Merge branch 'sam_rtos_debugging' into sam_testing

Firmware/.vscode/launch.json

@@ -11,6 +11,7 @@
             "request": "launch",
             "name": "Debug ODrive",
             "executable": "${workspaceRoot}/build/ODriveFirmware.elf",
+            "rtos": "FreeRTOS",
             "configFiles": [
                 "interface/stlink-v2.cfg",
                 "target/stm32f4x_stlink.cfg",

Firmware/FreeRTOS-openocd.c

@@ -0,0 +1,20 @@
+/*
+ * Since at least FreeRTOS V7.5.3 uxTopUsedPriority is no longer
+ * present in the kernel, so it has to be supplied by other means for
+ * OpenOCD's threads awareness.
+ *
+ * Add this file to your project, and, if you're using --gc-sections,
+ * ``--undefined=uxTopUsedPriority'' (or
+ * ``-Wl,--undefined=uxTopUsedPriority'' when using gcc for final
+ * linking) to your LDFLAGS; same with all the other symbols you need.
+ */
+
+#include "FreeRTOS.h"
+
+#ifdef __GNUC__
+#define USED __attribute__((used))
+#else
+#define USED
+#endif
+
+const int USED uxTopUsedPriority = configMAX_PRIORITIES - 1;

Firmware/Tupfile.lua

@@ -90,6 +90,7 @@ LDFLAGS += '-T'..boarddir..'/STM32F405RGTx_FLASH.ld'
 LDFLAGS += '-L'..boarddir..'/Drivers/CMSIS/Lib' -- lib dir
 LDFLAGS += '-lc -lm -lnosys -larm_cortexM4lf_math' -- libs
 LDFLAGS += '-mthumb -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi=hard -specs=nosys.specs -specs=nano.specs -u _printf_float -u _scanf_float -Wl,--cref -Wl,--gc-sections'
+LDFLAGS += '-Wl,--undefined=uxTopUsedPriority'
 
 
 -- common flags for ASM, C and C++
@@ -147,7 +148,8 @@ build{
         'MotorControl/encoder.cpp',
         'MotorControl/controller.cpp',
         'MotorControl/sensorless_estimator.cpp',
-        'MotorControl/main.cpp'
+        'MotorControl/main.cpp',
+        'FreeRTOS-openocd.c'
     },
     includes={
         'Drivers/DRV8301',