On Wed, Aug 01, 2012 at 02:11:48PM -0700, V, Aneesh wrote: > Hi Allen, > > On Wed, Aug 1, 2012 at 1:32 PM, Allen Martin > <[email protected]<mailto:[email protected]>> wrote: > If CONFIG_SYS_THUMB_BUILD is enabled, use thumb interworking return > instructions from libgcc routines, otherwise use ARM returns. > > Signed-off-by: Allen Martin <[email protected]<mailto:[email protected]>> > --- > arch/arm/include/asm/assembler.h | 10 ++++++++++ > arch/arm/lib/_ashldi3.S | 3 ++- > arch/arm/lib/_ashrdi3.S | 3 ++- > arch/arm/lib/_divsi3.S | 15 +++++++++++---- > arch/arm/lib/_lshrdi3.S | 3 ++- > arch/arm/lib/_modsi3.S | 9 ++++++++- > arch/arm/lib/_udivsi3.S | 8 +++++--- > arch/arm/lib/_umodsi3.S | 18 +++++++++++++++++- > arch/arm/lib/memcpy.S | 10 ++++++++++ > arch/arm/lib/memset.S | 3 ++- > 10 files changed, 69 insertions(+), 13 deletions(-) > > diff --git a/arch/arm/include/asm/assembler.h > b/arch/arm/include/asm/assembler.h > index 5e4789b..25ece01 100644 > --- a/arch/arm/include/asm/assembler.h > +++ b/arch/arm/include/asm/assembler.h > @@ -13,6 +13,7 @@ > * Do not include any C declarations in this file - it is included by > * assembler source. > */ > +#include <config.h> > > /* > * Endian independent macros for shifting bytes within registers. > @@ -58,3 +59,12 @@ > * Cache alligned > */ > #define CALGN(code...) code > + > +/* > + * return instruction > + */ > +#ifdef CONFIG_SYS_THUMB_BUILD > +#define RET bx lr > +#else > +#define RET mov pc, lr > > Why not "bx lr" in all cases? In that case you can just replace all the > instances of > "mov pc, lr" directly by "bx lr" instead of this macro. That looks cleaner to > me.
I didn't want to break any older ARM architectures that don't support the bx instruction but use this code. > BTW, as far as I remember when I did this originally my compiler was compiling > all assembly functions in ARM and it was automatically converting "mov pc, > lr" to > "bx lr" ,where necessary. Maybe that was just my compiler and I don't remember > the details now. Did you really face any issue with "mov pc, lr" making wrong > jumps? Yes, without this change if I disassemble the code I'm seeing it's still a mov instruction and it hangs. -Allen -- nvpublic _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
