RIOT/cpu/esp8266/Makefile.include

# check some environment variables first

ifndef ESP8266_NEWLIB_DIR
    $(info ESP8266_NEWLIB_DIR should be defined as /path/to/newlib directory)
    $(info ESP8266_NEWLIB_DIR is set by default to /opt/esp/newlib-xtensa)
    export ESP8266_NEWLIB_DIR=/opt/esp/newlib-xtensa
endif

ifndef ESP8266_SDK_DIR
    $(info ESP8266_SDK_DIR should be defined as /path/to/sdk directory)
    $(info ESP8266_SDK_DIR is set by default to /opt/esp/esp-open-sdk/sdk)
    export ESP8266_SDK_DIR=/opt/esp/esp-open-sdk/sdk
endif

# Options to control the compilation

ifeq ($(USE_SDK), 1)
    USEMODULE += esp_sdk
endif

ifeq ($(ENABLE_GDB), 1)
    USEMODULE += esp_gdb
endif

ifeq ($(ENABLE_GDBSTUB), 1)
    USEMODULE += esp_gdbstub
endif

# SPECIAL module dependencies
# cannot be done in Makefile.dep since Makefile.dep is included too late

ifneq (, $(filter esp_sw_timer, $(USEMODULE)))
    USEMODULE += esp_sdk
endif

ifneq (, $(filter esp_now esp_wifi, $(USEMODULE)))
    $(eval GNRC_NETIF_NUMOF=$(shell echo $$(($(GNRC_NETIF_NUMOF)+1))))
    USEMODULE += esp_sdk
    USEMODULE += netopt
endif

ifneq (, $(filter esp_gdbstub, $(USEMODULE)))
    USEMODULE += esp_gdb
endif

# regular Makefile

export TARGET_ARCH ?= xtensa-lx106-elf

# ESP8266 pseudomodules
PSEUDOMODULES += esp_gdb
PSEUDOMODULES += esp_sdk
PSEUDOMODULES += esp_sw_timer
PSEUDOMODULES += esp_spiffs

USEMODULE += esp
USEMODULE += mtd
USEMODULE += periph
USEMODULE += ps
USEMODULE += random
USEMODULE += sdk
USEMODULE += xtensa

ifneq (, $(filter pthread, $(USEMODULE)))
    # has to be included before $(ESP8266_NEWLIB_DIR)
    INCLUDES += -I$(RIOTBASE)/sys/posix/pthread/include
endif

INCLUDES += -I$(ESP8266_NEWLIB_DIR)/$(TARGET_ARCH)/include
INCLUDES += -I$(RIOTBOARD)/common/$(CPU)/include
INCLUDES += -I$(RIOTCPU)/esp_common/vendor/
INCLUDES += -I$(RIOTCPU)/$(CPU)
INCLUDES += -I$(RIOTCPU)/$(CPU)/vendor
INCLUDES += -I$(RIOTCPU)/$(CPU)/vendor/espressif

CFLAGS  += -DESP_OPEN_SDK -DSCHED_PRIO_LEVELS=32 -DCONTEXT_SWITCH_BY_INT
CFLAGS  += -Wno-unused-parameter -Wformat=0
CFLAGS  += -mlongcalls -mtext-section-literals
CFLAGS  += -fdata-sections -fzero-initialized-in-bss
ASFLAGS += --longcalls --text-section-literals

ifneq (, $(filter esp_sdk, $(USEMODULE)))
    INCLUDES += -I$(ESP8266_SDK_DIR)/include
    CFLAGS   += -DUSE_US_TIMER
endif

ifneq (, $(filter esp_gdbstub, $(USEMODULE)))
    GDBSTUB_DIR ?= $(RIOTCPU)/$(CPU)/vendor/esp-gdbstub
    CFLAGS      += -DGDBSTUB_FREERTOS=0
    INCLUDES    += -I$(GDBSTUB_DIR)
endif

ifneq (, $(filter esp_gdb, $(USEMODULE)))
    CFLAGS += -Og -ggdb -g3
else
    CFLAGS += -Os
endif

ifeq ($(QEMU), 1)
    CFLAGS += -DQEMU
endif

ifeq ($(FLASH_MODE), qio)
    CFLAGS += -DFLASH_MODE_QIO
endif

ifeq ($(FLASH_MODE), qout)
    CFLAGS += -DFLASH_MODE_QOUT
endif

LINKFLAGS += -L$(ESP8266_NEWLIB_DIR)/$(TARGET_ARCH)/lib
LINKFLAGS += -L$(ESP8266_SDK_DIR)/lib

ifneq (, $(filter esp_sdk, $(USEMODULE)))
    LINKFLAGS += -Wl,--start-group $(BINDIR)/sdk.a
    ifneq (, $(filter esp_now, $(USEMODULE)))
        LINKFLAGS += -lespnow
    endif
    LINKFLAGS += -lmain -lnet80211 -lcrypto -lwpa2 -lwpa -llwip -lpp -lphy -lc -lhal
    LINKFLAGS += -Wl,--end-group
    LINKFLAGS += -T$(RIOTCPU)/$(CPU)/ld/esp8266.riot-os.sdk.app.ld
else
    LINKFLAGS += -Wl,--start-group -lphy -lhal -lc -Wl,--end-group
    LINKFLAGS += -T$(RIOTCPU)/$(CPU)/ld/esp8266.riot-os.no_sdk.app.ld
endif

LINKFLAGS += -T$(RIOTCPU)/$(CPU)/ld/eagle.rom.addr.v6.ld
LINKFLAGS += -nostdlib -lgcc -u ets_run -Wl,-gc-sections # -Wl,--print-gc-sections
LINKFLAGS += -Wl,--warn-unresolved-symbols

# configure preflasher to convert .elf to .bin before flashing
FLASH_SIZE = -fs 8m
PREFLASHER ?= esptool.py
PREFFLAGS  ?= elf2image $(FLASH_SIZE) $(ELFFILE)
FLASHDEPS  ?= preflash

# flasher configuration
ifeq ($(QEMU), 1)
    FLASHER = cat
    FFLAGS += $(ELFFILE)-0x00000.bin /dev/zero | head -c $$((0x10000)) | cat -
    FFLAGS += $(ELFFILE)-0x10000.bin /dev/zero | head -c $$((0xfc000)) | cat -
    FFLAGS += $(RIOTCPU)/$(CPU)/bin/esp_init_data_default.bin > $(ELFFILE).bin
else
    FLASH_MODE ?= dout
    export PROGRAMMER_SPEED ?= 460800
    FLASHER = esptool.py
    FFLAGS += -p $(PORT) -b $(PROGRAMMER_SPEED) write_flash
    FFLAGS += -fm $(FLASH_MODE)
    FFLAGS += 0 $(ELFFILE)-0x00000.bin
    FFLAGS += 0x10000 $(ELFFILE)-0x10000.bin; esptool.py -p $(PORT) run
endif