Thanks Dianne for the suggestion.

I will consider this, and implement it later.
For now, I am focusing on testing my application, and making it work.

Thanks,
Puneet Jindal

On Jul 13, 12:06 pm, Dianne Hackborn <hack...@android.com> wrote:
> You are making this device world readable and writeable to all
> applications...  this is probably not what you want.  Generally we define a
> group id for access to a device, and allow apps to get access to it with a
> permission that is associated with the group id.  (Or actually more often
> have a system service that opens and manages the device, and can return an
> fd to the client if appropriate.)
>
> On Mon, Jul 13, 2009 at 10:57 AM, Puneet <puneetjindal.1...@gmail.com>wrote:
>
>
>
>
>
> > Hi everybody,
>
> > I have solved the above problem as follows :
>
> > I edited the file : <android-workspace>/system/core/init/devices.c
> > and, added the line :  { "/dev/ttyUSB0", 0666, AID_ROOT, AID_ROOT,
> > 0 },
> > to the data structure : static struct perms_ devperms[].
>
> > Now, whenever /dev/ttyUSB0 is created, it has the permissions :
> >     crw-rw-rw- root  root
>
> > Any comments, whether this is a good solution ?
>
> > And, does anyone know whether it is possible to do it with "udev
> > scripts" ?
>
> > Thanks,
> > Puneet Jindal
>
> > On Jul 4, 2:49 pm, Puneet <puneetjindal.1...@gmail.com> wrote:
> > > Hi everybody,
>
> > > I am trying to run Android on my prototype phone. The phone has a
> > > sensor (a device that reports its orientation to the phone) attached
> > > to it through the USB interface.
>
> > > I have developed a hardware module for that sensor, the name of the
> > > shared library for the module being "sensors.default.so". The module
> > > communicates with the sensor through the device file /dev/ttyUSB0.
>
> > > The problem I am facing is that the device file /dev/ttyUSB0 has
> > > permissions as:
> > > crw-------          root       root       188,   0
> > > 1980-01-10       18:47     ttyUSB0
>
> > > So, when I test the module's functionality by running a test android
> > > application, the application doesn't have enough privileges to read/
> > > write from/to the device file. So, the results are negative.
>
> > > And, if I test the same functionality by running a native test
> > > application (via the adb shell, so it runs as root), the results are
> > > positive.
>
> > > I tried to solve this issue by modifying the startup scripts (these
> > > run as root) to change the device file permissions at startup, but it
> > > seems that the device file is created after the scripts have completed
> > > their execution.
>
> > > Any suggestions on what should be done, to make the android
> > > application able to read/write from/to the device file ?
> > > How to change the device file permissions at the time of creation ?
>
> > > Thanks,
> > > Puneet Jindal
>
> --
> Dianne Hackborn
> Android framework engineer
> hack...@android.com
>
> Note: please don't send private questions to me, as I don't have time to
> provide private support, and so won't reply to such e-mails.  All such
> questions should be posted on public forums, where I and others can see and
> answer them.
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