Hi Am 20.04.21 um 11:27 schrieb Geert Uytterhoeven: > Hi Gerd, > > On Tue, Apr 20, 2021 at 11:22 AM Gerd Hoffmann wrote: >>>>> Patches 4 to 8 add the simpledrm driver. It's build on simple DRM helpers >>>>> and SHMEM. It supports 16-bit, 24-bit and 32-bit RGB framebuffers. During >>>> >>>> .... if support for 8-bit frame buffers would be added? >>> >>> Is that 8-bit greyscale or 8-bit indexed with 256 entry palette? Former >>> shouldn't be a big thing, but the latter is only really supported by the >>> overall drm ecosystem in theory. Most userspace assumes that xrgb8888 >>> works, and we keep that illusion up by emulating it in kernel for hw which >>> just doesn't support it. But reformatting xrgb8888 to c8 is tricky at >>> best. >> >> Well. cirrus converts xrgb8888 on the fly to rgb888 or rgb565 >> (depending on display resolution). We could pull off the same trick >> here and convert to rgb332 (assuming we can program the palette with the >> color cube needed for that). Wouldn't look pretty, but would probably >> work better than expecting userspace know what color palettes are in >> 2021 ... > > Yeah, I already had a similar idea for Amiga HAM ;-) I vaguely remember that HAM mode uses some crazy format where pixel colors depend in the values of their neighbors. (?) How complicated is it to write a conversion from RGB to HAM? Best regards Thomas > > Gr{oetje,eeting}s, > > Geert > -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Felix Imendörffer