2005-09-26 06:04:21 +00:00
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# This file is included by the global makefile so that you can add your own
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2021-10-13 06:36:22 +00:00
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# architecture-specific flags and dependencies.
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2005-09-26 06:04:21 +00:00
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#
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# This file is subject to the terms and conditions of the GNU General Public
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# License. See the file "COPYING" in the main directory of this archive
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# for more details.
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#
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# Copyright (C) 1994 by Linus Torvalds
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# Changes for PPC by Gary Thomas
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# Rewritten by Cort Dougan and Paul Mackerras
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#
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HAS_BIARCH := $(call cc-option-yn, -m32)
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# Set default 32 bits cross compilers for vdso and boot wrapper
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CROSS32_COMPILE ?=
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ifeq ($(HAS_BIARCH),y)
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ifeq ($(CROSS32_COMPILE),)
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2018-05-30 12:19:19 +00:00
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ifdef CONFIG_PPC32
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# These options will be overridden by any -mcpu option that the CPU
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# or platform code sets later on the command line, but they are needed
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# to set a sane 32-bit cpu target for the 64-bit cross compiler which
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# may default to the wrong ISA.
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KBUILD_CFLAGS += -mcpu=powerpc
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KBUILD_AFLAGS += -mcpu=powerpc
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endif
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2005-09-26 06:04:21 +00:00
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endif
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endif
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2018-12-05 17:53:55 +00:00
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ifdef CONFIG_PPC_BOOK3S_32
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KBUILD_CFLAGS += -mcpu=powerpc
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endif
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2019-02-07 05:16:52 +00:00
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# If we're on a ppc/ppc64/ppc64le machine use that defconfig, otherwise just use
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# ppc64_defconfig because we have nothing better to go on.
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uname := $(shell uname -m)
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KBUILD_DEFCONFIG := $(if $(filter ppc%,$(uname)),$(uname),ppc64)_defconfig
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2005-11-18 05:39:08 +00:00
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2005-09-26 06:04:21 +00:00
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new_nm := $(shell if $(NM) --help 2>&1 | grep -- '--synthetic' > /dev/null; then echo y; else echo n; fi)
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ifeq ($(new_nm),y)
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NM := $(NM) --synthetic
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endif
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2016-08-11 06:03:14 +00:00
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# BITS is used as extension for files which are available in a 32 bit
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# and a 64 bit version to simplify shared Makefiles.
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# e.g.: obj-y += foo_$(BITS).o
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export BITS
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ifdef CONFIG_PPC64
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BITS := 64
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else
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BITS := 32
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2005-09-26 06:04:21 +00:00
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endif
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2016-08-11 06:03:15 +00:00
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machine-y = ppc
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machine-$(CONFIG_PPC64) += 64
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machine-$(CONFIG_CPU_LITTLE_ENDIAN) += le
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UTS_MACHINE := $(subst $(space),,$(machine-y))
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2005-10-13 06:14:15 +00:00
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2017-07-26 05:00:42 +00:00
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# XXX This needs to be before we override LD below
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ifdef CONFIG_PPC32
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KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
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else
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kbuild: LD_VERSION redenomination
Commit ccbef1674a15 ("Kbuild, lto: add ld-version and ld-ifversion
macros") introduced scripts/ld-version.sh for GCC LTO.
At that time, this script handled 5 version fields because GCC LTO
needed the downstream binutils. (https://lkml.org/lkml/2014/4/8/272)
The code snippet from the submitted patch was as follows:
# We need HJ Lu's Linux binutils because mainline binutils does not
# support mixing assembler and LTO code in the same ld -r object.
# XXX check if the gcc plugin ld is the expected one too
# XXX some Fedora binutils should also support it. How to check for that?
ifeq ($(call ld-ifversion,-ge,22710001,y),y)
...
However, GCC LTO was not merged into the mainline after all.
(https://lkml.org/lkml/2014/4/8/272)
So, the 4th and 5th fields were never used, and finally removed by
commit 0d61ed17dd30 ("ld-version: Drop the 4th and 5th version
components").
Since then, the last 4-digits returned by this script is always zeros.
Remove the meaningless last 4-digits. This makes the version format
consistent with GCC_VERSION, CLANG_VERSION, LLD_VERSION.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-12-12 16:54:30 +00:00
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ifeq ($(call ld-ifversion, -ge, 22500, y),y)
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2017-07-26 05:00:42 +00:00
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# Have the linker provide sfpr if possible.
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# There is a corresponding test in arch/powerpc/lib/Makefile
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KBUILD_LDFLAGS_MODULE += --save-restore-funcs
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else
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KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
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endif
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endif
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2018-08-06 16:42:03 +00:00
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ifdef CONFIG_CPU_LITTLE_ENDIAN
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2018-05-30 12:19:21 +00:00
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KBUILD_CFLAGS += -mlittle-endian
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2018-08-23 23:20:39 +00:00
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KBUILD_LDFLAGS += -EL
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2013-09-23 02:05:11 +00:00
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LDEMULATION := lppc
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GNUTARGET := powerpcle
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MULTIPLEWORD := -mno-multiple
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2014-03-12 04:12:01 +00:00
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KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-save-toc-indirect)
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2013-09-23 02:05:11 +00:00
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else
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2018-05-30 12:19:21 +00:00
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KBUILD_CFLAGS += $(call cc-option,-mbig-endian)
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2018-08-23 23:20:39 +00:00
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KBUILD_LDFLAGS += -EB
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2013-09-23 02:05:11 +00:00
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LDEMULATION := ppc
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GNUTARGET := powerpc
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MULTIPLEWORD := -mmultiple
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endif
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2016-11-27 02:46:20 +00:00
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ifdef CONFIG_PPC64
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2019-11-19 04:57:10 +00:00
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ifndef CONFIG_CC_IS_CLANG
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2022-05-09 05:36:06 +00:00
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cflags-$(CONFIG_PPC64_ELF_ABI_V1) += $(call cc-option,-mabi=elfv1)
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cflags-$(CONFIG_PPC64_ELF_ABI_V1) += $(call cc-option,-mcall-aixdesc)
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aflags-$(CONFIG_PPC64_ELF_ABI_V1) += $(call cc-option,-mabi=elfv1)
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aflags-$(CONFIG_PPC64_ELF_ABI_V2) += -mabi=elfv2
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2016-11-27 02:46:20 +00:00
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endif
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2019-11-19 04:57:10 +00:00
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endif
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2016-11-27 02:46:20 +00:00
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2018-10-30 13:26:33 +00:00
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ifndef CONFIG_CC_IS_CLANG
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2016-08-09 12:43:46 +00:00
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cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mno-strict-align
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endif
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2018-05-30 12:19:21 +00:00
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cflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mbig-endian)
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cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mlittle-endian
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2016-08-09 12:43:46 +00:00
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aflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mbig-endian)
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aflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mlittle-endian
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2005-09-26 06:04:21 +00:00
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|
ifeq ($(HAS_BIARCH),y)
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2018-05-30 12:19:21 +00:00
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KBUILD_CFLAGS += -m$(BITS)
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KBUILD_AFLAGS += -m$(BITS) -Wl,-a$(BITS)
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2018-08-23 23:20:39 +00:00
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KBUILD_LDFLAGS += -m elf$(BITS)$(LDEMULATION)
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2005-09-26 06:04:21 +00:00
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|
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endif
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2018-09-27 07:05:53 +00:00
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cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard=tls
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2018-09-27 07:05:55 +00:00
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ifdef CONFIG_PPC64
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cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard-reg=r13
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else
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2018-09-27 07:05:53 +00:00
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cflags-$(CONFIG_STACKPROTECTOR) += -mstack-protector-guard-reg=r2
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2018-09-27 07:05:55 +00:00
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endif
|
2018-09-27 07:05:53 +00:00
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2011-12-14 22:58:12 +00:00
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LDFLAGS_vmlinux-y := -Bstatic
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LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie
|
2021-08-13 20:05:11 +00:00
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LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) += -z notext
|
2011-12-14 22:58:12 +00:00
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LDFLAGS_vmlinux := $(LDFLAGS_vmlinux-y)
|
2005-09-26 06:04:21 +00:00
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|
2018-08-06 16:42:03 +00:00
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|
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ifdef CONFIG_PPC64
|
2012-11-26 17:41:08 +00:00
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ifeq ($(call cc-option-yn,-mcmodel=medium),y)
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# -mcmodel=medium breaks modules because it uses 32bit offsets from
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# the TOC pointer to create pointers where possible. Pointers into the
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# percpu data area are created by this method.
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#
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# The kernel module loader relocates the percpu data section from the
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# original location (starting with 0xd...) to somewhere in the base
|
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# kernel percpu data space (starting with 0xc...). We need a full
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|
# 64bit relocation for this to work, hence -mcmodel=large.
|
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KBUILD_CFLAGS_MODULE += -mcmodel=large
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else
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export NO_MINIMAL_TOC := -mno-minimal-toc
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|
|
|
endif
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endif
|
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|
2015-05-25 22:53:27 +00:00
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|
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CFLAGS-$(CONFIG_PPC64) := $(call cc-option,-mtraceback=no)
|
2019-11-19 04:57:10 +00:00
|
|
|
ifndef CONFIG_CC_IS_CLANG
|
2022-05-09 05:36:06 +00:00
|
|
|
ifdef CONFIG_PPC64_ELF_ABI_V2
|
2015-05-25 22:53:29 +00:00
|
|
|
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv2,$(call cc-option,-mcall-aixdesc))
|
2014-03-10 10:06:12 +00:00
|
|
|
AFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv2)
|
|
|
|
else
|
2016-11-27 02:46:20 +00:00
|
|
|
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv1)
|
2015-05-25 22:53:29 +00:00
|
|
|
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcall-aixdesc)
|
2016-11-27 02:46:20 +00:00
|
|
|
AFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv1)
|
2014-03-10 10:06:12 +00:00
|
|
|
endif
|
2019-11-19 04:57:10 +00:00
|
|
|
endif
|
2015-05-25 22:53:29 +00:00
|
|
|
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcmodel=medium,$(call cc-option,-mminimal-toc))
|
2012-12-12 14:43:12 +00:00
|
|
|
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mno-pointers-to-nested-functions)
|
2018-03-01 01:02:49 +00:00
|
|
|
|
2018-11-12 05:28:06 +00:00
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|
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# Clang unconditionally reserves r2 on ppc32 and does not support the flag
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|
|
|
# https://bugs.llvm.org/show_bug.cgi?id=39555
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|
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CFLAGS-$(CONFIG_PPC32) := $(call cc-option, -ffixed-r2)
|
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# Clang doesn't support -mmultiple / -mno-multiple
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|
|
|
# https://bugs.llvm.org/show_bug.cgi?id=39556
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|
|
CFLAGS-$(CONFIG_PPC32) += $(call cc-option, $(MULTIPLEWORD))
|
|
|
|
|
2018-03-01 01:02:49 +00:00
|
|
|
CFLAGS-$(CONFIG_PPC32) += $(call cc-option,-mno-readonly-in-sdata)
|
2012-04-17 18:45:28 +00:00
|
|
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|
2018-08-06 16:42:03 +00:00
|
|
|
ifdef CONFIG_PPC_BOOK3S_64
|
|
|
|
ifdef CONFIG_CPU_LITTLE_ENDIAN
|
2018-02-20 19:08:30 +00:00
|
|
|
CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=power8
|
2018-02-20 19:08:32 +00:00
|
|
|
CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power9,-mtune=power8)
|
2018-02-20 19:08:30 +00:00
|
|
|
else
|
2018-02-20 19:08:29 +00:00
|
|
|
CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power7,$(call cc-option,-mtune=power5))
|
|
|
|
CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mcpu=power5,-mcpu=power4)
|
2018-02-20 19:08:30 +00:00
|
|
|
endif
|
powerpc/Makefile: Don't pass -mcpu=powerpc64 when building 32-bit
When CONFIG_GENERIC_CPU=y (true for all our defconfigs) we pass
-mcpu=powerpc64 to the compiler, even when we're building a 32-bit
kernel.
This happens because we have an ifdef CONFIG_PPC_BOOK3S_64/else block in
the Makefile that was written before 32-bit supported GENERIC_CPU. Prior
to that the else block only applied to 64-bit Book3E.
The GCC man page says -mcpu=powerpc64 "[specifies] a pure ... 64-bit big
endian PowerPC ... architecture machine [type], with an appropriate,
generic processor model assumed for scheduling purposes."
It's unclear how that interacts with -m32, which we are also passing,
although obviously -m32 is taking precedence in some sense, as the
32-bit kernel only contains 32-bit instructions.
This was noticed by inspection, not via any bug reports, but it does
affect code generation. Comparing before/after code generation, there
are some changes to instruction scheduling, and the after case (with
-mcpu=powerpc64 removed) the compiler seems more keen to use r8.
Fix it by making the else case only apply to Book3E 64, which excludes
32-bit.
Fixes: 0e00a8c9fd92 ("powerpc: Allow CPU selection also on PPC32")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220215112858.304779-1-mpe@ellerman.id.au
2022-02-15 11:28:58 +00:00
|
|
|
else ifdef CONFIG_PPC_BOOK3E_64
|
2013-08-21 00:55:36 +00:00
|
|
|
CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64
|
|
|
|
endif
|
|
|
|
|
2018-09-14 05:08:53 +00:00
|
|
|
ifdef CONFIG_FUNCTION_TRACER
|
|
|
|
CC_FLAGS_FTRACE := -pg
|
2016-03-03 04:27:00 +00:00
|
|
|
ifdef CONFIG_MPROFILE_KERNEL
|
2018-09-14 05:08:53 +00:00
|
|
|
CC_FLAGS_FTRACE += -mprofile-kernel
|
|
|
|
endif
|
2016-03-03 04:27:00 +00:00
|
|
|
endif
|
|
|
|
|
2018-06-07 10:10:18 +00:00
|
|
|
CFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU))
|
2012-04-17 18:45:28 +00:00
|
|
|
|
2013-11-22 02:49:00 +00:00
|
|
|
# Altivec option not allowed with e500mc64 in GCC.
|
2018-08-06 16:42:03 +00:00
|
|
|
ifdef CONFIG_ALTIVEC
|
2013-11-22 02:49:00 +00:00
|
|
|
E5500_CPU := -mcpu=powerpc64
|
|
|
|
else
|
2013-08-21 00:55:36 +00:00
|
|
|
E5500_CPU := $(call cc-option,-mcpu=e500mc64,-mcpu=powerpc64)
|
2013-11-22 02:49:00 +00:00
|
|
|
endif
|
2013-08-21 00:55:36 +00:00
|
|
|
CFLAGS-$(CONFIG_E5500_CPU) += $(E5500_CPU)
|
|
|
|
CFLAGS-$(CONFIG_E6500_CPU) += $(call cc-option,-mcpu=e6500,$(E5500_CPU))
|
|
|
|
|
2018-08-06 16:42:03 +00:00
|
|
|
ifdef CONFIG_PPC32
|
|
|
|
ifdef CONFIG_PPC_E500MC
|
2013-08-16 00:19:10 +00:00
|
|
|
CFLAGS-y += $(call cc-option,-mcpu=e500mc,-mcpu=powerpc)
|
|
|
|
else
|
|
|
|
CFLAGS-$(CONFIG_E500) += $(call cc-option,-mcpu=8540 -msoft-float,-mcpu=powerpc)
|
|
|
|
endif
|
|
|
|
endif
|
|
|
|
|
2014-05-15 16:33:42 +00:00
|
|
|
asinstr := $(call as-instr,lis 9$(comma)foo@high,-DHAVE_AS_ATHIGH=1)
|
|
|
|
|
2019-05-13 06:22:16 +00:00
|
|
|
KBUILD_CPPFLAGS += -I $(srctree)/arch/$(ARCH) $(asinstr)
|
2019-01-11 03:22:32 +00:00
|
|
|
KBUILD_AFLAGS += $(AFLAGS-y)
|
2015-05-25 22:53:27 +00:00
|
|
|
KBUILD_CFLAGS += $(call cc-option,-msoft-float)
|
2019-01-11 03:22:32 +00:00
|
|
|
KBUILD_CFLAGS += -pipe $(CFLAGS-y)
|
2007-10-14 20:21:35 +00:00
|
|
|
CPP = $(CC) -E $(KBUILD_CFLAGS)
|
2005-09-26 06:04:21 +00:00
|
|
|
|
2016-08-11 06:03:14 +00:00
|
|
|
CHECKFLAGS += -m$(BITS) -D__powerpc__ -D__powerpc$(BITS)__
|
2016-07-12 00:54:51 +00:00
|
|
|
ifdef CONFIG_CPU_BIG_ENDIAN
|
|
|
|
CHECKFLAGS += -D__BIG_ENDIAN__
|
|
|
|
else
|
2022-05-09 05:36:08 +00:00
|
|
|
CHECKFLAGS += -D__LITTLE_ENDIAN__
|
2016-07-12 00:54:51 +00:00
|
|
|
endif
|
2005-09-26 06:04:21 +00:00
|
|
|
|
2018-08-06 16:42:03 +00:00
|
|
|
ifdef CONFIG_476FPE_ERR46
|
2014-02-24 07:00:56 +00:00
|
|
|
KBUILD_LDFLAGS_MODULE += --ppc476-workaround \
|
|
|
|
-T $(srctree)/arch/powerpc/platforms/44x/ppc476_modules.lds
|
|
|
|
endif
|
|
|
|
|
2012-04-17 18:45:28 +00:00
|
|
|
# No AltiVec or VSX instructions when building kernel
|
2007-10-14 20:21:35 +00:00
|
|
|
KBUILD_CFLAGS += $(call cc-option,-mno-altivec)
|
2012-04-17 18:45:28 +00:00
|
|
|
KBUILD_CFLAGS += $(call cc-option,-mno-vsx)
|
2005-10-29 05:31:17 +00:00
|
|
|
|
2007-10-18 21:53:19 +00:00
|
|
|
# No SPE instruction when building kernel
|
2008-09-01 14:23:02 +00:00
|
|
|
# (We use all available options to help semi-broken compilers)
|
2007-10-18 21:53:19 +00:00
|
|
|
KBUILD_CFLAGS += $(call cc-option,-mno-spe)
|
2008-09-01 14:23:02 +00:00
|
|
|
KBUILD_CFLAGS += $(call cc-option,-mspe=no)
|
2007-10-18 21:53:19 +00:00
|
|
|
|
2020-03-05 14:35:30 +00:00
|
|
|
# Don't emit .eh_frame since we have no use for it
|
|
|
|
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
|
|
|
|
|
2007-03-22 06:23:44 +00:00
|
|
|
# Never use string load/store instructions as they are
|
|
|
|
# often slow when they are implemented at all
|
2015-05-25 22:53:27 +00:00
|
|
|
KBUILD_CFLAGS += $(call cc-option,-mno-string)
|
2005-09-26 06:04:21 +00:00
|
|
|
|
2016-12-22 08:06:08 +00:00
|
|
|
cpu-as-$(CONFIG_40x) += -Wa,-m405
|
|
|
|
cpu-as-$(CONFIG_44x) += -Wa,-m440
|
2015-11-25 23:45:49 +00:00
|
|
|
cpu-as-$(CONFIG_ALTIVEC) += $(call as-option,-Wa$(comma)-maltivec)
|
2018-07-12 21:41:49 +00:00
|
|
|
cpu-as-$(CONFIG_E500) += -Wa,-me500
|
powerpc/Makefile: Fix PPC_BOOK3S_64 ASFLAGS
Ever since commit 15a3204d24a3 ("powerpc/64s: Set assembler machine type
to POWER4") we force -mpower4 to be passed to the assembler
irrespective of the CFLAGS used (for Book3s 64).
When building a powerpc64 kernel with clang, clang will not add -many
to the assembler flags, so any instructions that the compiler has
generated that are not available on power4 will cause an error:
/usr/bin/as -a64 -mppc64 -mlittle-endian -mpower8 \
-I ./arch/powerpc/include -I ./arch/powerpc/include/generated \
-I ./include -I ./arch/powerpc/include/uapi \
-I ./arch/powerpc/include/generated/uapi -I ./include/uapi \
-I ./include/generated/uapi -I arch/powerpc -I arch/powerpc \
-maltivec -mpower4 -o init/do_mounts.o /tmp/do_mounts-3b0a3d.s
/tmp/do_mounts-51ce54.s:748: Error: unrecognized opcode: `isel'
GCC does include -many, so the GCC driven gas call will succeed:
as -v -I ./arch/powerpc/include -I ./arch/powerpc/include/generated -I
./include -I ./arch/powerpc/include/uapi
-I ./arch/powerpc/include/generated/uapi -I ./include/uapi
-I ./include/generated/uapi -I arch/powerpc -I arch/powerpc
-a64 -mpower8 -many -mlittle -maltivec -mpower4 -o init/do_mounts.o
Note that isel is power7 and above for IBM CPUs. GCC only generates it
for Power9 and above, but the above test was run against the clang
generated assembly.
Peter Bergner explains:
When using -many -mpower4, gas will first try and find a matching
power4 mnemonic and failing that, it will then allow any valid
mnemonic that gas knows about. GCC's use of -many predates me
though.
IIRC, Alan looked at trying to remove it, but I forget why he
didn't. Could be either a gcc or gas issue at the time. I'm not sure
whether issue still exists or not. He and I have modified how gas
works internally a fair amount since he tried removing gcc use of
-many.
I will also note that when using -many, gas will choose the first
mnemonic that matches in the mnemonic table and we have (mostly)
sorted the table so that server mnemonics show up earlier in the
table than other mnemonics, so they'll be seen/chosen first.
By explicitly setting -many we can build with Clang and GCC while
retaining the -mpower4 option.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-11 02:43:03 +00:00
|
|
|
|
|
|
|
# When using '-many -mpower4' gas will first try and find a matching power4
|
|
|
|
# mnemonic and failing that it will allow any valid mnemonic that GAS knows
|
|
|
|
# about. GCC will pass -many to GAS when assembling, clang does not.
|
2021-12-21 05:59:00 +00:00
|
|
|
# LLVM IAS doesn't understand either flag: https://github.com/ClangBuiltLinux/linux/issues/675
|
|
|
|
# but LLVM IAS only supports ISA >= 2.06 for Book3S 64 anyway...
|
|
|
|
cpu-as-$(CONFIG_PPC_BOOK3S_64) += $(call as-option,-Wa$(comma)-mpower4) $(call as-option,-Wa$(comma)-many)
|
2018-06-14 15:27:42 +00:00
|
|
|
cpu-as-$(CONFIG_PPC_E500MC) += $(call as-option,-Wa$(comma)-me500mc)
|
2005-09-26 06:04:21 +00:00
|
|
|
|
2007-10-15 19:59:31 +00:00
|
|
|
KBUILD_AFLAGS += $(cpu-as-y)
|
2007-10-14 20:21:35 +00:00
|
|
|
KBUILD_CFLAGS += $(cpu-as-y)
|
2005-09-26 06:04:21 +00:00
|
|
|
|
2016-08-09 12:43:46 +00:00
|
|
|
KBUILD_AFLAGS += $(aflags-y)
|
|
|
|
KBUILD_CFLAGS += $(cflags-y)
|
|
|
|
|
2020-10-06 09:05:26 +00:00
|
|
|
head-$(CONFIG_PPC64) := arch/powerpc/kernel/head_64.o
|
|
|
|
head-$(CONFIG_PPC_BOOK3S_32) := arch/powerpc/kernel/head_book3s_32.o
|
2017-08-08 11:58:54 +00:00
|
|
|
head-$(CONFIG_PPC_8xx) := arch/powerpc/kernel/head_8xx.o
|
2007-08-20 12:27:07 +00:00
|
|
|
head-$(CONFIG_40x) := arch/powerpc/kernel/head_40x.o
|
2005-09-26 06:04:21 +00:00
|
|
|
head-$(CONFIG_44x) := arch/powerpc/kernel/head_44x.o
|
|
|
|
head-$(CONFIG_FSL_BOOKE) := arch/powerpc/kernel/head_fsl_booke.o
|
|
|
|
|
2005-10-10 12:36:14 +00:00
|
|
|
head-$(CONFIG_PPC64) += arch/powerpc/kernel/entry_64.o
|
2005-09-26 06:04:21 +00:00
|
|
|
head-$(CONFIG_PPC_FPU) += arch/powerpc/kernel/fpu.o
|
2009-06-02 21:17:37 +00:00
|
|
|
head-$(CONFIG_ALTIVEC) += arch/powerpc/kernel/vector.o
|
2012-11-26 17:39:03 +00:00
|
|
|
head-$(CONFIG_PPC_OF_BOOT_TRAMPOLINE) += arch/powerpc/kernel/prom_init.o
|
2005-09-26 06:04:21 +00:00
|
|
|
|
2006-01-12 23:55:58 +00:00
|
|
|
# Default to zImage, override when needed
|
2008-02-06 18:18:34 +00:00
|
|
|
all: zImage
|
2005-09-26 06:04:21 +00:00
|
|
|
|
2010-08-02 20:47:48 +00:00
|
|
|
# With make 3.82 we cannot mix normal and wildcard targets
|
2010-08-15 22:26:56 +00:00
|
|
|
BOOT_TARGETS1 := zImage zImage.initrd uImage
|
2011-12-01 19:35:08 +00:00
|
|
|
BOOT_TARGETS2 := zImage% dtbImage% treeImage.% cuImage.% simpleImage.% uImage.%
|
2005-09-30 06:16:52 +00:00
|
|
|
|
2010-08-02 20:47:48 +00:00
|
|
|
PHONY += $(BOOT_TARGETS1) $(BOOT_TARGETS2)
|
2005-09-30 06:16:52 +00:00
|
|
|
|
2005-11-16 02:38:21 +00:00
|
|
|
boot := arch/$(ARCH)/boot
|
2005-09-26 06:04:21 +00:00
|
|
|
|
2010-08-02 20:47:48 +00:00
|
|
|
$(BOOT_TARGETS1): vmlinux
|
powerpc: Stop passing ARCH=ppc64 to boot Makefile
Back in 2005 when the ppc/ppc64 merge started, we used to build the
kernel code in arch/powerpc but use the boot code from arch/ppc or
arch/ppc64 depending on whether we were building for 32 or 64-bit.
Originally we called the boot Makefile passing ARCH=$(OLDARCH), where
OLDARCH was ppc or ppc64.
In commit 20f629549b30 ("powerpc: Make building the boot image work for
both 32-bit and 64-bit") (2005-10-11) we split the call for 32/64-bit
using an ifeq check, because the two Makefiles took different targets,
and explicitly passed ARCH=ppc64 for the 64-bit case and ARCH=ppc for
the 32-bit case.
Then in commit 94b212c29f68 ("powerpc: Move ppc64 boot wrapper code over
to arch/powerpc") (2005-11-16) we moved the boot code into arch/powerpc
and dropped the ppc case, but kept passing ARCH=ppc64 to
arch/powerpc/boot/Makefile.
Since then there have been several more boot targets added, all of which
have copied the ARCH=ppc64 setting, such that now we have four targets
using it.
Currently it seems that nothing actually uses the ARCH value, but that's
basically just luck, and in particular it prevents us from using the
generic cpp_lds_S rule. It's also clearly wrong, ARCH=ppc64 is dead,
buried and cremated.
Fix it by dropping the setting of ARCH completely, the correct value is
exported by the top level Makefile.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-21 10:14:33 +00:00
|
|
|
$(Q)$(MAKE) $(build)=$(boot) $(patsubst %,$(boot)/%,$@)
|
2010-08-02 20:47:48 +00:00
|
|
|
$(BOOT_TARGETS2): vmlinux
|
powerpc: Stop passing ARCH=ppc64 to boot Makefile
Back in 2005 when the ppc/ppc64 merge started, we used to build the
kernel code in arch/powerpc but use the boot code from arch/ppc or
arch/ppc64 depending on whether we were building for 32 or 64-bit.
Originally we called the boot Makefile passing ARCH=$(OLDARCH), where
OLDARCH was ppc or ppc64.
In commit 20f629549b30 ("powerpc: Make building the boot image work for
both 32-bit and 64-bit") (2005-10-11) we split the call for 32/64-bit
using an ifeq check, because the two Makefiles took different targets,
and explicitly passed ARCH=ppc64 for the 64-bit case and ARCH=ppc for
the 32-bit case.
Then in commit 94b212c29f68 ("powerpc: Move ppc64 boot wrapper code over
to arch/powerpc") (2005-11-16) we moved the boot code into arch/powerpc
and dropped the ppc case, but kept passing ARCH=ppc64 to
arch/powerpc/boot/Makefile.
Since then there have been several more boot targets added, all of which
have copied the ARCH=ppc64 setting, such that now we have four targets
using it.
Currently it seems that nothing actually uses the ARCH value, but that's
basically just luck, and in particular it prevents us from using the
generic cpp_lds_S rule. It's also clearly wrong, ARCH=ppc64 is dead,
buried and cremated.
Fix it by dropping the setting of ARCH completely, the correct value is
exported by the top level Makefile.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-21 10:14:33 +00:00
|
|
|
$(Q)$(MAKE) $(build)=$(boot) $(patsubst %,$(boot)/%,$@)
|
2010-08-02 20:47:48 +00:00
|
|
|
|
|
|
|
|
2020-02-19 00:04:34 +00:00
|
|
|
PHONY += bootwrapper_install
|
2010-08-02 20:47:48 +00:00
|
|
|
bootwrapper_install:
|
powerpc: Stop passing ARCH=ppc64 to boot Makefile
Back in 2005 when the ppc/ppc64 merge started, we used to build the
kernel code in arch/powerpc but use the boot code from arch/ppc or
arch/ppc64 depending on whether we were building for 32 or 64-bit.
Originally we called the boot Makefile passing ARCH=$(OLDARCH), where
OLDARCH was ppc or ppc64.
In commit 20f629549b30 ("powerpc: Make building the boot image work for
both 32-bit and 64-bit") (2005-10-11) we split the call for 32/64-bit
using an ifeq check, because the two Makefiles took different targets,
and explicitly passed ARCH=ppc64 for the 64-bit case and ARCH=ppc for
the 32-bit case.
Then in commit 94b212c29f68 ("powerpc: Move ppc64 boot wrapper code over
to arch/powerpc") (2005-11-16) we moved the boot code into arch/powerpc
and dropped the ppc case, but kept passing ARCH=ppc64 to
arch/powerpc/boot/Makefile.
Since then there have been several more boot targets added, all of which
have copied the ARCH=ppc64 setting, such that now we have four targets
using it.
Currently it seems that nothing actually uses the ARCH value, but that's
basically just luck, and in particular it prevents us from using the
generic cpp_lds_S rule. It's also clearly wrong, ARCH=ppc64 is dead,
buried and cremated.
Fix it by dropping the setting of ARCH completely, the correct value is
exported by the top level Makefile.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-11-21 10:14:33 +00:00
|
|
|
$(Q)$(MAKE) $(build)=$(boot) $(patsubst %,$(boot)/%,$@)
|
2007-12-03 02:56:58 +00:00
|
|
|
|
2015-05-26 01:36:57 +00:00
|
|
|
# Used to create 'merged defconfigs'
|
|
|
|
# To use it $(call) it with the first argument as the base defconfig
|
|
|
|
# and the second argument as a space separated list of .config files to merge,
|
|
|
|
# without the .config suffix.
|
|
|
|
define merge_into_defconfig
|
|
|
|
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \
|
|
|
|
-m -O $(objtree) $(srctree)/arch/$(ARCH)/configs/$(1) \
|
|
|
|
$(foreach config,$(2),$(srctree)/arch/$(ARCH)/configs/$(config).config)
|
|
|
|
+$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
|
|
|
|
endef
|
|
|
|
|
|
|
|
PHONY += pseries_le_defconfig
|
|
|
|
pseries_le_defconfig:
|
|
|
|
$(call merge_into_defconfig,pseries_defconfig,le)
|
|
|
|
|
2015-09-23 05:40:35 +00:00
|
|
|
PHONY += ppc64le_defconfig
|
|
|
|
ppc64le_defconfig:
|
|
|
|
$(call merge_into_defconfig,ppc64_defconfig,le)
|
|
|
|
|
2018-11-15 06:49:50 +00:00
|
|
|
PHONY += ppc64le_guest_defconfig
|
|
|
|
ppc64le_guest_defconfig:
|
|
|
|
$(call merge_into_defconfig,ppc64_defconfig,le guest)
|
|
|
|
|
|
|
|
PHONY += ppc64_guest_defconfig
|
|
|
|
ppc64_guest_defconfig:
|
|
|
|
$(call merge_into_defconfig,ppc64_defconfig,be guest)
|
|
|
|
|
2017-07-24 12:50:45 +00:00
|
|
|
PHONY += powernv_be_defconfig
|
|
|
|
powernv_be_defconfig:
|
|
|
|
$(call merge_into_defconfig,powernv_defconfig,be)
|
|
|
|
|
2015-07-29 23:14:04 +00:00
|
|
|
PHONY += mpc85xx_defconfig
|
|
|
|
mpc85xx_defconfig:
|
2019-05-28 08:16:14 +00:00
|
|
|
$(call merge_into_defconfig,mpc85xx_base.config,\
|
2015-07-29 23:14:04 +00:00
|
|
|
85xx-32bit 85xx-hw fsl-emb-nonhw)
|
|
|
|
|
|
|
|
PHONY += mpc85xx_smp_defconfig
|
|
|
|
mpc85xx_smp_defconfig:
|
2019-05-28 08:16:14 +00:00
|
|
|
$(call merge_into_defconfig,mpc85xx_base.config,\
|
2015-07-29 23:14:04 +00:00
|
|
|
85xx-32bit 85xx-smp 85xx-hw fsl-emb-nonhw)
|
|
|
|
|
|
|
|
PHONY += corenet32_smp_defconfig
|
|
|
|
corenet32_smp_defconfig:
|
2019-05-28 08:16:14 +00:00
|
|
|
$(call merge_into_defconfig,corenet_base.config,\
|
2016-09-22 15:04:12 +00:00
|
|
|
85xx-32bit 85xx-smp 85xx-hw fsl-emb-nonhw dpaa)
|
2015-07-29 23:14:04 +00:00
|
|
|
|
|
|
|
PHONY += corenet64_smp_defconfig
|
|
|
|
corenet64_smp_defconfig:
|
2019-05-28 08:16:14 +00:00
|
|
|
$(call merge_into_defconfig,corenet_base.config,\
|
2016-09-22 15:04:12 +00:00
|
|
|
85xx-64bit 85xx-smp altivec 85xx-hw fsl-emb-nonhw dpaa)
|
2015-07-29 23:14:04 +00:00
|
|
|
|
2016-02-22 09:26:14 +00:00
|
|
|
PHONY += mpc86xx_defconfig
|
|
|
|
mpc86xx_defconfig:
|
2019-05-28 08:16:14 +00:00
|
|
|
$(call merge_into_defconfig,mpc86xx_base.config,\
|
2016-02-22 09:26:14 +00:00
|
|
|
86xx-hw fsl-emb-nonhw)
|
|
|
|
|
|
|
|
PHONY += mpc86xx_smp_defconfig
|
|
|
|
mpc86xx_smp_defconfig:
|
2019-05-28 08:16:14 +00:00
|
|
|
$(call merge_into_defconfig,mpc86xx_base.config,\
|
2016-02-22 09:26:14 +00:00
|
|
|
86xx-smp 86xx-hw fsl-emb-nonhw)
|
|
|
|
|
2018-07-09 14:24:25 +00:00
|
|
|
PHONY += ppc32_allmodconfig
|
|
|
|
ppc32_allmodconfig:
|
|
|
|
$(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/book3s_32.config \
|
|
|
|
-f $(srctree)/Makefile allmodconfig
|
|
|
|
|
2019-02-07 05:16:51 +00:00
|
|
|
PHONY += ppc_defconfig
|
|
|
|
ppc_defconfig:
|
|
|
|
$(call merge_into_defconfig,book3s_32.config,)
|
|
|
|
|
2018-07-09 14:24:26 +00:00
|
|
|
PHONY += ppc64le_allmodconfig
|
|
|
|
ppc64le_allmodconfig:
|
|
|
|
$(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/le.config \
|
|
|
|
-f $(srctree)/Makefile allmodconfig
|
|
|
|
|
2020-11-25 03:15:51 +00:00
|
|
|
PHONY += ppc64le_allnoconfig
|
|
|
|
ppc64le_allnoconfig:
|
|
|
|
$(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/ppc64le.config \
|
|
|
|
-f $(srctree)/Makefile allnoconfig
|
|
|
|
|
2018-07-09 14:24:26 +00:00
|
|
|
PHONY += ppc64_book3e_allmodconfig
|
|
|
|
ppc64_book3e_allmodconfig:
|
|
|
|
$(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/85xx-64bit.config \
|
|
|
|
-f $(srctree)/Makefile allmodconfig
|
|
|
|
|
2021-04-28 13:27:00 +00:00
|
|
|
PHONY += ppc32_randconfig
|
|
|
|
ppc32_randconfig:
|
|
|
|
$(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/32-bit.config \
|
|
|
|
-f $(srctree)/Makefile randconfig
|
|
|
|
|
|
|
|
PHONY += ppc64_randconfig
|
|
|
|
ppc64_randconfig:
|
|
|
|
$(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/64-bit.config \
|
|
|
|
-f $(srctree)/Makefile randconfig
|
|
|
|
|
2005-09-26 06:04:21 +00:00
|
|
|
define archhelp
|
2008-06-25 20:14:36 +00:00
|
|
|
@echo '* zImage - Build default images selected by kernel config'
|
|
|
|
@echo ' zImage.* - Compressed kernel image (arch/$(ARCH)/boot/zImage.*)'
|
|
|
|
@echo ' uImage - U-Boot native image format'
|
|
|
|
@echo ' cuImage.<dt> - Backwards compatible U-Boot image for older'
|
|
|
|
@echo ' versions which do not support device trees'
|
|
|
|
@echo ' dtbImage.<dt> - zImage with an embedded device tree blob'
|
|
|
|
@echo ' simpleImage.<dt> - Firmware independent image.'
|
|
|
|
@echo ' treeImage.<dt> - Support for older IBM 4xx firmware (not U-Boot)'
|
2005-09-26 06:04:21 +00:00
|
|
|
@echo ' install - Install kernel using'
|
2009-07-20 19:37:11 +00:00
|
|
|
@echo ' (your) ~/bin/$(INSTALLKERNEL) or'
|
|
|
|
@echo ' (distribution) /sbin/$(INSTALLKERNEL) or'
|
2005-09-26 06:04:21 +00:00
|
|
|
@echo ' install to $$(INSTALL_PATH) and run lilo'
|
2005-11-18 04:43:34 +00:00
|
|
|
@echo ' *_defconfig - Select default config from arch/$(ARCH)/configs'
|
2008-06-25 20:14:36 +00:00
|
|
|
@echo ''
|
|
|
|
@echo ' Targets with <dt> embed a device tree blob inside the image'
|
|
|
|
@echo ' These targets support board with firmware that does not'
|
|
|
|
@echo ' support passing a device tree directly. Replace <dt> with the'
|
|
|
|
@echo ' name of a dts file from the arch/$(ARCH)/boot/dts/ directory'
|
|
|
|
@echo ' (minus the .dts extension).'
|
2005-09-26 06:04:21 +00:00
|
|
|
endef
|
|
|
|
|
2020-02-19 00:04:34 +00:00
|
|
|
PHONY += install
|
2008-02-16 11:36:10 +00:00
|
|
|
install:
|
2022-05-03 02:47:16 +00:00
|
|
|
$(call cmd,install)
|
2007-04-10 11:05:31 +00:00
|
|
|
|
2020-09-27 09:16:33 +00:00
|
|
|
ifeq ($(KBUILD_EXTMOD),)
|
|
|
|
# We need to generate vdso-offsets.h before compiling certain files in kernel/.
|
|
|
|
# In order to do that, we should use the archprepare target, but we can't since
|
|
|
|
# asm-offsets.h is included in some files used to generate vdso-offsets.h, and
|
|
|
|
# asm-offsets.h is built in prepare0, for which archprepare is a dependency.
|
|
|
|
# Therefore we need to generate the header after prepare0 has been made, hence
|
|
|
|
# this hack.
|
|
|
|
prepare: vdso_prepare
|
|
|
|
vdso_prepare: prepare0
|
|
|
|
$(if $(CONFIG_VDSO32),$(Q)$(MAKE) \
|
2022-01-21 16:30:27 +00:00
|
|
|
$(build)=arch/powerpc/kernel/vdso include/generated/vdso32-offsets.h)
|
2020-09-27 09:16:33 +00:00
|
|
|
$(if $(CONFIG_PPC64),$(Q)$(MAKE) \
|
2022-01-21 16:30:27 +00:00
|
|
|
$(build)=arch/powerpc/kernel/vdso include/generated/vdso64-offsets.h)
|
2020-09-27 09:16:33 +00:00
|
|
|
endif
|
|
|
|
|
2005-09-26 06:04:21 +00:00
|
|
|
archprepare: checkbin
|
|
|
|
|
2018-12-17 10:40:36 +00:00
|
|
|
archheaders:
|
|
|
|
$(Q)$(MAKE) $(build)=arch/powerpc/kernel/syscalls all
|
|
|
|
|
2018-09-27 07:05:53 +00:00
|
|
|
ifdef CONFIG_STACKPROTECTOR
|
|
|
|
prepare: stack_protector_prepare
|
2005-09-26 06:04:21 +00:00
|
|
|
|
2020-02-19 00:04:34 +00:00
|
|
|
PHONY += stack_protector_prepare
|
2018-09-27 07:05:53 +00:00
|
|
|
stack_protector_prepare: prepare0
|
2018-09-27 07:05:55 +00:00
|
|
|
ifdef CONFIG_PPC64
|
|
|
|
$(eval KBUILD_CFLAGS += -mstack-protector-guard-offset=$(shell awk '{if ($$2 == "PACA_CANARY") print $$3;}' include/generated/asm-offsets.h))
|
|
|
|
else
|
2018-09-27 07:05:53 +00:00
|
|
|
$(eval KBUILD_CFLAGS += -mstack-protector-guard-offset=$(shell awk '{if ($$2 == "TASK_CANARY") print $$3;}' include/generated/asm-offsets.h))
|
|
|
|
endif
|
2018-09-27 07:05:55 +00:00
|
|
|
endif
|
2018-09-27 07:05:53 +00:00
|
|
|
|
2020-02-19 00:04:34 +00:00
|
|
|
PHONY += checkbin
|
2018-09-14 05:08:52 +00:00
|
|
|
# Check toolchain versions:
|
|
|
|
# - gcc-4.6 is the minimum kernel-wide version so nothing required.
|
2005-09-26 06:04:21 +00:00
|
|
|
checkbin:
|
powerpc/toc: Future proof kernel toc
This patch future-proofs the kernel against linker changes that might
put the toc pointer at some location other than .got+0x8000, by
replacing __toc_start+0x8000 with .TOC. throughout. If the kernel's
idea of the toc pointer doesn't agree with the linker, bad things
happen.
prom_init.c code relocating its toc is also changed so that a symbolic
__prom_init_toc_start toc-pointer relative address is calculated
rather than assuming that it is always at toc-pointer - 0x8000. The
length calculations loading values from the toc are also avoided.
It's a little incestuous to do that with unreloc_toc picking up
adjusted values (which is fine in practice, they both adjust by the
same amount if all goes well).
I've also changed the way .got is aligned in vmlinux.lds and
zImage.lds, mostly so that dumping out section info by objdump or
readelf plainly shows the alignment is 256. This linker script
feature was added 2005-09-27, available in FSF binutils releases from
2.17 onwards. Should be safe to use in the kernel, I think.
Finally, put *(.got) before the prom_init.o entry which only needs
*(.toc), so that the GOT header goes in the correct place. I don't
believe this makes any difference for the kernel as it would for
dynamic objects being loaded by ld.so. That change is just to stop
lusers who blindly copy kernel scripts being led astray. Of course,
this change needs the prom_init.c changes.
Some notes on .toc and .got.
.toc is a compiler generated section of addresses. .got is a linker
generated section of addresses, generally built when the linker sees
R_*_*GOT* relocations. In the case of powerpc64 ld.bfd, there are
multiple generated .got sections, one per input object file. So you
can somewhat reasonably write in a linker script an input section
statement like *prom_init.o(.got .toc) to mean "the .got and .toc
section for files matching *prom_init.o". On other architectures that
doesn't make sense, because the linker generally has just one .got
section. Even on powerpc64, note well that the GOT entries for
prom_init.o may be merged with GOT entries from other objects. That
means that if prom_init.o references, say, _end via some GOT
relocation, and some other object also references _end via a GOT
relocation, the GOT entry for _end may be in the range
__prom_init_toc_start to __prom_init_toc_end and if the kernel does
something special to GOT/TOC entries in that range then the value of
_end as seen by objects other than prom_init.o will be affected. On
the other hand the GOT entry for _end may not be in the range
__prom_init_toc_start to __prom_init_toc_end. Which way it turns out
is deterministic but a detail of linker operation that should not be
relied on.
A feature of ld.bfd is that input .toc (and .got) sections matching
one linker input section statement may be sorted, to put entries used
by small-model code first, near the toc base. This is why scripts for
powerpc64 normally use *(.got .toc) rather than *(.got) *(.toc), since
the first form allows more freedom to sort.
Another feature of ld.bfd is that indirect addressing sequences using
the GOT/TOC may be edited by the linker to relative addressing. In
many cases relative addressing would be emitted by gcc for
-mcmodel=medium if you appropriately decorate variable declarations
with non-default visibility.
The original patch is here:
https://lore.kernel.org/linuxppc-dev/20210310034813.GM6042@bubble.grove.modra.org/
Signed-off-by: Alan Modra <amodra@au1.ibm.com>
[aik: removed non-relocatable which is gone in 24d33ac5b8ffb]
[aik: added <=2.24 check]
[aik: because of llvm-as, kernel_toc_addr() uses "mr" instead of global register variable]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211221055904.555763-2-aik@ozlabs.ru
2021-12-21 05:58:59 +00:00
|
|
|
@if test "x${CONFIG_LD_IS_LLD}" != "xy" -a \
|
|
|
|
"x$(call ld-ifversion, -le, 22400, y)" = "xy" ; then \
|
2015-04-23 07:27:12 +00:00
|
|
|
echo -n '*** binutils 2.24 miscompiles weak symbols ' ; \
|
|
|
|
echo 'in some circumstances.' ; \
|
powerpc/toc: Future proof kernel toc
This patch future-proofs the kernel against linker changes that might
put the toc pointer at some location other than .got+0x8000, by
replacing __toc_start+0x8000 with .TOC. throughout. If the kernel's
idea of the toc pointer doesn't agree with the linker, bad things
happen.
prom_init.c code relocating its toc is also changed so that a symbolic
__prom_init_toc_start toc-pointer relative address is calculated
rather than assuming that it is always at toc-pointer - 0x8000. The
length calculations loading values from the toc are also avoided.
It's a little incestuous to do that with unreloc_toc picking up
adjusted values (which is fine in practice, they both adjust by the
same amount if all goes well).
I've also changed the way .got is aligned in vmlinux.lds and
zImage.lds, mostly so that dumping out section info by objdump or
readelf plainly shows the alignment is 256. This linker script
feature was added 2005-09-27, available in FSF binutils releases from
2.17 onwards. Should be safe to use in the kernel, I think.
Finally, put *(.got) before the prom_init.o entry which only needs
*(.toc), so that the GOT header goes in the correct place. I don't
believe this makes any difference for the kernel as it would for
dynamic objects being loaded by ld.so. That change is just to stop
lusers who blindly copy kernel scripts being led astray. Of course,
this change needs the prom_init.c changes.
Some notes on .toc and .got.
.toc is a compiler generated section of addresses. .got is a linker
generated section of addresses, generally built when the linker sees
R_*_*GOT* relocations. In the case of powerpc64 ld.bfd, there are
multiple generated .got sections, one per input object file. So you
can somewhat reasonably write in a linker script an input section
statement like *prom_init.o(.got .toc) to mean "the .got and .toc
section for files matching *prom_init.o". On other architectures that
doesn't make sense, because the linker generally has just one .got
section. Even on powerpc64, note well that the GOT entries for
prom_init.o may be merged with GOT entries from other objects. That
means that if prom_init.o references, say, _end via some GOT
relocation, and some other object also references _end via a GOT
relocation, the GOT entry for _end may be in the range
__prom_init_toc_start to __prom_init_toc_end and if the kernel does
something special to GOT/TOC entries in that range then the value of
_end as seen by objects other than prom_init.o will be affected. On
the other hand the GOT entry for _end may not be in the range
__prom_init_toc_start to __prom_init_toc_end. Which way it turns out
is deterministic but a detail of linker operation that should not be
relied on.
A feature of ld.bfd is that input .toc (and .got) sections matching
one linker input section statement may be sorted, to put entries used
by small-model code first, near the toc base. This is why scripts for
powerpc64 normally use *(.got .toc) rather than *(.got) *(.toc), since
the first form allows more freedom to sort.
Another feature of ld.bfd is that indirect addressing sequences using
the GOT/TOC may be edited by the linker to relative addressing. In
many cases relative addressing would be emitted by gcc for
-mcmodel=medium if you appropriately decorate variable declarations
with non-default visibility.
The original patch is here:
https://lore.kernel.org/linuxppc-dev/20210310034813.GM6042@bubble.grove.modra.org/
Signed-off-by: Alan Modra <amodra@au1.ibm.com>
[aik: removed non-relocatable which is gone in 24d33ac5b8ffb]
[aik: added <=2.24 check]
[aik: because of llvm-as, kernel_toc_addr() uses "mr" instead of global register variable]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211221055904.555763-2-aik@ozlabs.ru
2021-12-21 05:58:59 +00:00
|
|
|
echo '*** binutils 2.23 do not define the TOC symbol ' ; \
|
2015-04-23 07:27:12 +00:00
|
|
|
echo -n '*** Please use a different binutils version.' ; \
|
|
|
|
false ; \
|
|
|
|
fi
|