[OpenBIOS] Re: [PATCH] usbhid: Implement get-key-map method

[BALATON Zoltan]

On Sat, 28 Jan 2023, Mark Cave-Ayland wrote:
> On 27/01/2023 13:33, BALATON Zoltan wrote:
> > Mac OS X calls it during boot. This gets rid of an error saying
> > "call-method slw_update_keymap failed with error ffffffdf" but
> > otherwise does not seem to matter. It's probably used for getting the
> > pressed keys that can change some boot actions like enable verbose
> > mode with Cmd-V.
> > Signed-off-by: BALATON Zoltan
> >
> > drivers/usbhid.c | 8 ++++++++
> >   1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/usbhid.c b/drivers/usbhid.c
> > index b8e1548..d3ad4ef 100644
> > --- a/drivers/usbhid.c
> > +++ b/drivers/usbhid.c
> > @@ -52,12 +52,20 @@ keyboard_close(int *idx)
> >   {
> >   }
> >   +static void
> > +keyboard_get_key_map(void)
> > +{
> > static char keytable[32] = { 0 };
> > PUSH(pointer2cell(keytable));
> >
> > +}
> > static void keyboard_read(void);
> >   NODE_METHODS( usb_kbd ) = {
> >  { "open",		keyboard_open		},
> >  { "close",		keyboard_close		},
> >  { "read",               keyboard_read		},
> > { "get-key-map",        keyboard_get_key_map	},
> > };
> > #ifdef CONFIG_DEBUG_USB
>
> It looks like the ADB version is similar, apart from it also has this 
> comment:
>    /* Debugging BootX: the lines below force get-key-map to report that
>     * cmd-V is being held down, which forces BootX to run in verbose 
>
> mode
>         * for debugging.
>         *
>         * TODO: if we can find a mapping between the get-key-map bitmap and
>         * ADB scancodes, the keyboard driver should be altered to update 
> this
>         * accordingly.
>         */
>    /*
>    kbd->keytable[3] = 0x40;
>    kbd->keytable[28] = 0x10;
>
> Might be worth adding a similar comment (and maybe even testing it) for the 
> USB version, but regardless:

I don't think repeating that comment here is useful. This seems to be used 
by MacOS to check if keys are held down during boot such as changing to 
boot from cd, clear PRAM, enable safe mode, etc. So there are more than 
what the comment mentions but that may rather belong in arch/ppc somewhere 
with some way to override these during boot to simulate key press for 
debugging. This patch just gets rid of the warnings printed during booting 
MacOS but I haven't seen any other change. The non-working devices are 
probably due to some bug in QEMU's ohci emulation. If we actually want to 
implement this correctly then key presses may need to set and clear bits 
in this array but none of the current implementations do that and the 
meaning of the bits are also not known. Also it may be hard to actually 
hold down keys during boot as it's faster in emulation than on real 
hardware so to be useful it should have some other way to define this 
before start.

Regards,
BALATON Zoltan
> Reviewed-by: Mark Cave-Ayland
>
> ATB,
>
> Mark.
> _______________________________________________
> OpenBIOS mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]