We have the following in the tree: |commit af42feb9d255bc3ea3b514180f265479ea8834f9 |Author: Enrico Scholz <[email protected]> |Date: Mon Jan 2 11:49:17 2012 +0100 | | ARM: set SCTRL[A] only when architecture does not support unaligned access | | Recent gcc generates code with unaligned access when architecture | supports it. Setting A bit unconditionally causes data-aborts on such | code rendering barebox unusable. | | Signed-off-by: Enrico Scholz <[email protected]> | Signed-off-by: Sascha Hauer <[email protected]>
What the patch tried is correct: We should set the A bit only when the architecture does not support unaligned accesses. To figure out whether the architecture supports unaligned accesses the patch tested for the U bit which is wrong. The U bit may be 0 after a reset, so instead of testing for the U bit we have to set it. This can be done on armv6 and later. All others have the A bit set to trap unaligned accesses. Signed-off-by: Sascha Hauer <[email protected]> --- Enrico, can you confirm this is correct? Thanks Sascha arch/arm/cpu/start.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c index 3c282ee..523179d 100644 --- a/arch/arm/cpu/start.c +++ b/arch/arm/cpu/start.c @@ -81,13 +81,11 @@ void __naked __bare_init reset(void) r &= ~(CR_M | CR_C | CR_B | CR_S | CR_R | CR_V); r |= CR_I; - if (!(r & CR_U)) - /* catch unaligned access on architectures which do not - * support unaligned access */ - r |= CR_A; - else - r &= ~CR_A; - +#if __LINUX_ARM_ARCH__ >= 6 + r |= CR_U; +#else + r |= CR_A; +#endif #ifdef __ARMEB__ r |= CR_B; -- 1.7.10 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
