Difference between revisions of "Creating an app bin"

Revision as of 16:58, 22 February 2010

When creating a custom app.bin you should follow these guidelines:

• binaries should be placed in bin/ or sbin/ and not in usr/bin and usr/sbin
• libraries should be placed in lib/ and not in usr/lib
• modules should be placed in lib/modules/2.6.22.19-19-4
  • lib/modules/2.6.22.19-19-4 can contain a modules.dep file which will be added to /lib/modules/2.6.22.19-19-4/modules.dep for modprobe insertion of app.bin modules
• etc/init.d/ contains the init scripts that will be called when the system boots and when /sbin/resume is executed
  • init.d scripts should contain at the minimum start and stop cases
  • only SXX scripts are executed during rcS

For example, I have test-app.app.bin containing the following structure:
README
version
bin/test-bin01
bin/test-bin02
etc/init.d/S10test-app-init
lib/test-lib01.so
lib/test-lib01.so.0.3.0
lib/modules/2.6.22.19-19-4/modules.dep
lib/modules/2.6.22.19-19-4/test-module.ko
lib/modules/2.6.22.19-19-4/test-dep.ko
sbin/test-sbin01
sbin/test-sbin02
usr/bin/ignored-bin01
usr/sbin/ignored-sbin01

Note:

• The README file contains ancillary information and whatever required details/etc.
• version contains the version of the app.bin

After test-app.app.bin is mounted by /bin/crazymount at /apps/test-app/ the following things happen:

• /apps/test-app/bin and /apps/test-app/sbin are added to PATH
• /apps/test-app/lib is added to ld.so.conf
• ldconfig is refreshed
• /apps/test-app/lib/modules/2.6.22.19-19-4 is scanned for modules and any found are symlinked into /lib/modules/2.6.22.19-19-4
• /apps/test-app/lib/modules/2.6.22.19-19-4/modules.dep is cat'd onto the end of /lib/modules/2.6.22.19-19-4/modules.dep
• /apps/test-app/etc/init.d/S10test-app-init is symlinked into /tmp/init.d for execution by rcS/suspend/resume

Now /apps/test-app/usr/bin and /apps/test-app/usr/sbin both contain binaries...but those two locations are not scanned, therefore binaries in both locations will not be available without full path.

I included two kernel modules inside of test-app.app.bin, here is the contents of /apps/test-app/lib/modules/2.6.22.19-19-4/modules.dep:
/lib/modules/2.6.22.19-19-4/test-module.ko: /lib/modules/2.6.22.19-19-4/test-dep.ko
/lib/modules/2.6.22.19-19-4/test-dep.ko:

This means that test-module.ko depends on test-dep.ko and therefore when test-module.ko is modprobe'd test-dep.ko will be inserted first by the system. Take note that the modules.dep file contains locations that are inside of /lib/modules/2.6.22.19-19-4 and not /apps/test-app/lib/modules/2.6.22.19-19.