The dtb for a specific device will vary slightly for each different kernel, but only slightly
This device is a rockchip rk3399, so any other cpu-dtb will almost certainly be mismatched
Sometimes the uboot will have an effect, and also the compositer
For example, I have a debian10 that with tow-boot will not boot anything other than 5.5
unless the compositer is turned off, but with a bsp uboot will boot the default kernel (5.8)
(nearly all uboots will NOT show the menu, only samueldr/tow-boot)
Do be aware that if this is on SD, whatever uboot is on emmc will be found 1st and used
If you are 100% sure that you have a bootable SD, some other distro, that will boot for sure,,,
then copy mbr (1 sector old style, 34 sectors GPT style) ,1st 16M (of emmc), maybe to a usb stick,,
blank (/dev/zero) 1st 16M, restore mbr
Then the pbp will be forced to use uboot on SD, because there is no other
If you have a 100% bootable SD, you can easily restore the original 1st 16M
--more--
Are you saying that there was not a dtb for either pinebookpro or several rk3399 dtbs with the gentoo install?
This device is a rockchip rk3399, so any other cpu-dtb will almost certainly be mismatched
Sometimes the uboot will have an effect, and also the compositer
For example, I have a debian10 that with tow-boot will not boot anything other than 5.5
unless the compositer is turned off, but with a bsp uboot will boot the default kernel (5.8)
(nearly all uboots will NOT show the menu, only samueldr/tow-boot)
Do be aware that if this is on SD, whatever uboot is on emmc will be found 1st and used
If you are 100% sure that you have a bootable SD, some other distro, that will boot for sure,,,
then copy mbr (1 sector old style, 34 sectors GPT style) ,1st 16M (of emmc), maybe to a usb stick,,
blank (/dev/zero) 1st 16M, restore mbr
Then the pbp will be forced to use uboot on SD, because there is no other
If you have a 100% bootable SD, you can easily restore the original 1st 16M
--more--
Are you saying that there was not a dtb for either pinebookpro or several rk3399 dtbs with the gentoo install?