Strange Seg Fault on ARM asm

Hi There, I’m getting a strange segmentation fault whenever I try to run hand made ARMv7-A assembly code that makes computations between registers, for example look at this piece of simple code:

http://s22.postimg.org/o3miv36gh/Screenshot.png

The screenshot was taken from Ubuntu running on the Jetson TK1 dev kit

When I run GDB I can see that the Segmentation Fault is generated when the cpu executes the line 10 of the asm file, that is, an add between a register and an immediate number

Any ideas of why is happening that ? Am I missing any flag or directive ?

Thanks

Solved, gcc was compiling using thumb code, and the ASM file was using 4 byte-long instructions