11-08-2019, 07:31 PM
(This post was last modified: 11-08-2019, 07:45 PM by Arglebargle.)
(11-08-2019, 05:36 PM)bcnaz Wrote: >> The pre-boot is on the eMMC, that points it to boot from the sd card...
So if something is messed up on the EMMc it will not boot from the sd card..
I am not a pro at this, but I have read that in a bunch of posts.
The onboard rk3399 bootloader looks for a boot payload in this order: SPI > eMMC > SD; it then loads the first payload it finds (we're using u-boot) and the boot process continues.
Googling "rk3399 boot sequence" should give a bunch of useful information but this is a concise overview:
http://wiki.t-firefly.com/en/Firefly-RK3...-mode.html
Das u-boot is a little confusing right now: the default boot order is to look for bootable partitions on devices in this order: eMMC > SD. Mrfixit has released a patched u-boot that boots in the reverse order: SD > eMMC. If you have unpatched u-boot on your eMMC (old mrfixit image, or any ayufan image) and your eMMC system image is damaged to the point of failing to boot you're going to bootloop and be unable to boot from the SD card.
If you're unable to boot due to a broken u-boot or unbootable eMMC system image you could use the recovery switch on the mainboard to boot into recovery mode and reflash the eMMC over USB from another computer. I'm not sure how exactly to do this as I haven't ever needed to and the wiki documentation for the PBP is sparse right now so I'd go ask in IRC and see if someone can help. Once you've done that you should install the patched u-boot to your eMMC so that you can boot from an SD card in the future.
If you have a USB or SD adapter for your eMMC you can pop the eMMC out and patch your u-boot from another machine, then you'll be able to boot from an SD card to fix whatever is wrong with your eMMC system image.
Yes, all of this is a bit of a mess right now. If you're unable to boot your PBP at all and don't know what you're doing then go on the pine64 IRC and politely ask someone to help you fix things.
