linux/arch
Jonathan Austin b8083f86e8 ARM: 7666/1: decompressor: add -mno-single-pic-base for building the decompressor
Before jumping to (position independent) C-code from the decompressor's
assembler world we set-up the C environment. This setup currently does not
set r9, which for arm-none-uclinux-uclibceabi toolchains is by default
expected to be the PIC offset base register (IE should point to the
beginning of the GOT).

Currently, therefore, in order to build working kernels that use the
decompressor it is necessary to use an arm-linux-gnueabi toolchain, or
similar. uClinux toolchains cause a prefetch abort to occur at the beginning
of the decompress_kernel function.

This patch allows uClinux toolchains to build bootable zImages by forcing
the -mno-single-pic-base option, which ensures that the location of the GOT
is re-derived each time it is required, and r9 becomes free for use as a
general purpose register.

This has a small (4% in instruction terms) advantage over the alternative of
setting r9 to point to the GOT before calling into the C-world.

Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-03-06 23:45:42 +00:00
..
alpha arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
arc ARC: split elf.h into uapi and export it for userspace 2013-02-27 20:00:26 +05:30
arm ARM: 7666/1: decompressor: add -mno-single-pic-base for building the decompressor 2013-03-06 23:45:42 +00:00
arm64 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-03-02 08:34:06 -08:00
avr32 arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
blackfin Merge branch 'timer/cleanup' into late/mvebu2 2013-02-28 18:54:15 +01:00
c6x Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
cris Merge branch 'timer/cleanup' into late/mvebu2 2013-02-28 18:54:15 +01:00
frv arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
h8300 arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
hexagon Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
ia64 hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
m32r Merge branch 'timer/cleanup' into late/mvebu2 2013-02-28 18:54:15 +01:00
m68k Merge branch 'timer/cleanup' into late/mvebu2 2013-02-28 18:54:15 +01:00
metag ImgTec Meta architecture changes for v3.9-rc1 2013-03-03 12:06:09 -08:00
microblaze arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
mips Merge git://www.linux-watchdog.org/linux-watchdog 2013-03-03 10:23:29 -08:00
mn10300 arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
openrisc arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
parisc Merge branch 'fixes-for-3.9-latest' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2013-03-03 12:57:38 -08:00
powerpc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-03-02 08:34:06 -08:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
score arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
sh hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
sparc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-03-02 08:34:06 -08:00
tile arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
um Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-02-23 18:50:11 -08:00
unicore32 arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
x86 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
xtensa arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
.gitignore
Kconfig ImgTec Meta architecture changes for v3.9-rc1 2013-03-03 12:06:09 -08:00