Marvell has posted detailed datasheets on its previously opaque Armada 370 SoC, used in Linux-based NAS systems from Buffalo, Netgear, and Synology.
Until now, datasheets and other details about the ARM-based Armada 370 system-on-chips have been available only under NDA to Marvell customers and partners. Last week, however, the chipmaker released two detailed datasheets on the SoC, with no restriction or registration required. Both a functional spec datasheet and hardware spec datasheet were released, each of which is more like a manual than a typical datasheet.
We were tipped to the Marvell Armada 370 datasheet release 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 diagram for the Armada 370 model 88F6710 (left) and a diagram of the Armada 370′s coherency fabric interconnect to Mbus and DRAM controller
(click images to enlarge)
According to Free Electrons 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. Marvell has yet to release a datasheet on the related Armada XP. However, since most peripherals are identical with the Armada 370, XP developers should also find the datasheets useful, says Petazzoni.
According to Free Electrons, 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 Armada 370 Mirabox (supported in mainline)
- Netgear ReadyNAS RN10200 (supported in mainline)
- Netgear ReadyNAS RN10400 (supported in mainline)
- Synology DS214se (not yet supported in mainline)
- Synology DS414slim (not yet supported in mainline)
- Buffalo LinkStation 421e (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 Free Electrons CTO Thomas Petazzoni. “We strongly believe that the openness of these datasheets will allow hobbyists and developers to improve the support for Armada 370 in the open-source ecosystem, be it in the Linux kernel, in bootloaders like U-Boot or Barebox or even in other projects.”