CNXSoft – Embedded Software Development

Linaro 13.02 is now available, and features Linux Kernel 3.8 and Android 4.2.2.

The biggest news this month is probably the first release of a preliminary ARM64 Debian/Ubuntu Raring image. Other noticeable items include work on ARMv7 KVM, more improvements to OpenEmbedded ARMv8 implementation, as well as big.LITTLE MP implementation, and some modifications to the toolchain for Cortex A7 support. Origen images are not available for download this month, and there’s still no ALIP images since they have disappeared since Linaro upgraded to Ubuntu Quantal.

Here are the highlights of this release:

Visit https://wiki.linaro.org/Cycles/1302/Release for a list of known issues and further release details about the LEB, Android, Kernel, Graphics, Landing Team,  Platform, Power management and Toolchain (GCC / Qemu) components.

The SMILE Plug is a development kit, designed jointly by Marvell and Standford University, that brings Wi-Fi connectivity to a classroom, and allows up to 60 pupils / students to interact with their teacher via their phones’ or tablets’ web browser. Other possible applications include cloud computing, wireless AP, industrial control, medical instrumentation, office automation, as well as mesh and grid computing.

The SMILE Plug is now available with the following updated specifications:

• SoC – Marvell ARMv7 compliant Marvell ARMADA 370 CPU
• System Memory – 512 MB DDR3
• Storage – 1 GB NAND Flash + microSD slot
• Connectivity
  • WiFi 802.11 a/b/g/n via Marvell Avastar 88W8764 4×4 WiFi for up to 60 nodes
  • 2x Gigabit Ethernet
• USB – 2x USB 3.0
• External backup battery for hours of reserve power* (optional accessory)
• Power on button and restart
• Power Supply – 12V/2amp external power supply
• JTAG and UART port for programming and debugging
• Dimensions – 138 mm x 109 mm x 42 mm

The device runs on Arch Linux ARM, and high level software features SMILE server Inquiry Learning Based Environment application, Node.js and NPM (node packet manager).

The following SMILE software components will eventually be open sourced and available for download:

• Global SMILE for iOS
• SMILE for Android
• SMILE Server for Node.js
• SMILE Teacher Edition for Android
• SMILE Teacher Edition for Java

The SMILE Plug can be purchased for $199 (US model), or part of a combo with a JTAG debugger for $228. Shipping costs are reasonable to the US (~$11), but overseas it may cost you over $50 (Fedex International Economy). If you want a similar box, but you don’t need to provide Wi-Fi to lots of people / nodes, you can also check out the $149 Mirabox Devkit based on the same platform, but comes with 1GB Memory, and runs Debian 6.

Thanks to Bennett for the news.

[Update: An interesting piece of information is that the SMILE Plug costs $30 to produce in quantities according to a Charbax video]

Chris Simmonds, freelance consultant and trainer (2net ltd), discusses the future of embedded Linux now that storage and processing power are no longer an major issue, and try to find the best Linux platform for embedded systems at ELCE 2012.

Abstract:

Embedded Linux is at a cross roads where the combination of Moore’s law making devices more powerful and the mass production of consumer devices, especially mobile, making them cheaper means that the old ways no longer work. Only a few years ago we though in mega: MHz, MBytes, MBits/s. Now we have to think in giga. The days of the single core CPU are almost over, as are the days of the QVGA display.

All this means that there is a need to re-think how embedded devices are programmed. Two obvious roads lie ahead: Android and Ubuntu (or other desktop operating system of your choice). This talk considers the possibilities and challenges in following either route, and considers how embedded engineers can make the best choices for future projects.

Where is Embedded Linux Headed? Mainstream distro, embedded Linux distro, or Android?

Chris talk is structured as follows:

• Overview
• Evolution of embedded hardware
  • 10 years ago: 80 MHz MCU, 16 MB RAM, 8 MB NOR flash. Price: $500
  • Today: dual core @ 1.2 GHz, 1GB RAM, 4GB (and more) SD card  (Pandaboard). Price: $160
• Cost of hardware – The Beagleboard started the low-cost board revolution
• Embedded Linux past
  • Low RAM, clock speed, and amount of storage.  Headless, or simple user interface from keypad or touch screen.
  • Lots of specific tools – Cross toolchain, uClibc, busbox, read-only file systems, lots of custom BSP…
• Embedded Linux now and the future
  • Clock speed, RAM and storage no longer an issue (less need for busybox, uClibc and small rootfs)
  • Storage move from flash to eMMC and SD card (reduced need for jffs2)
• New problems: Complexity, user interface, maintainability and skill level.
• My ideal embedded Linux OS – Multi-platform fully open source OS with good board support, minimal rootfs availability, reduce writes to storage, proper logging, remote upgrade,  good debugging tools and long term support.
• Options – Choice between Mainstream Distro (e.g. Ubuntu, Debian, Fedora), Embedded Linux (e.g. Open Embedded, Yocto) and Android. He compares those 3 choices according to the criteria mentioned above.
• Android is the winner? – Android barely won the contest, but it is monolithic, inflexible,  not a community project, and only good for devices that look like smartphones and tablets.
• Conclusion – Future devices will take more from mainstream distros, but there’s more work to do, and there is always Android for some kind of devices

The presentation slides are available for download.

This is the last day of the year, so it’s probably a good time to look back and see what interested people on this blog. This has been a banner year for low cost ARM devices and boards starting with the Raspberry Pi, then MK802 and the new mini PCs / HDMI TV dongles / PCs-on-a-stick (whatever you want to call them) that came after, always cheaper and faster. Those low cost devices have in turn made people really interested in ARM Linux, and lots of development on those little devices and boards started.

The top 10 posts of 2012, according to page views, reflect just those trends:

1. 74 USD AllWinner A10 Android 4.0 Mini PC (May 2012) – MK802 started the whole “low cost mini PCs” craze, and drove the most traffic to this blog this year. People got excited about the price, form factor, and the possibility to run both Android and other Linux based operating systems.
2. MK802 II Mini PC Now Costs as Much as Raspberry Pi Model B. Let’s Compare Them! (December 2012) – This post features the 2 stars of 2012: the Raspberry Pi and MK802 II HDMI TV donglwe (MK802 with 1GB RAM). As both device can now be bought for $35, and allow you to do very similar things, it’s was time for a head-to-head comparison. I’ve just written about it last week, and it got Slashdotted.
3. WM8850-MID Android 4.0 Tablet Unboxing and Review (June 2012) – At the time, this Eken W70 clone featuring Wondermedia WM8850 Cortex A9 processor was a real bargain for $72 (including shipping). The firmware has a few issues however, and that’s what drove people to this post: looking for solutions.
4. AllWinner A10/A1X Processor Resources, Development Board and SDK (December 2011) – This post was written just about one year ago, but traffic was steady all year, as people want to find out how to hack their AllWinner A10 tablets, media players and mini PCs.
5. Mele A1000: AllWinner A10 (Cortex A8) Based Hackable Android STB (March 2012) – The Mele A1000 was my first Android device, and it got popular thanks to its relatively low cost, available ports (3x USB, SATA, VGA, HDMI…), and serial port which made it ideal for development of U-boot and the kernel. I still think it’s a good platform, but since then low cost development boards such as the Cubieboard has made it a little less attractive, and interest has somewhat faded in the last few months.
6. Valueplus Tizzbird Stick N1: Android 4.0 HDMI/USB Media Player Dongle (March 2012) -  The Tizzbird Stick N1 was one the first mini PCs, and was showcased at CeBit 2012 several months before MK802. Unfortunately, it took many more months to finalize the design, and the product never took off, as other cheaper Telechips TCC892x based mini PCs appeared on the market. The only reason it got traffic is because I mentioned it in the $74 MK802 post at the top of this list.
7. Mele A1000 Android 2.3 STB Unboxing and Review (April 2012) – In March, I was still waiting for the Raspberry Pi launch, but I noticed Barry Kauler (Puppy Linux) bought the Mele A1000 to keep him busy while he was also waiting for his Pi, and seeing the development around AllWinner A10, I decided to buy one as well. Apparently, I was not the only one interested as many people came here to read my review of this nice hackable media player.
8. Mele A2000 Android 2.3 Media Player Powered by AllWinner A10 (April 2012) – The Mele A2000 is the little sister of the Mele A1000, which the same hardware, just a difference casing.
9. Linaro Android Puts Stock Android To Shame on TI Pandaboard (OMAP4430) (June 2012) – Linaro showcased a demo showing an optimized version of Android could deliver twice the performance of stock Android on a particular benchmark running in Pandaboard. Bero commented on my post with details, and the post quickly became viral as developers wanted to give it a try. It turned out the improvement is actually more like 15 to 20%, but this is enough to double the framerate of this benchmark due to Vsync synchronization. It may also work in real games.
10. Raspberry Pi Emulator in Ubuntu with Qemu (October 2011) – In 2011 and early 2012, the Raspberry Pi foundation promised much in terms of schedule, but initially failed to deliver, and many people get desperate enough to check the instructions to emulate an ARMv6 device and run Debian in QEMU to get started with development, before the Raspberry Pi hardware is available.

That will be the last post of 2012, so the “hardware team” (pictured below) and I would like to wish you a very happy and prosperous new year 2013, which I’m sure will be as exciting as 2012 for Linux/Android gadgets and boards, and we should see the first big.LITTLE processors and corresponding devices, ever cheaper tablets, smartphones and mini PCs, an interesting Intel vs. ARM fight for mobile devices, a proper XBMC ARM set-top box close to $50, new mobile OSes based on Linux (Tizen, Sailfish OS, Firefox OS…), and more…

Every Friday, Olimex organizes an online competition where they give away one of their board. They’ll ask a (usually simple) technical question on their twitter account at 22h00 (GMT+7), and all you have to do is to reply to their tweet with the correct answer within one hour. The winner is then selected randomly with random.org. There are usually 50 to 100 respondents so the odds are pretty good.

I played a few times, and finally, I was lucky enough to win an A13-OLinuXino-MICRO development board at the beginning of December. I received it yesterday, after UPS took a whooping 15 days to deliver the board (Way to go UPS!). The board can be purchased on Olimex for 35 Euros plus shipping and taxes, or even lower if you order larger quantities.

A13-OLinuXino-MICRO is a stripped down version of A13-OLinuXino-WIFI with the following specs:

• SoC – AllWinner A13 Cortex A8 processor at 1GHz with Mali400 GPU
• System Memory – 256 MB RAM (128Mbit x 16)
• Storage – microSD card slot for booting the Linux image
• Video Output – VGA video output. LCD signals are available on connector.
• Audio I/O – 3.5mm headphone jack + Microphone input pads (no connector)
• USB – 1x USB host +1x USB OTG which can power the board
• UEXT connector – To connect UEXT modules like Zigbee, Bluetooth, Relays, etc
• 3 “GPIO” connectors (2x 40-pin and 1x 10-pin) – Those give access to NAND flash, GPIOs, I2C, UARTs and SDIO2 signals, as well as 5 system pins: +5V, +3.3V, GND, RESET, NMI.
• LCD Connector – You can connect an optional 7″ LCD provided by Olimex, or connect your own.
• Misc – 1 reset key, 1 U-boot/FEL key, 2 LEDs, 4 mounting holes, UART1 header and pads for JTAG and UART0.
• Power – 5V DC input power supply
• Dimensions – 100 x 85 mm

As usual, I will first post some unboxing pictures, then try Linux on the board, and give some kind of review.

A13-OLinuXino-MICRO Unboxing

The board comes in a small Olimex branded package, and as is the case for the Raspberry Pi, the only item in the package is the board.

Let’s have a look at the top of the board first, where all the components and connectors are placed.

Top of A13-OLinuXino-MICRO Board (Click to Enlarge)

The back of the board shows markings for the GPIO connectors, VGA, UARTs, JTAG and some test points for the different voltages on the board.

Bottom of A13-OLinuXino-MICRO Board (Click to Enlarge)

I’ve also taken a picture of the Olimex board with two other well-known low cost boards…

Raspberry Pi vs Cubieboard vs A13-OLinuxino-MICRO

A13-OLinuXino is larger than the Cubieboard and almost twice as big as the Raspberry Pi.

Getting Started with Olimex A13-OLinuXino-MICRO

First you’ll need to get some external accessories such as:

• A power supply – A 5V/2A power supply to connect to the 5+ jack or the miniUSB port. A microUSB port might have been preferably since most mobile phones used this type of USB connector.
• A USB hub – This is optional but since there’s only a USB Host port, it is required unless you only plan to connect one USB device (e.g. USB keyboard).
• USB to Serial Board – Again, this is optional but it is really useful for debugging purpose in case there’s an issue with the bootloader and/or kernel, or you simply don’t want/need to plug the board to a VGA monitor.
• Display – VGA monitor or LCD
• Keyboard and mouse
• Wi-Fi / Ethernet USB Dongle – Optional
• a microSD for Linux and storage

One good thing with Olimex is that they have free user’s manuals for their boards. That may seem trivial, but the Cubieboard simply do not have one, and the Raspberry Pi does have one, but you need to pay for it. Of course, all boards have some free resources online, but it’s still nice to have most of what you need in one document.

So let’s download A13-OLinuXino-MICRO user’s manual first. It a 30-page PDF document that gives you an overview of the board,  explains how to get started with the board, and gives a detailed hardware description of the board (pin and connectors descriptions), some information about AllWinner A13 SoC, and some links to the design files (schematics & PCB layout in PDF and Eagle format).

Since the board does not have flash, you need to load a Linux image to a microSD card first. Olimex currently just has a preliminary Debian image for the board (A13_Micro_Debian_first_preliminary_release-06122012.rar  – 737 MB). This is a compressed SD card image, so simply uncompress it, and dump it to a microSD card with dd (Linux) or Win32DiskImager (Windows).

Time to connect the board. I’ve inserted by Debian SD card, and connected a USB keyboard, the serial to USB adapter I use with the Mele A1000 to UART1, a VGA cable to my monitor and a power supply to the microUSB port.

Everything looks fine, I can see U-Boot and the kernel output in putty and the VGA monitors light, but the boots take over 2 minutes, as it’s stuck in udev, as it apparently tries to find another USB host that does not exists, and times out after 120 seconds.

Waiting for /dev to be fully populated...
udevadm settle - timeout of 120 seconds reached, the event queue contains:
 /sys/devices/platform/sw-ohci.1/usb3 (581)
 /sys/devices/platform/sw-ohci.1/usb3/3-0:1.0 (582)
 /sys/devices/platform/sw-ohci.1/usb3/usb_device/usbdev3.1 (583)

Finally, I can login (Username: root | Password: password), and check a few things about the board in the serial terminal:

Debian GNU/Linux wheezy/sid A13Micro ttyS0

A13Micro login: root
Password:
Last login: Thu Jan  1 00:17:25 UTC 1970 on ttyS0
Linux A13Micro 3.0.52+ #10 PREEMPT Wed Dec 5 16:01:52 EET 2012 armv7l

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
root@A13Micro:~# uname -a
Linux A13Micro 3.0.52+ #10 PREEMPT Wed Dec 5 16:01:52 EET 2012 armv7l GNU/Linux
root@A13Micro:~# free -mh
             total       used       free     shared    buffers     cached
Mem:          165M        32M       133M         0B       4.0M        12M
-/+ buffers/cache:        16M       149M
Swap:           0B         0B         0B
root@A13Micro:~# df -h
Filesystem      Size  Used Avail Use% Mounted on
rootfs          1.8G  729M  992M  43% /
/dev/root       1.8G  729M  992M  43% /
devtmpfs         83M     0   83M   0% /dev
tmpfs            17M  120K   17M   1% /run
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs            34M     0   34M   0% /tmp
tmpfs            34M     0   34M   0% /run/shm
root@A13Micro:~#

So there’s 165 MB available for Linux, as the rest of the 256MB RAM is mainly reversed for A13 GPU, and the rootfs is 1.8GB with 729 MB used. Since I’ve got a 4GB microSD card, let’s increase the rootfs size to make full use of the available space on the microSD:

1. Run fdisk to delete and re-create the rootfs partition (p2)

   fdisk /dev/mmcblk0

2. Reboot the board, and resize the partition:

   resize2fs /dev/mmcblk0p2

3. Enjoy the extra space:

   df -h
   Filesystem      Size  Used Avail Use% Mounted on
   rootfs          3.6G  731M  2.7G  22% /

When I’ve then tried to login via the VGA screen, I realize the USB keyboard did not work at all with this board, which could explain the many USB debug message I could see in the serial terminal…

If you want to use LCD instead of VGA, the script files to do so are in script_GPIO_LCD_800x480 directory in the FAT partition of the microSD card.

More Information and Technical Support

If you prefer to build u-boot & the kernel yourself, and use your own rootfs, you can follow the instructions in Building bootable SD-card with Debian Linux Image for A13-OLinuXino. Those are the instructions for A13-OLinuXino, so you may have to adapt the instructions for A13-OLinuXino-MICRO.

If you want to use/test the latest kernel and bootloader, there’s an easier method using sunxi-linux nightly builds. If you don’t want to keep the rootfs but update the kernel and U-boot you can do as follows:

wget https://github.com/linux-sunxi/sunxi-bsp/raw/master/scripts/sunxi-media-create.sh
chmod 755 sunxi-media-create.sh
wget http://dl.linux-sunxi.org/amery/sunxi-3.0/latest/a13_olinuxino_hwpack.tar.xz
/sunxi-media-create.sh /dev/sdX a13_olinuxino_hwpack.tar.xz norootfs

This will create an image for A13-OLinuXino board (512MB RAM), and if you try directly the system will crash at boot time. So until a13_olinuxino-micro_hwpack.tar.xz becomes available, you’ll need to copy the script.bin file from the Debian image to the FAT partition.

You can get hardware and software support on Olimex Forums and consult A13-OLinuXino-MICRO Wiki (In construction). If you are modifying the  the kernel or u-boot source code or find bugs related to the kernel/u-boot, contacting sunxi-linux mailing-list may be a better option.

Conclusion

If I just look at the board specifications and compare it to other low cost boards such as the Raspberry Pi or Cubieboard, Olimex A13-OLinuXino may not look the best value at 35 Euro + shipping, and Debian is not really stable on this board right now, although I’m pretty sure it will eventually be.

One of the advantage of the Olimex board is the VGA connector which is missing on the other 2 boards aforementioned. A13-OLinuXino-MICRO also has 4 expansion headers, including the UEXT connector that gives you access to over 20 low cost modules. This can make the board very attractive for embedded projects as it’s relatively straightforward to add some features such as GSM/GPRS, sensors, GPS. RF connectivity…

Finally, all Olimex boards are open source hardware, which means you’ll get access to hardware design files (and not only PDF) and source code, which is not fully the case for most other boards, especially for the schematics in original format and PCB layout.

I’ve just come across an Embedded System Study by UBM published in April 2012. The company surveyed over 1,700 professionals working on embedded systems who are mainly based in the US (56%),  but also in Europe (21%) and Asia (12%). The report is 87 long, but I found some of the slides are particularly interesting in regards to programming languages, operating systems and software life cycle, as well as processor/micro-controller choices.

Unsurprisingly C (65%), C++ (20%) and assembler (5%) are still the main languages used for embedded software development.

In this report, we also learn that the average team is composed of 14.5 members including 5.6 software engineers, 5.6 hardware engineers and 3.3 firmware engineers. 2012 was the first year they included QA Engineers and system integrators both with 2.6 members on average working on projects lasting from less than 6 months to over 25 months.

Last Embedded Project Duration

UBM survey also provides a breakdown of the project life cycle which shows most of time is spent on implementation and debugging, and documentation is basically an after thought.

Percentage of Time Spent on a Given Stage of Development

Embedded projects currently use as much Commercial OSes as open source OSes (with or without commercial support), but the trend appears to be favorable for open-source OS without commercial support.

Type of Operating System used in Current (left) and Next (right) Project

That’s a relief (to me) to learn that the operating system choice is mainly influenced by software engineering staff & managers. The top three reasons for OS selection are full source code availability (41%), real-time performance (31%) and no royalties (31%). 56% of respondents are currently using or consider using embedded Linux in their next project because it is low cost (72%) and easily adaptable and extensible (54%), but 44% would not use embedded Linux mainly because of software/app/driver incompatibility (39%)  and memory usage (25%). There are also 14% who cited legal reasons for not using embedded Linux.

As discussed by Linux.com, Android is clearly popular in smartphones and tablets, but is also experiencing tremendous growth in embedded systems with 34% of respondents considering using Android in one of their next project within 12 months.

Operating Systems Considered in the Next 12 Months for Embedded Projects.

Note that 4 of the top 5 operating systems (Android, FreeRTOS, Ubuntu and Micrium) are all open source, so there’s clearly an irreversible  move in this direction. The Linux based operating systems listed above (Ubuntu, Debian, Red Hat, Angstrom and MontaVista) represent 36% of the total, and 70% if we include Android in the total.

Most embedded projects use 32-bit micro-processors / micro-controllers (63%), following by 16% who use 16-bit tech, 13% 8-bit and 7% for 64-bit. The trend for 8-bit and 64-bit is stable, 16-bit usage is declining, and 32-bit usage is growing slowly. Most embedded projects have a main processor clock rate below 250 MHz.

Current Embedded Project Main Processor Clock Rate

Finally, when asked to cite ONE vendor with the best ecosystem for the needs of the respondent, Texas Instruments took the lead (19%), followed by Freescale (11%) and Microchip (10%).

Those are just the a few parts I found the most interesting, but you can read the full survey for more details.