Debugging Multiple Inferiors

Hi the experts,

Do you know if it is possible to debug two cortex-m in parallel with
one gdb session using inferiors?
Do I need to enable the non stop mode if I use the remote protocol?

Here my tests so far:
  (gdb) target remote :3333
  (gdb) file cortex1.elf
  (gdb) load cortex1.elf

  (gdb) add-inferior
  (gdb) inferior 2
  (gdb) maint info program-spaces
    Id   Executable
    1    cortex1.elf
         Bound inferiors: ID 1 (Remote target)
    * 2
         Bound inferiors: ID 2 (process 0)
  (gdb) target remote :3334
  A program is being debugged already.  Kill it? (y or n) y
  /home/.../gcc-arm/src/gdb/gdb/thread.c:639: internal-error:
thread_info* any_thread_of_process(int): Assertion `pid != 0' failed.
  A problem internal to GDB has been detected,
  further debugging may prove unreliable.
  Quit this debugging session? (y or n)

It seems that the remote target behaves as an Highlander, "there can
be only one"...

Regards,
Florent