kernel_optimize_test/arch/xtensa/kernel/Makefile
Max Filippov f8f02ca73c xtensa: build kernel with text-section-literals
vmlinux.lds.S doesn't do anything special with literals, so instead of
keeping them separate put them into the corresponding text sections.
Drop explicit .literal sections from the vmlinux.lds.S, use standard
section macros. Mark literal pool locations in the assembly sources.
Unfortunately assembler doesn't put literals into .init sections and
external libgcc may still have .literal sections, so sed transformation
to the linker script is still needed.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2017-12-10 14:48:51 -08:00

43 lines
1.7 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
#
# Makefile for the Linux/Xtensa kernel.
#
extra-y := head.o vmlinux.lds
obj-y := align.o coprocessor.o entry.o irq.o pci-dma.o platform.o process.o \
ptrace.o setup.o signal.o stacktrace.o syscall.o time.o traps.o \
vectors.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 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
# 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__ $< \
| sed $(sed-y) >$@
$(obj)/vmlinux.lds: $(src)/vmlinux.lds.S FORCE
$(call if_changed_dep,_cpp_lds_S)