kernel_optimize_test/arch/alpha/Makefile
Ivan Kokshaysky ede426923b alpha: link failure fix
With built-in scsi disk driver, the final link fails with a following
error:
`.exit.text' referenced in section `.rodata' of drivers/built-in.o:
defined in discarded section `.exit.text' of drivers/built-in.o

This happens with -Os (CONFIG_CC_OPTIMIZE_FOR_SIZE=y) with all gcc-4
versions, and also with -O2 and gcc-4.3.

The problem is in sd.c:sd_major() being inlined into __exit function
exit_sd(), and the compiler generating a jump table in .rodata section
for the 'switch' statement in sd_major(). So we have references to
discarded section.

Fixed with a big hammer in the form of -fno-jump-tables.

Note that jump tables vs. discarded sections is a generic problem,
other architectures are just lucky not to suffer from it. But with
a slightly more complex switch/case statement it can be reproduced
on x86 as well. So maybe at some point we should consider
-fno-jump-tables as a generic compile option...

Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-20 16:46:10 -07:00

70 lines
2.2 KiB
Makefile

#
# alpha/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 by Linus Torvalds
#
NM := $(NM) -B
LDFLAGS_vmlinux := -static -N #-relax
CHECKFLAGS += -D__alpha__ -m64
cflags-y := -pipe -mno-fp-regs -ffixed-8 -msmall-data
cflags-y += $(call cc-option, -fno-jump-tables)
cpuflags-$(CONFIG_ALPHA_EV4) := -mcpu=ev4
cpuflags-$(CONFIG_ALPHA_EV5) := -mcpu=ev5
cpuflags-$(CONFIG_ALPHA_EV56) := -mcpu=ev56
cpuflags-$(CONFIG_ALPHA_POLARIS) := -mcpu=pca56
cpuflags-$(CONFIG_ALPHA_SX164) := -mcpu=pca56
cpuflags-$(CONFIG_ALPHA_EV6) := -mcpu=ev6
cpuflags-$(CONFIG_ALPHA_EV67) := -mcpu=ev67
# If GENERIC, make sure to turn off any instruction set extensions that
# the host compiler might have on by default. Given that EV4 and EV5
# have the same instruction set, prefer EV5 because an EV5 schedule is
# more likely to keep an EV4 processor busy than vice-versa.
cpuflags-$(CONFIG_ALPHA_GENERIC) := -mcpu=ev5
cflags-y += $(cpuflags-y)
# For TSUNAMI, we must have the assembler not emulate our instructions.
# The same is true for IRONGATE, POLARIS, PYXIS.
# BWX is most important, but we don't really want any emulation ever.
KBUILD_CFLAGS += $(cflags-y) -Wa,-mev6
head-y := arch/alpha/kernel/head.o
core-y += arch/alpha/kernel/ arch/alpha/mm/
core-$(CONFIG_MATHEMU) += arch/alpha/math-emu/
drivers-$(CONFIG_OPROFILE) += arch/alpha/oprofile/
libs-y += arch/alpha/lib/
# export what is needed by arch/alpha/boot/Makefile
LIBS_Y := $(patsubst %/, %/lib.a, $(libs-y))
export LIBS_Y
boot := arch/alpha/boot
#Default target when executing make with no arguments
all boot: $(boot)/vmlinux.gz
$(boot)/vmlinux.gz: vmlinux
$(Q)$(MAKE) $(build)=$(boot) $@
bootimage bootpfile bootpzfile: vmlinux
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
archclean:
$(Q)$(MAKE) $(clean)=$(boot)
define archhelp
echo '* boot - Compressed kernel image (arch/alpha/boot/vmlinux.gz)'
echo ' bootimage - SRM bootable image (arch/alpha/boot/bootimage)'
echo ' bootpfile - BOOTP bootable image (arch/alpha/boot/bootpfile)'
echo ' bootpzfile - compressed kernel BOOTP image (arch/alpha/boot/bootpzfile)'
endef