Failed to open /dev/mem from Anroid opencore framework

by Ling Wan » Fri, 07 Aug 2009 02:36:50 GMT

Sponsored Links

We try to open "/dev/mem" from user space, within the opencore multimedia 
framework. The purpose is to allow access to hardware register of a 
peripheral, as well as map chunks of DMA safe memory between kernel and user 

 int fd = open("/dev/mem", O_RDONLY);

 While we can open and use "/dev/mem" under busybox (2.6.27 kernel and we have 
root permission), we got file descriptor -1 , when it's done from the opencore 
framework, where device driver is supposed to be added. We tried changing 777 
on "/dev/mem", no improvement.

What is the likely reason for that ? Is this due to Android's security
 restriction or some other reason? (We didn't enable SELinux option)

 And how do we solve it, or any alternative on sharing buffer between user / 
kernel space ? Some pointers / links would be great.




Other Threads

1. my question...

I'm looking for a code that can replace the following code since its no more 

 /** This function actually handles the KeyStroke-Injection. */ 
 private void doInjectKeyEvent(KeyEvent kEvent) { 
 try { 
 /* Inject the KeyEvent to the Window-Manager. */ 
 kEvent.getRepeatCount(), kEvent.getDownTime(), kEvent 
 .getEventTime(), true); 
 } catch (DeadObjectException e) { 

if u have a pieces of code that doing so I'll be glad to get it....


2. Any shared memory and named semaphores in Android

Is there any shared memory and named semaphores supported in Android?
Because that I try to use shmget API in android but I get the
following error message

shmget of 0 failed: Function not implemented

system calls in the android kernel, but not in the bionic (the bionic
has a syscall stub that point to sys_ni_syscall which always return
ENOSYS which is the "Not implemented" error).


3. GoogleMaps-Logo on MapView hidden - Maps ToS - Advocate Question

4. J2ME apps for Android --J2ME MIDP RUNNER

5. Jythonroid: Jython runs successfully on Android Emulator

6. The difference between "Runtime.getRuntime().freeMemory();" and "ActivityManager.MemoryInf.availMem"

7. File permission about MediaPlayer