diff --git a/components/esp_gdbstub/esp32c3/gdbstub_esp32c3.c b/components/esp_gdbstub/esp32c3/gdbstub_esp32c3.c
index 102cb322b5..53f98e1fd9 100644
--- a/components/esp_gdbstub/esp32c3/gdbstub_esp32c3.c
+++ b/components/esp_gdbstub/esp32c3/gdbstub_esp32c3.c
@@ -1,16 +1,9 @@
-// Copyright 2015-2020 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+/*
+ * SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 
 #include "soc/uart_periph.h"
 #include "soc/gpio_periph.h"
@@ -122,3 +115,26 @@ int esp_gdbstub_readmem(intptr_t addr)
     uint32_t shift = (addr & 3) * 8;
     return (val_aligned >> shift) & 0xff;
 }
+
+int esp_gdbstub_writemem(unsigned int addr, unsigned char data)
+{
+    if (!check_inside_valid_region(addr)) {
+        /* see esp_cpu_configure_region_protection */
+        return -1;
+    }
+
+    int *i = (int *)(addr & (~3));
+    if ((addr & 3) == 0) {
+        *i = (*i & 0xffffff00) | (data << 0);
+    }
+    if ((addr & 3) == 1) {
+        *i = (*i & 0xffff00ff) | (data << 8);
+    }
+    if ((addr & 3) == 2) {
+        *i = (*i & 0xff00ffff) | (data << 16);
+    }
+    if ((addr & 3) == 3) {
+        *i = (*i & 0x00ffffff) | (data << 24);
+    }
+    return 0;
+}
diff --git a/tools/test_apps/system/panic/README.md b/tools/test_apps/system/panic/README.md
index ac8bb22c88..d926dfa770 100644
--- a/tools/test_apps/system/panic/README.md
+++ b/tools/test_apps/system/panic/README.md
@@ -1,2 +1,27 @@
-| Supported Targets | ESP32 | ESP32-S2 |
-| ----------------- | ----- | -------- |
+| Supported Targets | ESP32 | ESP32-S2 | ESP32-S3 | ESP32-C3 |
+| ----------------- | ----- | -------- | -------- | -------- |
+
+# Building
+Several configurations are provided as `sdkconfig.ci.XXX` and serve as a template. 
+
+## Example with configuration "panic" for target ESP32
+```
+idf.py set-target esp32
+cat sdkconfig.defaults sdkconfig.ci.panic > sdkconfig
+idf.py build
+```
+
+# Running
+All the setup needs to be done as described in the [test apps README](../../README.md), except that the test cases need to be specified when running the app:
+
+```
+python app_test.py test_panic_illegal_instruction
+```
+
+Multiple test cases are passed as additional arguments:
+
+```
+python app_test.py test_panic_illegal_instruction test_panic_int_wdt test_panic_storeprohibited
+``` 
+
+*Note that you need to pick the correct test cases at run time according to the configuration you built before. The above examples are for configuration "panic"*