linux/arch/xtensa/kernel/Makefile
Masahiro Yamada 3216484550 kbuild: use obj-y instead extra-y for objects placed at the head
The objects placed at the head of vmlinux need special treatments:

 - arch/$(SRCARCH)/Makefile adds them to head-y in order to place
   them before other archives in the linker command line.

 - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of
   obj-y to avoid them going into built-in.a.

This commit gets rid of the latter.

Create vmlinux.a to collect all the objects that are unconditionally
linked to vmlinux. The objects listed in head-y are moved to the head
of vmlinux.a by using 'ar m'.

With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y
for builtin objects.

There is no *.o that is directly linked to vmlinux. Drop unneeded code
in scripts/clang-tools/gen_compile_commands.py.

$(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested
by Nathan Chancellor [1].

[1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-10-02 18:04:05 +09:00

47 lines
1.8 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
#
# Makefile for the Linux/Xtensa kernel.
#
extra-y := vmlinux.lds
obj-y := head.o align.o coprocessor.o entry.o irq.o platform.o process.o \
ptrace.o setup.o signal.o stacktrace.o syscall.o time.o traps.o \
vectors.o
obj-$(CONFIG_MMU) += pci-dma.o
obj-$(CONFIG_PCI) += pci.o
obj-$(CONFIG_MODULES) += xtensa_ksyms.o module.o
obj-$(CONFIG_FUNCTION_TRACER) += mcount.o
obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_SECONDARY_RESET_VECTOR) += mxhead.o
obj-$(CONFIG_XTENSA_VARIANT_HAVE_PERF_EVENTS) += perf_event.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_S32C1I_SELFTEST) += s32c1i_selftest.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-$(CONFIG_HIBERNATION) += hibernate.o
# In the Xtensa architecture, assembly generates literals which must always
# precede the L32R instruction with a relative offset less than 256 kB.
# Therefore, the .text and .literal section must be combined in parenthesis
# in the linker script, such as: *(.literal .text).
#
# We need to post-process the generated vmlinux.lds scripts to convert
# *(xxx.text) to *(xxx.literal xxx.text) for the following text sections:
# .text .ref.text .*init.text .*exit.text .text.*
#
# Replicate rules in scripts/Makefile.build
sed-y = -e ':a; s/\*(\([^)]*\)\.text\.unlikely/*(\1.literal.unlikely .{text}.unlikely/; ta; ' \
-e ':b; s/\*(\([^)]*\)\.text\(\.[a-z]*\)/*(\1.{text}\2.literal .{text}\2/; tb; ' \
-e ':c; s/\*(\([^)]*\)\(\.[a-z]*it\|\.ref\)\.text/*(\1\2.literal \2.{text}/; tc; ' \
-e ':d; s/\*(\([^)]\+ \|\)\.text/*(\1.literal .{text}/; td; ' \
-e 's/\.{text}/.text/g'
quiet_cmd__cpp_lds_S = LDS $@
cmd__cpp_lds_S = $(CPP) $(cpp_flags) -P -C -Uxtensa -D__ASSEMBLY__ \
-DLINKER_SCRIPT $< | sed $(sed-y) >$@
$(obj)/vmlinux.lds: $(src)/vmlinux.lds.S FORCE
$(call if_changed_dep,_cpp_lds_S)