I am running into an issue with support for security extensions on ARM. Can anyone suggest a fix? I have the following code: #include <stdio.h> /*__smc(0) void yeild(void);*/ __asm__(" smc #0"); int main(void) { unsigned int i; for (i = 0; i < 10; i++) { printf("hello from Normal world\n"); yeild(); } return 0; } And I get the following error: /tmp/cc2ntayz.s: Assembler messages: /tmp/cc2ntayz.s:17: Error: selected processor does not support ARM mode `smc #0' make: *** [/home/sansari/android/gas/obj/local/armeabi/objs/hello_tz/main_normal.o] Error 1 I found this link https://lists.linaro.org/pipermail/linaro-toolchain/2012-December/002997.html and this one: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58869 And tried what they suggested by adding the relevant switches to my Android.mk file with a LOCAL_CFLAGS options. But I still get the same error.