binman: Use an exit code when blobs are missing

At present binman returns success when told to handle missing/faked blobs
or missing bintools. This is confusing since in fact the resulting image
cannot work.

Use exit code 103 to signal this problem, with a -W option to convert
it to a warning.

Rename the flag to --ignore-missing since it controls bintools also.

Add documentation about exit codes while we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/binman/binman.rst

@@ -1461,6 +1461,10 @@ space-separated list of directories to search for binary blobs::
        odroid-c4/build/board/hardkernel/odroidc4/firmware \
        odroid-c4/build/scp_task" binman ...
 
+Note that binman fails with exit code 103 when there are missing blobs. If you
+wish binman to continue anyway, you can pass `-W` to binman.
+
+
 Code coverage
 -------------
 
@@ -1472,6 +1476,24 @@ To enable Python test coverage on Debian-type distributions (e.g. Ubuntu)::
    $ sudo apt-get install python-coverage python3-coverage python-pytest
 
 
+Exit status
+-----------
+
+Binman produces the following exit codes:
+
+0
+    Success
+
+1
+    Any sort of failure - see output for more details
+
+103
+    There are missing external blobs or bintools. This is only returned if
+    -M is passed to binman, otherwise missing blobs return an exit status of 1.
+    Note, if -W is passed as well as -M, then this is converted into a warning
+    and will return an exit status of 0 instead.
+
+
 Error messages
 --------------
 

tools/binman/cmdline.py

@@ -114,7 +114,7 @@ controlled by a description in the board device tree.'''
     build_parser.add_argument('-m', '--map', action='store_true',
         default=False, help='Output a map file for each image')
     build_parser.add_argument('-M', '--allow-missing', action='store_true',
-        default=False, help='Allow external blobs to be missing')
+        default=False, help='Allow external blobs and bintools to be missing')
     build_parser.add_argument('-n', '--no-expanded', action='store_true',
             help="Don't use 'expanded' versions of entries where available; "
                  "normally 'u-boot' becomes 'u-boot-expanded', for example")
@@ -128,6 +128,9 @@ controlled by a description in the board device tree.'''
         default=False, help='Update the binman node with offset/size info')
     build_parser.add_argument('--update-fdt-in-elf', type=str,
         help='Update an ELF file with the output dtb: infile,outfile,begin_sym,end_sym')
+    build_parser.add_argument(
+        '-W', '--ignore-missing', action='store_true', default=False,
+        help='Return success even if there are missing blobs/bintools (requires -M)')
 
     subparsers.add_parser(
         'bintool-docs', help='Write out bintool documentation (see bintool.rst)')

tools/binman/control.py

@@ -741,8 +741,15 @@ def Binman(args):
                 data = state.GetFdtForEtype('u-boot-dtb').GetContents()
                 elf.UpdateFile(*elf_params, data)
 
+            # This can only be True if -M is provided, since otherwise binman
+            # would have raised an error already
             if invalid:
-                tout.warning("\nSome images are invalid")
+                msg = '\nSome images are invalid'
+                if args.ignore_missing:
+                    tout.warning(msg)
+                else:
+                    tout.error(msg)
+                    return 103
 
             # Use this to debug the time take to pack the image
             #state.TimingShow()

tools/binman/ftest.py

@@ -340,7 +340,7 @@ class TestFunctional(unittest.TestCase):
                     use_expanded=False, verbosity=None, allow_missing=False,
                     allow_fake_blobs=False, extra_indirs=None, threads=None,
                     test_section_timeout=False, update_fdt_in_elf=None,
-                    force_missing_bintools=''):
+                    force_missing_bintools='', ignore_missing=False):
         """Run binman with a given test file
 
         Args:
@@ -403,6 +403,8 @@ class TestFunctional(unittest.TestCase):
                 args.append('-a%s=%s' % (arg, value))
         if allow_missing:
             args.append('-M')
+            if ignore_missing:
+                args.append('-W')
         if allow_fake_blobs:
             args.append('--fake-ext-blobs')
         if force_missing_bintools:
@@ -3725,9 +3727,22 @@ class TestFunctional(unittest.TestCase):
     def testExtblobMissingOk(self):
         """Test an image with an missing external blob that is allowed"""
         with test_util.capture_sys_output() as (stdout, stderr):
-            self._DoTestFile('158_blob_ext_missing.dts', allow_missing=True)
+            ret = self._DoTestFile('158_blob_ext_missing.dts',
+                                   allow_missing=True)
+        self.assertEqual(103, ret)
         err = stderr.getvalue()
         self.assertRegex(err, "Image 'main-section'.*missing.*: blob-ext")
+        self.assertIn('Some images are invalid', err)
+
+    def testExtblobMissingOkFlag(self):
+        """Test an image with an missing external blob allowed with -W"""
+        with test_util.capture_sys_output() as (stdout, stderr):
+            ret = self._DoTestFile('158_blob_ext_missing.dts',
+                                   allow_missing=True, ignore_missing=True)
+        self.assertEqual(0, ret)
+        err = stderr.getvalue()
+        self.assertRegex(err, "Image 'main-section'.*missing.*: blob-ext")
+        self.assertIn('Some images are invalid', err)
 
     def testExtblobMissingOkSect(self):
         """Test an image with an missing external blob that is allowed"""