I've been using TF-A with mainline U-Boot recently as firmware & boot
loader for a RK3399 Rockpro64 board. I'm compiling TF-A and U-boot based
on this guide , using gcc 8.3.0 from Debian.
TF-A v2.1 works fine for this, but I recently tried to switch to TF-A
latest master and found U-Boot gets stuck with this version.
The symptoms are: U-Boot TPL and SPL print starting messages like this:
U-Boot TPL 2019.10-rc4-00037-gdac51e9aaf (Oct 06 2019 - 21:42:50)
Trying to boot from BOOTROM
Returning to boot ROM...
U-Boot SPL 2019.10-rc4-00037-gdac51e9aaf (Oct 06 2019 - 21:42:50 +0000)
Trying to boot from MMC2
...and then there is no more output when normally U-Boot proper would
start, and go on to load the Linux kernel, etc.
Starting from v2.1, with git bisect I found the first 'bad' commit is:
0aad563c7480 rockchip: Update BL31_BASE to 0x40000
and that commit does change some RK3399-related files so seems likely.
I'm not sure how to debug further, any ideas on why boot is hanging
after that change or how to get more debugging information?