device: dynamic device handles were declared as const

When CONFIG_HAS_DYNAMIC_DEVICE_HANDLES is selected, devices handles are
placed in RAM region so that they can be modified at runtime. However,
the gen_handles.py script added the `const` attribute to the device
handle arrays regardless of this setting, leading to faults when running
the application. This may be an indicator that this feature is not
actively used.

Signed-off-by: Gerard Marull-Paretas <[email protected]>

Author: gmarull

CMakeLists.txt

@@ -897,6 +897,10 @@ zephyr_get_include_directories_for_lang(C
   )
 
 if(CONFIG_HAS_DTS)
+  if(CONFIG_HAS_DYNAMIC_DEVICE_HANDLES)
+    set(dynamic_handles --dynamic-handles)
+  endif()
+
   if(CONFIG_PM_DEVICE_POWER_DOMAIN_DYNAMIC)
     set(number_of_dynamic_devices ${CONFIG_PM_DEVICE_POWER_DOMAIN_DYNAMIC_NUM})
   else()
@@ -912,6 +916,7 @@ if(CONFIG_HAS_DTS)
     ${ZEPHYR_BASE}/scripts/build/gen_handles.py
     --output-source dev_handles.c
     --output-graphviz dev_graph.dot
+    ${dynamic_handles}
     --num-dynamic-devices ${number_of_dynamic_devices}
     --kernel $<TARGET_FILE:${ZEPHYR_LINK_STAGE_EXECUTABLE}>
     --zephyr-base ${ZEPHYR_BASE}

scripts/build/gen_handles.py

@@ -46,6 +46,8 @@ def parse_args():
 
     parser.add_argument("-k", "--kernel", required=True,
                         help="Input zephyr ELF binary")
+    parser.add_argument("--dynamic-handles", action="store_true",
+                        help="Indicates if device handles are dynamic")
     parser.add_argument("-d", "--num-dynamic-devices", required=False, default=0,
                         type=int, help="Input number of dynamic devices allowed")
     parser.add_argument("-o", "--output-source", required=True,
@@ -93,7 +95,7 @@ def dev_path_str(dev):
     lines.append(' */')
     return lines
 
-def c_handle_array(dev, handles, extra_support_handles=0):
+def c_handle_array(dev, handles, dynamic_handles, extra_support_handles=0):
     handles = [
         *[str(d.handle) for d in handles["depends"]],
         'DEVICE_HANDLE_SEP',
@@ -103,7 +105,10 @@ def c_handle_array(dev, handles, extra_support_handles=0):
         *(extra_support_handles * ['DEVICE_HANDLE_NULL']),
         'DEVICE_HANDLE_ENDS',
     ]
-    ctype = 'const Z_DECL_ALIGN(device_handle_t) __attribute__((__section__(".__device_handles_pass2")))'
+    ctype = (
+        '{:s}Z_DECL_ALIGN(device_handle_t) '
+        '__attribute__((__section__(".__device_handles_pass2")))'
+    ).format('const ' if not dynamic_handles else '')
     return [
         # The `extern` line pretends this was first declared in some .h
         # file to silence "should it be static?" warnings in some
@@ -153,7 +158,9 @@ def main():
             }
             extra_sups = args.num_dynamic_devices if dev.pm and dev.pm.is_power_domain else 0
             lines = c_handle_comment(dev, sorted_handles)
-            lines.extend(c_handle_array(dev, sorted_handles, extra_sups))
+            lines.extend(
+                c_handle_array(dev, sorted_handles, args.dynamic_handles, extra_sups)
+            )
             lines.extend([''])
             fp.write('\n'.join(lines))