kernel boot failier

hi,

i am have make some changes in my freebsd acutally have replaced mii bus
with my own switch bus and have put some code of switch but after i
successfully build kernel and world when i try to run it on machine it just
hangs up at boot time after this

ar7100> bootm
change bootargs
console=ttyS0,115200 root=31:03 rootfstype=jffs2 init=/sbin/init
mtdparts=ar7100-nor0:256k(u-boot),64k(u-boot-env),1152k_at_384k
(uImage),6592k_at_1536k(rootfs),64k_at_320k(ART),64k_at_8128M
## Booting image at 84000000 ...
   Image Name:   FreeBSD-9.0-Paxym AR7161
   Created:      2013-02-01   7:54:28 UTC
   Image Type:   MIPS NetBSD Kernel Image (gzip compressed)
   Data Size:    2301863 Bytes =  2.2 MB
   Load Address: 80050120
   Entry Point:  80050120
   Verifying Checksum ... crc32_fw: 84000040 - 84231fe6 (len:00231fa7)
calc...
OK
   Uncompressing Kernel Image ... OK
## Transferring control to NetBSD stage-2 loader (at address 80050120) ...

One method is that i should revert all changes which will take time, Is
there is other way to debug my code, and can identify correct problem

thanks