runners: bossac: calculate the offset instead of absolute address

BOSSA takes the offset within flash memory, not the absolute address.
This doesn't matter on most boards as the flash starts at zero but
does matter on the Due as the flash starts at +512 KiB.

Signed-off-by: Michael Hope <mlhx@google.com>

scripts/west_commands/runners/bossac.py

@@ -17,12 +17,11 @@ class BossacBinaryRunner(ZephyrBinaryRunner):
     '''Runner front-end for bossac.'''
 
     def __init__(self, cfg, bossac='bossac', port=DEFAULT_BOSSAC_PORT,
-                 offset=None, flash_address=None):
+                 offset=None):
         super().__init__(cfg)
         self.bossac = bossac
         self.port = port
         self.offset = offset
-        self.flash_address = flash_address
 
     @classmethod
     def name(cls):
@@ -44,15 +43,22 @@ class BossacBinaryRunner(ZephyrBinaryRunner):
                             help='serial port to use, default is /dev/ttyACM0')
 
     @classmethod
-    def do_create(cls, cfg, args):
-        # BOSSA means there's a bootloader so always fetch the flash address
-        args.dt_flash = True
+    def get_flash_offset(cls, cfg):
+        # Pull the bootloader size from the config
         build_conf = BuildConfiguration(cfg.build_dir)
-        flash_address = cls.get_flash_address(args, build_conf, None)
+        if build_conf['CONFIG_HAS_FLASH_LOAD_OFFSET']:
+            return build_conf['CONFIG_FLASH_LOAD_OFFSET']
+
+        return None
+
+    @classmethod
+    def do_create(cls, cfg, args):
+        offset = args.offset
 
+        if offset is None:
+            offset = cls.get_flash_offset(cfg)
         return BossacBinaryRunner(cfg, bossac=args.bossac,
-                                  port=args.bossac_port, offset=args.offset,
-                                  flash_address=flash_address)
+                                  port=args.bossac_port, offset=offset)
 
     def read_help(self):
         """Run bossac --help and return the output as a list of lines"""
@@ -75,8 +81,6 @@ class BossacBinaryRunner(ZephyrBinaryRunner):
         if supports_offset:
             if self.offset is not None:
                 return self.offset
-            if self.flash_address is not None:
-                return self.flash_address
 
             self.logger.warning(
                 'This version of BOSSA supports the --offset flag but' +
@@ -113,7 +117,7 @@ class BossacBinaryRunner(ZephyrBinaryRunner):
 
         offset = self.get_offset(self.supports('--offset'))
 
-        if offset is not None:
+        if offset:
             cmd_flash += ['-o', '%s' % offset]
 
         self.check_call(cmd_flash)

scripts/west_commands/tests/test_bossac.py

@@ -69,7 +69,7 @@ def test_bossac_init(cc, req, supports, runner_config):
 
 @patch('runners.bossac.BossacBinaryRunner.supports', return_value=True)
 @patch('runners.core.BuildConfiguration._init')
-@patch('runners.core.ZephyrBinaryRunner.get_flash_address',
+@patch('runners.bossac.BossacBinaryRunner.get_flash_offset',
        return_value=None)
 @patch('runners.core.ZephyrBinaryRunner.require', side_effect=require_patch)
 @patch('runners.core.ZephyrBinaryRunner.check_call')
@@ -86,7 +86,7 @@ def test_bossac_create(cc, req, gfa, bcfg, supports, runner_config):
 
 @patch('runners.bossac.BossacBinaryRunner.supports', return_value=True)
 @patch('runners.core.BuildConfiguration._init')
-@patch('runners.core.ZephyrBinaryRunner.get_flash_address',
+@patch('runners.bossac.BossacBinaryRunner.get_flash_offset',
        return_value=TEST_FLASH_ADDRESS)
 @patch('runners.core.ZephyrBinaryRunner.require', side_effect=require_patch)
 @patch('runners.core.ZephyrBinaryRunner.check_call')
@@ -105,7 +105,7 @@ def test_bossac_create_with_offset(cc, req, gfa, bcfg, supports,
 
 @patch('runners.bossac.BossacBinaryRunner.supports', return_value=True)
 @patch('runners.core.BuildConfiguration._init')
-@patch('runners.core.ZephyrBinaryRunner.get_flash_address',
+@patch('runners.bossac.BossacBinaryRunner.get_flash_offset',
        return_value=TEST_FLASH_ADDRESS)
 @patch('runners.core.ZephyrBinaryRunner.require', side_effect=require_patch)
 @patch('runners.core.ZephyrBinaryRunner.check_call')