converting initramdisk and vmlinuz to uImage and uInitrd:

export ubootAddress=0x00008000
export version=4.11.0-0.rc3.git2.1.fc27.aarch64
mkimage -A arm64 -O linux -T kernel -C none -a $ubootAddress -e $ubootAddress -n $version -d /lib/modules/$version/vmlinuz /boot/uImage-$version
mkimage -A arm64 -O linux -T ramdisk -C none -a 0 -e 0 -n initramfs -d /boot/initramfs-$version.img /boot/uInitrd-$version


U-Boot SPL 2017.03-g8211b6f (Mar 23 2017 - 02:28:07)
DRAM: 2048 MiB
Trying to boot from MMC1


U-Boot 2017.03-g8211b6f (Mar 23 2017 - 02:28:07 +0000) Allwinner Technology

CPU:   Allwinner A64 (SUN50I)
Model: Pine64+
DRAM:  2 GiB
MMC:   SUNXI SD/MMC: 0
*** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   phy interface7
eth0: ethernet@01c30000
starting USB...
USB0:   USB EHCI 1.00
USB1:   USB OHCI 1.0
scanning bus 0 for devices... 1 USB Device(s) found
       scanning usb for storage devices... 0 Storage Device(s) found
Hit any key to stop autoboot:  0
switch to partitions #0, OK
mmc0 is current device
Scanning mmc 0:3...
Found /boot/extlinux/extlinux.conf
Retrieving file: /boot/extlinux/extlinux.conf
997 bytes read in 334 ms (2 KiB/s)
Ignoring unknown command: ui
Ignoring malformed menu command:  autoboot
Ignoring unknown command: totaltimeout
Ignoring unknown command: default=Fedora
Fedora aarch64 Rawhide Boot Options.
1:	Fedora (4.11.0-0.rc3.git2.1.fc27.aarch64) 27 (Rawhide)
2:	Fedora Rawhide (4.11.0-0.rc3.git1.1.fc27.aarch64)
Enter choice: 1:	Fedora (4.11.0-0.rc3.git2.1.fc27.aarch64) 27 (Rawhide)
Retrieving file: /boot/uInitrd-4.11.0-0.rc3.git2.1.fc27.aarch64
12384971 bytes read in 1231 ms (9.6 MiB/s)
Retrieving file: /boot/uImage-4.11.0-0.rc3.git2.1.fc27.aarch64
7170470 bytes read in 876 ms (7.8 MiB/s)
append: enforcing=0 ro root=/dev/mmcblk0p3 console=tty0 console=ttyS0,115200 selinux=0 audit=0 LANG=en_GB.utf8
Retrieving file: /boot/dtb-4.11.0-0.rc3.git1.1.fc27.aarch64/allwinner/sun50i-a64-pine64-plus.dtb
7937 bytes read in 419 ms (17.6 KiB/s)
## Booting kernel from Legacy Image at 40080000 ...
   Image Name:   4.11.0-0.rc3.git2.1.fc27.aarch64
   Image Type:   AArch64 Linux Kernel Image (uncompressed)
   Data Size:    7170406 Bytes = 6.8 MiB
   Load Address: 00008000
   Entry Point:  00008000
   Verifying Checksum ... OK
## Loading init Ramdisk from Legacy Image at 4fe00000 ...
   Image Name:   initramfs
   Image Type:   AArch64 Linux RAMDisk Image (uncompressed)
   Data Size:    12384907 Bytes = 11.8 MiB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum ... OK
## Flattened Device Tree blob at 4fa00000
   Booting using the fdt blob at 0x4fa00000
   Loading Kernel Image ... OK
   Loading Ramdisk to 49430000, end 49fffa8b ... OK
   Loading Device Tree to 000000004942b000, end 000000004942ff00 ... OK

Starting kernel ...

"Synchronous Abort" handler, esr 0x02000000
ELR:     8000
LR:      bff5a2bc
x0 : 000000004942b000 x1 : 0000000000000000
x2 : 0000000000000000 x3 : 0000000000000000
x4 : 0000000000008000 x5 : 0000000000000001
x6 : 00000000000003c9 x7 : 0000000000000000
x8 : 00000000bbf31660 x9 : 0000000000000002
x10: 000000000a200023 x11: 0000000000000002
x12: 0000000000000002 x13: 0000000000001bff
x14: 0000000000001bf4 x15: 00000000bff59ae4
x16: 0000000000000003 x17: 000000004942ff01
x18: 00000000bbf37df8 x19: 0000000000000400
x20: 00000000bffb4d20 x21: 0000000000000000
x22: 0000000000000003 x23: 00000000bbf319b8
x24: 00000000bffaa7d0 x25: 0000000040080040
x26: 00000000bff5a260 x27: 0000000000008000
x28: 0000000000000400 x29: 00000000bbf317a0

Resetting CPU ...

resetting ...
"Synchronous Abort" handler, esr 0x02000000
ELR:     bffab4e8
LR:      bbf31440
x0 : 0000000084000009 x1 : 00000000bffa151c
x2 : 000000013bf316d7 x3 : 00000000bff97320
x4 : 00000000bbf31533 x5 : 00000000bbf31490
x6 : 00000000bff7d8f0 x7 : 00000000ffffffe8
x8 : 00000000bbf31560 x9 : 0000000000000002
x10: 00000000bbf31182 x11: 0000000000000010
x12: 00000000ffffffff x13: 0000000000001bff
x14: 0000000000001bf4 x15: 00000000bff59ae4
x16: 0000000000000003 x17: 000000004942ff01
x18: 00000000bbf37df8 x19: 00000000bbf316a0
x20: 0000000002000000 x21: 0000000000000000
x22: 0000000000000003 x23: 00000000bbf319b8
x24: 00000000bffaa7d0 x25: 0000000040080040
x26: 00000000bff5a260 x27: 0000000000008000
x28: 0000000000000400 x29: 00000000bbf31420

Resetting CPU ...