On 13 March 2014 17:17, JustinGuo@via-alliance.com wrote:
Dear Linaro toolchain support team:
I am Justin Guo from S3 graphics Inc. I am studying linaro's big-little codes and is using TC2 Platform.
I used ./linaro_kernel_build_cmds.sh to build kernel, I got no problem when I set CONFIG_DEBUG_INFO=y to build for kernel.
However, When I trace kernel, the traced line in source code level is jumping up/down, so I tried to turn off the optimization.
After modified Makefile as below to turn off optimization:
ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
KBUILD_CFLAGS += -Os $(call cc-disable-warning,maybe-uninitialized,)
else
KBUILD_CFLAGS += -O0
It is not possible to build the kernel with -O0 due to various requirements for inlining and register allocation. You could try -O1 or -Og (if your compiler supports it, gcc 4.8 and above).