Help on getting u-boot replacement on stock Buffalo LS421DE (3 replies)

I am starting this new thread as I also have a Buffalo LS421DE. I got serial working and here is the boot log:

BootROM 1.08
Booting from SPI flash
DDR3 Training Sequence - Ver 2.3.5
DDR3 Training Sequence - Ended Successfully
BootROM: Image checksum verification PASSED

=========================
==== Welcome to YANAGI ==
=========================

** LOADER **


U-Boot 2009.08 ( 8月 28 2013 - 21:36:20)Marvell version: 1.1.3 NQ
U-Boot Addressing:
Code: 00600000:006AFFF0
BSS: 006F8360
Stack: 0x5fff70
PageTable: 0x8e0000
Heap address: 0x900000:0xe00000
BUFFALO_BOOTVER=0.13
Board: Buffalo LS-M 88f6710
SoC: MV6710 A1
CPU: Marvell PJ4B v7 UP (Rev 1) LE
CPU @ 1200Mhz, L2 @ 600Mhz
DDR @ 600Mhz, TClock @ 200Mhz
DDR 16Bit Width, FastPath Memory Access
PEX 0: Root Complex Interface, Detected Link X1
PEX 1: Detected No Link.
DRAM: 512 MB
CS 0: base 0x00000000 size 512 MB
Addresses 14M - 0M are saved for the U-Boot usage.
SF: Detected MX25L8006E with page size 256, total 1048576 bytes
NAND: 512 MiB
u-boot envinit tval=e4b4c857
FPU not initialized
USB 0: Host Mode
USB 1: Host Mode
Shutting down unused interfaces:
AUDIO
TDM
Modules/Interfaces Detected:
SDIO
RGMII0 Phy
RGMII1 Phy
PEX0 (Lane 0)
PEX1 (Lane 1)
SATA0 (Lane 2)
SATA1 (Lane 3)

Marvell Serial ATA Adapter
Integrated Sata device found

MAC Address : 10:6F:3F:xx:xx:xx
MMC: MRVL_MMC: 0
Net: egiga0, egiga1 [PRIME]
hit any key to switch tftp boot.
Hit any key to stop autoboot: 0
switched to TFTP boot.
Hit any key to stop autoboot: 0
BUFFALO>>