It's a staged approach.
Please look here for more details.
http://www.qnx.com/developers/docs/6.4.1/io-pkt_en/user_guide/drivers.html#Debugging_with_gdb

Debugging network drivers or other dll's.

Note: if debugging networking qconn or pdebug has to be on another network stack. Instructions below do not apply to 
debuging over serial port.

If you using SDP 6.6 armv7le platform you need
- gdb patch for 6.6 from foundry (we have a patch for arm)
- patched IDE for 6.6 (at least of IDE or gdb has to be patched, for x86 only no need for patches)

Then in Momenitcs IDE
1) Create attach configuration for io-pkt, specify io-pkt binary from SDP (io-pkt used as example, use full binary name)

2) Run this configuration and attach to io-pkt. It will stop somewhere and show assembly.
3) Open gdb console from IDE (click on gdb "child" of the debugged process in Debug view, it should open gdb console)
4) In gdb console type
b function_name
where <function_name> is the function in your driver that you expect to execute first.
You should see the message that pending breakpoint is installed. Or you can put breakpoint on "dlsym" function if you 
don't know what function in your dll it will hit.
5) Resume the process
6) On device run mount command to load the driver. Or run any command that will activate it.
7) Breakpoint should be hit now. If not press Pause button. Go to gdb console and type
info shared
You should see your dll in list of loaded libraries. If not something is not right. It also should show that symbols are
 loaded.
Something like
warning: Could not load shared library symbols for libbar.so.
Do you need "set solib-search-path" or "set sysroot"?
From                To                  Syms Read   Shared Object Library

                                        No          libbar.so
0x0000004000000000  0x00000040002ba7b8  No          /Develop/staging/mainline/target/qnx7/x86_64/lib/libc.so.3   

8) Now you can type command to load symbols for this library, by setting the path on where to find symbols, i.e.
set solib-search-path /Develop/runtime-wipe/bar/build/x86_64-debug/
It would reply something like
Reading symbols from /Develop/runtime-wipe/bar/build/x86_64-debug/libbar.so...done.

9) Now you can insert breakpoint/and continue debugging.

If you do that alot save these command into .gdbini file and specify full path to this file in IDE launch configuration