diff --git a/samples/zephyr/run-tests.go b/samples/zephyr/run-tests.go
new file mode 100644
index 0000000..45c0a19
--- /dev/null
+++ b/samples/zephyr/run-tests.go
@@ -0,0 +1,427 @@
+// +build ignore
+//
+// Build multiple configurations of MCUboot for Zephyr, making sure
+// that they run properly.
+//
+// Run as:
+//
+//    go run run-tests.go [flags]
+//
+// Add -help as a flag to get help.  See comment below for logIn on
+// how to configure terminal output to a file so this program can see
+// the output of the Zephyr device.
+
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+)
+
+// logIn gives the pathname of the log output from the Zephyr device.
+// In order to see the serial output, but still be useful for human
+// debugging, the output of the terminal emulator should be teed to a
+// file that this program will read from.  This can be done with
+// something like:
+//
+//     picocom -b 115200 /dev/ttyACM0 | tee /tmp/zephyr.out
+//
+// Other terminal programs should also have logging options.
+var logIn = flag.String("login", "/tmp/zephyr.out", "File name of terminal log from Zephyr device")
+
+// Output from this test run is written to the given log file.
+var logOut = flag.String("logout", "tests.log", "Log file to write to")
+
+// The main driver of this consists of a series of tests.  Each test
+// then contains a series of commands and expect results.
+var tests = []struct {
+	name  string
+	tests []oneTest
+}{
+	{
+		name: "Good RSA",
+		tests: []oneTest{
+			{
+				commands: [][]string{
+					{"make", "test-good-rsa"},
+					{"pyocd-flashtool", "-ce"},
+					{"make", "flash_boot"},
+				},
+				expect: "Unable to find bootable image",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello1"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello2"},
+				},
+				expect: "Hello World from hello2",
+			},
+			{
+				commands: [][]string{
+					{"pyocd-tool", "reset"},
+				},
+				expect: "Hello World from hello1",
+			},
+		},
+	},
+	{
+		name: "Good ECDSA",
+		tests: []oneTest{
+			{
+				commands: [][]string{
+					{"make", "test-good-ecdsa"},
+					{"pyocd-flashtool", "-ce"},
+					{"make", "flash_boot"},
+				},
+				expect: "Unable to find bootable image",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello1"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello2"},
+				},
+				expect: "Hello World from hello2",
+			},
+			{
+				commands: [][]string{
+					{"pyocd-tool", "reset"},
+				},
+				expect: "Hello World from hello1",
+			},
+		},
+	},
+	{
+		name: "Overwrite",
+		tests: []oneTest{
+			{
+				commands: [][]string{
+					{"make", "test-overwrite"},
+					{"pyocd-flashtool", "-ce"},
+					{"make", "flash_boot"},
+				},
+				expect: "Unable to find bootable image",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello1"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello2"},
+				},
+				expect: "Hello World from hello2",
+			},
+			{
+				commands: [][]string{
+					{"pyocd-tool", "reset"},
+				},
+				expect: "Hello World from hello2",
+			},
+		},
+	},
+	{
+		name: "Bad RSA",
+		tests: []oneTest{
+			{
+				commands: [][]string{
+					{"make", "test-bad-rsa-upgrade"},
+					{"pyocd-flashtool", "-ce"},
+					{"make", "flash_boot"},
+				},
+				expect: "Unable to find bootable image",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello1"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello2"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"pyocd-tool", "reset"},
+				},
+				expect: "Hello World from hello1",
+			},
+		},
+	},
+	{
+		name: "Bad RSA",
+		tests: []oneTest{
+			{
+				commands: [][]string{
+					{"make", "test-bad-ecdsa-upgrade"},
+					{"pyocd-flashtool", "-ce"},
+					{"make", "flash_boot"},
+				},
+				expect: "Unable to find bootable image",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello1"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello2"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"pyocd-tool", "reset"},
+				},
+				expect: "Hello World from hello1",
+			},
+		},
+	},
+	{
+		name: "No bootcheck",
+		tests: []oneTest{
+			{
+				commands: [][]string{
+					{"make", "test-no-bootcheck"},
+					{"pyocd-flashtool", "-ce"},
+					{"make", "flash_boot"},
+				},
+				expect: "Unable to find bootable image",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello1"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello2"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"pyocd-tool", "reset"},
+				},
+				expect: "Hello World from hello1",
+			},
+		},
+	},
+	{
+		name: "Wrong RSA",
+		tests: []oneTest{
+			{
+				commands: [][]string{
+					{"make", "test-wrong-rsa"},
+					{"pyocd-flashtool", "-ce"},
+					{"make", "flash_boot"},
+				},
+				expect: "Unable to find bootable image",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello1"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello2"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"pyocd-tool", "reset"},
+				},
+				expect: "Hello World from hello1",
+			},
+		},
+	},
+	{
+		name: "Wrong ECDSA",
+		tests: []oneTest{
+			{
+				commands: [][]string{
+					{"make", "test-wrong-ecdsa"},
+					{"pyocd-flashtool", "-ce"},
+					{"make", "flash_boot"},
+				},
+				expect: "Unable to find bootable image",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello1"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"make", "flash_hello2"},
+				},
+				expect: "Hello World from hello1",
+			},
+			{
+				commands: [][]string{
+					{"pyocd-tool", "reset"},
+				},
+				expect: "Hello World from hello1",
+			},
+		},
+	},
+}
+
+type oneTest struct {
+	commands [][]string
+	expect   string
+}
+
+func main() {
+	err := run()
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func run() error {
+	flag.Parse()
+
+	lines := make(chan string, 30)
+	go readLog(lines)
+
+	// Write output to a log file
+	logFile, err := os.Create(*logOut)
+	if err != nil {
+		return err
+	}
+	defer logFile.Close()
+	lg := bufio.NewWriter(logFile)
+	defer lg.Flush()
+
+	for _, group := range tests {
+		fmt.Printf("Running %q\n", group.name)
+		fmt.Fprintf(lg, "-------------------------------------\n")
+		fmt.Fprintf(lg, "---- Running %q\n", group.name)
+
+		for _, test := range group.tests {
+			for _, cmd := range test.commands {
+				fmt.Printf("    %s\n", cmd)
+				fmt.Fprintf(lg, "---- Run: %s\n", cmd)
+				err = runCommand(cmd, lg)
+				if err != nil {
+					return err
+				}
+			}
+
+			err = expect(lg, lines, test.expect)
+			if err != nil {
+				return err
+			}
+
+			fmt.Fprintf(lg, "---- Passed\n")
+		}
+		fmt.Printf("    Passed!\n")
+	}
+
+	return nil
+}
+
+// Run a single command.
+func runCommand(cmd []string, lg io.Writer) error {
+	c := exec.Command(cmd[0], cmd[1:]...)
+	c.Stdout = lg
+	c.Stderr = lg
+	return c.Run()
+}
+
+// Expect the given string.
+func expect(lg io.Writer, lines <-chan string, exp string) error {
+	// Read lines, and if we hit a timeout before seeing our
+	// expected line, then consider that an error.
+	fmt.Fprintf(lg, "---- expect: %q\n", exp)
+
+	stopper := time.NewTimer(10 * time.Second)
+	defer stopper.Stop()
+outer:
+	for {
+		select {
+		case line := <-lines:
+			fmt.Fprintf(lg, "---- target: %q\n", line)
+			if strings.Contains(line, exp) {
+				break outer
+			}
+		case <-stopper.C:
+			fmt.Fprintf(lg, "timeout, didn't receive output\n")
+			return fmt.Errorf("timeout, didn't receive expected string: %q", exp)
+		}
+	}
+
+	return nil
+}
+
+// Read things from the log file, discarding everything already there.
+func readLog(sink chan<- string) {
+	file, err := os.Open(*logIn)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	_, err = file.Seek(0, 2)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	prefix := ""
+	for {
+		// Read lines until EOF, then delay a bit, and do it
+		// all again.
+		rd := bufio.NewReader(file)
+
+		for {
+			line, err := rd.ReadString('\n')
+			if err == io.EOF {
+				// A partial line can happen because
+				// we are racing with the writer.
+				if line != "" {
+					prefix = line
+				}
+				break
+			}
+			if err != nil {
+				log.Fatal(err)
+			}
+
+			line = prefix + line
+			prefix = ""
+			sink <- line
+			// fmt.Printf("line: %q\n", line)
+		}
+
+		// Pause a little
+		time.Sleep(250 * time.Millisecond)
+	}
+}