From mboxrd@z Thu Jan 1 00:00:00 1970 From: dave.martin@linaro.org (Dave Martin) Date: Tue, 17 May 2011 19:10:33 +0100 Subject: [PATCH] [klibc] arm: use bx on thumb2 v3 In-Reply-To: <1305649031-15622-1-git-send-email-max@stro.at> References: <1305649031-15622-1-git-send-email-max@stro.at> Message-ID: <20110517181033.GC27656@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, May 17, 2011 at 06:17:10PM +0200, maximilian attems wrote: > Use klibc way to define a system dependent preprocessor > definition: disabled by default and enabled for newer arm. > > Based on a patch by vorlon that got tested on his beagleboard, > should be functional equivalent. > Fixes: https://bugs.launchpad.net/ubuntu/+source/klibc/+bug/527720 > > Cc: Steve Langasek > Cc: Kirill A. Shutemov > Cc: Michael Tokarev > Signed-off-by: maximilian attems > --- > usr/include/arch/arm/klibc/archconfig.h | 6 +++++- > usr/include/arch/arm/klibc/asmmacros.h | 6 ++++++ > usr/include/klibc/sysconfig.h | 9 +++++++++ > usr/klibc/arch/arm/setjmp.S | 10 ++++++---- > usr/klibc/arch/arm/vfork.S | 5 +++-- > 5 files changed, 29 insertions(+), 7 deletions(-) > > diff --git a/usr/include/arch/arm/klibc/archconfig.h b/usr/include/arch/arm/klibc/archconfig.h > index e34bdb7..36e9ab5 100644 > --- a/usr/include/arch/arm/klibc/archconfig.h > +++ b/usr/include/arch/arm/klibc/archconfig.h > @@ -9,6 +9,10 @@ > #ifndef _KLIBC_ARCHCONFIG_H > #define _KLIBC_ARCHCONFIG_H > > -/* All defaults */ > +/* newer arm arch support bx instruction */ > +#if (!defined(__ARM_ARCH_2__) && !defined(__ARM_ARCH_3__) \ > + && !defined(__ARM_ARCH_3M__) && !defined(__ARM_ARCH_4__)) > +# define _KLIBC_ARM_USE_BX 1 > +#endif > > #endif /* _KLIBC_ARCHCONFIG_H */ > diff --git a/usr/include/arch/arm/klibc/asmmacros.h b/usr/include/arch/arm/klibc/asmmacros.h > index 8a21c94..45bea0e 100644 > --- a/usr/include/arch/arm/klibc/asmmacros.h > +++ b/usr/include/arch/arm/klibc/asmmacros.h > @@ -27,4 +27,10 @@ > (((x) & ~0xf000000f) == 0) || \ > (((x) & ~0xc000003f) == 0)) > > +#if _KLIBC_ARM_USE_BX > +# define BX(x) bx ##x > +#else > +# define BX(x) mov pc, ##x > +#endif > + What's the ## for? The C preprocessor collapses whitespace around this operator, so won't this expand to strings like "bxlr" in the _KLIBC_ARM_USE_BX case? Otherwise this looks OK, though I'm not a klibc expert. Cheers ---Dave