Hi Jeremy,
On 14.08.23 22:52, Compostella, Jeremy wrote:
We propose to take advantage of a proprietary driver Intel already supports, validates and includes in FSP silicon: the Intel Graphics PEIM (Pre-EFI Initialization Module) driver also known as the GOP (Graphical Output Protocol) driver.
just to make sure nobody makes wrong assumptions: Will the uGOP be open-source or proprietary as well? I first thought the latter. But your proposed code-flow looks like some sort of dynamic linking with coreboot.
We intend to keep providing such a binary base solution on the long run as it addresses our software convergence goals and is compatible with early platform development stage constraints. [libgfxinit] supports can always be added later by the open-source community once the Graphics Programmer Reference Manuals are published.
Sad to hear about this decision. It seems Intel is forgetting about non-consumer products (e.g. embedded market) where the code isn't needed years ahead of a platform launch.
We also noticed that microGOP is faster to bring-up graphics than libgfxinit. Indeed, according to previously captured numbers on Raptor Lake compared to some number of microGOP on Meteor Lake, microGOP is three times faster to bring up graphics than libgfxinit on an eDP panel (119 ms vs 373 ms).
Configuring the hardware and bringing up the eDP link should take about 20~30ms mostly depending on how long it takes to read the EDID. The longer delays are likely about panel power sequencing. IIRC, libgfxinit falls back to hardcoded default values if the sequencer is unconfigured, while the GOP just leaves it like that. Chromebooks often skip the configuration[1] in firmware and leave it to the OS driver. Using wrong delays probably doesn't hurt on a rare interactive boot. However, I guess doing this on regular boots might not be the best idea.
Nico