Booting on AR9331 based Easylink EL-M150

[Bernd Walter]

This is a devboard using an EL-M150 module.
The module has 64M RAM, but unlike the carambola 2 only 8M SPI flash.
otherwise it is very similar.
However, I get into problems starting the kernel.
I use a kernel build for the carambola 2, which I'd also used on a
Dragino system, so basicly it is a functional image.
the Dragino used a earlier address in SPI flash, so I had to modify
and saveenv:
setenv bootcmd bootm 0x9F050000
saveenv
On the EL-M150 also a different adress is used and a different kernel
start address.
Unfortunately it doesn't have a saveenv, so unless I can freely
change the addresses I will have to rebuild a kernel.
In the meantime I'd tried with manual set addresses, but failed
decrompessing the image.
Somehow before the string "FreeBSD" there is some garbadge, which
even gets printed when I try booting from erased flash.

      U-Boot 1.1.4  (Nov 26 2014 - 16:34:31)    

********************************************
*     U-boot for Easylink El-m150          *
*    Build by huangfc(QQ:343669866)        *
*    Taobao:http://huangfc.taobao.com      *
********************************************
DRAM:  64 MB
id read ox100000ff
FLASH: 8M

In:  serial
Out: serial
Err: serial
Net:   ag7240_enet_initialize...

Interface eth0 MAC address: 00:23:CD:04:1F:32
s26 reg init 
ag7240_phy_setup
athrs26_phy_setup ATHR_AUTONEG_ADVERT 4 :6f0
athrs26_phy_setup ATHR_PHY_CONTROL 4 :4800
Interface eth0 is up

Interface eth1 MAC address: 00:23:CD:04:1F:32
athrs26_reg_init_lan
ag7240_phy_setup
athrs26_phy_setup ATHR_AUTONEG_ADVERT 0 :de1
athrs26_phy_setup ATHR_PHY_CONTROL 0 :1000
athrs26_phy_setup ATHR_AUTONEG_ADVERT 1 :de1
athrs26_phy_setup ATHR_PHY_CONTROL 1 :1000
athrs26_phy_setup ATHR_AUTONEG_ADVERT 2 :de1
athrs26_phy_setup ATHR_PHY_CONTROL 2 :1000
athrs26_phy_setup ATHR_AUTONEG_ADVERT 3 :de1
athrs26_phy_setup ATHR_PHY_CONTROL 3 :1000
Interface eth1 is up
Hit any key to stop autobooting:   0 

Easy-Link> printenv
bootargs=console=ttyS0,115200 root=31:02 rootfstype=squashfs init=/sbin/init mtdparts=ar7240-nor0:128k(u-boot),1024k(kernel),2816k(rootfs),64k(config),64k(ART)
bootcmd=bootm 0x9F020000
bootdelay=2
baudrate=115200
ipaddr=192.168.1.1
serverip=192.168.1.100
bootfile="firmware.bin"
loadaddr=0x80800000
ncport=6666
stdin=serial
stdout=serial
stderr=serial
ethact=eth0

Environment size: 364 bytes

Easy-Link> tftpboot 0x80800000 kernel.CARAMBOLA2.lzma.uImage
Link down: eth0
Ethernet mode (duplex/speed): 1/1000 Mbps

TFTP from IP: 10.1.1.9
      Our IP: 10.1.1.107
    Filename: 'kernel.CARAMBOLA2.lzma.uImage'
Load address: 0x80800000
       Using: eth1

     Loading: ########################################
              ########################################
              ########################################
              ########################################
              ########################################
              ########################################
              ########################################
              ####################

TFTP transfer complete!

Bytes transferred: 1534515 (0x176a33)
Easy-Link> boot
Booting image at: 0x80800000

   Image name:   y/6T? FreeBSD
   Image type:   MIPS Linux Kernel Image (lzma compressed)
   Data size:    -1828074981 Bytes = 2352.6 MB
   Load address: 0x08C0C8DF
   Entry point:  0x4BBDBC84

Uncompressing kernel image... ## Error: LZMA error num: 1

This example is just loading the kernel, also in a different load
address than it is done for the carambola and dragino.
But the problem stays the same if I would use 0x80050000.
Of course I have no idea if 0x80050000 is unused, therefor I also
tried 0x80800000.
The kernel wasn't rebuild and I don't know if the kernel needs
to know about such an address change, but it seems I already have
problems with the image format itself.

-- 
B.Walter <bernd at bwct.de> http://www.bwct.de
Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.