No, this is not allowed. 2009/9/18 William Hua <[email protected]>
> > Hi all, > > I checked the source code, and found the permissin of /dev/graphics/ > fb0 is set by /system/core/init/devides.c, obviously, we can not > modify this file. So the only possible way to read framebuffe data > directly is to start the program as root (or user from graphics > group), or change effiective user id (euid) at run time. > > Here is my experiment: > > I build the c souce as executable first, and it is working fine on > emualtor and rooted devices. I also tried to complipe it as SO and > load it through JNI, what I found is the java process and the SO have > the same userid (100XX), and I failed to setuid() and seteuid(). > Then, we can see root previlidge is a must to access frame buffer > directly, and load through JNI also failed to do so. > > Then, on a non-rooted device, it is even impossileb to start a process > as root. As Romain mentioned, to use the framebuffer directly is not a > recommemed way, then is there any better way to get framebuffer data ? > > On 9月18日, 上午3时46分, Romain Guy <[email protected]> wrote: > > Also, you're not expected to use the framebuffer directly :) > > > > > > > > On Thu, Sep 17, 2009 at 12:43 PM, fadden <[email protected]> wrote: > > > > > On Sep 16, 6:30 pm, ZaichengQi <[email protected]> wrote: > > >> I wrote a JNI funtion from my test module using "fbfd = open("/dev/ > > >> graphics/fb0", O_RDWR)", but the errno from <errno.h> returns me > > >> EACCES. > > > > > # ls -l /dev/graphics/fb0 > > > crw-rw---- root graphics 29, 0 2009-09-17 11:00 fb0 > > > > > If you're not user "root" or group "graphics", the failure is > > > expected. > > > > > One of the other mailing lists might be more appropriate (android-ndk > > > for NDK questions, android-platform for permission stuff, etc). > > > > -- > > Romain Guy > > Android framework engineer > > [email protected] > > > > Note: please don't send private questions to me, as I don't have time > > to provide private support. All such questions should be posted on > > public forums, where I and others can see and answer them > > > -- Dianne Hackborn Android framework engineer [email protected] 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. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~----------~----~----~----~------~----~------~--~---
