App - System

Hi eb,
I get problem.
Challengle : ELF ARM - Alphanumeric shellcode.

shell code
$r7 = 0xb ; execve()
$r0 = addr contain string (/bin/sh)
svc 48.
I not understand my problem. why i don’t run command (get shell run command) ?

You see picture that I debug with agument and R7 is right.