Php Serial Port Communication Linux Kernel

this is from a question on stackoverflow titled 'Android USB host and hidden devices' (sorry, i can't add external URLs yet). it worked like a charm on a micromax A120 canvas 2 phone (kitkat 4.4.2). now i can control my Arduino! i used busybox tools to do all the command line work (otherwise chmod wouldn't work). my steps (perhaps some were not required):
(0) install PDAnet drivers on my Windows 8 computer.
(1) root the phone using Vroot (now called iRoot). Very simple, only catch is that the su grant/deny page is partly in chinese, no big deal.
(2) install busybox and jackpal's Android-Terminal-Emulator available on github and the google play store (free).
(3) open a terminal window and become the superuser:
# su
(4) the file system may be read-only, so you might have to remount it:
# mount -o rw,remount -t yaffs2 /
or
# mount -o rw,remount -t rootfs /
or
# mount -o rw,remount -t rootfs rootfs /system
(5) make default.prop read/write:
chmod 666 /default.prop
(6) edit /default.prop, make the following changes:
ro.secure=0
ro.debuggable=1
persist.service.adb.enable=1
... And this is the real meat of it:
(7) To enable USB host API support you should add a file named
android.hardware.usb.host.xml and containing the following lines:
<permissions>
<feature name='android.hardware.usb.host'/>
</permissions>
into folder
/system/etc/permissions
in that folder find file named
handheld_core_hardware.xml or tablet_core_hardware.xml
and add
<feature name='android.hardware.usb.host' />
into <permissions> section.
(8) Reboot your device. Usb host api should work.