My Cloud

In 2013, My Cloud NAS has been released by Wester Digital. My Cloud uses a Mindspeed Comcerto 2000 (M86261G-12) dual-core ARM Cortex-A9 Communication Processor running at 650 MHz. The Gigabit Ethernet port is a Broadcom BCM54612E Gigabit Ethernet Transceiver. Other components include 256 MB of Samsung K4B2G1646E DDR3 RAM and 512 MB of Winbound 25X40CL flash. The drive is a WD Red 2 TB (WD20EFRX).

My Cloud relies on air convection for cooling - there is no fan. As such, it runs very quitely and the only noise you hear is that of the WD Red drive.

Prices in October 2013 list a 2 TB My Cloud for $149.99. A 3 TB My Cloud is also shipping with a list price of $179.99. In November 2013, WD will start shipping a 4 TB model listing at $249.99.

WD My Cloud Specifications


  • 2TB (WDBCTL0020HWT)
  • 3TB (WDBCTL0030HWT)
  • 4TB (WDBCTL0040HWT)


  • USB 3.0
  • Gigabit Ethernet

Physical Dimensions

  • Height: 6.70 Inches
  • Depth: 5.50 Inches
  • Width: 1.90 Inches
  • Weight 2.12 Pounds


  • Operating: 41° F to 95° F or 5° C tot 35° C
  • Non-operating: -4° F to 149° F or -20° C tot 65° C

Mindspeed Comcerto 2000 (M86261G-12) dual-core ARM Cortex-A9 @650 MHz

256 MB of Samsung K4B2G1646E DDR3 RAM


  • AC Input Voltage: 100-240 VAC
  • AC Input Frequency: 47-63 Hz

OS Compatibility

2 years

WD My Cloud Hardware Hacking

Opening the MyCloud is similar to the MyBook.
The photos in the web show two different main boards.

At least the "L" shaped board has a serial interface inside:
The mainboard has an edge connector with 4 contacts on both sides. The contacts on the "inner" side are: GND, Rx, Tx, (gap), +3,3V.
(The photos of the other board also show that edge connector).
An edge connector is interesting, because you don't need to solder anything on the board. At least if you get a connector that fits here.
I build mine from some spare connectors lying around with correct contact distance (1mm) and some hot glue.

WD My Cloud Boot process

Before starting the kernel, the bootloader (barebox) is loaded from internal SPI-flash. The bootloader is configured to wait 5s after power up for a Magic-Network-Packet:
An ICMP Echo Request (also known as "ping" packets) with a special payload: 57442d49434d502d424541434f4e (="WD-ICMD-BEACON", directly behind the Sequence-Number).
If it receives that packet, the barebox boot loader will create a dhcp request and then try a tftp download of a script '' and execute that.
As the disk isn't used yet, I expect this should allow to unbrick a WD MyCloud as long you didn't kill the internal flash.

If that magic packet is not received, the loader can be interrupted with Ctrl-C via the serial terminal.
Without that it will continue to boot:

The kernel is loaded from a partition of the hard disk and is then started.

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