Re: [RFC] new APIs to use wskbd(4) input on non-wsdisplayttydevices

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

On Mon, Apr 08, 2024 at 23:27:11 +0900, Izumi Tsutsui wrote:

> macallan@ wrote:
[...]
> > Oh, so it's an entire terminal emulation, not just something that lets
> > you draw characters?
> 
> Ah, maybe I see misunderstandings among us.
> 
> In sgimips crmfb and newport cases, a putchar() function provided
> by the firmware just draws a character (glyph) at the cursor
> or specified position. All virtual terminal emulation ops are
> done in wsdisplay(9) and vcons(9) layer and MD drivers just draw
> characters (or whitespace) per vcons pseudo text VRAM attributes.
> 
> On the other hand, news68k (and sun) machines have putchar()
> that also handles virtual terminal ops like backspace, CR/LF,
> and even scrolling at the bottom of screen. In this case
> no VT emulation layer is necessary in the kernel side,
> so kernel's putc(9) just calls firmware's putchar(),
> and for userland processes we can simply pass translated
> wskbd inputs to line discipline of the tty device.
> 
> That's the reason why I proposed to add register/deregister
> APIs to pass wskbd data to romcons tty device.
> 
> What do you think about this case?

Add trivial wsemul_none (or wsemul_delegate, or whatever a suitable
name might be) that does even less than wsemul_dumb and only ever uses
putchar to pass chars to the firmware emulator?

-uwe