ifeq (, $(NEWLIB_BASE))
  NEWLIB_BASE := $(RIOTBASE)/toolchain/x86/i586-none-elf
endif

ifneq (0, $(shell test -e "$(NEWLIB_BASE)/lib/libc.a" && echo $$?))
  NEWLIB_PRECOMPILED_NAME := i586-newlib_2.2.0.20150623_tlsf-3337.tar.bz2
  NEWLIB_PRECOMPILED := http://download.riot-os.org/$(NEWLIB_PRECOMPILED_NAME)

  $(warning Precompiled newlib is missing in $(NEWLIB_BASE))
  $(warning Downloading from $(NEWLIB_PRECOMPILED))

  $(shell cd $(RIOTBASE) && $(DOWNLOAD_TO_STDOUT) "$(NEWLIB_PRECOMPILED)" | tar xj)
endif

ifeq (,$(BUILD_INCLUDE_BASE))
  GCC_BUILD_TRIPLET ?= $(shell gcc -dumpmachine)
  GCC_BUILD_VERSION ?= $(shell gcc -dumpversion)
  BUILD_INCLUDE_BASE = /usr/lib/gcc/$(GCC_BUILD_TRIPLET)/$(GCC_BUILD_VERSION)

  ifeq (,$(shell echo $(GCC_BUILD_TRIPLET) | sed -e 's,-.*,,' | grep -e '\(x\|i[3-7]\)86'))
    $(warning Your build machine is a(n) $(GCC_BUILD_TRIPLET).)
    $(warning Since this is not IA32 compatible, you must set BUILD_INCLUDE_BASE explicitly!)
  endif
endif

export INCLUDES += -isystem $(BUILD_INCLUDE_BASE)/include \
                   -isystem $(NEWLIB_BASE)/include \
                   -isystem $(NEWLIB_BASE)/sys-include \
                   -isystem $(BUILD_INCLUDE_BASE)/include-fixed \
                   -I$(RIOTBOARD)/x86-multiboot-common/include
export CPU = x86

# toolchain config
export CC ?= $(PREFIX)gcc
ifeq ($(LTO),1)
export AR = $(PREFIX)gcc-ar
else
export AR = $(PREFIX)ar
endif
export AS ?= $(PREFIX)as
export RANLIB ?= $(PREFIX)ranlib
export LINK ?= $(RIOTBASE)/boards/x86-multiboot-common/dist/link $(PREFIX)gcc
export SIZE ?= $(PREFIX)size
export OBJCOPY ?= $(PREFIX)objcopy

export CFLAGS += -m32 -mfpmath=387 -ffreestanding -nostdlib -nostdinc -fno-builtin
export OFLAGS = -O binary

LINKFLAGS += -m32 -nostdlib -nostdinc -nostartfiles -nodefaultlibs \
             --prefix=$(NEWLIB_BASE) \
             -Wl,-rpath,$(NEWLIB_BASE)/lib \
             -T$(RIOTBASE)/boards/x86-multiboot-common/linker.ld

# clean up unused functions
export CFLAGS += -ffunction-sections -fdata-sections
export LINKFLAGS += -Wl,--gc-sections

UNDEF += $(BINDIR)/x86-multiboot-common/startup.o

BASELIBS += $(NEWLIB_BASE)/lib/libc.a \
            $(NEWLIB_BASE)/lib/libm.a

all:

all-debug: export CFLAGS += -ggdb3 -O0
all-debug: all