Allow using Segger RTT as debug output (EdgeTX#3052)

Firmware needs to be built with -DDEBUG=YES and -DDEBUG_SEGGER_RTT=YES to use this feature.

.gitmodules

@@ -11,3 +11,6 @@
 	path = radio/src/thirdparty/FreeRTOS
 	url = https://github.com/FreeRTOS/FreeRTOS-Kernel.git
 	shallow = true
+[submodule "radio/src/thirdparty/Segger_RTT"]
+	path = radio/src/thirdparty/Segger_RTT
+	url = https://github.com/adfernandes/segger-rtt.git

radio/src/CMakeLists.txt

@@ -44,6 +44,7 @@ option(RAS "RAS (SWR) enabled" ON)
 option(TEMPLATES "Model templates menu" OFF)
 option(TRACE_SIMPGMSPACE "Turn on traces in simpgmspace.cpp" ON)
 option(TRACE_LUA_INTERNALS "Turn on traces for Lua internals" OFF)
+option(DEBUG_SEGGER_RTT "Debug output to Segger RTT" OFF)
 option(DEBUG_WINDOWS "Turn on windows traces" OFF)
 option(DEBUG_YAML "Turn on YAML traces" OFF)
 option(DEBUG_LABELS "Turn on Labels traces" OFF)
@@ -365,6 +366,11 @@ if(TRACE_LUA_INTERNALS)
   add_definitions(-DTRACE_LUA_INTERNALS_ENABLED)
 endif()
 
+if(DEBUG_SEGGER_RTT)
+    add_definitions(-DDEBUG_SEGGER_RTT)
+    set(SRC ${SRC} ${THIRDPARTY_DIR}/Segger_RTT/RTT/SEGGER_RTT.c)
+endif()
+
 if(DEBUG_WINDOWS)
   add_definitions(-DDEBUG_WINDOWS)
 endif()
@@ -520,7 +526,7 @@ if(NATIVE_BUILD)
   target_compile_options(radiolib_native PUBLIC -DSIMU)
   add_dependencies(radiolib_native ${RADIO_DEPENDENCIES})
   set_property(TARGET radiolib_native PROPERTY POSITION_INDEPENDENT_CODE ON)
-  
+
   add_subdirectory(targets/simu)
   add_subdirectory(tests)
 endif()

radio/src/debug.cpp

@@ -139,7 +139,7 @@ void dumpTraceBuffer()
     " notd",  // INT_OTG_FS_RX_NOT_DEVICE,
 #endif // #if defined(DEBUG_USB_INTERRUPTS)
   };
-#elif defined(PCBTARANIS) 
+#elif defined(PCBTARANIS)
   const char * const interruptNames[INT_LAST] = {
     "Tick ",   // INT_TICK,
     "5ms  ",   // INT_5MS,
@@ -201,7 +201,7 @@ void DebugTimer::stop()
   else {
     last *= 10000ul; //adjust unit to 1us
   }
-  evalStats(); 
+  evalStats();
 }
 
 DebugTimer debugTimers[DEBUG_TIMERS_COUNT];

radio/src/serial.cpp

@@ -45,6 +45,10 @@
   #include "extmodule_serial_driver.h"
 #endif
 
+#if defined(DEBUG_SEGGER_RTT)
+  #include "thirdparty/Segger_RTT/RTT/SEGGER_RTT.h"
+#endif
+
 #define PRINTF_BUFFER_SIZE    128
 
 static void (*dbg_serial_putc)(void*, uint8_t) = nullptr;
@@ -67,6 +71,33 @@ void dbgSerialSetSendCb(void* ctx, void (*cb)(void*, uint8_t))
   dbg_serial_putc = cb;
 }
 
+#if defined(DEBUG_SEGGER_RTT)
+
+extern "C" void dbgSerialPutc(char c)
+{
+  SEGGER_RTT_Write(0, (const void *)&c, 1);
+}
+
+extern "C" void dbgSerialPrintf(const char * format, ...)
+{
+  va_list arglist;
+  char tmp[PRINTF_BUFFER_SIZE+1];
+
+  // no need to do anything if we don't have an output
+  if (!dbg_serial_putc) return;
+
+  va_start(arglist, format);
+  vsnprintf(tmp, PRINTF_BUFFER_SIZE, format, arglist);
+  tmp[PRINTF_BUFFER_SIZE] = '\0';
+  va_end(arglist);
+
+  const char *t = tmp;
+  while (*t && dbg_serial_putc) {
+    SEGGER_RTT_Write(0, (const void *)t++, 1);
+  }
+}
+#else
+
 extern "C" void dbgSerialPutc(char c)
 {
   auto _putc = dbg_serial_putc;
@@ -81,7 +112,7 @@ extern "C" void dbgSerialPrintf(const char * format, ...)
 
   // no need to do anything if we don't have an output
   if (!dbg_serial_putc) return;
-  
+
   va_start(arglist, format);
   vsnprintf(tmp, PRINTF_BUFFER_SIZE, format, arglist);
   tmp[PRINTF_BUFFER_SIZE] = '\0';
@@ -92,6 +123,7 @@ extern "C" void dbgSerialPrintf(const char * format, ...)
     dbg_serial_putc(dbg_serial_ctx, *t++);
   }
 }
+#endif
 
 extern "C" void dbgSerialCrlf()
 {
@@ -157,7 +189,7 @@ static void serialSetCallBacks(int mode, void* ctx, const etx_serial_port_t* por
       getByte = drv->getByte;
       setRxCb = drv->setReceiveCb;
     }
-  }  
+  }
 
   // prevent compiler warnings
   (void)sendByte;
@@ -228,7 +260,7 @@ static void serialSetCallBacks(int mode, void* ctx, const etx_serial_port_t* por
     extmoduleSetSerialPort(drv);
     break;
 #endif
-    
+
 #endif
   }
 }
@@ -392,7 +424,7 @@ void serialInit(uint8_t port_nr, int mode)
 void initSerialPorts()
 {
   memset(serialPortStates, 0, sizeof(serialPortStates));
-  
+
   for (uint8_t port_nr = 0; port_nr < MAX_AUX_SERIAL; port_nr++) {
     auto mode = getSerialPortMode(port_nr);
     serialInit(port_nr, mode);

radio/src/targets/common/arm/stm32/bootloader/CMakeLists.txt

@@ -54,6 +54,13 @@ if(BLUETOOTH)
     )
 endif()
 
+if(DEBUG_SEGGER_RTT)
+  set(BOOTLOADER_SRC
+  ${BOOTLOADER_SRC}
+  ../../../../../thirdparty/Segger_RTT/RTT/SEGGER_RTT.c
+  )
+endif()
+
 
 if(PCB STREQUAL X10 OR PCB STREQUAL X12S OR PCB STREQUAL NV14)
   set(BOOTLOADER_SRC
@@ -73,7 +80,7 @@ if(PCB STREQUAL X10 OR PCB STREQUAL X12S OR PCB STREQUAL NV14)
   foreach(LVGL_FILE ${LVGL_SRC_FILES_MINIMAL})
     set(BOOTLOADER_SRC ${BOOTLOADER_SRC} ../../../../../${LVGL_FILE})
   endforeach()
-  
+
   if(USB_CHARGER)
     set(BOOTLOADER_SRC
       ${BOOTLOADER_SRC}
@@ -88,11 +95,11 @@ if(PCB STREQUAL X10 OR PCB STREQUAL X12S OR PCB STREQUAL NV14)
       ../../../../../targets/${TARGET_DIR}/extmodule_helper.cpp
       )
   endif()
-  
+
   if(DEBUG)
     set(BOOTLOADER_SRC
       ${BOOTLOADER_SRC}
-      ../../../../../${STM32LIB_DIR}/STM32F4xx_StdPeriph_Driver/src/stm32f4xx_usart.c
+#      ../../../../../${STM32LIB_DIR}/STM32F4xx_StdPeriph_Driver/src/stm32f4xx_usart.c
       ../../../../../serial.cpp
       ../../../../../targets/common/arm/stm32/aux_serial_driver.cpp
       ../../../../../targets/common/arm/stm32/stm32_usart_driver.cpp

radio/src/targets/common/arm/stm32/bootloader/boot.cpp

@@ -27,6 +27,10 @@
 #include "keys.h"
 #include "debug.h"
 
+#if defined(DEBUG_SEGGER_RTT)
+  #include "thirdparty/Segger_RTT/RTT/SEGGER_RTT.h"
+#endif
+
 #if defined(PCBXLITE)
   #define BOOTLOADER_KEYS                 0x0F
 #else
@@ -83,7 +87,7 @@ void interrupt10ms()
 #if defined(DEBUG)
   g_tmr10ms++;
 #endif
-  
+
   uint8_t index = 0;
   uint32_t in = readKeys();
 
@@ -228,6 +232,10 @@ void bootloaderInitApp()
   boardBootloaderInit();
 #endif
 
+#if defined(DEBUG_SEGGER_RTT)
+  SEGGER_RTT_ConfigUpBuffer(0, NULL, NULL, 0, SEGGER_RTT_MODE_NO_BLOCK_SKIP);
+#endif
+
   pwrInit();
   keysInit();
 
@@ -267,7 +275,7 @@ void bootloaderInitApp()
 #endif
 
   delaysInit(); // needed for lcdInit()
-  
+
 #if defined(DEBUG)
   initSerialPorts();
 #endif