Changed some source file paths for SRC_C to relative paths.

Added statements to validate GCCVERSION on Windows Command Prompt.

hw/bsp/adafruit_clue/board.mk

@@ -14,9 +14,15 @@ CFLAGS += -Wno-error=undef -Wno-error=unused-parameter -Wno-error=cast-align
 
 # due to tusb_hal_nrf_power_event
 GCCVERSION = $(firstword $(subst ., ,$(shell arm-none-eabi-gcc -dumpversion)))
+ifeq ($(UNAME),Windows)
+ifeq ($(shell if $(GCCVERSION) geq 8 echo 1), 1)
+CFLAGS += -Wno-error=cast-function-type
+endif
+else
 ifeq ($(shell expr $(GCCVERSION) \>= 8), 1)
 CFLAGS += -Wno-error=cast-function-type
 endif
+endif
 
 # All source paths should be relative to the top level.
 LD_FILE = hw/bsp/$(BOARD)/nrf52840_s140_v6.ld

hw/bsp/arduino_nano33_ble/board.mk

@@ -14,9 +14,15 @@ CFLAGS += -Wno-error=undef -Wno-error=unused-parameter -Wno-error=cast-align
 
 # due to tusb_hal_nrf_power_event
 GCCVERSION = $(firstword $(subst ., ,$(shell arm-none-eabi-gcc -dumpversion)))
+ifeq ($(UNAME),Windows)
+ifeq ($(shell if $(GCCVERSION) geq 8 echo 1), 1)
+CFLAGS += -Wno-error=cast-function-type
+endif
+else
 ifeq ($(shell expr $(GCCVERSION) \>= 8), 1)
 CFLAGS += -Wno-error=cast-function-type
 endif
+endif
 
 # All source paths should be relative to the top level.
 #LD_FILE = hw/bsp/$(BOARD)/linker_script.ld

hw/bsp/circuitplayground_bluefruit/board.mk

@@ -14,9 +14,15 @@ CFLAGS += -Wno-error=undef -Wno-error=unused-parameter -Wno-error=cast-align
 
 # due to tusb_hal_nrf_power_event
 GCCVERSION = $(firstword $(subst ., ,$(shell arm-none-eabi-gcc -dumpversion)))
+ifeq ($(UNAME),Windows)
+ifeq ($(shell if $(GCCVERSION) geq 8 echo 1), 1)
+CFLAGS += -Wno-error=cast-function-type
+endif
+else
 ifeq ($(shell expr $(GCCVERSION) \>= 8), 1)
 CFLAGS += -Wno-error=cast-function-type
 endif
+endif
 
 # All source paths should be relative to the top level.
 LD_FILE = hw/bsp/$(BOARD)/nrf52840_s140_v6.ld

hw/bsp/da14695_dk_usb/board.mk

@@ -21,7 +21,7 @@ SRC_C += \
 	$(MCU_FAMILY_DIR)/src/da1469x_clock.c \
 	$(MCU_FAMILY_DIR)/src/hal_gpio.c \
 
-SRC_S += $(TOP)/hw/bsp/$(BOARD)/gcc_startup_da1469x.S
+SRC_S += hw/bsp/$(BOARD)/gcc_startup_da1469x.S
 
 INC += \
 	$(TOP)/hw/bsp/$(BOARD) \

hw/bsp/da1469x_dk_pro/board.mk

@@ -21,7 +21,7 @@ SRC_C += \
 	$(MCU_FAMILY_DIR)/src/da1469x_clock.c \
 	$(MCU_FAMILY_DIR)/src/hal_gpio.c \
 
-SRC_S += $(TOP)/hw/bsp/$(BOARD)/gcc_startup_da1469x.S
+SRC_S += hw/bsp/$(BOARD)/gcc_startup_da1469x.S
 
 INC += \
 	$(TOP)/hw/bsp/$(BOARD) \

hw/bsp/double_m33_express/board.mk

@@ -26,7 +26,7 @@ SRC_C += \
 	$(MCU_DIR)/drivers/fsl_reset.c \
 	$(MCU_DIR)/drivers/fsl_usart.c \
 	$(MCU_DIR)/drivers/fsl_flexcomm.c \
-	$(TOP)/lib/sct_neopixel/sct_neopixel.c 
+	lib/sct_neopixel/sct_neopixel.c 
 
 INC += \
     $(TOP)/hw/bsp/ \

hw/bsp/feather_nrf52840_express/board.mk

@@ -14,9 +14,15 @@ CFLAGS += -Wno-error=undef -Wno-error=unused-parameter -Wno-error=cast-align
 
 # due to tusb_hal_nrf_power_event
 GCCVERSION = $(firstword $(subst ., ,$(shell arm-none-eabi-gcc -dumpversion)))
+ifeq ($(UNAME),Windows)
+ifeq ($(shell if $(GCCVERSION) geq 8 echo 1), 1)
+CFLAGS += -Wno-error=cast-function-type
+endif
+else
 ifeq ($(shell expr $(GCCVERSION) \>= 8), 1)
 CFLAGS += -Wno-error=cast-function-type
 endif
+endif
 
 # All source paths should be relative to the top level.
 LD_FILE = hw/bsp/$(BOARD)/nrf52840_s140_v6.ld

hw/bsp/feather_nrf52840_sense/board.mk

@@ -14,9 +14,15 @@ CFLAGS += -Wno-error=undef -Wno-error=unused-parameter -Wno-error=cast-align
 
 # due to tusb_hal_nrf_power_event
 GCCVERSION = $(firstword $(subst ., ,$(shell arm-none-eabi-gcc -dumpversion)))
+ifeq ($(UNAME),Windows)
+ifeq ($(shell if $(GCCVERSION) geq 8 echo 1), 1)
+CFLAGS += -Wno-error=cast-function-type
+endif
+else
 ifeq ($(shell expr $(GCCVERSION) \>= 8), 1)
 CFLAGS += -Wno-error=cast-function-type
 endif
+endif
 
 # All source paths should be relative to the top level.
 LD_FILE = hw/bsp/$(BOARD)/nrf52840_s140_v6.ld

hw/bsp/itsybitsy_nrf52840/board.mk

@@ -14,9 +14,15 @@ CFLAGS += -Wno-error=undef -Wno-error=unused-parameter -Wno-error=cast-align
 
 # due to tusb_hal_nrf_power_event
 GCCVERSION = $(firstword $(subst ., ,$(shell arm-none-eabi-gcc -dumpversion)))
+ifeq ($(UNAME),Windows)
+ifeq ($(shell if $(GCCVERSION) geq 8 echo 1), 1)
+CFLAGS += -Wno-error=cast-function-type
+endif
+else
 ifeq ($(shell expr $(GCCVERSION) \>= 8), 1)
 CFLAGS += -Wno-error=cast-function-type
 endif
+endif
 
 # All source paths should be relative to the top level.
 LD_FILE = hw/bsp/$(BOARD)/nrf52840_s140_v6.ld

hw/bsp/nrf52840_mdk_dongle/board.mk

@@ -13,9 +13,15 @@ CFLAGS += -Wno-error=undef -Wno-error=unused-parameter -Wno-error=cast-align
 
 # due to tusb_hal_nrf_power_event
 GCCVERSION = $(firstword $(subst ., ,$(shell arm-none-eabi-gcc -dumpversion)))
+ifeq ($(UNAME),Windows)
+ifeq ($(shell if $(GCCVERSION) geq 8 echo 1), 1)
+CFLAGS += -Wno-error=cast-function-type
+endif
+else
 ifeq ($(shell expr $(GCCVERSION) \>= 8), 1)
 CFLAGS += -Wno-error=cast-function-type
 endif
+endif
 
 # All source paths should be relative to the top level.
 LD_FILE = hw/bsp/$(BOARD)/$(BOARD).ld

hw/bsp/pca10056/board.mk

@@ -14,9 +14,15 @@ CFLAGS += -Wno-error=undef -Wno-error=unused-parameter -Wno-error=cast-align
 
 # due to tusb_hal_nrf_power_event
 GCCVERSION = $(firstword $(subst ., ,$(shell arm-none-eabi-gcc -dumpversion)))
+ifeq ($(UNAME),Windows)
+ifeq ($(shell if $(GCCVERSION) geq 8 echo 1), 1)
+CFLAGS += -Wno-error=cast-function-type
+endif
+else
 ifeq ($(shell expr $(GCCVERSION) \>= 8), 1)
 CFLAGS += -Wno-error=cast-function-type
 endif
+endif
 
 # All source paths should be relative to the top level.
 LD_FILE = hw/mcu/nordic/nrfx/mdk/nrf52840_xxaa.ld

hw/bsp/pca10059/board.mk

@@ -14,9 +14,15 @@ CFLAGS += -Wno-error=undef -Wno-error=unused-parameter -Wno-error=cast-align
 
 # due to tusb_hal_nrf_power_event
 GCCVERSION = $(firstword $(subst ., ,$(shell arm-none-eabi-gcc -dumpversion)))
+ifeq ($(UNAME),Windows)
+ifeq ($(shell if $(GCCVERSION) geq 8 echo 1), 1)
+CFLAGS += -Wno-error=cast-function-type
+endif
+else
 ifeq ($(shell expr $(GCCVERSION) \>= 8), 1)
 CFLAGS += -Wno-error=cast-function-type
 endif
+endif
 
 # All source paths should be relative to the top level.
 LD_FILE = hw/bsp/$(BOARD)/$(BOARD).ld

hw/bsp/pca10100/board.mk

@@ -14,9 +14,15 @@ CFLAGS += -Wno-error=undef -Wno-error=unused-parameter -Wno-error=cast-align
 
 # due to tusb_hal_nrf_power_event
 GCCVERSION = $(firstword $(subst ., ,$(shell arm-none-eabi-gcc -dumpversion)))
+ifeq ($(UNAME),Windows)
+ifeq ($(shell if $(GCCVERSION) geq 8 echo 1), 1)
+CFLAGS += -Wno-error=cast-function-type
+endif
+else
 ifeq ($(shell expr $(GCCVERSION) \>= 8), 1)
 CFLAGS += -Wno-error=cast-function-type
 endif
+endif
 
 # All source paths should be relative to the top level.
 LD_FILE = hw/mcu/nordic/nrfx/mdk/nrf52833_xxaa.ld

hw/bsp/raytac_mdbt50q_rx/board.mk

@@ -13,9 +13,15 @@ CFLAGS += -Wno-error=undef -Wno-error=unused-parameter -Wno-error=cast-align
 
 # due to tusb_hal_nrf_power_event
 GCCVERSION = $(firstword $(subst ., ,$(shell arm-none-eabi-gcc -dumpversion)))
+ifeq ($(UNAME),Windows)
+ifeq ($(shell if $(GCCVERSION) geq 8 echo 1), 1)
+CFLAGS += -Wno-error=cast-function-type
+endif
+else
 ifeq ($(shell expr $(GCCVERSION) \>= 8), 1)
 CFLAGS += -Wno-error=cast-function-type
 endif
+endif
 
 # All source paths should be relative to the top level.
 LD_FILE = hw/mcu/nordic/nrfx/mdk/nrf52840_xxaa.ld