ZBT WG3526 kernel 4.9 can't boot

For Developers
1

I have a ZBT WG3526, Soc is mt7621, I tried linux kernel 4.9, but it can't boot the kernel, when the control pass to the kennel, it print nothing and freeze, Can someone give me some tips? Thanks

2

Kernel 4.9 Output
MT7621 # setenv bootargs console=ttyS0,115200 rootfstype=squashfs,jffs2
MT7621 # printenv
bootcmd=tftp
bootdelay=1
baudrate=115200
ethaddr="00:AA:BB:CC:DD:10"
stdin=serial
stdout=serial
stderr=serial
filesize=3e8a02
fileaddr=81000000
netmask=255.255.255.0
ipaddr=192.168.1.1
serverip=192.168.1.100
bootargs=console=ttyS0,115200 rootfstype=squashfs,jffs2

Environment size: 300/4092 bytes
MT7621 # bootm

Press Reset button enter upgrade mode!
## Booting image at 81000000 ...
   Image Name:   MIPS LEDE Linux-4.9.14
   Image Type:   MIPS Linux Kernel Image (lzma compressed)
   Data Size:    4098498 Bytes =  3.9 MB
   Load Address: 80001000
   Entry Point:  80001000
   Verifying Checksum ... OK
   Uncompressing Kernel Image ... OK
No initrd
## Transferring control to Linux (at address 80001000) ...
## Giving linux memsize in MB, 512

Starting kernel ...