added board files

hw/bsp/gr_citrus/board.mk

@@ -0,0 +1,54 @@
+CFLAGS += \
+  -nostartfiles \
+  -nostdinc \
+  -ffunction-sections \
+  -fdata-sections \
+  -mcpu=rx610 \
+  -misa=v1 \
+  -mlittle-endian-data \
+  -DCFG_TUSB_MCU=OPT_MCU_RX63X
+
+# Cross Compiler for RX
+CROSS_COMPILE = rx-elf-
+
+ifeq ($(CMDEXE),1)
+OPTLIBINC="$(shell for /F "usebackq delims=" %%i in (`where rx-elf-gcc`) do echo %%~dpi..\rx-elf\optlibinc)"
+else
+OPTLIBINC=$(shell dirname `which rx-elf-gcc`)../rx-elf/optlibinc
+endif
+
+# mcu driver cause following warnings
+CFLAGS += -isystem $(OPTLIBINC)
+
+LIBS += -loptm -loptc
+
+MCU_DIR = hw/mcu/renesas/rx63n
+
+# All source paths should be relative to the top level.
+LD_FILE = hw/bsp/$(BOARD)/r5f5631fd.ld
+
+SRC_C += \
+	$(MCU_DIR)/vects.c
+
+INC += \
+	$(TOP)/hw/bsp/$(BOARD) \
+	$(TOP)/$(MCU_DIR)
+
+SRC_S += $(MCU_DIR)/start.S
+
+# For TinyUSB port source
+VENDOR = renesas
+CHIP_FAMILY = usba
+
+# For freeRTOS port source
+FREERTOS_PORT = RX600
+
+# For flash-jlink target
+JLINK_DEVICE = R5F5631F
+JLINK_IF     = JTAG
+
+# For flash-pyocd target
+PYOCD_TARGET =
+
+# flash using jlink
+flash: flash-jlink