Pico 2 W OTA Update Example (#559)

* Initial commit of OTA update example

* Speedup and add hashing

* Tidy up

* Tidy up and use pico_use_partition_firmware function

* Little extra fixes

* Remove bootrom structs dependency

* Update to work with latest SDK version

* Move private.pem back to separate directories

* Fix Risc-V alignment & stack issues

* Increase partition sizes

* Improve poll performance

* Use CYW43_FIRMWARE_FAMILY_ID

* Add example to readme

* Remove poll version

* Add separate README, move the python script, and add note about no_flash commented out lines

* firmware -> wifi_firmware

* tweak cmake guard

* oops

* add comment

---------

Co-authored-by: Graham Sanderson <[email protected]>
Co-authored-by: Graham Sanderson <[email protected]>

Author: will-v-pi

README.md

@@ -210,6 +210,7 @@ App|Description
 [picow_http_client](pico_w/wifi/http_client) | Demonstrates how to make http and https requests
 [picow_http_client_verify](pico_w/wifi/http_client) | Demonstrates how to make a https request with server authentication
 [picow_mqtt_client](pico_w/wifi/mqtt) | Demonstrates how to implement a MQTT client application
+[picow_ota_update](pico_w/wifi/ota_update) | A minimal OTA update server (RP235x Only). See the separate [README](pico_w/wifi/ota_update/README.md) for more details.
 
 #### FreeRTOS examples
 

pico_w/wifi/CMakeLists.txt

@@ -20,9 +20,11 @@ else()
     add_subdirectory_exclude_platforms(http_client)
     add_subdirectory_exclude_platforms(mqtt)
 
-    if (NOT PICO_MBEDTLS_PATH)
-        message("Skipping tls examples as PICO_MBEDTLS_PATH is not defined")
+    if (NOT TARGET pico_mbedtls)
+        message("Skipping tls_client and ota_update examples as Mbed TLS is not available")
     else()
         add_subdirectory_exclude_platforms(tls_client)
+        # note ota_update doesn't use Mbed TLS, but it requires picotool with Mbed TLS, so the above check is a good proxy
+        add_subdirectory_exclude_platforms(ota_update rp2040)
     endif()
 endif()

pico_w/wifi/ota_update/CMakeLists.txt

@@ -0,0 +1,33 @@
+add_executable(picow_ota_update
+        picow_ota_update.c
+        )
+target_compile_definitions(picow_ota_update PRIVATE
+        WIFI_SSID=\"${WIFI_SSID}\"
+        WIFI_PASSWORD=\"${WIFI_PASSWORD}\"
+        PICO_CRT0_IMAGE_TYPE_TBYB=1
+        )
+target_include_directories(picow_ota_update PRIVATE
+        ${CMAKE_CURRENT_LIST_DIR}
+        ${CMAKE_CURRENT_LIST_DIR}/.. # for our common lwipopts
+        )
+target_link_libraries(picow_ota_update
+        pico_cyw43_arch_lwip_threadsafe_background
+        pico_stdlib
+        pico_sha256
+        boot_uf2_headers
+        )
+
+pico_use_wifi_firmware_partition(picow_ota_update)
+
+pico_hash_binary(picow_ota_update)
+pico_sign_binary(picow_ota_update ${CMAKE_CURRENT_LIST_DIR}/private.pem)
+
+# By default this example requires a partition table in flash, and will
+# update the partition that is not currently in use. To use it without
+# a partition table in flash, uncomment the following lines to make it
+# a no_flash binary, so it can update the currently running program.
+
+# pico_set_binary_type(picow_ota_update no_flash)
+# pico_package_uf2_output(picow_ota_update 0x10000000)
+
+pico_add_extra_outputs(picow_ota_update)

pico_w/wifi/ota_update/README.md

@@ -0,0 +1,20 @@
+This example requires a partition table in flash. This can be loaded by creating a UF2 from the partition table JSON in this folder:
+```
+picotool partition create main.json pt.uf2
+```
+then dragging & dropping this UF2 onto the device, or loading it using `picotool` and rebooting:
+```
+picotool load pt.uf2
+picotool reboot -u
+```
+
+Once the partition table is loaded, you first need to load the Wi-Fi firmware UF2 (`picow_ota_update_wifi_firmware.uf2`) followed by loading & executing the main program (`picow_ota_update.uf2`) - either by dragging and dropping them in order, or using `picotool`:
+```
+picotool load picow_ota_update_wifi_firmware.uf2
+picotool load -x picow_ota_update.uf2
+```
+
+Once running, you can use [python_ota_update.py](python_ota_update.py) to upload new UF2s to it using it's IP address:
+```
+python python_ota_update.py 192.168.0.103 picow_ota_update.uf2
+```

pico_w/wifi/ota_update/lwipopts.h

@@ -0,0 +1,10 @@
+#ifndef _LWIPOPTS_H
+#define _LWIPOPTS_H
+
+// Generally you would define your own explicit list of lwIP options
+// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html)
+//
+// This example uses a common include to avoid repetition
+#include "lwipopts_examples_common.h"
+
+#endif

pico_w/wifi/ota_update/main.json

@@ -0,0 +1,64 @@
+{
+  "version": [1, 0],
+  "unpartitioned": {
+    "families": ["absolute"],
+    "permissions": {
+      "secure": "rw",
+      "nonsecure": "rw",
+      "bootloader": "rw"
+    }
+  },
+  "partitions": [
+    {
+      "name": "Main A",
+      "id": 0,
+      "size": "1744K",
+      "families": ["rp2350-arm-s", "rp2350-riscv"],
+      "permissions": {
+        "secure": "rw",
+        "nonsecure": "rw",
+        "bootloader": "rw"
+      }
+    },
+    {
+      "name": "Main B",
+      "id": 0,
+      "size": "1744K",
+      "families": ["rp2350-arm-s", "rp2350-riscv"],
+      "permissions": {
+        "secure": "rw",
+        "nonsecure": "rw",
+        "bootloader": "rw"
+      },
+      "link": ["a", 0]
+    },
+    {
+      "name": "Firmware A",
+      "id": "0x776966696669726d",
+      "start": "3500k",
+      "size": "256K",
+      "families": ["cyw43-firmware"],
+      "permissions": {
+        "secure": "rw",
+        "nonsecure": "rw",
+        "bootloader": "rw"
+      },
+      "ignored_during_riscv_boot": true,
+      "no_reboot_on_uf2_download": true
+    },
+    {
+      "name": "Firmware B",
+      "id": 12345,
+      "size": "256K",
+      "families": ["cyw43-firmware"],
+      "permissions": {
+        "secure": "rw",
+        "nonsecure": "rw",
+        "bootloader": "rw"
+      },
+      "link": ["a", 2],
+      "ignored_during_riscv_boot": true,
+      "no_reboot_on_uf2_download": true
+    }
+  ]
+}