west: runners: jlink: prefer .hex over .bin

Update the jlink runner to prefer flashing .hex files instead of .bin.
This can increase programming speed in cases where there are large
amounts of padding in an application.

Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>

scripts/west_commands/runners/jlink.py

@@ -35,6 +35,7 @@ class JLinkBinaryRunner(ZephyrBinaryRunner):
                  gdbserver='JLinkGDBServer', gdb_port=DEFAULT_JLINK_GDB_PORT,
                  tui=False, tool_opt=[]):
         super().__init__(cfg)
+        self.hex_name = cfg.hex_file
         self.bin_name = cfg.bin_file
         self.elf_name = cfg.elf_file
         self.gdb_cmd = [cfg.gdb] if cfg.gdb else None
@@ -179,15 +180,26 @@ class JLinkBinaryRunner(ZephyrBinaryRunner):
 
     def flash(self, **kwargs):
         self.require(self.commander)
-        self.ensure_output('bin')
 
         lines = ['r'] # Reset and halt the target
 
         if self.erase:
             lines.append('erase') # Erase all flash sectors
 
-        lines.append('loadfile {} 0x{:x}'.format(self.bin_name,
-                                                 self.flash_addr))
+        # Get the build artifact to flash, prefering .hex over .bin
+        if self.hex_name is not None and os.path.isfile(self.hex_name):
+            flash_file = self.hex_name
+            flash_fmt = 'loadfile {}'
+        elif self.bin_name is not None and os.path.isfile(self.bin_name):
+            flash_file = self.bin_name
+            flash_fmt = 'loadfile {} 0x{:x}'
+        else:
+            err = 'Cannot flash; no hex ({}) or bin ({}) files found.'
+            raise ValueError(err.format(self.hex_name, self.bin_name))
+
+        # Flash the selected build artifact
+        lines.append(flash_fmt.format(flash_file, self.flash_addr))
+
         if self.reset_after_load:
             lines.append('r') # Reset and halt the target
 
@@ -226,5 +238,5 @@ class JLinkBinaryRunner(ZephyrBinaryRunner):
                     '-CommanderScript', fname] +
                    self.tool_opt)
 
-            self.logger.info('Flashing file: {}'.format(self.bin_name))
+            self.logger.info('Flashing file: {}'.format(flash_file))
             self.check_call(cmd)