Hello,
I noticed two issues with Das U-Boot on the Raspberry Pi 3 Model B in combination with Debian (stretch). I'm running the Raspberry Pi in arm64 mode.
The boot process is as follows: The Raspberry Pi's firmware loads Das U-Boot which in turn loads the Linux kernel and initramfs.
The issues I have are the following:
1. Starting with the Linux 4.17 kernel from the stretch-backports repository the kernel grew too big for the slot between kernel_addr_r and ramdisk_addr_r. As a result the kernel would not boot.
On my Raspberry Pi ramdisk_addr_r=0x10000000 seems to work well with Linux 4.18, too. I don't know if that's a good choice, but I ask you to select a better default.
2. After upgrading from u-boot-rpi (2016.11+dfsg1-4) to u-boot-rpi (2018.11+dfsg-1) the initramfs can't find the SD card anymore (there is no /dev/mmcblk0).
When I go back to 2016.11, the system comes up just fine.
Keep up the great work. Cheers, Takashi