Debian Linux on the D-Link DNS-320 & DNS-325 NAS

DNS-320L

The DNS-320L is the replacement to the DNS-320, and largely similar hardware. The main difference being that the Weltrend chip controls much more than it previously did. I do not have one, but other people have worked on it. Have a look at:

• http://www.aboehler.at/cms/projects-a-hacks/50-dns320l
• https://github.com/martignlo/DNS-320L

Chassis & dissassembly

Dissassembling a DNS-325 is very easy, and no "warranty void" stickers in the way.

1. At the back of the unit, remove 4 circular rubber pads and screws underneath, remove plastic back
2. Remove 4 small silver screws from metal plate underneath the plastic back
3. Slide entire circuit board out

The DNS-320 is slightly more involved, but still has no stickers in the way.

1. Take off lid
2. Undo 2 screws around catch
3. Remove 4 rubber feet and screws underneath
4. Pull innards out
5. Undo 4 screws either side of front panel and remove it
6. Undo 4 nuts holding chassis onto mainboard

Serial Port

There is an unpopulated space for a serial port standard 0.1" pitch header. The serial port runs at 3.3v TTL so requires either a MAX3232 adapter or a USB serial adaptor designed to run at 3.3v. A TTL-232R-3V3-AJ cable is reasonably cheap, and a headphone jack for serial can be added in a reasonably neat fashion.

The pinout is as follows:-

NB: Tip/Ring may be reversed, this was from memory

DNS-320 (JP3)

The header is the center of board so a header can be soldered on the top side without getting in the way of the HDDs. Using an old CD-audio cable I fashioned a header to stereo headphone jack cable. The headphone jack is mounted by drilling a hole next to the lid catch.

DNS-325 (JP1)

There is no space for a proper header connector whilst the case is closed. I soldered wire directly to the motherboard, and put a stereo jack on the other end, looped through and taped to the back of the case.

To communicate to the NAS, open the serial port at 115200 baud, 8-n-1, flow control off. You should be able to see it boot, however D-link put in some petty measures to stop you tinkering. If you want to stop u-boot booting, then press space then 1 when prompted to press any key. To get a prompt once the original firmware is booted, type the break-in code 5784468.

JTAG

The JTAG port is a 2x5 pin header, the same as a DNS-323. It is described here.

Stefan Herbrechtsmeier says "The image and table have different signal names for pin 2 and 9. I made the mistake using the image and not the table when I solder the adapter for my JTAG debugger. Because of this I can not reset the processor correct and have some trouble to reflash the memory."

On the DNS-320 it's JP4, on the DNS-325 it's JP2. Both are next to the serial console header.

Other connectors

DNS-320

There is space for 2 extra headers resembling serial ports, JP1 (3.3v) and JP2 (5v) and a button (SW1). These are connected to the Welltrend processor and probably not much use. There is a GPIO pin available on the space for U5, possibly where the G751-2f would have gone?

DNS-325

There is a space labelled U11 on the underside, which appears to expose I2C.

Datasheets

• Marvell 88F6281
• HT48C06E
• G751-2f
• Samsung DRAM product information