Not sure where else to put this: developing U-Boot improvement (graphical) on RK3588

[shimmy00]

I've had this going for quite some time now regarding Rockchip RK3588 boards, specifically for me, the somewhat PC-alike Firefly ITX-3588J, and trying to see if it is possible to create or refine the various software out there so that it could be made to work like a PC, e.g. with EFI booting off USB sticks, GRUB, etc. for loading an OS without needing an external computer. This has been tried on and off over the past year, without much luck owing to how incomplete the software for this board type is. However, it seems that in the most recent versions of mainline U-Boot (i.e. U-Boot 2023) at least, there's enough RK3588 support to get it up and running, and I have my machine going with the U-Boot prompt available on serial. In particular, I was interested in using a more up-to-date version with the hope it could provide expanded UEFI support.

 

And what I'm trying to do now is to add a graphics driver to produce a video console. Rockchip/Firefly gave a rather complex, messy looking "DRM" driver as part of their non-mainline U-Boot and I was seeing if it was possible to integrate this driver into a recent U-Boot version (not anticipating making it mainstream necessarily, just trying it out so one can have a seamless working platform at least for this). I actually managed to get a lot of it in, however I'm finding that in particular it is unable to access the graphics unit, or VOP, on the chip. When it tries to do a memory access to read the contents of the VOP registers at initial bring-up, it crashes with an ESR = 0x96000010 synchronous abort exception, and I'm unsure why that is happening.

 

Does anyone familiar with kernel-level or U-Boot device driver programming here have any clues as to what could be going on? This whole project has pretty much been my entire foray into the land of driver programming and while I've learned a fair bit over the past year, I'm sure there's a lot more that could be learned and I seem to be at a point I need help but I've been very much unsure where asking about it would both be on-topic and where I'd be likely to receive a response.

 

Thanks!