I have tested two USB joysticks:
<inputConfig type="joystick" deviceName="BSGPAC02 Series" deviceGUID="03000000d81d00000e00000010010000" deviceNbAxes="4" deviceNbHats="1" deviceNbButtons="13">
<input name="a" type="button" id="1" value="1" code="305" />
<input name="b" type="button" id="0" value="1" code="304" />
<input name="down" type="axis" id="1" value="1" code="1" />
<input name="hotkey" type="button" id="8" value="1" code="312" />
<input name="l2" type="button" id="7" value="1" code="311" />
<input name="l3" type="button" id="10" value="1" code="314" />
<input name="left" type="axis" id="0" value="-1" code="0" />
<input name="pagedown" type="button" id="2" value="1" code="306" />
<input name="pageup" type="button" id="6" value="1" code="310" />
<input name="r2" type="button" id="3" value="1" code="307" />
<input name="r3" type="button" id="11" value="1" code="315" />
<input name="right" type="axis" id="0" value="1" code="0" />
<input name="select" type="button" id="8" value="1" code="312" />
<input name="start" type="button" id="9" value="1" code="313" />
<input name="up" type="axis" id="1" value="-1" code="1" />
<input name="x" type="button" id="5" value="1" code="309" />
<input name="y" type="button" id="4" value="1" code="308" />
</inputConfig>
<inputConfig type="joystick" deviceName="PS3/PC Gamepad" deviceGUID="03000000100800000300000010010000" deviceNbAxes="5" deviceNbHats="1" deviceNbButtons="12">
<input name="a" type="button" id="2" value="1" code="290" />
<input name="b" type="button" id="6" value="1" code="294" />
<input name="down" type="axis" id="1" value="1" code="1" />
<input name="hotkey" type="button" id="8" value="1" code="296" />
<input name="l2" type="button" id="5" value="1" code="293" />
<input name="left" type="axis" id="0" value="-1" code="0" />
<input name="pagedown" type="button" id="1" value="1" code="289" />
<input name="pageup" type="button" id="0" value="1" code="288" />
<input name="r2" type="button" id="7" value="1" code="295" />
<input name="right" type="axis" id="0" value="1" code="0" />
<input name="select" type="button" id="8" value="1" code="296" />
<input name="start" type="button" id="9" value="1" code="297" />
<input name="up" type="axis" id="1" value="-1" code="1" />
<input name="x" type="button" id="3" value="1" code="291" />
<input name="y" type="button" id="4" value="1" code="292" />
</inputConfig>
with this last joystick, select + start doesn't exit on amiberry emulator.