[PATCH v8 7/8] test: vboot: refactor run_bootm

- split off a generic part of run_bootm. The helper function is for
  future use in similar commands
- moves u-boot restart below section opening for better log structuring
- only look for expected string in last command. This way a failed
  assert() doesn't dump unrelated output.
- use f-strings in the refactored code while at it

Reviewed-by: Simon Glass <[email protected]>
Signed-off-by: Ludwig Nussel <[email protected]>
---

(no changes since v6)

Changes in v6:
- Add missing return value documentation to run_fit_commands()
- use f-strings for the refactored code
- drop not needed length check for command list

Changes in v5:
- new patch

 test/py/tests/test_vboot.py | 55 +++++++++++++++++++++++++++----------
 1 file changed, 41 insertions(+), 14 deletions(-)

diff --git a/test/py/tests/test_vboot.py b/test/py/tests/test_vboot.py
index 6459c7c313e..df5db157a52 100644
--- a/test/py/tests/test_vboot.py
+++ b/test/py/tests/test_vboot.py
@@ -151,6 +151,39 @@ def test_vboot(ubman, name, sha_algo, padding, sign_options, required,
                                  tmpdir, '-I', tmpdir])
         os.environ['PYTHONPATH'] = pythonpath
 
+
+    def run_fit_commands(commands, expect_string, fit=None):
+        """Load fit image and run commands in U-Boot.
+
+        Asserts that 'expect_string' is contained in the output of the last command
+
+        This always starts a fresh U-Boot instance since the device tree may
+        contain a new public key.
+
+        Args:
+            commands: list of commands to run
+            expect_string: A string which is expected in the output
+            fit: FIT filename to load and verify
+
+        Returns:
+            The joined output of the last command run.
+        """
+
+        ubman.restart_uboot()
+
+        if not fit:
+            fit = f'{tmpdir}test.fit'
+        # run commands that just prepare for the actually relevant one
+        ubman.run_command(f'host load hostfs - 100 {fit}')
+        for cmd in commands[:-1]:
+            ubman.run_command(cmd)
+
+        output = ''.join(ubman.run_command(commands[-1]))
+
+        assert expect_string in output
+
+        return output
+
     def run_bootm(sha_algo, test_type, expect_string, boots, fit=None):
         """Run a 'bootm' command U-Boot.
 
@@ -166,20 +199,14 @@ def test_vboot(ubman, name, sha_algo, padding, sign_options, required,
                     we are expected to not boot
             fit: FIT filename to load and verify
         """
-        if not fit:
-            fit = '%stest.fit' % tmpdir
-        ubman.restart_uboot()
-        with ubman.log.section('Verified boot %s %s' % (sha_algo, test_type)):
-            output = ubman.run_command_list(
-                ['host load hostfs - 100 %s' % fit,
-                 'fdt addr 100',
-                 'bootm 100'])
-        assert expect_string in ''.join(output)
-        if boots:
-            assert 'sandbox: continuing, as we cannot run' in ''.join(output)
-        else:
-            assert('sandbox: continuing, as we cannot run'
-                   not in ''.join(output))
+
+        with ubman.log.section(f'Verified boot {sha_algo} {test_type}: looking for "{expect_string}"'):
+            output = run_fit_commands(['fdt addr 100', 'bootm 100'], expect_string, fit)
+
+            if boots:
+                assert 'sandbox: continuing, as we cannot run' in output
+            else:
+                assert 'sandbox: continuing, as we cannot run' not in output
 
     def sign_fit(sha_algo, options):
         """Sign the FIT
-- 
2.43.0