06-27-2021, 03:01 PM
There are ways to preserve the console through the boot process, U-Boot can tell the kernel about the existing frame buffer via a description in the devicetree, or if booting the kernel via EFI there's a similar protocol in EFI, but they require coordination between U-Boot and the OS, and also the OS needs to properly switch from simple or efifb to the full rockchipdrm driver when it's ready. I think I saw some patches for rockchipdrm to handle this on the linux-rockchip mailing list, which suggests it doesn't work at the moment but someone's working on it.