Saving log during GDB execution

You can define logs to be saved during GDB executing this way:

(gdb) set logging on
Copying output to gdb.txt.
(gdb) commands 5
Type commands for when breakpoint 5 is hit, one per line.
End with a line saying just "end".
>x/1s $r7
>x/1s $r5
>cont
>end
(gdb) commands 6
Type commands for when breakpoint 6 is hit, one per line.
End with a line saying just "end".
>x/1s $r4
>x/1s $r6
>cont
>end

Source: http://forum.xda-developers.com/showthread.php?t=1374345