Add fast RAM support, CCM or TCM depending on processor

src/main/flight/mixer.c

@@ -108,10 +108,10 @@ PG_REGISTER_ARRAY(motorMixer_t, MAX_SUPPORTED_MOTORS, customMotorMixer, PG_MOTOR
 
 #define TRICOPTER_ERROR_RATE_YAW_SATURATED 75 // rate at which tricopter yaw axis becomes saturated, determined experimentally by TriFlight
 
-static uint8_t motorCount;
+static FAST_RAM uint8_t motorCount;
-static float motorMixRange;
+static FAST_RAM float motorMixRange;
 
-float motor[MAX_SUPPORTED_MOTORS];
+float FAST_RAM motor[MAX_SUPPORTED_MOTORS];
 float motor_disarmed[MAX_SUPPORTED_MOTORS];
 
 mixerMode_e currentMixerMode;
@@ -306,12 +306,12 @@ const mixer_t mixers[] = {
 };
 #endif // !USE_QUAD_MIXER_ONLY
 
-float motorOutputHigh, motorOutputLow;
+FAST_RAM float motorOutputHigh, motorOutputLow;
 
-static float disarmMotorOutput, deadbandMotor3dHigh, deadbandMotor3dLow;
+static FAST_RAM float disarmMotorOutput, deadbandMotor3dHigh, deadbandMotor3dLow;
-static uint16_t rcCommand3dDeadBandLow;
+static FAST_RAM uint16_t rcCommand3dDeadBandLow;
-static uint16_t rcCommand3dDeadBandHigh;
+static FAST_RAM uint16_t rcCommand3dDeadBandHigh;
-static float rcCommandThrottleRange, rcCommandThrottleRange3dLow, rcCommandThrottleRange3dHigh;
+static FAST_RAM float rcCommandThrottleRange, rcCommandThrottleRange3dLow, rcCommandThrottleRange3dHigh;
 
 uint8_t getMotorCount(void)
 {
@@ -513,12 +513,12 @@ void stopPwmAllMotors(void)
     delayMicroseconds(1500);
 }
 
-static float throttle = 0;
+static FAST_RAM float throttle = 0;
-static float motorOutputMin;
+static FAST_RAM float motorOutputMin;
-static float motorRangeMin;
+static FAST_RAM float motorRangeMin;
-static float motorRangeMax;
+static FAST_RAM float motorRangeMax;
-static float motorOutputRange;
+static FAST_RAM float motorOutputRange;
-static int8_t motorOutputMixSign;
+static FAST_RAM int8_t motorOutputMixSign;
 
 static FAST_CODE void calculateThrottleAndCurrentMotorEndpoints(timeUs_t currentTimeUs)
 {

src/main/flight/pid.c

@@ -51,14 +51,14 @@
 #include "sensors/gyro.h"
 #include "sensors/acceleration.h"
 
-uint32_t targetPidLooptime;
+FAST_RAM uint32_t targetPidLooptime;
-static bool pidStabilisationEnabled;
+static FAST_RAM bool pidStabilisationEnabled;
 
-static bool inCrashRecoveryMode = false;
+static FAST_RAM bool inCrashRecoveryMode = false;
 
-float axisPID_P[3], axisPID_I[3], axisPID_D[3];
+FAST_RAM float axisPID_P[3], axisPID_I[3], axisPID_D[3];
 
-static float dT;
+static FAST_RAM float dT;
 
 PG_REGISTER_WITH_RESET_TEMPLATE(pidConfig_t, pidConfig, PG_PID_CONFIG, 1);
 
@@ -143,7 +143,7 @@ void pidResetITerm(void)
     }
 }
 
-static float itermAccelerator = 1.0f;
+static FAST_RAM float itermAccelerator = 1.0f;
 
 void pidSetItermAccelerator(float newItermAccelerator)
 {
@@ -157,12 +157,12 @@ void pidStabilisationState(pidStabilisationState_e pidControllerState)
 
 const angle_index_t rcAliasToAngleIndexMap[] = { AI_ROLL, AI_PITCH };
 
-static filterApplyFnPtr dtermNotchFilterApplyFn;
+static FAST_RAM filterApplyFnPtr dtermNotchFilterApplyFn;
-static void *dtermFilterNotch[2];
+static FAST_RAM void *dtermFilterNotch[2];
-static filterApplyFnPtr dtermLpfApplyFn;
+static FAST_RAM filterApplyFnPtr dtermLpfApplyFn;
-static void *dtermFilterLpf[2];
+static FAST_RAM void *dtermFilterLpf[2];
-static filterApplyFnPtr ptermYawFilterApplyFn;
+static FAST_RAM filterApplyFnPtr ptermYawFilterApplyFn;
-static void *ptermYawFilter;
+static FAST_RAM void *ptermYawFilter;
 
 typedef union dtermFilterLpf_u {
     pt1Filter_t pt1Filter[2];
@@ -249,22 +249,22 @@ void pidInitFilters(const pidProfile_t *pidProfile)
     }
 }
 
-static float Kp[3], Ki[3], Kd[3];
+static FAST_RAM float Kp[3], Ki[3], Kd[3];
-static float maxVelocity[3];
+static FAST_RAM float maxVelocity[3];
-static float relaxFactor;
+static FAST_RAM float relaxFactor;
-static float dtermSetpointWeight;
+static FAST_RAM float dtermSetpointWeight;
-static float levelGain, horizonGain, horizonTransition, horizonCutoffDegrees, horizonFactorRatio;
+static FAST_RAM float levelGain, horizonGain, horizonTransition, horizonCutoffDegrees, horizonFactorRatio;
-static float ITermWindupPointInv;
+static FAST_RAM float ITermWindupPointInv;
-static uint8_t horizonTiltExpertMode;
+static FAST_RAM uint8_t horizonTiltExpertMode;
-static timeDelta_t crashTimeLimitUs;
+static FAST_RAM timeDelta_t crashTimeLimitUs;
-static timeDelta_t crashTimeDelayUs;
+static FAST_RAM timeDelta_t crashTimeDelayUs;
-static int32_t crashRecoveryAngleDeciDegrees;
+static FAST_RAM int32_t crashRecoveryAngleDeciDegrees;
-static float crashRecoveryRate;
+static FAST_RAM float crashRecoveryRate;
-static float crashDtermThreshold;
+static FAST_RAM float crashDtermThreshold;
-static float crashGyroThreshold;
+static FAST_RAM float crashGyroThreshold;
-static float crashSetpointThreshold;
+static FAST_RAM float crashSetpointThreshold;
-static float crashLimitYaw;
+static FAST_RAM float crashLimitYaw;
-static float itermLimit;
+static FAST_RAM float itermLimit;
 
 void pidInitConfig(const pidProfile_t *pidProfile)
 {

src/main/scheduler/scheduler.c

@@ -42,21 +42,21 @@
 // 2 - time spent in scheduler
 // 3 - time spent executing check function
 
-static cfTask_t *currentTask = NULL;
+static FAST_RAM cfTask_t *currentTask = NULL;
 
-static uint32_t totalWaitingTasks;
+static FAST_RAM uint32_t totalWaitingTasks;
-static uint32_t totalWaitingTasksSamples;
+static FAST_RAM uint32_t totalWaitingTasksSamples;
 
-static bool calculateTaskStatistics;
+static FAST_RAM bool calculateTaskStatistics;
-uint16_t averageSystemLoadPercent = 0;
+FAST_RAM uint16_t averageSystemLoadPercent = 0;
 
 
-static int taskQueuePos = 0;
+static FAST_RAM int taskQueuePos = 0;
-STATIC_UNIT_TESTED int taskQueueSize = 0;
+STATIC_UNIT_TESTED FAST_RAM int taskQueueSize = 0;
 
 // No need for a linked list for the queue, since items are only inserted at startup
 
-STATIC_UNIT_TESTED cfTask_t* taskQueueArray[TASK_COUNT + 1]; // extra item for NULL pointer at end of queue
+STATIC_UNIT_TESTED FAST_RAM cfTask_t* taskQueueArray[TASK_COUNT + 1]; // extra item for NULL pointer at end of queue
 
 void queueClear(void)
 {

src/main/sensors/acceleration.c

@@ -67,7 +67,7 @@
 #endif
 
 
-acc_t acc;                       // acc access functions
+FAST_RAM acc_t acc;                       // acc access functions
 
 static float accumulatedMeasurements[XYZ_AXIS_COUNT];
 static int accumulatedMeasurementCount;

src/main/sensors/gyro.c

@@ -74,12 +74,12 @@
 #define USE_GYRO_SLEW_LIMITER
 #endif
 
-gyro_t gyro;
+FAST_RAM gyro_t gyro;
-static uint8_t gyroDebugMode;
+static FAST_RAM uint8_t gyroDebugMode;
 
-static float accumulatedMeasurements[XYZ_AXIS_COUNT];
+static FAST_RAM float accumulatedMeasurements[XYZ_AXIS_COUNT];
-static timeUs_t accumulatedMeasurementTimeUs;
+static FAST_RAM timeUs_t accumulatedMeasurementTimeUs;
-static timeUs_t accumulationLastTimeSampledUs;
+static FAST_RAM timeUs_t accumulationLastTimeSampledUs;
 
 typedef struct gyroCalibration_s {
     int32_t sum[XYZ_AXIS_COUNT];
@@ -111,7 +111,7 @@ typedef struct gyroSensor_s {
     biquadFilter_t notchFilterDyn[XYZ_AXIS_COUNT];
 } gyroSensor_t;
 
-static gyroSensor_t gyroSensor1;
+static FAST_RAM gyroSensor_t gyroSensor1;
 
 static void gyroInitSensorFilters(gyroSensor_t *gyroSensor);
 

src/main/target/common_fc_pre.h

@@ -82,6 +82,17 @@
 #define FAST_CODE
 #endif
 
+#ifdef USE_FAST_RAM
+#ifdef __APPLE__
+#define FAST_RAM                    __attribute__ ((section("__DATA,__.fastram_bss"), aligned(4)))
+#else
+#define FAST_RAM                    __attribute__ ((section(".fastram_bss"), aligned(4)))
+#endif
+#else
+#define FAST_RAM
+#endif // USE_FAST_RAM
+
+
 #define USE_CLI
 #define USE_PPM
 #define USE_PWM

src/main/target/common_osd_slave.h

@@ -57,6 +57,7 @@
 #endif
 
 #define FAST_CODE
+#define FAST_RAM
 
 //CLI needs FC dependencies removed before we can compile it, disabling for now
 //#define USE_CLI

src/main/target/link/stm32_flash.ld

@@ -126,6 +126,15 @@ SECTIONS
     __bss_end__ = _ebss;
   } >RAM
   
+  .fastram_bss (NOLOAD) :
+  {
+    __fastram_bss_start__ = .;
+    *(.fastram_bss)
+    *(SORT_BY_ALIGNMENT(.fastram_bss*))
+    . = ALIGN(4);
+    __fastram_bss_end__ = .;
+  } >FASTRAM
+
   /* User_heap_stack section, used to check that there is enough RAM left */
   _heap_stack_end = ORIGIN(STACKRAM)+LENGTH(STACKRAM) - 8; /* 8 bytes to allow for alignment */
   _heap_stack_begin = _heap_stack_end - _Min_Stack_Size  - _Min_Heap_Size;

src/main/target/link/stm32_flash_f103_128k.ld

@@ -20,5 +20,6 @@ MEMORY
 }
 
 REGION_ALIAS("STACKRAM", RAM)
+REGION_ALIAS("FASTRAM", RAM)
 
 INCLUDE "stm32_flash.ld"

src/main/target/link/stm32_flash_f103_128k_opbl.ld

@@ -21,5 +21,6 @@ MEMORY
 }
 
 REGION_ALIAS("STACKRAM", RAM)
+REGION_ALIAS("FASTRAM", RAM)
 
 INCLUDE "stm32_flash.ld"

src/main/target/link/stm32_flash_f103_256k.ld

@@ -20,5 +20,6 @@ MEMORY
 }
 
 REGION_ALIAS("STACKRAM", RAM)
+REGION_ALIAS("FASTRAM", RAM)
 
 INCLUDE "stm32_flash.ld"

src/main/target/link/stm32_flash_f103_64k.ld

@@ -20,5 +20,6 @@ MEMORY
 }
 
 REGION_ALIAS("STACKRAM", RAM)
+REGION_ALIAS("FASTRAM", RAM)
 
 INCLUDE "stm32_flash.ld"

src/main/target/link/stm32_flash_f303_128k.ld

@@ -21,5 +21,6 @@ MEMORY
 }
 
 REGION_ALIAS("STACKRAM", CCM)
+REGION_ALIAS("FASTRAM", CCM)
 
 INCLUDE "stm32_flash.ld"

src/main/target/link/stm32_flash_f303_256k.ld

@@ -21,5 +21,6 @@ MEMORY
 }
 
 REGION_ALIAS("STACKRAM", CCM)
+REGION_ALIAS("FASTRAM", CCM)
 
 INCLUDE "stm32_flash.ld"

src/main/target/link/stm32_flash_f405.ld

@@ -33,5 +33,6 @@ MEMORY
 }
 
 REGION_ALIAS("STACKRAM", CCM)
+REGION_ALIAS("FASTRAM", CCM)
 
 INCLUDE "stm32_flash_split.ld"

src/main/target/link/stm32_flash_f405_opbl.ld

@@ -33,5 +33,6 @@ MEMORY
 }
 
 REGION_ALIAS("STACKRAM", CCM)
+REGION_ALIAS("FASTRAM", CCM)
 
 INCLUDE "stm32_flash_split.ld"

src/main/target/link/stm32_flash_f411.ld

@@ -27,9 +27,11 @@ MEMORY
     FLASH1 (rx)       : ORIGIN = 0x08008000, LENGTH = 480K
 
     RAM (rwx)         : ORIGIN = 0x20000000, LENGTH = 128K
+    CCM (xrw)         : ORIGIN = 0x10000000, LENGTH = 64K
     MEMORY_B1 (rx)    : ORIGIN = 0x60000000, LENGTH = 0K
 }
 
-REGION_ALIAS("STACKRAM", RAM)
+REGION_ALIAS("STACKRAM", CCM)
+REGION_ALIAS("FASTRAM", CCM)
 
 INCLUDE "stm32_flash_split.ld"

src/main/target/link/stm32_flash_f411_opbl.ld

@@ -33,5 +33,6 @@ MEMORY
 }
 
 REGION_ALIAS("STACKRAM", CCM)
+REGION_ALIAS("FASTRAM", CCM)
 
 INCLUDE "stm32_flash_split.ld"

src/main/target/link/stm32_flash_f446.ld

@@ -31,5 +31,6 @@ MEMORY
 }
 
 REGION_ALIAS("STACKRAM", RAM)
+REGION_ALIAS("FASTRAM", RAM)
 
 INCLUDE "stm32_flash_split.ld"

src/main/target/link/stm32_flash_f722.ld

@@ -39,5 +39,6 @@ MEMORY
 
 /* note TCM could be used for stack */
 REGION_ALIAS("STACKRAM", TCM)
+REGION_ALIAS("FASTRAM", TCM)
 
 INCLUDE "stm32_flash_split.ld"

src/main/target/link/stm32_flash_f745.ld

@@ -32,5 +32,6 @@ MEMORY
 }
 /* note CCM could be used for stack */
 REGION_ALIAS("STACKRAM", TCM)
+REGION_ALIAS("FASTRAM", TCM)
 
 INCLUDE "stm32_flash_split.ld"

src/main/target/link/stm32_flash_f746.ld

@@ -32,5 +32,6 @@ MEMORY
 }
 /* note CCM could be used for stack */
 REGION_ALIAS("STACKRAM", TCM)
+REGION_ALIAS("FASTRAM", TCM)
 
 INCLUDE "stm32_flash_split.ld"

src/main/target/link/stm32_flash_split.ld

@@ -126,6 +126,15 @@ SECTIONS
     __bss_end__ = _ebss;
   } >RAM
 
+  .fastram_bss (NOLOAD) :
+  {
+    __fastram_bss_start__ = .;
+    *(.fastram_bss)
+    *(SORT_BY_ALIGNMENT(.fastram_bss*))
+    . = ALIGN(4);
+    __fastram_bss_end__ = .;
+  } >FASTRAM
+
   /* User_heap_stack section, used to check that there is enough RAM left */
   _heap_stack_end = ORIGIN(STACKRAM)+LENGTH(STACKRAM) - 8; /* 8 bytes to allow for alignment */
   _heap_stack_begin = _heap_stack_end - _Min_Stack_Size  - _Min_Heap_Size;

src/test/unit/platform.h

@@ -26,6 +26,7 @@
 #define U_ID_2 2
 
 #define FAST_CODE
+#define FAST_RAM
 
 #define MAX_PROFILE_COUNT 3
 #define USE_MAG