u-root/u-root/cmds/core/gpt",
-		"github.com/u-root/u-root/cmds/core/grep",
-		//"github.com/u-root/u-root/cmds/core/gzip",
-		"github.com/u-root/u-root/cmds/core/hexdump",
-		//////"github.com/u-root/u-root/cmds/core/hostname",
-		//"github.com/u-root/u-root/cmds/core/hwclock",
-		//"github.com/u-root/u-root/cmds/core/id",
-		//////"github.com/u-root/u-root/cmds/core/init",
-		//"github.com/u-root/u-root/cmds/core/insmod",
-		//////"github.com/u-root/u-root/cmds/core/io",
-		//"github.com/u-root/u-root/cmds/core/ip",
-		//"github.com/u-root/u-root/cmds/core/kexec",
-		"github.com/u-root/u-root/cmds/core/kill",
-		//"github.com/u-root/u-root/cmds/core/lddfiles",
-		//"github.com/u-root/u-root/cmds/core/ln",
-		//"github.com/u-root/u-root/cmds/core/lockmsrs",
-		//"github.com/u-root/u-root/cmds/core/losetup",
-		"github.com/u-root/u-root/cmds/core/ls",
-		//"github.com/u-root/u-root/cmds/core/lsdrivers",
-		//"github.com/u-root/u-root/cmds/core/lsmod",
-		//"github.com/u-root/u-root/cmds/core/man",
-		//"github.com/u-root/u-root/cmds/core/md5sum",
-		"github.com/u-root/u-root/cmds/core/mkdir",
-		//////"github.com/u-root/u-root/cmds/core/mkfifo",
-		//////"github.com/u-root/u-root/cmds/core/mknod",
-		//"github.com/u-root/u-root/cmds/core/mktemp",
-		"github.com/u-root/u-root/cmds/core/more",
-		//"github.com/u-root/u-root/cmds/core/mount",
-		//"github.com/u-root/u-root/cmds/core/msr",
-		"github.com/u-root/u-root/cmds/core/mv",
-		//"github.com/u-root/u-root/cmds/core/netcat",
-		//////"github.com/u-root/u-root/cmds/core/ntpdate",
-		//"github.com/u-root/u-root/cmds/core/pci",
-		//"github.com/u-root/u-root/cmds/core/ping",
-		//"github.com/u-root/u-root/cmds/core/poweroff",
-		//"github.com/u-root/u-root/cmds/core/printenv",
-		"github.com/u-root/u-root/cmds/core/ps",
-		"github.com/u-root/u-root/cmds/core/pwd",
-		//"github.com/u-root/u-root/cmds/core/readlink",
-		"github.com/u-root/u-root/cmds/core/rm",
-		//"github.com/u-root/u-root/cmds/core/rmmod",
-		//"github.com/u-root/u-root/cmds/core/rsdp",
-		//"github.com/u-root/u-root/cmds/core/scp",
-		//"github.com/u-root/u-root/cmds/core/seq",
-		//"github.com/u-root/u-root/cmds/core/shasum",
-		//"github.com/u-root/u-root/cmds/core/shutdown",
-		//"github.com/u-root/u-root/cmds/core/sleep",
-		//"github.com/u-root/u-root/cmds/core/sluinit",
-		"github.com/u-root/u-root/cmds/core/sort",
-		//////"github.com/u-root/u-root/cmds/core/sshd",
-		//////"github.com/u-root/u-root/cmds/core/strace",
-		//"github.com/u-root/u-root/cmds/core/strings",
-		//////"github.com/u-root/u-root/cmds/core/stty",
-		//////"github.com/u-root/u-root/cmds/core/switch_root",
-		//"github.com/u-root/u-root/cmds/core/sync",
-		//"github.com/u-root/u-root/cmds/core/tail",
-		//"github.com/u-root/u-root/cmds/core/tar",
-		//"github.com/u-root/u-root/cmds/core/tee",
-		//"github.com/u-root/u-root/cmds/core/time",
-		//"github.com/u-root/u-root/cmds/core/timeout",
-		"github.com/u-root/u-root/cmds/core/tr",
-		"github.com/u-root/u-root/cmds/core/true",
-		//"github.com/u-root/u-root/cmds/core/truncate",
-		//"github.com/u-root/u-root/cmds/core/ts",
-		//"github.com/u-root/u-root/cmds/core/umount",
-		//////"github.com/u-root/u-root/cmds/core/uname",
-		"github.com/u-root/u-root/cmds/core/uniq",
-		//"github.com/u-root/u-root/cmds/core/unmount",
-		//"github.com/u-root/u-root/cmds/core/unshare",
-		//"github.com/u-root/u-root/cmds/core/uptime",
-		//"github.com/u-root/u-root/cmds/core/watchdog",
-		//"github.com/u-root/u-root/cmds/core/watchdogd",
-		"github.com/u-root/u-root/cmds/core/wc",
-		//"github.com/u-root/u-root/cmds/core/wget",
-		//////"github.com/u-root/u-root/cmds/core/which",
-		"github.com/u-root/u-root/cmds/core/yes",
-		//// One of these commands in exp tickles a busybox bug.
-		////"github.com/u-root/u-root/cmds/exp/acpicat",
-		////"github.com/u-root/u-root/cmds/exp/acpigrep",
-		////"github.com/u-root/u-root/cmds/exp/ansi",
-		////"github.com/u-root/u-root/cmds/exp/bootvars",
-		////"github.com/u-root/u-root/cmds/exp/bzimage",
-		////"github.com/u-root/u-root/cmds/exp/cbmem",
-		////"github.com/u-root/u-root/cmds/exp/console",
-		////"github.com/u-root/u-root/cmds/exp/crc",
-		////"github.com/u-root/u-root/cmds/exp/disk_unlock",
-		////"github.com/u-root/u-root/cmds/exp/dmidecode",
-		////"github.com/u-root/u-root/cmds/exp/dumpebda",
-		////"github.com/u-root/u-root/cmds/exp/ectool",
-		////"github.com/u-root/u-root/cmds/exp/ed",
-		////"github.com/u-root/u-root/cmds/exp/efivarfs",
-		////"github.com/u-root/u-root/cmds/exp/esxiboot",
-		////"github.com/u-root/u-root/cmds/exp/fbsplash",
-		////"github.com/u-root/u-root/cmds/exp/fdtdump",
-		////"github.com/u-root/u-root/cmds/exp/field",
-		////"github.com/u-root/u-root/cmds/exp/fixrsdp",
-		////"github.com/u-root/u-root/cmds/exp/forth",
-		////"github.com/u-root/u-root/cmds/exp/freq",
-		////"github.com/u-root/u-root/cmds/exp/getty",
-		////"github.com/u-root/u-root/cmds/exp/gosh",
-		////"github.com/u-root/u-root/cmds/exp/hdparm",
-		////"github.com/u-root/u-root/cmds/exp/ipmidump",
-		////"github.com/u-root/u-root/cmds/exp/kconf",
-		////"github.com/u-root/u-root/cmds/exp/lsfabric",
-		////"github.com/u-root/u-root/cmds/exp/madeye",
-		////"github.com/u-root/u-root/cmds/exp/modprobe",
-		////"github.com/u-root/u-root/cmds/exp/netbootxyz",
-		////"github.com/u-root/u-root/cmds/exp/newsshd",
-		////"github.com/u-root/u-root/cmds/exp/nvme_unlock",
-		////"github.com/u-root/u-root/cmds/exp/page",
-		////"github.com/u-root/u-root/cmds/exp/partprobe",
-		////"github.com/u-root/u-root/cmds/exp/pflask",
-		////"github.com/u-root/u-root/cmds/exp/pox",
-		////"github.com/u-root/u-root/cmds/exp/pxeserver",
-		////"github.com/u-root/u-root/cmds/exp/readpe",
-		////"github.com/u-root/u-root/cmds/exp/run",
-		////"github.com/u-root/u-root/cmds/exp/rush",
-		////"github.com/u-root/u-root/cmds/exp/smbios_transfer",
-		////"github.com/u-root/u-root/cmds/exp/smn",
-		////"github.com/u-root/u-root/cmds/exp/srvfiles",
-		////"github.com/u-root/u-root/cmds/exp/ssh",
-		//////"github.com/u-root/u-root/cmds/exp/syscallfilter",
-		////"github.com/u-root/u-root/cmds/exp/tac",
-		////"github.com/u-root/u-root/cmds/exp/tcz",
-		////"github.com/u-root/u-root/cmds/exp/uefiboot",
-		////"github.com/u-root/u-root/cmds/exp/vboot",
-		////"github.com/u-root/u-root/cmds/exp/watch",
-		////"github.com/u-root/u-root/cmds/exp/zbi",
-		////"github.com/u-root/u-root/cmds/exp/zimage",
-	},
-}
diff --git a/u-root.go b/u-root.go
index 7b5d38e3c0..ea6934b16a 100644
--- a/u-root.go
+++ b/u-root.go
@@ -2,154 +2,28 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Command u-root builds CPIO archives with the given files and Go commands.
 package main
 
 import (
-	"encoding/json"
 	"errors"
 	"flag"
 	"fmt"
 	"log"
+	"log/slog"
 	"os"
-	"path"
-	"path/filepath"
-	"runtime"
-	"sort"
-	"strings"
-	"time"
 
+	"github.com/dustin/go-humanize"
 	"github.com/u-root/gobusybox/src/pkg/golang"
-	"github.com/u-root/gobusybox/src/pkg/uflag"
-	"github.com/u-root/u-root/pkg/shlex"
-	"github.com/u-root/u-root/pkg/ulog"
-	"github.com/u-root/u-root/pkg/uroot"
-	"github.com/u-root/u-root/pkg/uroot/builder"
-	"github.com/u-root/u-root/pkg/uroot/initramfs"
+	"github.com/u-root/mkuimage/uimage"
+	"github.com/u-root/mkuimage/uimage/mkuimage"
+	"github.com/u-root/uio/llog"
 )
 
-// multiFlag is used for flags that support multiple invocations, e.g. -files
-type multiFlag []string
-
-func (m *multiFlag) String() string {
-	return fmt.Sprint(*m)
-}
-
-func (m *multiFlag) Set(value string) error {
-	*m = append(*m, value)
-	return nil
-}
-
-// errors from the u-root command
 var (
-	ErrEmptyFilesArg = errors.New("empty argument to -files")
+	errEmptyFilesArg = errors.New("empty argument to -files")
 )
 
-// Flags for u-root builder.
-var (
-	build, format, tmpDir, base, outputPath *string
-	uinitCmd, initCmd                       *string
-	defaultShell                            *string
-	useExistingInit                         *bool
-	noCommands                              *bool
-	extraFiles                              multiFlag
-	statsOutputPath                         *string
-	statsLabel                              *string
-	shellbang                               *bool
-	// For the new gobusybox support
-	usegobusybox *bool
-	genDir       *string
-	// For the new "filepath only" logic
-	urootSourceDir *string
-)
-
-func init() {
-	var sh string
-	switch golang.Default().GOOS {
-	case "plan9":
-		sh = ""
-	default:
-		sh = "gosh"
-	}
-
-	build = flag.String("build", "gbb", "u-root build format (e.g. bb/gbb or binary).")
-	format = flag.String("format", "cpio", "Archival format.")
-
-	tmpDir = flag.String("tmpdir", "", "Temporary directory to put binaries in.")
-
-	base = flag.String("base", "", "Base archive to add files to. By default, this is a couple of directories like /bin, /etc, etc. u-root has a default internally supplied set of files; use base=/dev/null if you don't want any base files.")
-	useExistingInit = flag.Bool("useinit", false, "Use existing init from base archive (only if --base was specified).")
-	outputPath = flag.String("o", "", "Path to output initramfs file.")
-
-	initCmd = flag.String("initcmd", "init", "Symlink target for /init. Can be an absolute path or a u-root command name. Use initcmd=\"\" if you don't want the symlink.")
-	uinitCmd = flag.String("uinitcmd", "", "Symlink target and arguments for /bin/uinit. Can be an absolute path or a u-root command name. Use uinitcmd=\"\" if you don't want the symlink. E.g. -uinitcmd=\"echo foobar\"")
-	defaultShell = flag.String("defaultsh", sh, "Default shell. Can be an absolute path or a u-root command name. Use defaultsh=\"\" if you don't want the symlink.")
-
-	noCommands = flag.Bool("nocmd", false, "Build no Go commands; initramfs only")
-
-	flag.Var(&extraFiles, "files", "Additional files, directories, and binaries (with their ldd dependencies) to add to archive. Can be specified multiple times.")
-
-	shellbang = flag.Bool("shellbang", false, "Use #! instead of symlinks for busybox")
-
-	statsOutputPath = flag.String("stats-output-path", "", "Write build stats to this file (JSON)")
-	statsLabel = flag.String("stats-label", "", "Use this statsLabel when writing stats")
-
-	// Flags for the gobusybox, which we hope to move to, since it works with modules.
-	genDir = flag.String("gen-dir", "", "Directory to generate source in")
-
-	// Flag for the new filepath only mode. This will be required to find the u-root commands and make templates work
-	// In almost every case, "." is fine.
-	urootSourceDir = flag.String("uroot-source", ".", "Path to the locally checked out u-root source tree in case commands from there are desired.")
-}
-
-type buildStats struct {
-	Label      string  `json:"label,omitempty"`
-	Time       int64   `json:"time"`
-	Duration   float64 `json:"duration"`
-	OutputSize int64   `json:"output_size"`
-}
-
-func writeBuildStats(stats buildStats, path string) error {
-	var allStats []buildStats
-	if data, err := os.ReadFile(*statsOutputPath); err == nil {
-		json.Unmarshal(data, &allStats)
-	}
-	found := false
-	for i, s := range allStats {
-		if s.Label == stats.Label {
-			allStats[i] = stats
-			found = true
-			break
-		}
-	}
-	if !found {
-		allStats = append(allStats, stats)
-		sort.Slice(allStats, func(i, j int) bool {
-			return strings.Compare(allStats[i].Label, allStats[j].Label) == -1
-		})
-	}
-	data, err := json.MarshalIndent(allStats, "", "  ")
-	if err != nil {
-		return err
-	}
-	if err := os.WriteFile(*statsOutputPath, data, 0o644); err != nil {
-		return err
-	}
-	return nil
-}
-
-func generateLabel(env *golang.Environ) string {
-	var baseCmds []string
-	if len(flag.Args()) > 0 {
-		// Use the last component of the name to keep the label short
-		for _, e := range flag.Args() {
-			baseCmds = append(baseCmds, path.Base(e))
-		}
-	} else {
-		baseCmds = []string{"core"}
-	}
-	return fmt.Sprintf("%s-%s-%s-%s", *build, env.GOOS, env.GOARCH, strings.Join(baseCmds, "_"))
-}
-
 // checkArgs checks for common mistakes that cause confusion.
 //  1. -files as the last argument
 //  2. -files followed by any switch, indicating a shell expansion problem
@@ -166,14 +40,14 @@ func checkArgs(args ...string) error {
 	}
 
 	if args[len(args)-1] == "-files" {
-		return fmt.Errorf("last argument is -files:%w", ErrEmptyFilesArg)
+		return fmt.Errorf("last argument is -files:%w", errEmptyFilesArg)
 	}
 
 	// We know the last arg is not -files; scan the arguments for -files
 	// followed by a switch.
 	for i := 0; i < len(args)-1; i++ {
 		if args[i] == "-files" && args[i+1][0] == '-' {
-			return fmt.Errorf("-files argument %d is followed by a switch: %w", i, ErrEmptyFilesArg)
+			return fmt.Errorf("-files argument %d is followed by a switch: %w", i, errEmptyFilesArg)
 		}
 	}
 
@@ -181,249 +55,58 @@ func checkArgs(args ...string) error {
 }
 
 func main() {
+	log.SetFlags(log.Ltime)
 	if err := checkArgs(os.Args...); err != nil {
 		log.Fatal(err)
 	}
 
-	gbbOpts := &golang.BuildOpts{}
-	gbbOpts.RegisterFlags(flag.CommandLine)
-	// Register an alias for -go-no-strip for backwards compatibility.
-	flag.CommandLine.BoolVar(&gbbOpts.NoStrip, "no-strip", false, "Build unstripped binaries")
-
-	env := golang.Default()
-	env.RegisterFlags(flag.CommandLine)
-	tags := (*uflag.Strings)(&env.BuildTags)
-	flag.CommandLine.Var(tags, "tags", "Go build tags -- repeat the flag for multiple values")
-
-	flag.Parse()
-
-	l := log.New(os.Stderr, "", log.Ltime)
-
-	if usrc := os.Getenv("UROOT_SOURCE"); usrc != "" && *urootSourceDir == "" {
-		*urootSourceDir = usrc
-	}
-
-	if env.CgoEnabled {
-		l.Printf("Disabling CGO for u-root...")
-		env.CgoEnabled = false
-	}
-	l.Printf("Build environment: %s", env)
-	if env.GOOS != "linux" {
-		l.Printf("GOOS is not linux. Did you mean to set GOOS=linux?")
-	}
-
-	start := time.Now()
-
-	// Main is in a separate functions so defers run on return.
-	if err := Main(l, env, gbbOpts); err != nil {
-		l.Fatalf("Build error: %v", err)
-	}
-
-	elapsed := time.Now().Sub(start)
-
-	stats := buildStats{
-		Label:    *statsLabel,
-		Time:     start.Unix(),
-		Duration: float64(elapsed.Milliseconds()) / 1000,
-	}
-	if stats.Label == "" {
-		stats.Label = generateLabel(env)
-	}
-	if stat, err := os.Stat(*outputPath); err == nil && stat.ModTime().After(start) {
-		l.Printf("Successfully built %q (size %d).", *outputPath, stat.Size())
-		stats.OutputSize = stat.Size()
-		if *statsOutputPath != "" {
-			if err := writeBuildStats(stats, *statsOutputPath); err == nil {
-				l.Printf("Wrote stats to %q (label %q)", *statsOutputPath, stats.Label)
-			} else {
-				l.Printf("Failed to write stats to %s: %v", *statsOutputPath, err)
-			}
-		}
-	}
-}
-
-var recommendedVersions = []string{
-	"go1.20",
-	"go1.21",
-}
-
-func isRecommendedVersion(v string) bool {
-	for _, r := range recommendedVersions {
-		if strings.HasPrefix(v, r) {
-			return true
-		}
-	}
-	return false
-}
-
-func canFindSource(dir string) error {
-	d := filepath.Join(dir, "cmds", "core")
-	if _, err := os.Stat(d); err != nil {
-		return fmt.Errorf("can not build u-root in %q:%w (-uroot-source may be incorrect or not set)", *urootSourceDir, os.ErrNotExist)
-	}
-	return nil
-}
-
-// Main is a separate function so defers are run on return, which they wouldn't
-// on exit.
-func Main(l ulog.Logger, env *golang.Environ, buildOpts *golang.BuildOpts) error {
-	v, err := env.Version()
-	if err != nil {
-		l.Printf("Could not get environment's Go version, using runtime's version: %v", err)
-		v = runtime.Version()
-	}
-	if !isRecommendedVersion(v) {
-		l.Printf(`WARNING: You are not using one of the recommended Go versions (have = %s, recommended = %v).
-			Some packages may not compile.
-			Go to https://golang.org/doc/install to find out how to install a newer version of Go,
-			or use https://godoc.org/golang.org/dl/%s to install an additional version of Go.`,
-			v, recommendedVersions, recommendedVersions[0])
-	}
-
-	archiver, err := initramfs.GetArchiver(*format)
-	if err != nil {
-		return err
+	env := golang.Default(golang.DisableCGO())
+	f := &mkuimage.Flags{
+		Commands:      mkuimage.CommandFlags{Builder: "bb"},
+		ArchiveFormat: "cpio",
+		OutputFile:    defaultFile(env),
 	}
+	f.RegisterFlags(flag.CommandLine)
 
-	// Open the target initramfs file.
-	if *outputPath == "" {
-		if len(env.GOOS) == 0 && len(env.GOARCH) == 0 {
-			return fmt.Errorf("passed no path, GOOS, and GOARCH to CPIOArchiver.OpenWriter")
-		}
-		*outputPath = fmt.Sprintf("/tmp/initramfs.%s_%s.cpio", env.GOOS, env.GOARCH)
-	}
-	w, err := archiver.OpenWriter(l, *outputPath)
-	if err != nil {
-		return err
-	}
+	l := llog.Default()
+	l.RegisterVerboseFlag(flag.CommandLine, "v", slog.LevelDebug)
 
-	var baseFile initramfs.Reader
-	if *base != "" {
-		bf, err := os.Open(*base)
-		if err != nil {
-			return err
-		}
-		defer bf.Close()
-		baseFile = archiver.Reader(bf)
-	} else {
-		baseFile = uroot.DefaultRamfs().Reader()
-	}
+	tf := &mkuimage.TemplateFlags{}
+	tf.RegisterFlags(flag.CommandLine)
+	flag.Parse()
 
-	tempDir := *tmpDir
-	if tempDir == "" {
-		var err error
-		tempDir, err = os.MkdirTemp("", "u-root")
-		if err != nil {
-			return err
-		}
-		defer os.RemoveAll(tempDir)
-	} else if _, err := os.Stat(tempDir); os.IsNotExist(err) {
-		if err := os.MkdirAll(tempDir, 0o755); err != nil {
-			return fmt.Errorf("temporary directory %q did not exist; tried to mkdir but failed: %v", tempDir, err)
-		}
+	// Set defaults.
+	m := []uimage.Modifier{
+		uimage.WithReplaceEnv(env),
+		uimage.WithBaseArchive(uimage.DefaultRamfs()),
+		uimage.WithCPIOOutput(defaultFile(env)),
+		uimage.WithInit("init"),
 	}
-
-	var (
-		c           []uroot.Commands
-		initCommand = *initCmd
-	)
-	if !*noCommands {
-		var b builder.Builder
-		switch *build {
-		case "bb", "gbb":
-			l.Printf("NOTE: building with the new gobusybox; to get the old behavior check out commit 8b790de")
-			b = builder.GBBBuilder{ShellBang: *shellbang}
-		case "binary":
-			b = builder.BinaryBuilder{}
-		case "source":
-			return fmt.Errorf("source mode has been deprecated")
-		default:
-			return fmt.Errorf("could not find builder %q", *build)
-		}
-
-		// Resolve globs into package imports.
-		//
-		// Currently allowed format:
-		//   Paths to Go package directories; e.g. $GOPATH/src/github.com/u-root/u-root/cmds/*
-		//   u-root templates; e.g. all, core, minimal (requires uroot-source be valid)
-		//   Import paths of u-root commands; e.g. github.com/u-root/u-root/cmds/* (requires uroot-source)
-		var pkgs []string
-		for _, a := range flag.Args() {
-			p, ok := templates[a]
-			if !ok {
-				if !validateArg(a) {
-					l.Printf("%q is not a valid path, allowed are only existing relative or absolute file paths!", a)
-					continue
-				}
-				pkgs = append(pkgs, a)
-				continue
-			}
-			pkgs = append(pkgs, p...)
-		}
-		if len(pkgs) == 0 {
-			pkgs = []string{"github.com/u-root/u-root/cmds/core/*"}
-		}
-
-		// The command-line tool only allows specifying one build mode
-		// right now.
-		c = append(c, uroot.Commands{
-			Builder:  b,
-			Packages: pkgs,
-		})
+	if golang.Default().GOOS != "plan9" {
+		m = append(m, uimage.WithShell("gosh"))
 	}
 
-	opts := uroot.Opts{
-		Env:             env,
-		Commands:        c,
-		UrootSource:     *urootSourceDir,
-		TempDir:         tempDir,
-		ExtraFiles:      extraFiles,
-		OutputFile:      w,
-		BaseArchive:     baseFile,
-		UseExistingInit: *useExistingInit,
-		InitCmd:         initCommand,
-		DefaultShell:    *defaultShell,
-		BuildOpts:       buildOpts,
+	pkgs := flag.Args()
+	// Only add default packages if no config template was given.
+	//
+	// Otherwise, the template can't erase the default packages and all
+	// templates would be forced to use cmds/core/*.
+	if len(pkgs) == 0 && tf.Config == "" {
+		pkgs = []string{"github.com/u-root/u-root/cmds/core/*"}
 	}
-	uinitArgs := shlex.Argv(*uinitCmd)
-	if len(uinitArgs) > 0 {
-		opts.UinitCmd = uinitArgs[0]
+	if err := mkuimage.CreateUimage(l, m, tf, f, pkgs); err != nil {
+		l.Errorf("mkuimage error: %v", err)
+		os.Exit(1)
 	}
-	if len(uinitArgs) > 1 {
-		opts.UinitArgs = uinitArgs[1:]
-	}
-	return uroot.CreateInitramfs(l, opts)
-}
 
-func validateArg(arg string) bool {
-	// Do the simple thing first: stat the path.
-	// This saves incorrect diagnostics when the
-	// path is a perfectly valid relative path.
-	if _, err := os.Stat(arg); err == nil {
-		return true
+	if stat, err := os.Stat(f.OutputFile); err == nil && f.ArchiveFormat == "cpio" {
+		l.Infof("Successfully built %q (size %d bytes -- %s).", f.OutputFile, stat.Size(), humanize.IBytes(uint64(stat.Size())))
 	}
-	if !checkPrefix(arg) {
-		paths, err := filepath.Glob(arg)
-		if err != nil {
-			return false
-		}
-		for _, path := range paths {
-			if !checkPrefix(path) {
-				return false
-			}
-		}
-	}
-
-	return true
 }
 
-func checkPrefix(arg string) bool {
-	prefixes := []string{".", "/", "-", "cmds", "github.com/u-root/u-root"}
-	for _, prefix := range prefixes {
-		if strings.HasPrefix(arg, prefix) {
-			return true
-		}
+func defaultFile(env *golang.Environ) string {
+	if len(env.GOOS) == 0 || len(env.GOARCH) == 0 {
+		return "/tmp/initramfs.cpio"
 	}
-
-	return false
+	return fmt.Sprintf("/tmp/initramfs.%s_%s.cpio", env.GOOS, env.GOARCH)
 }
diff --git a/uroot_test.go b/uroot_test.go
index cadc8fc546..95a3698552 100644
--- a/uroot_test.go
+++ b/uroot_test.go
@@ -357,9 +357,9 @@ func TestCheckArgs(t *testing.T) {
 		args []string
 		err  error
 	}{
-		{"-files is only arg", []string{"-files"}, ErrEmptyFilesArg},
-		{"-files followed by -files", []string{"-files", "-files"}, ErrEmptyFilesArg},
-		{"-files followed by any other switch", []string{"-files", "-abc"}, ErrEmptyFilesArg},
+		{"-files is only arg", []string{"-files"}, errEmptyFilesArg},
+		{"-files followed by -files", []string{"-files", "-files"}, errEmptyFilesArg},
+		{"-files followed by any other switch", []string{"-files", "-abc"}, errEmptyFilesArg},
 		{"no args", []string{}, nil},
 		{"u-root alone", []string{"u-root"}, nil},
 		{"u-root with -files and other args", []string{"u-root", "-files", "/bin/bash", "core"}, nil},