Hi Màxim, On Tue, Aug 18, 2026 at 12:48:21AM +0200, Màxim Pedraza Padilla wrote: > 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.
Format concerns are - in addition to lack of time to work on it - what is keeping me from sending a new revision. Any kind of compression would need to be unwinded - probably on a per-pixel basis - making the required CPU time unreasonable for large images (at least if boot time optimization is the ultimate goal - linke in my case). Of course, on "low-resolution" displays the size-vs-time tradeoff might be the sweet spot - but the target here was to being as much generic as possible. > > 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. My typical embedded setup is exactly that one - Falcon boot, a simple boot logic inside the SPL, and possibly no initramfs. I find this to be the most portable solution, as it does not require complex drivers and handover logic in the bootloader. In case you decide to take my series for a re-spin, feel free to ask if something is unclear. > Thanks again -- it helped me draw the line between the two. > > Max Reagrds, Francesco
