Reduce size to zero-out

Most tools will use a 1MiB offset for the first partition

scripts/wk/kit/ufd.py

@@ -123,7 +123,7 @@ def build_ufd() -> None:
   if not args['--update']:
     ui.print_info('Prep UFD')
     try_print.run(
-      message='Zeroing first 64MiB...',
+      message='Zeroing first 1MiB...',
       function=zero_device,
       dev_path=ufd_dev,
       )
@@ -671,12 +671,12 @@ def verify_ufd(dev_path) -> pathlib.Path:
 
 
 def zero_device(dev_path) -> None:
-  """Zero-out first 64MB of device."""
+  """Zero-out first 1MB of device."""
   cmd = [
     'sudo',
     'dd',
-    'bs=4M',
-    'count=16',
+    'bs=1M',
+    'count=1',
     'if=/dev/zero',
     f'of={dev_path}',
     ]