Scrolling in framebuffer syscons

[Oleksandr Tymoshenko]

On 2/16/2013 5:20 AM, Phileas Fogg wrote:
> Hi,
>
> i have a question about how the scrolling in a framebuffer syscons works.
> I'm trying to speed up the syscons on the PS3 console  which is a 
> simple framebuffer syscons.
> It uses the renderer _gfbrndrsw_ (see dev/syscons/scgfbrndr.c) to draw 
> into the framebuffer of the PS3 console.
> The _gfb_draw_ function implements a simple scrolling that moves data 
> from bottom to top with _vidd_copy_.
> And that's where i have a problem because _vidd_copy_ calls the 
> function _ps3fb_copy_ (see powerpc/ps3/ps3_syscons.c).
> But the function _ps3fb_copy_ is NOT implemented yet. So, the question 
> is how does the scrolling work then ?
> I took a look at other syscons implementation based on a framebuffer, 
> and almost all of them do NOT implement _vidd_copy_
> function, e.g. XBOX syscons.

I think driver re-renders whole screen character by character. That's 
why no copy operation is invoked.