Hi all,

It has been a busy end of year 2015 and beginning of 2016: So let's share with you some of the enhancements added to our Linux offer.
Don't hesitate to follow us as well on Linux4SAM.org and our lively Github account where you can browse the log of our latest source code modifications.

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Table of contents:

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Linux4SAM demo version 5.1

We continue our update of Linux4SAM.org with newer demo revisions for SAMA5D3 Xplained and SAMA5D2 Xplained board demo. Here are the highlights of this new revision:

• Linux4SAM demos now include screen support, with the addition of the PDA inc. screen sizes: 4.3" and 7"
• No need to edit any SAM-BA script or launch a graphical application from the command line: just download the package associated to your board+screen combination ; flash with the proper SAM-BA tool and see the demo appear on the screen!
• Now, for each SoC, for each PDA screen, we distribute a separate archive that can be flashed on the main boot media type (NAND or SPI flash) and an SD Card image. Choose your screen option, prepare the SD Card, insert it in your board and you're ready to go:
  http://www.at91.com/linux4sam/bin/view/Linux4SAM/Sama5d2XplainedMainPage#Demo_archives
  http://www.at91.com/linux4sam/bin/view/Linux4SAM/Sama5d3XplainedMainPage#Demo_archives
• component updates:
  • AT91Bootstrap 3.8.1
  • the U-Boot bootloader based on the 2015.01 release
  • Linux kernel based on the 4.1 release. Check the changelog summary here:
    http://www.at91.com/linux4sam/bin/view/Linux4SAM/LinuxKernel#linux4sam_5_1_tag
  • a Yocto Project root filesystem based on the version 2.0.1 named "jethro"
  • use of the full featured graphic library QT 5.5.1

Note that the update for SAMA5D4 Xplained is pending, until we resolve GStreamer related issues, which should happen in the near future. In the meantime we still recommend to use the 5.0 or 4.7 demo archives.

Linux kernel 4.4 is out

Mid-January, we benefited from this new Linux kernel release. What is so special about this particular one is that it has been elected as the Long Term Support (LTS) during the Kernel Summit that took place in Seoul on October 2015. Greg Kroah-Hartman announced it on his Google+ account..

For an interesting reading you can have a look at the KernelNewbies 4.4 pages:
http://kernelnewbies.org/Linux_4.4
http://kernelnewbies.org/Linux_4.4-DriversArch

For Atmel processors, this release was fruitful with many enhancements for all supported devices and boards. You can check the Device Tree pull-requests for an overview:
http://lists.infradead.org/pipermail/linux-arm-kernel/2015-October/373814.html
http://lists.infradead.org/pipermail/linux-arm-kernel/2015-October/379951.html
You'll notice that Device Tree changes are now by far the most important additions to each kernel revision for AT91. It means that our cleanup actions are now completed and that the core of our architecture is very stable and sane.

The fixes pull-requests added also some important updates as well:
http://lists.infradead.org/pipermail/linux-arm-kernel/2015-November/385678.html
http://lists.infradead.org/pipermail/linux-arm-kernel/2015-December/390211.html

The big addition is for sure the update of SAMA5D2 support and the landing of a masterpiece which had been discussed at length: the GPIO controller. The flexcom (SPI/I2C/USART), LCD and Class D audio amplifier drivers are also there to continue the effort to enhance the Mainline support that began for this particular chip in kernel 4.3.

All these goodies combined encourage us to choose this kernel revision for the next branch that we will be supported on Linux4SAM: the future linux-4.4-at91 branch.

New AT91 boards appearing in Mainline Linux

In addition to the Atmel Xplained boards, several companies also propose their microcontroller based products with a Linux Mainline support. This prove their commitment to having the best-in-class Linux support while securing the availability of their product in the Latest-and-greatest Linux revision. So, recently, we followed the addition of board Device Trees for:

• Overkiz Kizbox controller
• DENX Computer Systems MA5D4 SoM and EVK
• Landis + Gyr VInCo platform
• Ka-Ro electronics TXA5-5010/-5011 CoM

Activity on the linux-arm-kernel mailing-list

Here is a brief summary of the most important discussions that happened around the Atmel microprocessor family (aka AT91) during the last three months:

• Hardware crypto accelerators: fixes and enhancements by Cyrille. More work has to be done for chaining AES and SHA to create a Authenticated Encryption with Associated Data channel. This is used by IPSec to create secured communication channels.
• QSPI: the big discussion about this new support in Linux kernel goes on with modification to the spi-nor driver and the deepest aspects are now addressed together with the MTD subsystem maintainer
• the NAND Flash adaptation for SAMA5D2 is being developed within the community by Romain
• as you saw on the first paragraph of this newletter, SAMA5D2 specific drivers are the bulk of our current work
• SAMA5D2 Ultra Low Power mode 1 (ULP1) is being added with a discussion going on about the Device Tree description led by Wenyou
• Alexandre is working on the Linux Real Time "preempt-rt" and is integrating the possibility to easily add this important patch set to our offer
• Boris is working on the HDMI interface that is present with our SAMA5D4 boards. Having a good Mainline solution with our KMS/DRM graphical driver can ease the use of our flagship and its video decoder!
• Alexandre and I sent pull-requests for the upcoming 4.5 kernel revision that have been accepted: always in time for a fresh Linux kernel!

We hope that the content is interesting for you and don't hesitate to contact us for any remark about this newsletter.
Bye,

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Nicolas Ferre and the whole OS team