kirkwood: add support for Iomega Storcenter ix4-200d

[sanderpqr]

Iomega Storcenter ix4-200d is a four-bay SATA NAS powered by a Marvell
Kirkwood SoC clocked at 1.2GHz. It has 512MB of RAM and 32MB of
flash memory, 3x USB 2.0 and 2x 1Gbit/s NIC

Specification:

• SoC: Marvell Kirkwood 88F6281
• CPU/Speed: 1200Mhz
• Flash size: 32 MiB
• RAM: 512MB
• LAN: 2x 1Gbit/s
• 3x USB 2.0

Notes:

• The blue drive LED is triggered by HDD activity, it can not be controlled via GPIO.
• The LCD screen requires proprietary code and does not function at this time.
• Due to a kernel-related issue with the Marvell 88SE6121 SATA controller, currently only trays numbered 3 and 4 work, 1 and 2 do not. [1]

Serial pinout:

CN4
--------------
| 10 8 6 4 2 |
|  9 7 5 3 1 |
-------------- PIN 1 Mark (fat line)

 1 = RXD
 4 = TXD
 6 = GND
 9 = 3.3V (not necessary to connect)

Installation instructions:

1. download initramfs-uImage and copy into tftp server
2. connect the tftp server to network port #1
3. access uboot environment with serial cable and run 
    ```
    setenv mainlineLinux yes
    setenv arcNumber 1682
    setenv console 'console=ttyS0,115200n8'
    setenv mtdparts 'mtdparts=orion_nand:0x100000@0x000000(u-boot)ro,0x20000@0xA0000(u-boot environment)ro,0x300000@0x100000(kernel),0x1C00000@0x400000(ubi)'
    setenv bootargs_root 'root='
    setenv bootcmd 'setenv bootargs ${console} ${mtdparts} ${bootargs_root}; nand read.e 0x800000 0x100000 0x300000; bootm 0x00800000'
    saveenv
    setenv serverip 192.168.1.1
    setenv ipaddr 192.168.1.2
    tftpboot 0x00800000 [initramfs-uImage filename]
    bootm 0x00800000
    ```
4. connect to LAN on network port #2, log into openwrt and sysupgrade to install into flash

[1] https://bugzilla.kernel.org/show_bug.cgi?id=216094

[chunkeey]

Merged. Thanks!

[mundodisco-argentina]

Hi @sanderpqr ,

I have just managed to install OpenWRT on my (ex Iomega) ix4-200d NAS. Process went OK, NAS is up and running... However, I am worried about my drives. I have four 2TB HDD's, but just two of them are being detected. I have read an old post saying it was something related to the kernel... has there been any news about that? Should I still have faith?
My other concerns (not so important as the drive detection, of course) are:

Concerning RAID management, is there a proper Luci -graphical- module to create RAID's, format drives, etc.?
Is it possible to give a proper shutdown function to the Power button in front of the NAS? And is it possible to deactivate the auto powering on when plugging the power cord?
(and last one!) Is it possible to add some functionality to the LCD screen of this NAS?

Thank you all in advance!
Regards,
Gabriel (from Buenos Aires, Argentina)