For discussion: Take a methodical approach to dealing with flash overflows.

Makefile

@@ -90,6 +90,9 @@ HSE_VALUE       ?= 8000000
 # used for turning on features like VCP and SDCARD
 FEATURES        =
 
+# used to disable features based on flash space shortage (larger => more features disabled)
+FLASH_RESTRICTEDNESS_LEVEL =
+
 include $(ROOT)/make/targets.mk
 
 REVISION := $(shell git log -1 --format="%h")
@@ -155,6 +158,10 @@ ifneq ($(HSE_VALUE),)
 DEVICE_FLAGS  := $(DEVICE_FLAGS) -DHSE_VALUE=$(HSE_VALUE)
 endif
 
+ifneq ($(FLASH_RESTRICTEDNESS_LEVEL),)
+DEVICE_FLAGS  := $(DEVICE_FLAGS) -DFLASH_RESTRICTEDNESS_LEVEL=$(FLASH_RESTRICTEDNESS_LEVEL)
+endif
+
 TARGET_DIR     = $(ROOT)/src/main/target/$(BASE_TARGET)
 TARGET_DIR_SRC = $(notdir $(wildcard $(TARGET_DIR)/*.c))
 

src/main/target/SPRACINGF3NEO/target.h

@@ -23,40 +23,6 @@
 #define TARGET_BOARD_IDENTIFIER "SP3N"
 #define USE_TARGET_CONFIG
 
-// Removed to make the firmware fit into flash (in descending order of priority):
-// NOTE: Don't disable USE_GYRO_OVERFLOW_CHECK - board has ICM20602 gyro
-//#undef USE_GYRO_OVERFLOW_CHECK
-//#undef USE_GYRO_LPF2
-
-#undef USE_MSP_DISPLAYPORT
-#undef USE_MSP_OVER_TELEMETRY
-
-#undef USE_DYN_LPF
-#undef USE_D_CUT
-#undef USE_LAUNCH_CONTROL
-
-#undef USE_ITERM_RELAX
-#undef USE_RC_SMOOTHING_FILTER
-#undef USE_THRUST_LINEARIZATION
-
-#undef USE_HUFFMAN
-#undef USE_PINIO
-#undef USE_PINIOBOX
-
-#undef USE_TELEMETRY_HOTT
-#undef USE_TELEMETRY_MAVLINK
-#undef USE_TELEMETRY_LTM
-#undef USE_SERIALRX_XBUS
-#undef USE_SERIALRX_SUMH
-#undef USE_PWM
-
-#undef USE_BOARD_INFO
-#undef USE_EXTENDED_CMS_MENUS
-#undef USE_RTC_TIME
-#undef USE_RX_MSP
-#undef USE_ESC_SENSOR_INFO
-
-
 #define LED0_PIN                PB9
 #define LED1_PIN                PB2
 

src/main/target/SPRACINGF3NEO/target.mk

@@ -1,6 +1,8 @@
 F3_TARGETS  += $(TARGET)
 FEATURES    = VCP SDCARD_SPI
 
+FLASH_RESTRICTEDNESS_LEVEL = 8
+
 TARGET_SRC = \
             drivers/accgyro/accgyro_mpu.c \
             drivers/accgyro/accgyro_mpu6500.c \

src/main/target/common_pre.h

@@ -138,15 +138,12 @@
 #define USE_GYRO_REGISTER_DUMP  // Adds gyroregisters command to cli to dump configured register values
 #define USE_IMU_CALC
 #define USE_PPM
-#define USE_PWM
 #define USE_SERIAL_RX
 #define USE_SERIALRX_CRSF       // Team Black Sheep Crossfire protocol
 #define USE_SERIALRX_IBUS       // FlySky and Turnigy receivers
 #define USE_SERIALRX_SBUS       // Frsky and Futaba receivers
 #define USE_SERIALRX_SPEKTRUM   // SRXL, DSM2 and DSMX protocol
 #define USE_SERIALRX_SUMD       // Graupner Hott protocol
-#define USE_SERIALRX_SUMH       // Graupner legacy protocol
-#define USE_SERIALRX_XBUS       // JR
 
 #if (FLASH_SIZE > 64)
 #define MAX_PROFILE_COUNT 3
@@ -162,29 +159,20 @@
 #define USE_SERVOS
 #define USE_TELEMETRY
 #define USE_TELEMETRY_FRSKY_HUB
-#define USE_TELEMETRY_HOTT
-#define USE_TELEMETRY_LTM
 #define USE_TELEMETRY_SMARTPORT
 #endif
 
 #if (FLASH_SIZE > 128)
+#define USE_GYRO_OVERFLOW_CHECK
+
 #define USE_CAMERA_CONTROL
 #define USE_CMS
-#define USE_EXTENDED_CMS_MENUS
 #define USE_DSHOT_DMAR
-#define USE_GYRO_OVERFLOW_CHECK
 #define USE_YAW_SPIN_RECOVERY
-#define USE_HUFFMAN
-#define USE_LAUNCH_CONTROL
 #define USE_MSP_DISPLAYPORT
 #define USE_MSP_OVER_TELEMETRY
-#define USE_PINIO
-#define USE_PINIOBOX
 #define USE_RCDEVICE
-#define USE_RTC_TIME
-#define USE_RX_MSP
 #define USE_SERIALRX_FPORT      // FrSky FPort
-#define USE_TPA_MODE
 #define USE_TELEMETRY_CRSF
 #define USE_TELEMETRY_SRXL
 #define USE_VIRTUAL_CURRENT_METER
@@ -192,19 +180,42 @@
 #define USE_VTX_CONTROL
 #define USE_VTX_SMARTAUDIO
 #define USE_VTX_TRAMP
-#define USE_GYRO_LPF2
 #define USE_ESC_SENSOR
-#define USE_ESC_SENSOR_INFO
+#define USE_SERIAL_4WAY_BLHELI_BOOTLOADER //TODO: Fix this conditional.
-#define USE_CRSF_CMS_TELEMETRY
-#define USE_BOARD_INFO
-#define USE_THROTTLE_BOOST
-#define USE_RC_SMOOTHING_FILTER
-#define USE_ITERM_RELAX
-#define USE_DYN_LPF
-#define USE_INTEGRATED_YAW_CONTROL
-#define USE_THRUST_LINEARIZATION
-#define USE_D_CUT
 
+#if ((FLASH_SIZE > 256) || (FLASH_RESTRICTEDNESS_LEVEL < 9))
+#define USE_GYRO_LPF2
+#endif
+
+#if ((FLASH_SIZE > 256) || (FLASH_RESTRICTEDNESS_LEVEL < 8))
+#define USE_LAUNCH_CONTROL
+#define USE_DYN_LPF
+#define USE_D_CUT
+#endif
+
+#if ((FLASH_SIZE > 256) || (FLASH_RESTRICTEDNESS_LEVEL < 7))
+#define USE_THROTTLE_BOOST
+#define USE_INTEGRATED_YAW_CONTROL
+#endif
+
+#if ((FLASH_SIZE > 256) || (FLASH_RESTRICTEDNESS_LEVEL < 6))
+#define USE_ITERM_RELAX
+#define USE_RC_SMOOTHING_FILTER
+#define USE_THRUST_LINEARIZATION
+#define USE_TPA_MODE
+#endif
+
+#if ((FLASH_SIZE > 256) || (FLASH_RESTRICTEDNESS_LEVEL < 5))
+#define USE_PWM
+#endif
+
+#if ((FLASH_SIZE > 256) || (FLASH_RESTRICTEDNESS_LEVEL < 4))
+#define USE_HUFFMAN
+#define USE_PINIO
+#define USE_PINIOBOX
+#endif
+
+#if ((FLASH_SIZE > 256) || (FLASH_RESTRICTEDNESS_LEVEL < 3))
 #ifdef USE_SERIALRX_SPEKTRUM
 #define USE_SPEKTRUM_BIND
 #define USE_SPEKTRUM_BIND_PLUG
@@ -215,9 +226,26 @@
 #define USE_SPEKTRUM_VTX_TELEMETRY
 #define USE_SPEKTRUM_CMS_TELEMETRY
 #endif
-#define USE_SERIAL_4WAY_BLHELI_BOOTLOADER
 #endif
 
+#if ((FLASH_SIZE > 256) || (FLASH_RESTRICTEDNESS_LEVEL < 2))
+#define USE_TELEMETRY_HOTT
+#define USE_TELEMETRY_LTM
+#define USE_SERIALRX_SUMH       // Graupner legacy protocol
+#define USE_SERIALRX_XBUS       // JR
+#endif
+
+#if ((FLASH_SIZE > 256) || (FLASH_RESTRICTEDNESS_LEVEL < 1))
+#define USE_BOARD_INFO
+#define USE_EXTENDED_CMS_MENUS
+#define USE_RTC_TIME
+#define USE_RX_MSP
+#define USE_ESC_SENSOR_INFO
+#define USE_CRSF_CMS_TELEMETRY
+#endif
+
+#endif // FLASH_SIZE > 128
+
 #if (FLASH_SIZE > 256)
 #define USE_DASHBOARD
 #define USE_GPS