android - Push my apk to /system/app

Question

How can I push my application package to Android emulator "/system/app" folder?

I've already tried to use:
"adb push myApk.apk /system/app"
and it gives me this:

"failed to copy: ... No space left on device"

Although from settings -> sdCard & Phone Storage, I get 37Mb of internal free space.

The whole point of this need is
related to permissions.

I need to have INSTALL_PACKAGES permission
and I know that by puting my application there,
in /system/app, I get that permission.

Answer 1

I can install an APK to /system/app with following steps.

1. Push APK to SD card.

   $ adb push SecureSetting.apk /sdcard/  
   

2. Enter the console and get the shell

   $ adb shell
   

3. Switch to superuser. If your device is not rooted, get it rooted first. (If you don't know how to do that, just Google.)

   $ su 
   

4. Remount the system partition with WRITE permission.

   $ mount -o remount,rw -t yaffs2 /dev/block/mtdblock3 /system 
   

5. Cat your APK from /sdcard/ to /system/ , some guys get a fail with cp command due to cp is not supported. So use cat instead.

   $ cat /sdcard/SecureSetting.apk > /system/app/SecureSetting.apk 
   

6. Remout /system partition back to READ-ONLY, and exit

   $ mount -o remount,ro -t yaffs2 /dev/block/mtdblock3 /system
   $ exit
   

Then reboot your device, the APK should have been installed on /system/app.