[Updated: Dec. 25, 2015] — Linaro has launched an open-source spec for ARM SBCs called “96Boards,” first available in a $129 “HiKey” SBC, featuring a Huawei octa-core Cortex-A53 SoC.
Linaro, the ARM-backed not-for-profit engineering organization that has aimed to standardize open source Linux and Android software for Cortex-A processors, is now trying to do the same thing for hardware. Linaro, which is owned by ARM and many of its top system-on-chip licensees, has launched 96Boards.org, a cross between a single board computer hacker community and an x86-style hardware standards organization.
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96Boards.org has released a Consumer Edition (CE) of the spec with an 85 x 54mm or 85 x 100mm footprint, and both 40- and 60-pin expansion connectors for stackable boards. This will be followed in the second quarter by an Enterprise Edition (EE).
The HiKey was initially built by CircuitCo and distributed by Avnet and Arrow, for $129. Shenzhen China based Lemaker has developed its own version of the HiKey and is currently accepting orders for it, for $75 (1GB RAM) and $99 (2GB RAM).
The HiKey runs on an octacore Cortex-A53 SoC, making it the first 64-bit ARM hacker board. ARM’s Juno Versatile Express development board features an octacore Juno SoC design with ARMv8 Cortex-A57 and –A53 cores. In October, Allwinner tipped a Nobel64 development board based on an upcoming ARMv8 Allwinner H64 SoC, but it has yet to reach market. That leaves the HiKey alone for a moment as the only affordable ARMv8 SBC.
Marvell and Action Technology are also prepping 96Boards-compatible products. (See farther below for more on the CE spec, the HiKey board, and the Marvell news.)
The 96Boards initiative will offer a series of specs for small-footprint 32- and 64-bit Cortex-A boards “from the full range of ARM SoC vendors,” says Linaro. The specs will support the mobile, embedded, digital home, networking, and even server segments. It will target software developers, the maker community, higher education, and embedded OEMs.
Each spec defines a fixed set of minimum functions including USB, SD, HDMI, and standardized low speed and high speed peripheral connectors. Standardized expansion buses for peripheral I/O, display, and cameras “allow the hardware ecosystem to develop a range of compatible add-on products that will work on any 96Boards product over the lifetime of the platform,” stated Linaro. “We expect this to extend the platform life, increase the market for add-on hardware, and accelerate open source upstreaming of support for new SoC features.”
SBC vendors can add customized hardware and feature sets on top of the minimum set. Certification is available from 96Boards and requires membership in the Linaro Community Board Group (LCG), which oversees the initiative. Linaro will work with board manufacturers and chip suppliers to bring up core software and ensure stability, and will provide continuous integration testing using Linaro’s Automated Validation Architecture (LAVA) platform.
Android and Debian Linux builds are available, built on a recent mainline kernel, and the spec supports a wide variety of Linux distros, including Ubuntu and Yocto. The 96Boards website provides software downloads and updates, information on compatible products, and a forum for software developers, makers, and OEMs.
Although 96Boards will support both ARMv7-A and ARMv8-A platforms, the focus is clearly on new 64-bit ARMv8 platforms like the HiKey. “Linaro’s initiative is perfectly timed to strengthen the 64-bit developer community,” stated Vincent Korstanje, vice president of marketing, systems and software group, ARM.
The wide open community of ARMv7 SBCs has always been beyond ARM’s control, and it’s probably too late to start now. The closest thing to an ARM SBC standard is the 26- or 40-pin Raspberry Pi expansion interfaces and perhaps an Arduino connector, as well. Other projects have centered on a few SoC platforms such as the Allwinner A20 or A31 SoCs with Mali-400 GPUs, which has helped consolidate software development.
By contrast, the x86 community has spawned a number of widely adopted SBC form-factor initiatives such as Mini-ITX and Pico-ITX, which have also been used by some embedded OEMs making ARM-based SBCs. In the community-backed ARM SBC world, however, the design is largely guided by the particular SoC’s capabilities, as well as the whims of the designers. According to the 96Boards site, the spec aims to move away from a dynamic where “the external ecosystem is tied to a particular SoC” while evolving to a platform that “will support multiple SoCs over a period of years.”
Consumer Edition Spec
The 96Boards Consumer Edition (CE) spec is available in standard (85 x 54mm) or extended (85 x 100mm) footprints. Any ARM Cortex-A SoC will do, and two placement options are available. If there’s high heat dissipation, vendors will likely use the underside location, which will usually require thermal management and an enclosure. The top-side SoC location option is designed for lower dissipation, and will require a low profile heatsink or fan. Any mezzanine boards stacked above must not include any components directly over the SoC.
96Boards CE form-factor specs for standard (left) and extended versions
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The minimum CE spec calls for 512MB of RAM (1GB for Android), a microSD slot, and at least one of the following display interfaces: HDMI, DisplayPort, or the MHL (mobile high-definition link) version of HDMI.
WiFi and Bluetooth 4.0 are required, but no Ethernet is specified. CE boards require the presence of dual USB host ports and a micro-USB client or OTG port. The CE spec requires both a 40-pin low-speed interface for GPIO, as well as a 60-pin high-speed interface. Despite being a 40-pin array, the low-speed connector bears no resemblance to the Raspberry Pi‘s 40-pin expansion header, both in terms of signal assignments and pin-to-pin pitch.
96Boards CE spec’s low-speed (left) and high-speed connector pinouts
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Mezzanine boards are expected to be deployed in configurations with either a single low-speed board (which has a 1.8V connection to the SoC) or both low- and high-speed boards stacked together. The top-stacking mezzanine boards require a board-to-mezzanine spacing of 7mm or 8mm, and can be much larger than the SBC itself. In addition to these required CE features, 96Boards CE boards can add custom storage, as well as interfaces like Ethernet and CAN, and PCI expansion via mini-PCIe or M.2 connectors.
CircuitCo is planning to release a low-cost “maker mezzanine board” that provides a Raspberry Pi compatible CSI camera (FFC) connector and an Arduino Uno compatible shield interface. The board will also offer a standard UART interface, a low-speed I/O header, and I/O level shifters to 3.3V/5V.
The 96Boards CE spec calls for the following minimum set of features:
- Processor — ARM Cortex-A (placement options include top or bottom of SBC)
- 512MB (1GB strongly recommended for Android)
- MicroSD slot for up to 64GB
- 8MB bootable flash (required if no bootable microSD card available)
- Display (at least one of the following in specified locations):
- HDMI with audio (full-sized or micro)
- MHL (HDMI) with audio (via micro-USB)
- DisplayPort with audio (via USB Type C)
- Wireless — 802.11g/n; Bluetooth 4.0 LE (BLE)
- Other I/O (all with specified locations):
- 2x USB host ports (USB 2.0 or 3.0, Type A or C)
- Micro-USB client or OTG for PC connection (USB 2.0 or 3.0, Type AB/B for power, Type C for no power)
- 40-pin low-speed GPIO expansion connection (female header) for maker/community use with required serial UART and I2S/PCM (audio) and optional I2C, SD/SPI; 2×20, 2mm pitch
- 60-pin high-speed connection (female module header) for advanced maker/OEM use with USB and MIPI-DSI (both required), or optional MIPI CSI-2, MIPI-HSIC, etc.; 2×30, 0.8mm pitch
- 8V to 18V supply from DC jack, SYS-DCIN port on low-speed connector, or USB 3.1 Type C (5V)
- No simultaneous power supported
- Current sense resistor required for power consumption measurement
- Power and reset buttons required
- Optional onboard battery power/charging support
- Power to external devices (minimums required):
- 7W to mezzanine via SYS-DCIN (with DC jack only)
- 5W to mezzanine via regulated +5V
- 5W to ext. USB device via host ports
- 0.18W to mezzanine via regulated +1.8V
- Other features — 6x LEDs required (WiFi, BT, and 4x user)
- Dimensions — 85 x 54 x 12mm (standard) or 85 x 100 x 12mm (extended)
- Operating system — Open source Linux or Android (builds initially available for Debian 8.0 and Android, with support coming from Ubuntu, Fedora/Red Hat, and OpenEmbedded/Yocto
The first SBC to support the 96Boards CE spec is the HiKey, which is branded by 96Boards.org, and distributed by Avnet and Arrow. The standard-sized CE board is manufactured by CircuitCo, the company that makes the BeagleBone, among other SBCs.
HiKey port detail
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The HiKey builds on a new Kirin 6220 SoC from Huawei’s HiSilicon processor division. Announced in December, the 64-bit Kirin 6220 combines eight 1.2GHz Cortex-A53 cores, a Mali-450MP4 GPU, and an LTE module with 150Mbps download support. According to Huawei, the 28nm fabricated SoC is designed to compete in the mid-range market with Qualcomm’s Snapdragon 610 and MediaTek’s 64-bit SoCs. The SoC is claimed to offer 10,000 Dhrystone VAX MIPS performance.
HiKey component detail, front and back
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The HiKey SBC ships with 1GB of LPDDR3-800 RAM, 4GB of eMMC flash, and a microSD socket. The required features are all here, including WiFi, Bluetooth, dual USB 2.0 host ports, a micro-USB OTG port, and a HDMI 1.3 port.
HiKey display I/O architecture
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Both low- and high-speed connectors are implemented, with the latter supporting the optional CSI camera interface as well as the required DSI connection. An 8-18V DC 2A power supply is provided along with a JTAG header.
96Boards SBC coming from Marvell
Testimonials for 96Boards were posted from Avnet and Arrow, as well as AMD, which hopes to use the spec to “enable the developer community with a cost-effective platform for ARM server software development.” Also speaking up for 96Boards was Chinese embedded vendor Action Technology, the manufacturing wing of Action Semiconductors, which has made MIPS processors in the past, but is now focused mostly on ARM SoCs. Action Technology makes a Linux- and Android-ready Cortex-A9-based ActDuino S200 SBC.
Marvell also announced support for 96Boards, and said it would join the Linaro Community Boards Group (LCG) that supports the project. In the coming weeks, the company plans to announce a 96Boards-compatible product that uses the PXA1928, Marvell’s 1.5GHz, quad-core, Cortex-A53 networking SoC. Announced a year ago, the PXA1928 incorporates LTE and other cellular modems, as well as an integrated Marvell Avastar 88W8887 wireless module with WiFi, Bluetooth, FM, and NFC. There’s also a Marvell 88L2000 GPS/GNSS chip. The PXA1928 has been adopted by Google for its modular Project Ara smartphone, which goes on sale in Puerto Rico this year.
The 96Boards CE specification is available now at 96Boards.org, along with more information on the HiKey SBC. Pre-orders for the HiKey are available at Avnet Express, which shows the $129 HiKey out of stock, but available for pre-order, with seven-week factory lead time. Arrow has the HiKey as being out of stock, but available for backorder at $167.55.