Help needed with kexec on arm64

Booting Linux on physical CPU 0x0
[ ? ?0.000000] Linux version 4.5.0-rc6-00038-gae2804a-dirty (hrai at nmglablinux22) (gcc version 4.8.3 20140401 (prerelease) (Linaro GCC 4.8-2014.04) ) #2 SMP PREEMPT Fri Mar 11 14:45:30 IST 2016
[ ? ?0.000000] Boot CPU: AArch64 Processor [411fd071]
[ ? ?0.000000] Ignoring memory range 0x80000000 - 0x8c000000
[ ? ?0.000000] earlycon: Early serial console at MMIO 0x21c0600 (options '')
[ ? ?0.000000] bootconsole [uart0] enabled
[ ? ?0.000000] efi: Getting EFI parameters from FDT:
[ ? ?0.000000] efi: UEFI not found.
[ ? ?0.000000] crashkernel has wrong address or size

This implies a root cause. (See arch/arm64/mm/init.c)
Hint: add memblock=debug to kernel parameters of crash dump kernel

Thanks for the hint. I will try this out
One thing which comes to my mind is that I am using the production kernel image for crash kernel and Documentation/kdump doesn't mention that arm64 supports that. Can this be a cause for the above problem?

Regards
Harry++