diff --git a/src/main/drivers/pwm_output.c b/src/main/drivers/pwm_output.c
index 7c88bf57d..7578b2ecb 100644
--- a/src/main/drivers/pwm_output.c
+++ b/src/main/drivers/pwm_output.c
@@ -31,12 +31,12 @@
 #include "timer.h"
 #include "drivers/pwm_output.h"
 
-static FAST_RAM pwmWriteFn *pwmWrite;
-static FAST_RAM pwmOutputPort_t motors[MAX_SUPPORTED_MOTORS];
-static FAST_RAM pwmCompleteWriteFn *pwmCompleteWrite = NULL;
+static FAST_RAM_ZERO_INIT pwmWriteFn *pwmWrite;
+static FAST_RAM_ZERO_INIT pwmOutputPort_t motors[MAX_SUPPORTED_MOTORS];
+static FAST_RAM_ZERO_INIT pwmCompleteWriteFn *pwmCompleteWrite = NULL;
 
 #ifdef USE_DSHOT
-FAST_RAM loadDmaBufferFn *loadDmaBuffer;
+FAST_RAM_ZERO_INIT loadDmaBufferFn *loadDmaBuffer;
 #endif
 
 #ifdef USE_SERVOS
@@ -51,7 +51,7 @@ static uint16_t freqBeep = 0;
 static bool pwmMotorsEnabled = false;
 static bool isDshot = false;
 #ifdef USE_DSHOT_DMAR
-FAST_RAM bool useBurstDshot = false;
+FAST_RAM_ZERO_INIT bool useBurstDshot = false;
 #endif
 
 static void pwmOCConfig(TIM_TypeDef *tim, uint8_t channel, uint16_t value, uint8_t output)
diff --git a/src/main/drivers/pwm_output_dshot_hal.c b/src/main/drivers/pwm_output_dshot_hal.c
index 74e6306e9..8e36a8ebd 100644
--- a/src/main/drivers/pwm_output_dshot_hal.c
+++ b/src/main/drivers/pwm_output_dshot_hal.c
@@ -33,9 +33,9 @@
 #include "dma.h"
 #include "rcc.h"
 
-static FAST_RAM uint8_t dmaMotorTimerCount = 0;
-static FAST_RAM motorDmaTimer_t dmaMotorTimers[MAX_DMA_TIMERS];
-static FAST_RAM motorDmaOutput_t dmaMotors[MAX_SUPPORTED_MOTORS];
+static FAST_RAM_ZERO_INIT uint8_t dmaMotorTimerCount = 0;
+static FAST_RAM_ZERO_INIT motorDmaTimer_t dmaMotorTimers[MAX_DMA_TIMERS];
+static FAST_RAM_ZERO_INIT motorDmaOutput_t dmaMotors[MAX_SUPPORTED_MOTORS];
 
 motorDmaOutput_t *getMotorDmaOutput(uint8_t index)
 {
diff --git a/src/main/drivers/serial_uart_pinconfig.c b/src/main/drivers/serial_uart_pinconfig.c
index 5b4c22f83..d9d6f9ad9 100644
--- a/src/main/drivers/serial_uart_pinconfig.c
+++ b/src/main/drivers/serial_uart_pinconfig.c
@@ -39,8 +39,8 @@
 #include "drivers/serial_uart.h"
 #include "drivers/serial_uart_impl.h"
 
-FAST_RAM uartDevice_t uartDevice[UARTDEV_COUNT];      // Only those configured in target.h
-FAST_RAM uartDevice_t *uartDevmap[UARTDEV_COUNT_MAX]; // Full array
+FAST_RAM_ZERO_INIT uartDevice_t uartDevice[UARTDEV_COUNT];      // Only those configured in target.h
+FAST_RAM_ZERO_INIT uartDevice_t *uartDevmap[UARTDEV_COUNT_MAX]; // Full array
 
 void uartPinConfigure(const serialPinConfig_t *pSerialPinConfig)
 {
diff --git a/src/main/fc/fc_init.c b/src/main/fc/fc_init.c
index 4ddaf906d..6eea85939 100644
--- a/src/main/fc/fc_init.c
+++ b/src/main/fc/fc_init.c
@@ -275,7 +275,7 @@ void init(void)
 #endif
 
 #ifdef USE_FAST_RAM
-    /* Load FAST_RAM_INITIALIZED variable intializers into FAST RAM */
+    /* Load FAST_RAM variable intializers into DTCM RAM */
     extern uint8_t _sfastram_data;
     extern uint8_t _efastram_data;
     extern uint8_t _sfastram_idata;
diff --git a/src/main/flight/mixer.c b/src/main/flight/mixer.c
index af857fe77..bc4d94764 100644
--- a/src/main/flight/mixer.c
+++ b/src/main/flight/mixer.c
@@ -115,10 +115,10 @@ PG_REGISTER_ARRAY(motorMixer_t, MAX_SUPPORTED_MOTORS, customMotorMixer, PG_MOTOR
 
 #define PWM_RANGE_MID 1500
 
-static FAST_RAM uint8_t motorCount;
-static FAST_RAM float motorMixRange;
+static FAST_RAM_ZERO_INIT uint8_t motorCount;
+static FAST_RAM_ZERO_INIT float motorMixRange;
 
-float FAST_RAM motor[MAX_SUPPORTED_MOTORS];
+float FAST_RAM_ZERO_INIT motor[MAX_SUPPORTED_MOTORS];
 float motor_disarmed[MAX_SUPPORTED_MOTORS];
 
 mixerMode_e currentMixerMode;
@@ -313,12 +313,12 @@ const mixer_t mixers[] = {
 };
 #endif // !USE_QUAD_MIXER_ONLY
 
-FAST_RAM float motorOutputHigh, motorOutputLow;
+FAST_RAM_ZERO_INIT float motorOutputHigh, motorOutputLow;
 
-static FAST_RAM float disarmMotorOutput, deadbandMotor3dHigh, deadbandMotor3dLow;
-static FAST_RAM uint16_t rcCommand3dDeadBandLow;
-static FAST_RAM uint16_t rcCommand3dDeadBandHigh;
-static FAST_RAM float rcCommandThrottleRange, rcCommandThrottleRange3dLow, rcCommandThrottleRange3dHigh;
+static FAST_RAM_ZERO_INIT float disarmMotorOutput, deadbandMotor3dHigh, deadbandMotor3dLow;
+static FAST_RAM_ZERO_INIT uint16_t rcCommand3dDeadBandLow;
+static FAST_RAM_ZERO_INIT uint16_t rcCommand3dDeadBandHigh;
+static FAST_RAM_ZERO_INIT float rcCommandThrottleRange, rcCommandThrottleRange3dLow, rcCommandThrottleRange3dHigh;
 
 uint8_t getMotorCount(void)
 {
@@ -519,12 +519,12 @@ void stopPwmAllMotors(void)
     delayMicroseconds(1500);
 }
 
-static FAST_RAM float throttle = 0;
-static FAST_RAM float motorOutputMin;
-static FAST_RAM float motorRangeMin;
-static FAST_RAM float motorRangeMax;
-static FAST_RAM float motorOutputRange;
-static FAST_RAM int8_t motorOutputMixSign;
+static FAST_RAM_ZERO_INIT float throttle = 0;
+static FAST_RAM_ZERO_INIT float motorOutputMin;
+static FAST_RAM_ZERO_INIT float motorRangeMin;
+static FAST_RAM_ZERO_INIT float motorRangeMax;
+static FAST_RAM_ZERO_INIT float motorOutputRange;
+static FAST_RAM_ZERO_INIT int8_t motorOutputMixSign;
 
 static void calculateThrottleAndCurrentMotorEndpoints(timeUs_t currentTimeUs)
 {
diff --git a/src/main/flight/pid.c b/src/main/flight/pid.c
index 10859b5dc..0292d2c28 100644
--- a/src/main/flight/pid.c
+++ b/src/main/flight/pid.c
@@ -56,14 +56,14 @@
 #include "sensors/acceleration.h"
 
 
-FAST_RAM uint32_t targetPidLooptime;
-FAST_RAM pidAxisData_t pidData[XYZ_AXIS_COUNT];
+FAST_RAM_ZERO_INIT uint32_t targetPidLooptime;
+FAST_RAM_ZERO_INIT pidAxisData_t pidData[XYZ_AXIS_COUNT];
 
-static FAST_RAM bool pidStabilisationEnabled;
+static FAST_RAM_ZERO_INIT bool pidStabilisationEnabled;
 
-static FAST_RAM bool inCrashRecoveryMode = false;
+static FAST_RAM_ZERO_INIT bool inCrashRecoveryMode = false;
 
-static FAST_RAM float dT;
+static FAST_RAM_ZERO_INIT float dT;
 
 PG_REGISTER_WITH_RESET_TEMPLATE(pidConfig_t, pidConfig, PG_PID_CONFIG, 2);
 
@@ -162,7 +162,7 @@ void pidResetITerm(void)
     }
 }
 
-static FAST_RAM_INITIALIZED float itermAccelerator = 1.0f;
+static FAST_RAM float itermAccelerator = 1.0f;
 
 void pidSetItermAccelerator(float newItermAccelerator)
 {
@@ -189,14 +189,14 @@ typedef union dtermLowpass_u {
 #endif
 } dtermLowpass_t;
 
-static FAST_RAM filterApplyFnPtr dtermNotchApplyFn;
-static FAST_RAM biquadFilter_t dtermNotch[2];
-static FAST_RAM filterApplyFnPtr dtermLowpassApplyFn;
-static FAST_RAM dtermLowpass_t dtermLowpass[2];
-static FAST_RAM filterApplyFnPtr dtermLowpass2ApplyFn;
-static FAST_RAM pt1Filter_t dtermLowpass2[2];
-static FAST_RAM filterApplyFnPtr ptermYawLowpassApplyFn;
-static FAST_RAM pt1Filter_t ptermYawLowpass;
+static FAST_RAM_ZERO_INIT filterApplyFnPtr dtermNotchApplyFn;
+static FAST_RAM_ZERO_INIT biquadFilter_t dtermNotch[2];
+static FAST_RAM_ZERO_INIT filterApplyFnPtr dtermLowpassApplyFn;
+static FAST_RAM_ZERO_INIT dtermLowpass_t dtermLowpass[2];
+static FAST_RAM_ZERO_INIT filterApplyFnPtr dtermLowpass2ApplyFn;
+static FAST_RAM_ZERO_INIT pt1Filter_t dtermLowpass2[2];
+static FAST_RAM_ZERO_INIT filterApplyFnPtr ptermYawLowpassApplyFn;
+static FAST_RAM_ZERO_INIT pt1Filter_t ptermYawLowpass;
 
 void pidInitFilters(const pidProfile_t *pidProfile)
 {
@@ -289,25 +289,25 @@ typedef struct pidCoefficient_s {
     float Kd;
 } pidCoefficient_t;
 
-static FAST_RAM pidCoefficient_t pidCoefficient[3];
-static FAST_RAM float maxVelocity[3];
-static FAST_RAM float relaxFactor;
-static FAST_RAM float dtermSetpointWeight;
-static FAST_RAM float levelGain, horizonGain, horizonTransition, horizonCutoffDegrees, horizonFactorRatio;
-static FAST_RAM float ITermWindupPointInv;
-static FAST_RAM uint8_t horizonTiltExpertMode;
-static FAST_RAM timeDelta_t crashTimeLimitUs;
-static FAST_RAM timeDelta_t crashTimeDelayUs;
-static FAST_RAM int32_t crashRecoveryAngleDeciDegrees;
-static FAST_RAM float crashRecoveryRate;
-static FAST_RAM float crashDtermThreshold;
-static FAST_RAM float crashGyroThreshold;
-static FAST_RAM float crashSetpointThreshold;
-static FAST_RAM float crashLimitYaw;
-static FAST_RAM float itermLimit;
-FAST_RAM float throttleBoost;
+static FAST_RAM_ZERO_INIT pidCoefficient_t pidCoefficient[3];
+static FAST_RAM_ZERO_INIT float maxVelocity[3];
+static FAST_RAM_ZERO_INIT float relaxFactor;
+static FAST_RAM_ZERO_INIT float dtermSetpointWeight;
+static FAST_RAM_ZERO_INIT float levelGain, horizonGain, horizonTransition, horizonCutoffDegrees, horizonFactorRatio;
+static FAST_RAM_ZERO_INIT float ITermWindupPointInv;
+static FAST_RAM_ZERO_INIT uint8_t horizonTiltExpertMode;
+static FAST_RAM_ZERO_INIT timeDelta_t crashTimeLimitUs;
+static FAST_RAM_ZERO_INIT timeDelta_t crashTimeDelayUs;
+static FAST_RAM_ZERO_INIT int32_t crashRecoveryAngleDeciDegrees;
+static FAST_RAM_ZERO_INIT float crashRecoveryRate;
+static FAST_RAM_ZERO_INIT float crashDtermThreshold;
+static FAST_RAM_ZERO_INIT float crashGyroThreshold;
+static FAST_RAM_ZERO_INIT float crashSetpointThreshold;
+static FAST_RAM_ZERO_INIT float crashLimitYaw;
+static FAST_RAM_ZERO_INIT float itermLimit;
+FAST_RAM_ZERO_INIT float throttleBoost;
 pt1Filter_t throttleLpf;
-static FAST_RAM bool itermRotation;
+static FAST_RAM_ZERO_INIT bool itermRotation;
 
 void pidInitConfig(const pidProfile_t *pidProfile)
 {
diff --git a/src/main/scheduler/scheduler.c b/src/main/scheduler/scheduler.c
index 3e2071322..d5ea17b74 100644
--- a/src/main/scheduler/scheduler.c
+++ b/src/main/scheduler/scheduler.c
@@ -45,21 +45,21 @@
 // 2 - time spent in scheduler
 // 3 - time spent executing check function
 
-static FAST_RAM cfTask_t *currentTask = NULL;
+static FAST_RAM_ZERO_INIT cfTask_t *currentTask = NULL;
 
-static FAST_RAM uint32_t totalWaitingTasks;
-static FAST_RAM uint32_t totalWaitingTasksSamples;
+static FAST_RAM_ZERO_INIT uint32_t totalWaitingTasks;
+static FAST_RAM_ZERO_INIT uint32_t totalWaitingTasksSamples;
 
-static FAST_RAM bool calculateTaskStatistics;
-FAST_RAM uint16_t averageSystemLoadPercent = 0;
+static FAST_RAM_ZERO_INIT bool calculateTaskStatistics;
+FAST_RAM_ZERO_INIT uint16_t averageSystemLoadPercent = 0;
 
 
-static FAST_RAM int taskQueuePos = 0;
-STATIC_UNIT_TESTED FAST_RAM int taskQueueSize = 0;
+static FAST_RAM_ZERO_INIT int taskQueuePos = 0;
+STATIC_UNIT_TESTED FAST_RAM_ZERO_INIT int taskQueueSize = 0;
 
 // No need for a linked list for the queue, since items are only inserted at startup
 
-STATIC_UNIT_TESTED FAST_RAM cfTask_t* taskQueueArray[TASK_COUNT + 1]; // extra item for NULL pointer at end of queue
+STATIC_UNIT_TESTED FAST_RAM_ZERO_INIT cfTask_t* taskQueueArray[TASK_COUNT + 1]; // extra item for NULL pointer at end of queue
 
 void queueClear(void)
 {
diff --git a/src/main/sensors/acceleration.c b/src/main/sensors/acceleration.c
index ea2e589bc..c1616fca0 100644
--- a/src/main/sensors/acceleration.c
+++ b/src/main/sensors/acceleration.c
@@ -82,7 +82,7 @@
 #endif
 
 
-FAST_RAM acc_t acc;                       // acc access functions
+FAST_RAM_ZERO_INIT acc_t acc;                       // acc access functions
 
 static float accumulatedMeasurements[XYZ_AXIS_COUNT];
 static int accumulatedMeasurementCount;
diff --git a/src/main/sensors/gyro.c b/src/main/sensors/gyro.c
index 501afad69..9af0a71ef 100644
--- a/src/main/sensors/gyro.c
+++ b/src/main/sensors/gyro.c
@@ -83,18 +83,18 @@
 #define USE_GYRO_SLEW_LIMITER
 #endif
 
-FAST_RAM gyro_t gyro;
-static FAST_RAM uint8_t gyroDebugMode;
+FAST_RAM_ZERO_INIT gyro_t gyro;
+static FAST_RAM_ZERO_INIT uint8_t gyroDebugMode;
 
 static uint8_t gyroToUse = 0;
 
 #ifdef USE_GYRO_OVERFLOW_CHECK
-static FAST_RAM uint8_t overflowAxisMask;
+static FAST_RAM_ZERO_INIT uint8_t overflowAxisMask;
 #endif
-static FAST_RAM float accumulatedMeasurements[XYZ_AXIS_COUNT];
-static FAST_RAM float gyroPrevious[XYZ_AXIS_COUNT];
-static FAST_RAM timeUs_t accumulatedMeasurementTimeUs;
-static FAST_RAM timeUs_t accumulationLastTimeSampledUs;
+static FAST_RAM_ZERO_INIT float accumulatedMeasurements[XYZ_AXIS_COUNT];
+static FAST_RAM_ZERO_INIT float gyroPrevious[XYZ_AXIS_COUNT];
+static FAST_RAM_ZERO_INIT timeUs_t accumulatedMeasurementTimeUs;
+static FAST_RAM_ZERO_INIT timeUs_t accumulationLastTimeSampledUs;
 
 static bool gyroHasOverflowProtection = true;
 
@@ -152,9 +152,9 @@ typedef struct gyroSensor_s {
 
 } gyroSensor_t;
 
-STATIC_UNIT_TESTED FAST_RAM gyroSensor_t gyroSensor1;
+STATIC_UNIT_TESTED FAST_RAM_ZERO_INIT gyroSensor_t gyroSensor1;
 #ifdef USE_DUAL_GYRO
-STATIC_UNIT_TESTED FAST_RAM gyroSensor_t gyroSensor2;
+STATIC_UNIT_TESTED FAST_RAM_ZERO_INIT gyroSensor_t gyroSensor2;
 #endif
 
 #ifdef UNIT_TEST
diff --git a/src/main/sensors/gyroanalyse.c b/src/main/sensors/gyroanalyse.c
index 8059c6fa8..a5958894b 100644
--- a/src/main/sensors/gyroanalyse.c
+++ b/src/main/sensors/gyroanalyse.c
@@ -57,27 +57,27 @@
 
 #define BIQUAD_Q 1.0f / sqrtf(2.0f)         // quality factor - butterworth
 
-static FAST_RAM uint16_t fftSamplingScale;
+static FAST_RAM_ZERO_INIT uint16_t fftSamplingScale;
 
 // gyro data used for frequency analysis
-static float FAST_RAM gyroData[XYZ_AXIS_COUNT][FFT_WINDOW_SIZE];
+static float FAST_RAM_ZERO_INIT gyroData[XYZ_AXIS_COUNT][FFT_WINDOW_SIZE];
 
-static FAST_RAM arm_rfft_fast_instance_f32 fftInstance;
-static FAST_RAM float fftData[FFT_WINDOW_SIZE];
-static FAST_RAM float rfftData[FFT_WINDOW_SIZE];
-static FAST_RAM gyroFftData_t fftResult[XYZ_AXIS_COUNT];
+static FAST_RAM_ZERO_INIT arm_rfft_fast_instance_f32 fftInstance;
+static FAST_RAM_ZERO_INIT float fftData[FFT_WINDOW_SIZE];
+static FAST_RAM_ZERO_INIT float rfftData[FFT_WINDOW_SIZE];
+static FAST_RAM_ZERO_INIT gyroFftData_t fftResult[XYZ_AXIS_COUNT];
 
 // use a circular buffer for the last FFT_WINDOW_SIZE samples
-static FAST_RAM uint16_t fftIdx;
+static FAST_RAM_ZERO_INIT uint16_t fftIdx;
 
 // bandpass filter gyro data
-static FAST_RAM biquadFilter_t fftGyroFilter[XYZ_AXIS_COUNT];
+static FAST_RAM_ZERO_INIT biquadFilter_t fftGyroFilter[XYZ_AXIS_COUNT];
 
 // filter for smoothing frequency estimation
-static FAST_RAM biquadFilter_t fftFreqFilter[XYZ_AXIS_COUNT];
+static FAST_RAM_ZERO_INIT biquadFilter_t fftFreqFilter[XYZ_AXIS_COUNT];
 
 // Hanning window, see https://en.wikipedia.org/wiki/Window_function#Hann_.28Hanning.29_window
-static FAST_RAM float hanningWindow[FFT_WINDOW_SIZE];
+static FAST_RAM_ZERO_INIT float hanningWindow[FFT_WINDOW_SIZE];
 
 void initHanning(void)
 {
@@ -128,10 +128,10 @@ const gyroFftData_t *gyroFftData(int axis)
 void gyroDataAnalyse(const gyroDev_t *gyroDev, biquadFilter_t *notchFilterDyn)
 {
     // accumulator for oversampled data => no aliasing and less noise
-    static FAST_RAM float fftAcc[XYZ_AXIS_COUNT];
-    static FAST_RAM uint32_t fftAccCount;
+    static FAST_RAM_ZERO_INIT float fftAcc[XYZ_AXIS_COUNT];
+    static FAST_RAM_ZERO_INIT uint32_t fftAccCount;
 
-    static FAST_RAM uint32_t gyroDataAnalyseUpdateTicks;
+    static FAST_RAM_ZERO_INIT uint32_t gyroDataAnalyseUpdateTicks;
 
     // if gyro sampling is > 1kHz, accumulate multiple samples
     for (int axis = 0; axis < XYZ_AXIS_COUNT; axis++) {
diff --git a/src/main/target/common_fc_pre.h b/src/main/target/common_fc_pre.h
index 3e714192f..bbcf6c6dc 100644
--- a/src/main/target/common_fc_pre.h
+++ b/src/main/target/common_fc_pre.h
@@ -101,11 +101,11 @@
 #endif // USE_ITCM_RAM
 
 #ifdef USE_FAST_RAM
-#define FAST_RAM                    __attribute__ ((section(".fastram_bss"), aligned(4)))
-#define FAST_RAM_INITIALIZED        __attribute__ ((section(".fastram_data"), aligned(4)))
+#define FAST_RAM_ZERO_INIT             __attribute__ ((section(".fastram_bss"), aligned(4)))
+#define FAST_RAM                    __attribute__ ((section(".fastram_data"), aligned(4)))
 #else
+#define FAST_RAM_ZERO_INIT
 #define FAST_RAM
-#define FAST_RAM_INITIALIZED
 #endif // USE_FAST_RAM
 
 #ifdef STM32F4
diff --git a/src/main/target/common_osd_slave.h b/src/main/target/common_osd_slave.h
index 99988fda4..1f155d940 100644
--- a/src/main/target/common_osd_slave.h
+++ b/src/main/target/common_osd_slave.h
@@ -60,6 +60,7 @@
 #endif
 
 #define FAST_CODE
+#define FAST_RAM_ZERO_INIT
 #define FAST_RAM
 
 //CLI needs FC dependencies removed before we can compile it, disabling for now
diff --git a/src/test/unit/platform.h b/src/test/unit/platform.h
index 633cf2dfc..940d771b6 100644
--- a/src/test/unit/platform.h
+++ b/src/test/unit/platform.h
@@ -27,8 +27,8 @@
 
 #define NOINLINE
 #define FAST_CODE
+#define FAST_RAM_ZERO_INIT
 #define FAST_RAM
-#define FAST_RAM_INITIALIZED
 
 #define MAX_PROFILE_COUNT 3
 #define USE_MAG