I have NanoPi R2S RK3328 based board.
I compiled Uboot to support booting from SPI chip that i soldered on the board.
SPI works, board works, Uboot works - almost.
There is a problem with reseting the board.
If board boots from SPI Flash Chip to command line, reset command will bring board to MASKROM mode like no SPI chip is soldered.
What helps, is a complete power cut and plug back - then it will work again.
Interesing part is that my Uboot is TPL+SPL with ATF compiled. Same happens with Mainline Uboot.
I have NanoPi R2S RK3328 based board. I compiled Uboot to support booting from SPI chip that i soldered on the board. SPI works, board works, Uboot works - almost.
There is a problem with reseting the board.
If board boots from SPI Flash Chip to command line, reset command will bring board to MASKROM mode like no SPI chip is soldered. What helps, is a complete power cut and plug back - then it will work again.
Interesing part is that my Uboot is TPL+SPL with ATF compiled. Same happens with Mainline Uboot.
If i hit reset button before "NOTICE: BL31: v2.8(release):10f4d1a" appears - it will reset without problems.
Same happens in Linux Kernel 4.4, reboot command brings board to MASKROM mode.
Having a working SD card in slot will bring board from SDCARD. Then SDCard continues to Boot from SPI well.
Where to search for a problem? Looks like Uboot is messing with some CPU registers and powering it down resets all back to normal.