Variables are defined in buildroot/package/Makefile.in

• $(TARGET_CC) - cross compiler gcc binary (i.e.: TARGET_CC=/home/user/project/out/host/usr/bin/ccache /home/user/project/out/host/usr/bin/arm-linux-gcc)
• $(TARGET_AR) $(TARGET_AS) $(TARGET_CPP) $(TARGET_CXX) _FC _LD _NM _RANLIB _READELF _OBJCOPY _OBJDUMP
• $(TARGET_CC_NOCCACHE)
• $(TARGET_CXX_NOCCACHE)

• $(TARGET_CFLAGS) - (i.e: TARGET_CFLAGS=-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -Os -g2)
• $(TARGEt_CPPFLAGS)
• $(TARGET_CXXFLAGS)
• $(TARGET_LDFLAGS)

• $(TARGET_MAKE_ENV) - env which has to be set for cross compilation. It overrides search path, to get cross compiler first. (i.e:PATH=“/home/user/project/out/host/bin:/home/user/project/out/host/ …)
• $(TARGET_DIR) - device root filesystem (i.e: needed for installing packages into $(TARGET_DIR)/usr/bin)
• $(STAGING_DIR) - development target root filesystem (contains all needed libraries to build other packages, contains debug info and not stripped binary)

Additional variables (not needed in normal use)

• $(CCACHE) - full path to ccache binary or empty (i.e: CCACHE=/home/user/project/out/host/usr/bin/ccache)
• $(TARGET_CROSS) - prefix with full path to cross compiler (i.e: TARGET_CROSS=/home/user/project/out/host/usr/bin/arm-linux-)
• $(ABI) - gnueabi[hf] | eabi[hf]
• $(GNU_TARGET_NAME) GNU_TARGET_NAME=arm-buildroot-linux-uclibcgnueabi

################################################################################
#
# genromfs
#
################################################################################

GENROMFS_VERSION = 0.5.2
GENROMFS_SITE = http://downloads.sourceforge.net/project/romfs/genromfs/$(GENROMFS_VERSION)
GENROMFS_LICENSE = GPLv2+
GENROMFS_LICENSE_FILES = COPYING

define GENROMFS_BUILD_CMDS
        $(TARGET_MAKE_ENV) $(MAKE) -C $(@D) \
                CC="$(TARGET_CC)" \
                CFLAGS="$(TARGET_CFLAGS)" \
                LDFLAGS="$(TARGET_LDFLAGS)"
endef

define GENROMFS_INSTALL_TARGET_CMDS
        $(TARGET_MAKE_ENV) $(MAKE) -C $(@D) PREFIX=$(TARGET_DIR) install
endef

define HOST_GENROMFS_BUILD_CMDS
        $(HOST_MAKE_ENV) $(MAKE) -C $(@D)
endef

define HOST_GENROMFS_INSTALL_CMDS
        $(HOST_MAKE_ENV) $(MAKE) -C $(@D) PREFIX=$(HOST_DIR) install
endef

$(eval $(generic-package))
$(eval $(host-generic-package))