boot fail when bootelf kernel but not when using the ubldr

[Craig Butler]

Hello Folks

Little frustrating fail.  I have a kernel for the cm-t335 board 
thatworks fine under uboot -> ubldr ->  nfs'ing the kernel in and booting.
It fails when u-boot -> nand read into ram -> bootelf the kernel 
directly.  Annoyingly it does not drop into the debugger

CM-T335 # bootelf ${kloadaddr}
## Starting application at 0xc0200100 ...
KDB: debugger backends: ddb
KDB: current backend: ddb
Copyright (c) 1992-2016 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
         The Regents of the University of California. All rights reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.
FreeBSD 10.3-RELEASE #20: Sat Apr 16 11:41:14 BST 2016
     root at xxxxx arm
FreeBSD clang version 3.4.1 (tags/RELEASE_34/dot1-final 208032) 20140512
CPU: Cortex A8-r3 rev 2 (Cortex-A core)
  Supported features: ARM_ISA THUMB2 JAZELLE THUMBEE ARMv4 Security_Ext
  WB disabled EABT branch prediction enabled
LoUU:2 LoC:3 LoUIS:1
Cache level 1:
  32KB/64B 4-way data cache WT WB Read-Alloc
  32KB/64B 4-way instruction cache Read-Alloc
Cache level 2:
  256KB/64B 8-way unified cache WT WB Read-Alloc Write-Alloc

hangs here :/

It doesn't do this under 10.1-RELEASE src, but is doing it under 
10.3-RELEASE src

any clues on what might be wrong, or how to debug further ?

Thanks

Craig