fix c3 build

Author: jonasniesner

platformio.ini

@@ -159,8 +159,12 @@ build_flags =
 	${env:esp32-s3-N32R8-extuart.build_flags}
 	-DOPENDISPLAY_ZLIB_WINDOW_BITS=15
 
+; C3/C6 need Arduino-ESP32 3.x / IDF 5 (pioarduino). Stock PlatformIO `espressif32`
+; (Arduino 2.x) does not link mbedtls CMAC (`mbedtls_cipher_cmac_*`) and on C6 also
+; leaves CONFIG_BT_LE_CONTROLLER_NPL_OS_PORTING_SUPPORT on without the controller's
+; r_os_mem* ROM symbols, so NimBLE-Arduino fails at link time.
 [env:esp32-c3-N4]
-platform = espressif32
+platform = https://github.com/pioarduino/platform-espressif32/releases/download/stable/platform-espressif32.zip
 framework = arduino
 build_flags = 
   -DTARGET_ESP32
@@ -174,19 +178,24 @@ board_build.partitions = huge_app.csv
 board = esp32-c3-devkitm-1
 monitor_speed = 115200
 
-; C6 needs Arduino-ESP32 3.x / IDF 5 (pioarduino). Stock PlatformIO `espressif32`
-; leaves CONFIG_BT_LE_CONTROLLER_NPL_OS_PORTING_SUPPORT on without linking the
-; controller's r_os_mem* ROM symbols, so NimBLE-Arduino fails at link time.
 [env:esp32-c6-N4]
 platform = https://github.com/pioarduino/platform-espressif32/releases/download/stable/platform-espressif32.zip
 framework = arduino
-build_flags = 
+build_flags =
   -DTARGET_ESP32
   #-DOPENDISPLAY_ZLIB_WINDOW_BITS=15
   -DOPENDISPLAY_ZLIB_USE_HEAP_WINDOW=1
   -DARDUINO_USB_MODE=1
   -DARDUINO_USB_CDC_ON_BOOT=1
   -DCONFIG_FREERTOS_WATCHDOG_TIMEOUT_S=120
+  ; C6 sdkconfig sets CONFIG_BT_LE_CONTROLLER_NPL_OS_PORTING_SUPPORT, so
+  ; NimBLE-Arduino skips compiling os_mempool and expects r_os_mem* from
+  ; libble_app. Force-pull those objects — a single-pass link on GitHub
+  ; Actions otherwise leaves the refs undefined.
+  -lble_app
+  -Wl,-u,r_os_mempool_init
+  -Wl,-u,r_os_memblock_get
+  -Wl,-u,r_os_memblock_put
 board_build.filesystem = littlefs
 board_build.partitions = huge_app.csv
 board = esp32-c6-devkitm-1
@@ -197,7 +206,7 @@ monitor_speed = 115200
 ; device config. DIO flash mode leaves GPIO12/13 free for general GPIO use
 ; (e.g. a battery-latch MOSFET).
 [env:esp32-c3-N16]
-platform = espressif32
+platform = https://github.com/pioarduino/platform-espressif32/releases/download/stable/platform-espressif32.zip
 framework = arduino
 build_flags =
   -DTARGET_ESP32