[ext] Add local config inclusion for FreeRTOS

ext/aws/FreeRTOSConfig.h.in

@@ -141,7 +141,10 @@ standard names. */
 #define vPortSVCHandler SVC_Handler
 #define xPortSysTickHandler SysTick_Handler
 
-/* A header file that defines trace macro can be included here. */
+/* A header file that overwrites with local project settings. */
+#if __has_include(<FreeRTOSConfigLocal.h>)
+#include <FreeRTOSConfigLocal.h>
+#endif
 
 #endif /* FREERTOS_CONFIG_H */
 

ext/aws/FreeRTOSIPConfig.h.in

@@ -305,4 +305,9 @@ disconnecting stage will timeout after a period of non-activity. */
 #define ipconfigZERO_COPY_TX_DRIVER                   1
 #define ipconfigUSE_LINKED_RX_MESSAGES                1
 
+/* A header file that overwrites with local project settings. */
+#if __has_include(<FreeRTOSIPConfigLocal.h>)
+#include <FreeRTOSIPConfigLocal.h>
+#endif
+
 #endif // FREERTOS_IP_CONFIG_H

ext/aws/module.lb

@@ -14,7 +14,19 @@
 class FreeRTOS_TCP(Module):
     def init(self, module):
         module.name = "tcp"
-        module.description = "FreeRTOS-Plus-TCP"
+        module.description = """
+# a:FreeRTOS-Plus-TCP
+
+This module defines a default FreeRTOS IP config. If you need to change a
+configuration setting, then you can define a `FreeRTOSConfigIPLocal.h` file, which
+is included *after* at the end of the config. You must therefore first `#undef`
+the config macros, then redefine them with your options, for example:
+
+```c
+#undef ipconfigUSE_DNS
+#define ipconfigUSE_DNS 1
+```
+"""
 
     def prepare(self, module, options):
         return True
@@ -33,6 +45,18 @@ def init(module):
 # a:FreeRTOS
 
 Amazon FreeRTOS port for modm to be used with via the `modm:processing:rtos` module.
+
+## Custom Configuration
+
+This module defines a default FreeRTOS config. If you need to change a
+configuration setting, then you can define a `FreeRTOSConfigLocal.h` file, which
+is included *after* at the end of the config. You must therefore first `#undef`
+the config macros, then redefine them with your options, for example:
+
+```c
+#undef configCHECK_FOR_STACK_OVERFLOW
+#define configCHECK_FOR_STACK_OVERFLOW 0
+```
 """
 
 def prepare(module, options):