test/py: Document required tools/packages

index 829c7efbb2d7..ea4b66a41ccb 100644
@@ -22,12 +22,17 @@ need to implement various "hook" scripts that are called by the test suite at
 the appropriate time.
 
 On Debian or Debian-like distributions, the following packages are required.
-Similar package names should exist in other distributions.
+Some packages are required to execute any test, and others only for specific
+tests. Similar package names should exist in other distributions.
 
 | Package        | Version tested (Ubuntu 14.04) |
 | -------------- | ----------------------------- |
 | python         | 2.7.5-5ubuntu3                |
 | python-pytest  | 2.5.1-1                       |
+| gdisk          | 0.8.8-1ubuntu0.1              |
+| dfu-util       | 0.5-1                         |
+| dtc            | 1.4.0+dfsg-1                  |
+| openssl        | 1.0.1f-1ubuntu2.22            |
 
 The test script supports either:
 

index 65e1d75626cf..e2fc7fd7ef78 100644
@@ -429,12 +429,12 @@ def setup_boardspec(item):
     for board in mark.args:
         if board.startswith('!'):
             if ubconfig.board_type == board[1:]:
-                pytest.skip('board not supported')
+                pytest.skip('board "%s" not supported' % ubconfig.board_type)
                 return
         else:
             required_boards.append(board)
     if required_boards and ubconfig.board_type not in required_boards:
-        pytest.skip('board not supported')
+        pytest.skip('board "%s" not supported' % ubconfig.board_type)
 
 def setup_buildconfigspec(item):
     """Process any 'buildconfigspec' marker for a test.

@@ -455,7 +455,7 @@ def setup_buildconfigspec(item):
         return
     for option in mark.args:
         if not ubconfig.buildconfig.get('config_' + option.lower(), None):
-            pytest.skip('.config feature not enabled')
+            pytest.skip('.config feature "%s" not enabled' % option.lower())
 
 def start_test_section(item):
     anchors[item.name] = log.start_section(item.name)

index e2fc7fd7ef78..6e66a48c15fd 100644
@@ -457,6 +457,34 @@ def setup_buildconfigspec(item):
         if not ubconfig.buildconfig.get('config_' + option.lower(), None):
             pytest.skip('.config feature "%s" not enabled' % option.lower())
 
+def tool_is_in_path(tool):
+    for path in os.environ["PATH"].split(os.pathsep):
+        fn = os.path.join(path, tool)
+        if os.path.isfile(fn) and os.access(fn, os.X_OK):
+            return True
+    return False
+
+def setup_requiredtool(item):
+    """Process any 'requiredtool' marker for a test.
+
+    Such a marker lists some external tool (binary, executable, application)
+    that the test requires. If tests are being executed on a system that
+    doesn't have the required tool, the test is marked to be skipped.
+
+    Args:
+        item: The pytest test item.
+
+    Returns:
+        Nothing.
+    """
+
+    mark = item.get_marker('requiredtool')
+    if not mark:
+        return
+    for tool in mark.args:
+        if not tool_is_in_path(tool):
+            pytest.skip('tool "%s" not in $PATH' % tool)
+
 def start_test_section(item):
     anchors[item.name] = log.start_section(item.name)
 

@@ -476,6 +504,7 @@ def pytest_runtest_setup(item):
     start_test_section(item)
     setup_boardspec(item)
     setup_buildconfigspec(item)
+    setup_requiredtool(item)
 
 def pytest_runtest_protocol(item, nextitem):
     """pytest hook: Called to execute a test.

index fba67d585b9f..8f6877c5c264 100644
@@ -113,6 +113,7 @@ test_sizes_default = (
 first_usb_dev_port = None
 
 @pytest.mark.buildconfigspec('cmd_dfu')
+ at pytest.mark.requiredtool('dfu-util')
 def test_dfu(u_boot_console, env__usb_dev_port, env__dfu_config):
     """Test the "dfu" command; the host system must be able to enumerate a USB
     device when "dfu" is running, various DFU transfers are tested, and the

index 7e6b96dae45a..4b32bb18b8b3 100755
@@ -111,6 +111,7 @@ sb save hostfs 0 %(loadables2_addr)x %(loadables2_out)s %(loadables2_size)x
 
 @pytest.mark.boardspec('sandbox')
 @pytest.mark.buildconfigspec('fit_signature')
+ at pytest.mark.requiredtool('dtc')
 def test_fit(u_boot_console):
     def make_fname(leaf):
         """Make a temporary filename

index e2bbd08e6d42..ec25fbbc5a10 100644
@@ -38,15 +38,14 @@ class GptTestDiskImage(object):
             fd = os.open(self.path, os.O_RDWR | os.O_CREAT)
             os.ftruncate(fd, 4194304)
             os.close(fd)
-            sgdisk = '/sbin/sgdisk'
-            cmd = (sgdisk, '-U', '375a56f7-d6c9-4e81-b5f0-09d41ca89efe',
+            cmd = ('sgdisk', '-U', '375a56f7-d6c9-4e81-b5f0-09d41ca89efe',
                 self.path)
             u_boot_utils.run_and_log(u_boot_console, cmd)
-            cmd = (sgdisk, '--new=1:2048:2560', self.path)
+            cmd = ('sgdisk', '--new=1:2048:2560', self.path)
             u_boot_utils.run_and_log(u_boot_console, cmd)
-            cmd = (sgdisk, '--new=2:4096:4608', self.path)
+            cmd = ('sgdisk', '--new=2:4096:4608', self.path)
             u_boot_utils.run_and_log(u_boot_console, cmd)
-            cmd = (sgdisk, '-l', self.path)
+            cmd = ('sgdisk', '-l', self.path)
             u_boot_utils.run_and_log(u_boot_console, cmd)
 
 gtdi = None

@@ -64,6 +63,7 @@ def state_disk_image(u_boot_console):
 
 @pytest.mark.boardspec('sandbox')
 @pytest.mark.buildconfigspec('cmd_gpt')
+ at pytest.mark.requiredtool('sgdisk')
 def test_gpt_guid(state_disk_image, u_boot_console):
     """Test the gpt guid command."""
 

@@ -73,6 +73,7 @@ def test_gpt_guid(state_disk_image, u_boot_console):
 
 @pytest.mark.boardspec('sandbox')
 @pytest.mark.buildconfigspec('cmd_gpt')
+ at pytest.mark.requiredtool('sgdisk')
 def test_gpt_save_guid(state_disk_image, u_boot_console):
     """Test the gpt guid command to save GUID into a string."""
 

@@ -86,6 +87,7 @@ def test_gpt_save_guid(state_disk_image, u_boot_console):
 @pytest.mark.boardspec('sandbox')
 @pytest.mark.buildconfigspec('cmd_gpt')
 @pytest.mark.buildconfigspec('cmd_gpt_rename')
+ at pytest.mark.requiredtool('sgdisk')
 def test_gpt_rename_partition(state_disk_image, u_boot_console):
     """Test the gpt rename command to write partition names."""
 

@@ -101,6 +103,7 @@ def test_gpt_rename_partition(state_disk_image, u_boot_console):
 @pytest.mark.buildconfigspec('cmd_gpt')
 @pytest.mark.buildconfigspec('cmd_gpt_rename')
 @pytest.mark.buildconfigspec('cmd_part')
+ at pytest.mark.requiredtool('sgdisk')
 def test_gpt_swap_partitions(state_disk_image, u_boot_console):
     """Test the gpt swap command to exchange two partition names."""
 

index 6e62820743fe..c4da79d11407 100644
@@ -31,6 +31,10 @@ import u_boot_utils as util
 
 @pytest.mark.boardspec('sandbox')
 @pytest.mark.buildconfigspec('fit_signature')
+ at pytest.mark.requiredtool('dtc')
+ at pytest.mark.requiredtool('fdtget')
+ at pytest.mark.requiredtool('fdtput')
+ at pytest.mark.requiredtool('openssl')
 def test_vboot(u_boot_console):
     """Test verified boot signing with mkimage and verification with 'bootm'.