Fix broken README links

examples/bluetooth/bluedroid/ble/blufi/README.md

@@ -7,7 +7,7 @@ To test this demo, you need to prepare a mobile phone with blufi application ins
 
 Blufi is completely open source, here is the download link:
 
-* [blufi source code](https://github.com/espressif/esp-idf/tree/master/examples/bluetooth/blufi)
+* [blufi source code](https://github.com/espressif/esp-idf/tree/master/examples/bluetooth/bluedroid/ble/blufi)
 
 * [BluFi protocol](https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/blufi.html?highlight=blufi#the-frame-formats-defined-in-blufi)
 

examples/bluetooth/bluedroid/coex/gattc_gatts_coex/README.md

@@ -5,10 +5,10 @@ This example demonstrates the coexistence of gattc and gatts.
 
 This example creates a GATT service and starts ADV. The ADV name is `ESP_GATTS_DEMO`, then waits to be connected. At the same time, a gatt client is created, the ADV name is `ESP_GATTS_DEMO`, the device is connected, and the data is exchanged. If the device is not found within 120 seconds, the example will stop scanning.
 
-ESP-IDF also allows users to create a GATT service via an attribute table, rather than add attributes one by one. And it is recommended for users to use. For more information about this method, please refer to [gatt_server_service_table_demo](../gatt_server_service_table).
+ESP-IDF also allows users to create a GATT service via an attribute table, rather than add attributes one by one. And it is recommended for users to use. For more information about this method, please refer to [gatt_server_service_table_demo](../../ble/gatt_server_service_table).
 
-To test this example, you can run the [gatt_client_demo](../gatt_client), which can scan for and connect to this example automatically, and run [gatt_server_demo](../gatt_server), Waiting to be connected. They will start exchanging data once the GATT client has enabled the notification function of the GATT server.
+To test this example, you can run the [gatt_client_demo](../../ble/gatt_client), which can scan for and connect to this example automatically, and run [gatt_server_demo](../../ble/gatt_server), Waiting to be connected. They will start exchanging data once the GATT client has enabled the notification function of the GATT server.
 
-Please check the [tutorial](tutorial/Gatt_Server_Example_Walkthrough.md) for more information about the gatts part of this example.
-Please check the [tutorial](tutorial/Gatt_Client_Example_Walkthrough.md) for more information about the gattc part of this example.
+Please check the [tutorial](../../ble/gatt_server/tutorial/Gatt_Server_Example_Walkthrough.md) for more information about the gatts part of this example.
+Please check the [tutorial](../../ble/gatt_client/tutorial/Gatt_Client_Example_Walkthrough.md) for more information about the gattc part of this example.
 

examples/bluetooth/esp_ble_mesh/README.md

@@ -1,6 +1,6 @@
 # ESP-BLE-MESH Examples
 
-[ESP-BLE-MESH]($IDF_PATH/components/bt/esp_ble_mesh/) is the official Bluetooth® Mesh stack of Espressif Systems. We will provide long-term support for new features, performance optimization, etc.
+[ESP-BLE-MESH](../../../components/bt/esp_ble_mesh/) is the official Bluetooth® Mesh stack of Espressif Systems. We will provide long-term support for new features, performance optimization, etc.
 
 Please help note that breaking changes may be introduced into ESP-BLE-MESH on [minor IDF versions](https://docs.espressif.com/projects/esp-idf/en/latest/versions.html).
 

examples/protocols/pppos_client/README.md

@@ -14,7 +14,7 @@ When PPP connection has been established, the IP packet flow from application si
 ### Hardware Required
 
 To run this example, you need an ESP32 dev board (e.g. ESP32-WROVER Kit) or ESP32 core board (e.g. ESP32-DevKitC).
-For test purpose, you also need a cellular modem module. Here we take the [SIM800L](http://www.simcom.com/product/showproduct.php?lang=en&id=277) and [BG96](https://www.quectel.com/product/bg96.htm) as an example.
+For test purpose, you also need a cellular modem module. Here we take the [SIM800L](https://www.simcom.com/product/SIM800.html) and [BG96](https://www.quectel.com/product/bg96.htm) as an example.
 You can also try other modules as long as they embedded PPP protocol.
 
 **Note:** Since SIM800L only support **2G** which will **not** work in some countries. And also keep in mind that in some other countries it will stop working soon (many remaining 2G networks will be switched off in the next 2-3 years). So you should **check with your local providers for further details** if you try this example with any 2G modules.

examples/system/app_trace_to_host/README.md

@@ -176,7 +176,7 @@ This is the log we have been looking for, complete with timestamps as if printed
 
 ## Example Output
 
-Check the full example code [app_trace_to_host](main/app_trace_to_host_test.c) that combines both tests above and runs them in a loop showing instantly the number of samples collected:
+Check the full example code [app_trace_to_host](main/app_trace_to_host_example_main.c) that combines both tests above and runs them in a loop showing instantly the number of samples collected:
 
 ```
 I (4289) example: Sampling ADC and sending data to the host...

examples/system/ota/otatool/README.md

@@ -1,6 +1,6 @@
 # OTA Tool Example
 
-This example demonstrates common operations the OTA tool [otatool.py](../../../components/app_update/otatool.py) allows the user to perform:
+This example demonstrates common operations the OTA tool [otatool.py](../../../../components/app_update/otatool.py) allows the user to perform:
 
 - reading, writing and erasing OTA partitions,
 - switching boot partitions, and