[Updated 12:00PM] — Marvell has posted detailed datasheets on its previously opaque Armada 370 and XP SoCs, used in Linux-based NAS systems from Buffalo, Netgear, and Synology.

Until now, datasheets and other details about the ARM-based Armada 370 and Armada XP system-on-chips have been available only under NDA to Marvell customers and partners. During the past month, however, the chipmaker released detailed datasheets on the SoCs, with no restriction or registration required. Both functional and hardware spec datasheets were released, each of which is more like a manual than a typical datasheet.

We were tipped to the Marvell Armada 370 and XP datasheet releases by embedded Linux development and training specialist Free Electrons. (The company is well known here for its regular contributions of videos and slide decks from shows like the Embedded Linux Conference, released under a Creative Commons license.)

Block diagrams: Armada 370 (left) and Armada XP
(click images to enlarge)

According to a Free Electrons blog post by CTO Thomas Petazzoni, his company has for several years been contributing support for the somewhat mysterious Marvell Armada 370 and Armada XP processors to the mainline Linux kernel. The ARM-based SoCs are commonly found in Linux-based network-attached storage devices from Netgear, Synology, and Buffalo.


Netgear ReadyNAS RN10200 (left) and Buffalo LinkStation 421e
(click images to enlarge)

The Marvell Armada 370, which is also found in devices such as the Pwnie Express pen tester, is a homegrown ARMv7 SoC design clocked to 1.2GHz that falls between the 1GHz Armada 300 and the 1GHz Cortex-A9-based, dual-core Armada 375. The Armada XP, which is 370’s sibling, is described by Pettazoni as “a nice monster” containing “up to 4 cores (PJ4B cores, which are roughly equivalent to Cortex-A9 but with LPAE support), up to 10 PCIe lanes, multiple SATA interfaces, up to four Gigabit network interfaces, and many, many other things (XOR engine, cryptographic engine, etc.).”

Synology DS214se

Petazzoni writes that the Marvell Armada 370 is available in the following commercial, Linux-based products, all of which except the general-purpose Mirabox development platform are consumer/SOHO NAS devices:

• Globalscale’s Armada 370 Mirabox (supported in mainline)
• Netgear’s ReadyNAS RN10200 and ReadyNAS RN10400 (supported in mainline)
• Synology’s DS214se and DS414slim (not yet supported in mainline)
• Buffalo’s LinkStation 421e (not yet supported in mainline)

PlatHome OpenBlocks AX3 microserver

Lynksys WRT1900AC

The more powerful Armada XP SoC, meanwhile, serves as the brains of these devices:

• PlatHome’s OpenBlocks AX3 microserver (supported in mainline)
• Netgear’s RN2120 rack-mounted NAS (supported in mainline)
• Lenovo’s ix4-300d NAS (in the process of being supported in mainline)
• Linksys’s WRT1900AC wireless AC router (not yet supported in mainline)
• Synology’s DS214 and DS414 (not yet supported in mainline)

NAS systems have long been a hacking playground for Linux developers, but usually only after a lot of hard work by the open source community. For example, in 2009, Debian hacker Martin Michlmayr ported Debian 5.0 to a Qnap Systems TS-219 Pro and Marvell’s SheevaPlug Plug Computer, both based on Marvell’s Kirkwood 88F6281 SoC, a forerunner of the Armada 370. Marvell in particular has often shrouded its processors in mystery.

“Free Electrons is happy to see that Marvell is making more and more progress towards mainlining their kernel support and opening their datasheets publicly,” writes Petazzoni. “We strongly believe that the openness of these datasheets will allow hobbyists and developers to improve the support for Armada [370 and XP] in the open-source ecosystem, be it in the Linux kernel, in bootloaders like U-Boot or Barebox or even in other projects.”

 
Further information

The newly released datasheets listed on the Marvell Armada 300 and Armada XP product pages can be downloaded in PDF format from the following links:

• Armada 300 hardware spec
• Armada 300 functional spec
• Armada XP hardware spec
• Armada XP functional spec

Petazzoni’s blog posts relating to Marvell’s release of its Armada SoC datasheets may be found here: Armada 370 and Armada XP.