Re: [RFC PATCH 0/6] Boot logo supplied by the device tree

Hi Sam,

Thank you -- that's a useful pointer, and it settles the question of how
a splash should be drawn without fbcon: a DRM client at
drm_client_setup(), next to drm_log, not a drm_fb_helper hook.

Francesco's series is genuinely inspiring work, and it would be very
useful to me if it could take a CLUT224 image -- unfortunately it can't.
It only accepts an uncompressed 24-bit RGB888 BMP, whereas our logo is
paletted, which is what keeps it small: 17 KiB for 800x480 rather than
around a megabyte. So as it stands the format doesn't line up with what
we carry.

Reading it did make the distinction clearer to me, though. drm_splash
*draws* an image into a fresh buffer, which means a first modeset and the
blanking that comes with it. What our hardware leaves us with is a
framebuffer U-Boot has already drawn and a CRTC still scanning it out, so
for our case the natural thing is to *adopt* that state rather than
redraw it -- which is what hardware state readout does, with no redraw
and no flicker.

Where drm_splash is the right tool is the case with no state to adopt --
Falcon boot, where U-Boot proper never runs, or a handover where the
buffer doesn't survive. I'll follow Francesco's series for that.

Thanks again -- it helped me draw the line between the two.

Max