Re: [Qemu-devel] [PATCH] input-keymap.c: Add keypad equal and power keys

[Gerd Hoffmann <kraxel@redhat.com>]

  Hi,

> > number is modeled after pc scancodes, so you can't just pick random
> > numbers.
> 
> Really? I thought the only requirement was each scancode had to be unique. 

No, it's not.  ps2 emulation assumes those codes are the real ones.

> > So, if there are no scancodes for the keys you want handle, you can now
> > drop the scancodes from the workflow.
> 
> Are you saying not to add the power and keypad equal keys to the input-keymap.c  file?

If standard scancodes exist for them we can add them.  Needs some care
though, ps2 keyboards have different modes and different keymaps in each
mode.

> >  Switch cocoa to generate and
> > submit qkeycodes.
> 
> This is already done.

Good.

> >   Switch the apple keyboard(s) to accept qkeycodes (see
> > yesterdays mail on adb keyboard).
> 
> On my to-do list.

Good.

> >  Then the key events from the host
> > keyboard are forwarded to the guest without ever being converted into pc
> > scancodes.
> 
> How do I do this? You said to use qemu_input_event_send_key_qcode() to
> send QKeyCodes to QEMU. Is this what you still want?

Yes.

> Eventually wouldn't the qcode_to_number array in input-keymap.c try to
> translate the keypad equals to a ps/2 value?

Depends on what the emulated device is doing.

Devices which still use the old input interface to register a input
handler will get scancodes (example: current adb code).

Devices which are switched over to the new input interface will receive
InputEvent *evt.  Then they can then use either
qemu_input_key_value_to_scancode() to translate the event into a
sequence of scancodes (Example: ps2 keyboard).  Or they can use
qemu_input_key_value_to_qcode() to get a qkeycode.

So, with cocoa using qemu_input_event_send_key_qcode() and adb using
qemu_input_key_value_to_qcode() the keys are never translated into
scancodes, and they'll work fine even without a scancode being assigned
to them in the qcode <-> number (aka scancode) translation maps.

> If the keypad equals key isn't set in this array, the array might
> return a default value of 0 and the user will see 'a' printed whenever
> the keypad equals key is pushed.

Once the adb code is switched over to use qemu_input_key_value_to_qcode
this will stop happening.

Of course, when emulating a x86 guest with ps/2 keyboard you still run
into the problem that there might be no ps/2 scancode for certain keys.
But there is nothing we can do about that.  Inventing random scancodes
wouldn't make guests interpret them as expected ...

cheers,
  Gerd