ce697ccee1
Kbuild puts the objects listed in head-y at the head of vmlinux. Conventionally, we do this for head*.S, which contains the kernel entry point. A counter approach is to control the section order by the linker script. Actually, the code marked as __HEAD goes into the ".head.text" section, which is placed before the normal ".text" section. I do not know if both of them are needed. From the build system perspective, head-y is not mandatory. If you can achieve the proper code placement by the linker script only, it would be cleaner. I collected the current head-y objects into head-object-list.txt. It is a whitelist. My hope is it will be reduced in the long run. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
3.2 KiB
SPDX-License-Identifier: GPL-2.0-only
Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
KBUILD_DEFCONFIG := haps_hs_smp_defconfig
ifeq ($(CROSS_COMPILE),) CROSS_COMPILE := $(call cc-cross-prefix, arc-linux- arceb-linux-) endif
cflags-y += -fno-common -pipe -fno-builtin -mmedium-calls -D__linux__
tune-mcpu-def-$(CONFIG_ISA_ARCOMPACT) := -mcpu=arc700 tune-mcpu-def-$(CONFIG_ISA_ARCV2) := -mcpu=hs38
ifeq ($(CONFIG_ARC_TUNE_MCPU),) cflags-y += $(tune-mcpu-def-y) else tune-mcpu := $(CONFIG_ARC_TUNE_MCPU) ifneq ($(call cc-option,$(tune-mcpu)),) cflags-y += $(tune-mcpu) else
The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
(probably the compiler is too old). Use ISA default mcpu flag instead as a safe option.
$(warning ** WARNING ** CONFIG_ARC_TUNE_MCPU flag '$(tune-mcpu)' is unknown, fallback to '$(tune-mcpu-def-y)') cflags-y += $(tune-mcpu-def-y) endif endif
ifdef CONFIG_ARC_CURR_IN_REG
For a global register definition, make sure it gets passed to every file
We had a customer reported bug where some code built in kernel was NOT using
any kernel headers, and missing the r25 global register
Can't do unconditionally because of recursive include issues
due to <linux/thread_info.h>
LINUXINCLUDE += -include $(srctree)/arch/arc/include/asm/current.h endif
cflags-y += -fsection-anchors
cflags-$(CONFIG_ARC_HAS_LLSC) += -mlock cflags-$(CONFIG_ARC_HAS_SWAPE) += -mswape
ifdef CONFIG_ISA_ARCV2
ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS cflags-y += -munaligned-access else cflags-y += -mno-unaligned-access endif
ifndef CONFIG_ARC_HAS_LL64 cflags-y += -mno-ll64 endif
ifndef CONFIG_ARC_HAS_DIV_REM cflags-y += -mno-div-rem endif
endif
cfi := $(call as-instr,.cfi_startproc\n.cfi_endproc,-DARC_DW2_UNWIND_AS_CFI) cflags-$(CONFIG_ARC_DW2_UNWIND) += -fasynchronous-unwind-tables $(cfi)
small data is default for elf32 tool-chain. If not usable, disable it
This also allows repurposing GP as scratch reg to gcc reg allocator
disable_small_data := y cflags-$(disable_small_data) += -mno-sdata -fcall-used-gp
cflags-$(CONFIG_CPU_BIG_ENDIAN) += -mbig-endian ldflags-$(CONFIG_CPU_BIG_ENDIAN) += -EB
LIBGCC = $(shell $(CC) $(cflags-y) --print-libgcc-file-name)
Modules with short calls might break for calls into builtin-kernel
KBUILD_CFLAGS_MODULE += -mlong-calls -mno-millicode
Finally dump eveything into kernel build system
KBUILD_CFLAGS += $(cflags-y) KBUILD_AFLAGS += $(KBUILD_CFLAGS) KBUILD_LDFLAGS += $(ldflags-y)
w/o this dtb won't embed into kernel binary
core-y += arch/arc/boot/dts/
core-y += arch/arc/plat-sim/ core-$(CONFIG_ARC_PLAT_TB10X) += arch/arc/plat-tb10x/ core-$(CONFIG_ARC_PLAT_AXS10X) += arch/arc/plat-axs10x/ core-$(CONFIG_ARC_SOC_HSDK) += arch/arc/plat-hsdk/
libs-y += arch/arc/lib/ $(LIBGCC)
boot := arch/arc/boot
boot_targets := uImage.bin uImage.gz uImage.lzma
PHONY += $(boot_targets) $(boot_targets): vmlinux $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
uimage-default-y := uImage.bin uimage-default-$(CONFIG_KERNEL_GZIP) := uImage.gz uimage-default-$(CONFIG_KERNEL_LZMA) := uImage.lzma
PHONY += uImage uImage: $(uimage-default-y) @ln -sf $< $(boot)/uImage @$(kecho) ' Image $(boot)/uImage is ready'
CLEAN_FILES += $(boot)/uImage