From d60504ef8362bea09071a766c43956e71fdb81dc Mon Sep 17 00:00:00 2001 From: NiLuJe Date: Wed, 3 Oct 2012 16:07:03 +0200 Subject: [PATCH] More comments on the whole unaligned access mess on FW 2.x. Don't even think about setting the alignment trap to a mode that includes warn, that simply kills the performance because of the storm of faults the syslog gets... --- Makefile | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 9a8843a89..0f27d4a1a 100644 --- a/Makefile +++ b/Makefile @@ -36,7 +36,9 @@ BASE_CFLAGS:=-O2 -ffast-math -pipe -fomit-frame-pointer # Use this for debugging: #BASE_CFLAGS:=-O0 -g # Misc GCC tricks to ensure backward compatibility with the K2, even when using a fairly recent TC (Linaro/MG). -# NOTE: -mno-unaligned-access is needed for Linaro 4.6/4.7 and GCC 4.7 TC, or weird crap happens on FW 2.x. We unfortunately can't set it by default, since it's a new flag. +# NOTE: -mno-unaligned-access is needed for TC based on Linaro 4.6/4.7 or GCC 4.7, or weird crap happens on FW 2.x. We unfortunately can't set it by default, since it's a new flag. +# A possible workaround would be to set the alignment trap to fixup (echo 2 > /proc/cpu/alignment) in the launch script, but that's terribly ugly, and might severly nerf performance... +# That said, MG 2012.03 is still using GCC 4.6.3, so we're good ;). ARM_BACKWARD_COMPAT_CFLAGS:=-fno-stack-protector -U_FORTIFY_SOURCE -D_GNU_SOURCE -fno-finite-math-only ARM_BACKWARD_COMPAT_CXXFLAGS:=-fno-use-cxa-atexit ARM_ARCH:=-march=armv6j -mtune=arm1136jf-s -mfpu=vfp -mfloat-abi=softfp -marm