Tag: linux

Marvell publishes the datasheet of the Armada XP processor

thumb-armada-xpA bit more than a month after publishing the datasheet of the Armada 370 processor, Marvell has now released a similar datasheet for the more powerful Armada XP processor. The datasheet is available as a PDF document, with no registration, at http://www.marvell.com/embedded-processors/armada-xp/assets/ARMADA-XP-Functional-SpecDatasheet.pdf, with a link to it clearly visible on the Armada XP product page.

As most of our readers probably know, Bootlin has been working and continues to work significantly on the Linux kernel support for Marvell processors. Thanks to this work done for more than two years now, the mainline Linux kernel has pretty good support for the Armada XP processor. This processor is a nice monster: up to 4 cores (PJ4B cores, which are roughly equivalent to Cortex-A9 but with LPAE support), up to 10 PCIe interfaces, multiple SATA interfaces, up to four Gigabit network interfaces, and many, many other things (XOR engine, cryptographic engine, etc.). Many of the processor features are already supported in mainline, and lately we’ve been focusing on power management features: cpuidle support for Armada XP will be part of 3.16, cpufreq support will either be part of 3.17 or 3.18, and suspend/resume should hopefully be part of 3.18.

The Armada XP processor is used in publicly available products:

At Bootlin, we are again really happy to see Marvell opening this datasheet, as it will allow all community developers to further improve support for this processor in the Linux kernel, but also in other open-source projects.

Linux 3.15 released, an overview of Bootlin contributions

The 3.15 of the Linux kernel was released just a few days ago by Linus Torvalds. As explained by LWN.net, the headline features in 3.15 include some significant memory management improvements, the renameat2() system call, file-private POSIX locks, a new device mapper target called dm-era, faster resume from suspend, and more. One can also read the coverage by LWN.net of the first part and the second part of the merge window to get more details about the major new features in this release.

As usual, Bootlin contributed to the Linux kernel during this 3.15 cycle, and with a total of 218 patches contributed, it’s a new record for Bootlin. According to the KPS statistics, Bootlin ranked #12 in the list of companies contributing to the Linux kernel for the 3.15 kernel (if you exclude the “Unknown” and “Hobbyists” categories, which aren’t really companies).

The main features contributed by Bootlin again centered around the support for ARM processors:

  • By far, the largest contribution this cycle was the initial support for the new Armada 375 and Armada 38x processors from Marvell. Gregory Clement, Ezequiel Garcia and Thomas Petazzoni have been working on the code to support these processors since a few months ago, and started pushing the patches to the public in February this year. For the Marvell Armada 38x processor, it means that the code was pushed in mainline even before the processor was announced publicly! The features supported in 3.15 for these processors are: interrupts, GPIO, clocks, pin-muxing, serial, I2C, SPI, timer, L2 cache, SDIO (only for 375), SATA (only 375), XOR, PCIe, MBus, networking (only for 38x), NOR and NAND support. Many other features such as SMP, I/O coherency and various other peripherals will be supported in 3.16.
  • Convert support for the Atmel AT91SAM9RL processor to the Device Tree, done by Alexandre Belloni.
  • Addition of iio-hwmon to the Freescale i.MX23 and i.MX28 processors, which allows to use the internal temperature sensor of the processor. Done by Alexandre Belloni.
  • Multiple fixes and improvements to the AT91 ADC support. Done by Alexandre Belloni.
  • Support for the watchdog in Armada 370 and Armada XP was added, done by Ezequiel Garcia.
  • A driver for the SPI controller found in Allwinner A31 SoC was added, as well as all the Device Tree information to describe this controller and related clocks. Done by Maxime Ripard.
  • Support for the I2C controller found in the Allwinner A31 SoC was added into the existing mv64xxx-i2c driver, as well as the necessary Device Tree information to use I2C on this SoC. Done by Maxime Ripard.
  • Audio support was enabled on the Armada 370 SoC, re-using existing code for Kirkwood, and therefore making audio work on the Armada 370 DB platform. Done by Thomas Petazzoni.
  • A number of issues in the PCIe support for Marvell processors have been fixed, thanks to the reports from a number of users. Done by Thomas Petazzoni, with help from these users.

We also contributed other things than just support for ARM processors:

  • The main contribution in this area is the addition of UBI block, a driver that allows to use read-only block filesystems such as squashfs on top of a UBI volume. The code was originally written by David Wagner who was an intern at Bootlin, and later taken by Ezequiel Garcia who did a lot of additional cleanup work and community discussion to get the driver merged. Some details about this feature can be found in the Linux-MTD documentation.
  • A generic Device Tree binding to express NAND ECC related information in the Device Tree was contributed by Ezequiel Garcia.
  • The quest to remove IRQF_DISABLED continued, by Michael Opdenacker.

In details, all our contributions are:

Marvell publishes the datasheet of the Armada 370 processor

thumb-armada-xpOver the last two years, Bootlin has contributed support for the Marvell Armada 370 and Marvell Armada XP processors to the mainline Linux kernel. These ARM processors are used mainly in Network Attached Storage devices but also in other devices such as printers. Until now the datasheet for these processors was only available for Marvell customers and partners under NDA, but last week, Marvell finally released the datasheet of the Armada 370 publicly, with no restriction, no registration, no NDA. The Armada 370 processor can already be found in several consumer grade products:

From now on, on the Marvell page (broken link removed) related to the Armada 3xx family, the Armada 370 Functional Specification (broken link removed) as well as the Armada 370 Hardware Specifications (broken link removed) can be found. While the Armada XP datasheet is not available at this time, it is worth mentioning that the vast majority of the peripherals are exactly the same between Armada 370 and Armada XP, so even Armada XP users will find useful information in this datasheet.

Bootlin is happy to see that Marvell is making more and more progress towards mainlining their kernel support and opening their datasheets publicly. 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.

Embedded Linux course in Madrid – July 7-11

We are happy to announce a new Embedded Linux training course on July 7-11, in Madrid, Spain.

IGEPv2 boardIt is organized by our partners ISEE (the makers of the IGEPv2 board that we are using in this course), and Silica, a well known component is distributor who is welcoming the session in its offices in Madrid.

The course will be instructed in English by our trainer Marcin Bis. Marcin Bis

The registrations are directly handled by ISEE. See details.

Linux 3.14 released, Bootlin contributions inside!

Linus Torvalds has just released the 3.14 version of the Linux kernel. As usual, it incorporates a large number of changes, for which a good summary is available on the KernelNewbies site.

This time around, Bootlin is the 19th company contributing to this kernel release, by number of patches, right between Cisco and Renesas. Six of our engineers have contributed to this release: Maxime Ripard, Alexandre Belloni, Ezequiel Garcia, Grégory Clement, Michael Opdenacker and Thomas Petazzoni. In total, they have contributed 121 patches to this kernel release.

  • By far, the largest number of patches are related to the addition of NAND support for the Armada 370 and Armada XP processors. This required a significant effort, done by Ezequiel Garcia, to re-use the existing pxa3xx_nand driver and extend it to cover the specificities of the Armada 370/XP NAND controller. And these specificities were quite complicated, involving a large number of changes to the driver, which all had to also be validated on existing PXA3xx hardware to not introduce any regression.
  • Support for high speed timers on various Allwinner SOCs has been added by Maxime Ripard.
  • Support for the Allwinner reset controller has been implemented by Maxime Ripard.
  • SMP support for the Allwinner A31 SOC was added by Maxime Ripard.
  • A number of small fixes and improvements were made to the AT91 pinctrl driver and the pinctrl subsystem by Alexandre Belloni.
  • Michael Opdenacker continued his quest to finally get rid of the IRQF_DISABLED flag.
  • A number of fixes and improvements were made by Grégory Clement and Thomas Petazzoni on various Armada 370/XP drivers: fix for the I2C controller on certain early Armada XP revisions, fixes to make the Armada 370/XP network driver usable as a module, etc.

In detail, our contributions were:

Bootlin at Embedded World 2014, Nuremberg, Germany

Embedded World 2014, Germany

Embedded World is the world’s largest trade show about embedded systems. In 2013, it attracted around 900 exhibitors, over 22,000 visitors and almost 1,500 congress participants.

This year, Bootlin will be represented by our CEO Michael Opdenacker. This should be a great opportunity for us to understand our customers better, by meeting embedded system makers, by seeing what their needs are and what technologies they use. It will also be an opportunity to meet well known members of the technical community. In particular, here are a few well know people who are going to speak at the congress:

Don’t hesitate to contact us if you are attending this event too and are interested in knowing Bootlin better, for business, partnership or even career opportunities!

Bootlin contributions to Linux 3.13

Version 3.13 of the Linux kernel was released by Linus Torvalds on January, 19th 2014. The kernelnewbies.org site has an excellent page that covers the most important improvements and feature additions that this new kernel release brings.

As usual Bootlin contributed to this kernel: with 121 patches merged in 3.13 on a total of 12127 patches contributed, Bootlin is ranked 17th in the list of companies contributing to the Linux kernel. We also appeared on Jonathan Corbet kernel contribution statistics at LWN.net, as a company having contributed 1% of the kernel changes, right between Renesas Electronics and Huawei Technologies.

Amongst the contributions we made for 3.13:

  • Standby support added to the Marvell Kirkwood processors, done by Ezequiel Garcia.
  • Various fixes and improvements to the PXA3xx NAND driver, as well as to the Marvell Armada 370/XP clocks, in preparation to the introduction of NAND support for Armada 370/XP, which will arrive in 3.14. Work done by Ezequiel Garcia.
  • Added support for the Performance Monitoring Unit in the AM33xx Device Tree files, which allows to use perf and oprofile on platforms such as the BeagleBone. Work done by Alexandre Belloni.
  • Support added for the I2C controllers on certain Allwinner SOCs, as well as several other cleanups and minor improvements for these SoCs. Work done by Maxime Ripard.
  • Continued the work to get rid of IRQF_DISABLED, as well as other janitorial tasks such as removing unused Kconfig symbols. Work done by Michael Opdenacker.
  • Added support for MSI (Message Signaled Interrupts) for the Armada 370 and XP SoCs. Work done by Thomas Petazzoni.
  • Added support for the Marvell Matrix board (an Armada XP based platform) and the OpenBlocks A7 (a Kirkwood based platform manufactured by PlatHome). Work done by Thomas Petazzoni.

In detail, the patches contributed by Bootlin are:

New training materials: boot time reduction workshop

We are happy to release new training materials that we have developed in 2013 with funding from Atmel Corporation.

The materials correspond to a 1-day embedded Linux boot time reduction workshop. In addition to boot time reduction theory, consolidating some of our experience from our embedded Linux boot time reduction projects, the workshop allows participants to practice with the most common techniques. This is done on SAMA5D3x Evaluation Kits from Atmel.

The system to optimize is a video demo from Atmel. We reduce the time to start a GStreamer based video player. During the practical labs, you will practice with techniques to:

  • Measure the various steps of the boot process
  • Analyze time spent starting system services, using bootchartd
  • Simplify your init scripts
  • Trace application startup with strace
  • Find kernel functions taking the most time during the boot process
  • Reduce kernel size and boot time
  • Replace U-Boot by the Barebox bootloader, and save a lot of time
    thanks to the activation of the data cache.

Creative commonsAs usual, our training materials are available under the terms of the Creative Commons Attribution-ShareAlike 3.0 license. This essentially means that you are free to download, distribute and even modify them, provided you mention us as the original authors and that you share these documents under the same conditions.

Special thanks to Atmel for allowing us to share these new materials under this license!

Here are the documents at last:

The first public session of this workshop will be announced in the next weeks.
Don’t hesitate to contact us if you are interested in organizing a session on your site.

Linux init failures now easier to debug

If you are an embedded Linux developer too, you have probably been frustrated by the lack of information from the Linux kernel when it failed to start the init process when you’re building a new root filesystem. The only thing you get is No init found, and this could hide many different causes:

  • No init program candidate found at all
  • Some init program candidates exist but they can’t be executed, for multiple possible causes (missing execute permissions, failed to load shared libraries, executable compiled for an unknown architecture…)

The good news is that this source of frustration will be gone in Linux 3.13. Thanks to a Bootlin commit merged on Nov. 13, 2013, whenever an attempt to execute an init program candidate fails, there is a message in the console detailing the executable path and the error code. For example:

Starting init: /sbin/init exists but couldn't execute it (error -13)

When you get such a message, all you have to do is lookup the error code in include/uapi/asm-generic/errno-base.h or maybe in uapi/asm-generic/errno.h. In the above example, the -13 code meant permission denied, typically because of missing execution rights.

This had been annoying me for a long time, and I am glad that the Linux kernel community accepted my improvement!

By the way, many more improvements to the Linux kernel from Bootlin are currently getting merged in 3.13. See all our contributions to the Linux kernel.

Linux 3.12 released, Bootlin 14th contributor by number of commits

Emperor penguins pictureThe 3.12 kernel has just been released by Linus Torvalds, who summarized what he considers to be the major improvements offered by this release: improvements to the dynamic tick code, support infrastructure for DRM render nodes, TSO sizing and the FQ scheduler in the network layer, support for user namespaces in the XFS filesystem, multithreaded RAID5 in the MD subsystem, offline data deduplication in the Btrfs filesystem.

As usual, Bootlin contributed to the Linux kernel during this cycle, and according to the statistics at KPS, Bootlin is the 14th contributor in terms of number of commits, as a company. Bootlin contributed 185 patches to this kernel release, on a total of 10920 patches. Note that this classification includes the “Unknown” company which ranks first, gathering the contributions from all the contributors that are not known to be affiliated to any company.

The highlights of our contributions are:

  • Addition of support for the HX8369 LCD controller to the driver we had contributed earlier for the HX8357 LCD controller, in drivers/video/backlight/hx8357.c. These LCD controllers are used by the Crystalfontz i.MX28 boards, and this new development was done primarily by Alexandre Belloni.
  • Addition of a driver for the Nuvoton NAU7802 ADC chip on I2C, in drivers/iio/adc/nau7802.c. Some initial work was done by Maxime Ripard, but lots of debugging and additional work was done by Alexandre Belloni, who also pushed the driver to the mainline.
  • Added Device Tree information for the PMU unit on Atmel SAMA5D3 platforms, which allows to use perf on these platforms. Done by Alexandre Belloni.
  • Addition of a Device Tree binding to the mvebu-mbus driver, which controls the configuration of the MBus on Marvell EBU platforms (Armada 370/XP, Kirkwood, Dove, etc.). This binding took a lot of discussion time, and many iterations before reaching a state that was considered acceptable for mainline, but it has finally been merged in 3.12. The core of this work was done by Ezequiel Garcia, with several contributions from Thomas Petazzoni to convert existing platforms to the new APIs.
  • Many cleanups and improvements to the nand_pxa3xx driver, which for the moment is used for the NAND controller on PXA3xx, but that we are currently extending to also cover the NAND controller of Armada 370/XP platforms. In 3.12, only some cleanups have been integrated, and we are currently submitting the more important patches for mainline integration. This work was done by Ezequiel Garcia.
  • Cleanups, and conversion to CLOCKSOURCE_OF_DECLARE of the Armada 370/XP clocksource driver. Done by Ezequiel Garcia.
  • Extension of the Marvell I2C driver to use a new feature of the I2C controller found on Armada 370/XP, which allows to program an entire transaction at once, instead of having interrupts at each step of the transaction. This work was done by Gregory Clement.
  • The quest of removing unneeded ->init_irq() callbacks in machine descriptors continued, with Maxime Ripard removing 4 additional occurrences of this in mach-shmobile.
  • Cleanups and improvements to the sun4i clocksource driver, used on Allwinner SOCs. Done by Maxime Ripard.
  • Introduction of the initial support for the Allwinner A31 SOC and its WITS Columbus evaluation kit, as well as initial support for the Allwinner A20 SOC and the Olimex A20-Olinuxino-Micro and Cubieboard2 board, both based on the Allwinner A20 SOC. This includes clock support, pinctrl support, Ethernet support where applicable, and more. Work done by Maxime Ripard.
  • Michael Opdenacker continued his fight against IRQF_DISABLED and removed more occurrences of them. Michael also fixed a few issues in some Kconfig files.
  • Fixed big-endian issues in the Marvell mvneta Ethernet driver and the Marvell XOR driver, in preparation for the addition of big-endian support to the mach-mvebu platform. Done by Thomas Petazzoni.
  • Conversion of a few more Kirkwood platforms to the Device Tree, and removal of legacy support for other Kirkwood platforms that were already converted to the Device Tree. Done by Thomas Petazzoni.
  • Addition of the support for the Armada XP based AXP-WiFi AP board, from Marvell. Done by Thomas Petazzoni.
  • Improvements of the MSI infrastructure in the kernel: consolidation of code between architectures, addition of a registry of msi_chip. This preparatory work was needed to introduce MSI support for Armada 370/XP, which should hopefully make its way into 3.13. Work done by Thomas Petazzoni.

In details, our contributions were: