src/kernel/linux/v4.19/arch/mips/Makefile

#
# This file is subject to the terms and conditions of the GNU General Public
# License.  See the file "COPYING" in the main directory of this archive
# for more details.
#
# Copyright (C) 1994, 95, 96, 2003 by Ralf Baechle
# DECStation modifications by Paul M. Antoine, 1996
# Copyright (C) 2002, 2003, 2004  Maciej W. Rozycki
#
# This file is included by the global makefile so that you can add your own
# architecture-specific flags and dependencies. Remember to do have actions
# for "archclean" cleaning up for this architecture.
#

archscripts: scripts_basic
	$(Q)$(MAKE) $(build)=arch/mips/boot/tools relocs

KBUILD_DEFCONFIG := 32r2el_defconfig
KBUILD_DTBS      := dtbs

#
# Select the object file format to substitute into the linker script.
#
ifdef CONFIG_CPU_LITTLE_ENDIAN
32bit-tool-archpref	= mipsel
64bit-tool-archpref	= mips64el
32bit-bfd		= elf32-tradlittlemips
64bit-bfd		= elf64-tradlittlemips
32bit-emul		= elf32ltsmip
64bit-emul		= elf64ltsmip
else
32bit-tool-archpref	= mips
64bit-tool-archpref	= mips64
32bit-bfd		= elf32-tradbigmips
64bit-bfd		= elf64-tradbigmips
32bit-emul		= elf32btsmip
64bit-emul		= elf64btsmip
endif

ifdef CONFIG_32BIT
tool-archpref		= $(32bit-tool-archpref)
UTS_MACHINE		:= mips
endif
ifdef CONFIG_64BIT
tool-archpref		= $(64bit-tool-archpref)
UTS_MACHINE		:= mips64
endif

ifneq ($(SUBARCH),$(ARCH))
  ifeq ($(CROSS_COMPILE),)
    CROSS_COMPILE := $(call cc-cross-prefix, $(tool-archpref)-linux-  $(tool-archpref)-linux-gnu-  $(tool-archpref)-unknown-linux-gnu-)
  endif
endif

ifdef CONFIG_FUNCTION_GRAPH_TRACER
  ifndef KBUILD_MCOUNT_RA_ADDRESS
    ifeq ($(call cc-option-yn,-mmcount-ra-address), y)
      cflags-y += -mmcount-ra-address -DKBUILD_MCOUNT_RA_ADDRESS
    endif
  endif
endif
cflags-y += $(call cc-option, -mno-check-zero-division)

ifdef CONFIG_32BIT
ld-emul			= $(32bit-emul)
vmlinux-32		= vmlinux
vmlinux-64		= vmlinux.64

cflags-y		+= -mabi=32
endif

ifdef CONFIG_64BIT
ld-emul			= $(64bit-emul)
vmlinux-32		= vmlinux.32
vmlinux-64		= vmlinux

cflags-y		+= -mabi=64
endif

all-$(CONFIG_BOOT_ELF32)	:= $(vmlinux-32)
all-$(CONFIG_BOOT_ELF64)	:= $(vmlinux-64)
all-$(CONFIG_SYS_SUPPORTS_ZBOOT)+= vmlinuz

#
# GCC uses -G 0 -mabicalls -fpic as default.  We don't want PIC in the kernel
# code since it only slows down the whole thing.  At some point we might make
# use of global pointer optimizations but their use of $28 conflicts with
# the current pointer optimization.
#
# The DECStation requires an ECOFF kernel for remote booting, other MIPS
# machines may also.  Since BFD is incredibly buggy with respect to
# crossformat linking we rely on the elf2ecoff tool for format conversion.
#
cflags-y			+= -G 0 -mno-abicalls -fno-pic -pipe -mno-branch-likely
cflags-y			+= -msoft-float
LDFLAGS_vmlinux			+= -G 0 -static -n -nostdlib
ifdef CONFIG_64BIT
KBUILD_AFLAGS_MODULE		+= -mlong-calls
KBUILD_CFLAGS_MODULE		+= -mlong-calls
else
  ifdef CONFIG_DYNAMIC_FTRACE
    KBUILD_AFLAGS_MODULE	+= -mlong-calls
    KBUILD_CFLAGS_MODULE	+= -mlong-calls
  else
    KBUILD_AFLAGS_MODULE	+= -mno-long-calls
    KBUILD_CFLAGS_MODULE	+= -mno-long-calls
  endif
endif

ifeq ($(CONFIG_RELOCATABLE),y)
LDFLAGS_vmlinux			+= --emit-relocs
endif

#
# pass -msoft-float to GAS if it supports it.  However on newer binutils
# (specifically newer than 2.24.51.20140728) we then also need to explicitly
# set ".set hardfloat" in all files which manipulate floating point registers.
#
ifneq ($(call as-option,-Wa$(comma)-msoft-float,),)
	cflags-y		+= -DGAS_HAS_SET_HARDFLOAT -Wa,-msoft-float
endif

cflags-y += -ffreestanding

#
# We explicitly add the endianness specifier if needed, this allows
# to compile kernels with a toolchain for the other endianness. We
# carefully avoid to add it redundantly because gcc 3.3/3.4 complains
# when fed the toolchain default!
#
# Certain gcc versions up to gcc 4.1.1 (probably 4.2-subversion as of
# 2006-10-10 don't properly change the predefined symbols if -EB / -EL
# are used, so we kludge that here.  A bug has been filed at
# http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29413.
#
# clang doesn't suffer from these issues and our checks against -dumpmachine
# don't work so well when cross compiling, since without providing --target
# clang's output will be based upon the build machine. So for clang we simply
# unconditionally specify -EB or -EL as appropriate.
#
ifeq ($(cc-name),clang)
cflags-$(CONFIG_CPU_BIG_ENDIAN)		+= -EB
cflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -EL
else
undef-all += -UMIPSEB -U_MIPSEB -U__MIPSEB -U__MIPSEB__
undef-all += -UMIPSEL -U_MIPSEL -U__MIPSEL -U__MIPSEL__
predef-be += -DMIPSEB -D_MIPSEB -D__MIPSEB -D__MIPSEB__
predef-le += -DMIPSEL -D_MIPSEL -D__MIPSEL -D__MIPSEL__
cflags-$(CONFIG_CPU_BIG_ENDIAN)		+= $(shell $(CC) -dumpmachine |grep -q 'mips.*el-.*' && echo -EB $(undef-all) $(predef-be))
cflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= $(shell $(CC) -dumpmachine |grep -q 'mips.*el-.*' || echo -EL $(undef-all) $(predef-le))
endif

cflags-$(CONFIG_SB1XXX_CORELIS)	+= $(call cc-option,-mno-sched-prolog) \
				   -fno-omit-frame-pointer

# Some distribution-specific toolchains might pass the -fstack-check
# option during the build, which adds a simple stack-probe at the beginning
# of every function.  This stack probe is to ensure that there is enough
# stack space, else a SEGV is generated.  This is not desirable for MIPS
# as kernel stacks are small, placed in unmapped virtual memory, and do not
# grow when overflowed.  Especially on SGI IP27 platforms, this check will
# lead to a NULL pointer dereference in _raw_spin_lock_irq.
#
# In disassembly, this stack probe appears at the top of a function as:
#    sd		zero,<offset>(sp)
# Where <offset> is a negative value.
#
cflags-y += -fno-stack-check

#
# CPU-dependent compiler/assembler options for optimization.
#
cflags-$(CONFIG_CPU_R3000)	+= -march=r3000
cflags-$(CONFIG_CPU_TX39XX)	+= -march=r3900
cflags-$(CONFIG_CPU_R4300)	+= -march=r4300 -Wa,--trap
cflags-$(CONFIG_CPU_VR41XX)	+= -march=r4100 -Wa,--trap
cflags-$(CONFIG_CPU_R4X00)	+= -march=r4600 -Wa,--trap
cflags-$(CONFIG_CPU_TX49XX)	+= -march=r4600 -Wa,--trap
cflags-$(CONFIG_CPU_MIPS32_R1)	+= -march=mips32 -Wa,--trap
cflags-$(CONFIG_CPU_MIPS32_R2)	+= -march=mips32r2 -mtune=34kc -Wa,--trap
cflags-$(CONFIG_CPU_MIPS32_R6)	+= -march=mips32r6 -Wa,--trap -modd-spreg
cflags-$(CONFIG_CPU_MIPS64_R1)	+= -march=mips64 -Wa,--trap
cflags-$(CONFIG_CPU_MIPS64_R2)	+= -march=mips64r2 -Wa,--trap
cflags-$(CONFIG_CPU_MIPS64_R6)	+= -march=mips64r6 -Wa,--trap
cflags-$(CONFIG_CPU_R5000)	+= -march=r5000 -Wa,--trap
cflags-$(CONFIG_CPU_R5432)	+= $(call cc-option,-march=r5400,-march=r5000) \
			-Wa,--trap
cflags-$(CONFIG_CPU_R5500)	+= $(call cc-option,-march=r5500,-march=r5000) \
			-Wa,--trap
cflags-$(CONFIG_CPU_NEVADA)	+= $(call cc-option,-march=rm5200,-march=r5000) \
			-Wa,--trap
cflags-$(CONFIG_CPU_RM7000)	+= $(call cc-option,-march=rm7000,-march=r5000) \
			-Wa,--trap
cflags-$(CONFIG_CPU_SB1)	+= $(call cc-option,-march=sb1,-march=r5000) \
			-Wa,--trap
cflags-$(CONFIG_CPU_SB1)	+= $(call cc-option,-mno-mdmx)
cflags-$(CONFIG_CPU_SB1)	+= $(call cc-option,-mno-mips3d)
cflags-$(CONFIG_CPU_R8000)	+= -march=r8000 -Wa,--trap
cflags-$(CONFIG_CPU_R10000)	+= $(call cc-option,-march=r10000,-march=r8000) \
			-Wa,--trap
cflags-$(CONFIG_CPU_CAVIUM_OCTEON) += $(call cc-option,-march=octeon) -Wa,--trap
ifeq (,$(findstring march=octeon, $(cflags-$(CONFIG_CPU_CAVIUM_OCTEON))))
cflags-$(CONFIG_CPU_CAVIUM_OCTEON) += -Wa,-march=octeon
endif
cflags-$(CONFIG_CAVIUM_CN63XXP1) += -Wa,-mfix-cn63xxp1
cflags-$(CONFIG_CPU_BMIPS)	+= -march=mips32 -Wa,-mips32 -Wa,--trap

cflags-$(CONFIG_CPU_R4000_WORKAROUNDS)	+= $(call cc-option,-mfix-r4000,)
cflags-$(CONFIG_CPU_R4400_WORKAROUNDS)	+= $(call cc-option,-mfix-r4400,)
cflags-$(CONFIG_CPU_DADDI_WORKAROUNDS)	+= $(call cc-option,-mno-daddi,)

# For smartmips configurations, there are hundreds of warnings due to ISA overrides
# in assembly and header files. smartmips is only supported for MIPS32r1 onwards
# and there is no support for 64-bit. Various '.set mips2' or '.set mips3' or
# similar directives in the kernel will spam the build logs with the following warnings:
# Warning: the `smartmips' extension requires MIPS32 revision 1 or greater
# or
# Warning: the 64-bit MIPS architecture does not support the `smartmips' extension
# Pass -Wa,--no-warn to disable all assembler warnings until the kernel code has
# been fixed properly.
mips-cflags				:= $(cflags-y)
ifeq ($(CONFIG_CPU_HAS_SMARTMIPS),y)
smartmips-ase				:= $(call cc-option-yn,$(mips-cflags) -msmartmips)
cflags-$(smartmips-ase)			+= -msmartmips -Wa,--no-warn
endif
ifeq ($(CONFIG_CPU_MICROMIPS),y)
micromips-ase				:= $(call cc-option-yn,$(mips-cflags) -mmicromips)
cflags-$(micromips-ase)			+= -mmicromips
endif
ifeq ($(CONFIG_CPU_HAS_MSA),y)
toolchain-msa				:= $(call cc-option-yn,$(mips-cflags) -mhard-float -mfp64 -Wa$(comma)-mmsa)
cflags-$(toolchain-msa)			+= -DTOOLCHAIN_SUPPORTS_MSA
endif
toolchain-virt				:= $(call cc-option-yn,$(mips-cflags) -mvirt)
cflags-$(toolchain-virt)		+= -DTOOLCHAIN_SUPPORTS_VIRT
# For -mmicromips, use -Wa,-fatal-warnings to catch unsupported -mxpa which
# only warns
xpa-cflags-y				:= $(mips-cflags)
xpa-cflags-$(micromips-ase)		+= -mmicromips -Wa$(comma)-fatal-warnings
toolchain-xpa				:= $(call cc-option-yn,$(xpa-cflags-y) -mxpa)
cflags-$(toolchain-xpa)			+= -DTOOLCHAIN_SUPPORTS_XPA
toolchain-crc				:= $(call cc-option-yn,$(mips-cflags) -Wa$(comma)-mcrc)
cflags-$(toolchain-crc)			+= -DTOOLCHAIN_SUPPORTS_CRC

#
# Firmware support
#
libs-$(CONFIG_FW_ARC)		+= arch/mips/fw/arc/
libs-$(CONFIG_FW_CFE)		+= arch/mips/fw/cfe/
libs-$(CONFIG_FW_SNIPROM)	+= arch/mips/fw/sni/
libs-y				+= arch/mips/fw/lib/

#
# Kernel compression
#
ifdef CONFIG_SYS_SUPPORTS_ZBOOT
COMPRESSION_FNAME		= vmlinuz
else
COMPRESSION_FNAME		= vmlinux
endif

#
# Board-dependent options and extra files
#
include arch/mips/Kbuild.platforms

ifdef CONFIG_PHYSICAL_START
load-y					= $(CONFIG_PHYSICAL_START)
endif

# Sign-extend the entry point to 64 bits if retrieved as a 32-bit number.
entry-y		= $(shell $(OBJDUMP) -f vmlinux 2>/dev/null \
			| sed -n '/^start address / { \
				s/^.* //; \
				s/0x\([0-7].......\)$$/0x00000000\1/; \
				s/0x\(........\)$$/0xffffffff\1/; p }')

cflags-y			+= -I$(srctree)/arch/mips/include/asm/mach-generic
drivers-$(CONFIG_PCI)		+= arch/mips/pci/

#
# Automatically detect the build format. By default we choose
# the elf format according to the load address.
# We can always force a build with a 64-bits symbol format by
# passing 'KBUILD_SYM32=no' option to the make's command line.
#
ifdef CONFIG_64BIT
  ifndef KBUILD_SYM32
    ifeq ($(shell expr $(load-y) \< 0xffffffff80000000), 0)
      KBUILD_SYM32 = y
    endif
  endif

  ifeq ($(KBUILD_SYM32)$(call cc-option-yn,-msym32), yy)
    cflags-y += -msym32 -DKBUILD_64BIT_SYM32
  else
    ifeq ($(CONFIG_CPU_DADDI_WORKAROUNDS), y)
      $(error CONFIG_CPU_DADDI_WORKAROUNDS unsupported without -msym32)
    endif
  endif
endif

KBUILD_AFLAGS	+= $(cflags-y)
KBUILD_CFLAGS	+= $(cflags-y)
KBUILD_CPPFLAGS += -DVMLINUX_LOAD_ADDRESS=$(load-y)
KBUILD_CPPFLAGS += -DDATAOFFSET=$(if $(dataoffset-y),$(dataoffset-y),0)

bootvars-y	= VMLINUX_LOAD_ADDRESS=$(load-y) \
		  VMLINUX_ENTRY_ADDRESS=$(entry-y) \
		  PLATFORM="$(platform-y)" \
		  ITS_INPUTS="$(its-y)"
ifdef CONFIG_32BIT
bootvars-y	+= ADDR_BITS=32
endif
ifdef CONFIG_64BIT
bootvars-y	+= ADDR_BITS=64
endif

# This is required to get dwarf unwinding tables into .debug_frame
# instead of .eh_frame so we don't discard them.
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables

KBUILD_LDFLAGS		+= -m $(ld-emul)

ifdef CONFIG_MIPS
CHECKFLAGS += $(shell $(CC) $(KBUILD_CFLAGS) -dM -E -x c /dev/null | \
	egrep -vw '__GNUC_(|MINOR_|PATCHLEVEL_)_' | \
	sed -e "s/^\#define /-D'/" -e "s/ /'='/" -e "s/$$/'/" -e 's/\$$/&&/g')
endif

OBJCOPYFLAGS		+= --remove-section=.reginfo

head-y := arch/mips/kernel/head.o

libs-y			+= arch/mips/lib/
libs-$(CONFIG_MIPS_FPU_EMULATOR)	+= arch/mips/math-emu/

# See arch/mips/Kbuild for content of core part of the kernel
core-y += arch/mips/

drivers-$(CONFIG_MIPS_CRC_SUPPORT) += arch/mips/crypto/
drivers-$(CONFIG_OPROFILE)	+= arch/mips/oprofile/

# suspend and hibernation support
drivers-$(CONFIG_PM)	+= arch/mips/power/

# boot image targets (arch/mips/boot/)
boot-y			:= vmlinux.bin
boot-y			+= vmlinux.ecoff
boot-y			+= vmlinux.srec
ifeq ($(shell expr $(load-y) \< 0xffffffff80000000 2> /dev/null), 0)
boot-y			+= uImage
boot-y			+= uImage.bin
boot-y			+= uImage.bz2
boot-y			+= uImage.gz
boot-y			+= uImage.lzma
boot-y			+= uImage.lzo
endif
boot-y			+= vmlinux.itb
boot-y			+= vmlinux.gz.itb
boot-y			+= vmlinux.bz2.itb
boot-y			+= vmlinux.lzma.itb
boot-y			+= vmlinux.lzo.itb

# compressed boot image targets (arch/mips/boot/compressed/)
bootz-y			:= vmlinuz
bootz-y			+= vmlinuz.bin
bootz-y			+= vmlinuz.ecoff
bootz-y			+= vmlinuz.srec
ifeq ($(shell expr $(zload-y) \< 0xffffffff80000000 2> /dev/null), 0)
bootz-y			+= uzImage.bin
endif

ifdef CONFIG_LASAT
rom.bin rom.sw: vmlinux
	$(Q)$(MAKE) $(build)=arch/mips/lasat/image \
		$(bootvars-y) $@
endif

#
# Some machines like the Indy need 32-bit ELF binaries for booting purposes.
# Other need ECOFF, so we build a 32-bit ELF binary for them which we then
# convert to ECOFF using elf2ecoff.
#
quiet_cmd_32 = OBJCOPY $@
	cmd_32 = $(OBJCOPY) -O $(32bit-bfd) $(OBJCOPYFLAGS) $< $@
vmlinux.32: vmlinux
	$(call cmd,32)

#
# The 64-bit ELF tools are pretty broken so at this time we generate 64-bit
# ELF files from 32-bit files by conversion.
#
quiet_cmd_64 = OBJCOPY $@
	cmd_64 = $(OBJCOPY) -O $(64bit-bfd) $(OBJCOPYFLAGS) $< $@
vmlinux.64: vmlinux
	$(call cmd,64)

all:	$(all-y) $(KBUILD_DTBS)

# boot
$(boot-y): $(vmlinux-32) FORCE
	$(Q)$(MAKE) $(build)=arch/mips/boot VMLINUX=$(vmlinux-32) \
		$(bootvars-y) arch/mips/boot/$@

ifdef CONFIG_SYS_SUPPORTS_ZBOOT
# boot/compressed
$(bootz-y): $(vmlinux-32) FORCE
	$(Q)$(MAKE) $(build)=arch/mips/boot/compressed \
		$(bootvars-y) 32bit-bfd=$(32bit-bfd) $@
else
vmlinuz: FORCE
	@echo '   CONFIG_SYS_SUPPORTS_ZBOOT is not enabled'
	/bin/false
endif


CLEAN_FILES += vmlinux.32 vmlinux.64

# device-trees
core-$(CONFIG_BUILTIN_DTB) += arch/mips/boot/dts/

%.dtb %.dtb.S %.dtb.o: | scripts
	$(Q)$(MAKE) $(build)=arch/mips/boot/dts arch/mips/boot/dts/$@

PHONY += dtbs
dtbs: scripts
	$(Q)$(MAKE) $(build)=arch/mips/boot/dts

PHONY += dtbs_install
dtbs_install:
	$(Q)$(MAKE) $(dtbinst)=arch/mips/boot/dts

archprepare:
ifdef CONFIG_MIPS32_N32
	@$(kecho) '  Checking missing-syscalls for N32'
	$(Q)$(MAKE) $(build)=. missing-syscalls missing_syscalls_flags="-mabi=n32"
endif
ifdef CONFIG_MIPS32_O32
	@$(kecho) '  Checking missing-syscalls for O32'
	$(Q)$(MAKE) $(build)=. missing-syscalls missing_syscalls_flags="-mabi=32"
endif

install:
	$(Q)install -D -m 755 vmlinux $(INSTALL_PATH)/vmlinux-$(KERNELRELEASE)
ifdef CONFIG_SYS_SUPPORTS_ZBOOT
	$(Q)install -D -m 755 vmlinuz $(INSTALL_PATH)/vmlinuz-$(KERNELRELEASE)
endif
	$(Q)install -D -m 644 .config $(INSTALL_PATH)/config-$(KERNELRELEASE)
	$(Q)install -D -m 644 System.map $(INSTALL_PATH)/System.map-$(KERNELRELEASE)

archclean:
	$(Q)$(MAKE) $(clean)=arch/mips/boot
	$(Q)$(MAKE) $(clean)=arch/mips/boot/compressed
	$(Q)$(MAKE) $(clean)=arch/mips/boot/tools
	$(Q)$(MAKE) $(clean)=arch/mips/lasat

define archhelp
	echo '  install              - install kernel into $(INSTALL_PATH)'
	echo '  vmlinux.ecoff        - ECOFF boot image'
	echo '  vmlinux.bin          - Raw binary boot image'
	echo '  vmlinux.srec         - SREC boot image'
	echo '  vmlinux.32           - 64-bit boot image wrapped in 32bits (IP22/IP32)'
	echo '  vmlinuz              - Compressed boot(zboot) image'
	echo '  vmlinuz.ecoff        - ECOFF zboot image'
	echo '  vmlinuz.bin          - Raw binary zboot image'
	echo '  vmlinuz.srec         - SREC zboot image'
	echo '  uImage               - U-Boot image'
	echo '  uImage.bin           - U-Boot image (uncompressed)'
	echo '  uImage.bz2           - U-Boot image (bz2)'
	echo '  uImage.gz            - U-Boot image (gzip)'
	echo '  uImage.lzma          - U-Boot image (lzma)'
	echo '  uImage.lzo           - U-Boot image (lzo)'
	echo '  uzImage.bin          - U-Boot image (self-extracting)'
	echo '  dtbs                 - Device-tree blobs for enabled boards'
	echo '  dtbs_install         - Install dtbs to $(INSTALL_DTBS_PATH)'
	echo
	echo '  These will be default as appropriate for a configured platform.'
	echo
	echo '  If you are targeting a system supported by generic kernels you may'
	echo '  configure the kernel for a given architecture target like so:'
	echo
	echo '  {micro32,32,64}{r1,r2,r6}{el,}_defconfig <BOARDS="list of boards">'
	echo
	echo '  Where BOARDS is some subset of the following:'
	for board in $(sort $(BOARDS)); do echo "    $${board}"; done
	echo
	echo '  Specifically the following generic default configurations are'
	echo '  supported:'
	echo
	$(foreach cfg,$(generic_defconfigs),
	  printf "  %-24s - Build generic kernel for $(call describe_generic_defconfig,$(cfg))\n" $(cfg);)
	echo
	echo '  The following legacy default configurations have been converted to'
	echo '  generic and can still be used:'
	echo
	$(foreach cfg,$(sort $(legacy_defconfigs)),
	  printf "  %-24s - Build $($(cfg)-y)\n" $(cfg);)
	echo
	echo '  Otherwise, the following default configurations are available:'
endef

generic_config_dir = $(srctree)/arch/$(ARCH)/configs/generic
generic_defconfigs :=

#
# If the user generates a generic kernel configuration without specifying a
# list of boards to include the config fragments for, default to including all
# available board config fragments.
#
ifeq ($(BOARDS),)
BOARDS = $(patsubst board-%.config,%,$(notdir $(wildcard $(generic_config_dir)/board-*.config)))
endif

#
# Generic kernel configurations which merge generic_defconfig with the
# appropriate config fragments from arch/mips/configs/generic/, resulting in
# the ability to easily configure the kernel for a given architecture,
# endianness & set of boards without duplicating the needed configuration in
# hundreds of defconfig files.
#
define gen_generic_defconfigs
$(foreach bits,$(1),$(foreach rev,$(2),$(foreach endian,$(3),
target := $(bits)$(rev)$(filter el,$(endian))_defconfig
generic_defconfigs += $$(target)
$$(target): $(generic_config_dir)/$(bits)$(rev).config
$$(target): $(generic_config_dir)/$(endian).config
)))
endef

$(eval $(call gen_generic_defconfigs,32 64,r1 r2 r6,eb el))
$(eval $(call gen_generic_defconfigs,micro32,r2,eb el))

define describe_generic_defconfig
$(subst 32r,MIPS32 r,$(subst 64r,MIPS64 r,$(subst el, little endian,$(patsubst %_defconfig,%,$(1)))))
endef

.PHONY: $(generic_defconfigs)
$(generic_defconfigs):
	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
		-m -O $(objtree) $(srctree)/arch/$(ARCH)/configs/generic_defconfig $^ | \
		grep -Ev '^#'
	$(Q)cp $(KCONFIG_CONFIG) $(objtree)/.config.$@
	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig \
		KCONFIG_CONFIG=$(objtree)/.config.$@ >/dev/null
	$(Q)$(CONFIG_SHELL) $(srctree)/arch/$(ARCH)/tools/generic-board-config.sh \
		$(srctree) $(objtree) $(objtree)/.config.$@ $(KCONFIG_CONFIG) \
		"$(origin BOARDS)" $(BOARDS)
	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig

#
# Prevent generic merge_config rules attempting to merge single fragments
#
$(generic_config_dir)/%.config: ;

#
# Prevent direct use of generic_defconfig, which is intended to be used as the
# basis of the various ISA-specific targets generated above.
#
.PHONY: generic_defconfig
generic_defconfig:
	$(Q)echo "generic_defconfig is not intended for direct use, but should instead be"
	$(Q)echo "used via an ISA-specific target from the following list:"
	$(Q)echo
	$(Q)for cfg in $(generic_defconfigs); do echo "  $${cfg}"; done
	$(Q)echo
	$(Q)false

#
# Legacy defconfig compatibility - these targets used to be real defconfigs but
# now that the boards have been converted to use the generic kernel they are
# wrappers around the generic rules above.
#
legacy_defconfigs		+= ocelot_defconfig
ocelot_defconfig-y		:= 32r2el_defconfig BOARDS=ocelot

legacy_defconfigs		+= sead3_defconfig
sead3_defconfig-y		:= 32r2el_defconfig BOARDS=sead-3

legacy_defconfigs		+= sead3micro_defconfig
sead3micro_defconfig-y		:= micro32r2el_defconfig BOARDS=sead-3

legacy_defconfigs		+= xilfpga_defconfig
xilfpga_defconfig-y		:= 32r2el_defconfig BOARDS=xilfpga

.PHONY: $(legacy_defconfigs)
$(legacy_defconfigs):
	$(Q)$(MAKE) -f $(srctree)/Makefile $($@-y)