Free Electrons at the Linux Plumbers 2017 conference

The Linux Plumbers conference has established itself as a major conference in the Linux ecosystem, discussing numerous aspects of the low-level layers of the Linux software stack. Linux Plumbers is organized around a number of micro-conferences, plus a number of more regular talks.

Linux Plumbers 2017

Free Electrons already participated to several previous editions of Linux Plumbers, and will again participate to this year’s edition that takes place in Los Angeles on September 13-15. Free Electrons engineers Boris Brezillon, Alexandre Belloni, Grégory Clement and Thomas Petazzoni will attend the conference.

If you’re attending this conference, or are located in the Los Angeles area, and want to meet us, do not hesitate to drop us a line at info@free-electrons.com. You can also follow Free Electrons Twitter feed for updates during the conference.

Free Electrons at Embedded and Kernel Recipes 2017

Kernel RecipesEmbedded RecipesThe Kernel Recipes conference has become over the last few years a very interesting conference, with an original single track format and a limited number of attendees, which fosters communication and networking. Held in Paris, France, it is obviously a conference of choice for Free Electrons engineers to attend and speak at. We participated to multiple editions, Free Electrons engineer Maxime Ripard gave a talk at the 2014 edition, while Thomas Petazzoni gave a talk at the 2013 edition.

In 2017, the organizers decided to complement the 3-day Kernel Recipes conference with a 1-day Embedded Recipes event, and Free Electrons will participate by having two engineers attend those events and give talks:

  • Mylène Josserand will give an Introduction to Yocto Project and OpenEmbedded during the Embedded Recipes event
  • Maxime Ripard will give an Introduction to the Linux DRM subsystem during the Kernel Recipes event

If you’re interested in attending one of those events, make sure to register on time, there are only 100 seats available!

Updated bleeding edge toolchains on toolchains.free-electrons.com

Two months ago, we announced a new service from Free Electrons: free and ready-to-use Linux cross-compilation toolchains, for a large number of architectures and C libraries, available at http://toolchains.free-electrons.com/.

Bleeding edge toolchain updates

All our bleeding edge toolchains have been updated, with the latest version of the toolchain components:

  • gcc 7.2.0, which was released 2 days ago
  • glibc 2.26, which was released 2 weeks ago
  • binutils 2.29
  • gdb 8.0

Those bleeding edge toolchains are now based on Buildroot 2017.08-rc2, which brings a nice improvement: the host tools (gcc, binutils, etc.) are no longer linked statically against gmp, mpfr and other host libraries. They are dynamically linked against them with an appropriate rpath encoded into the gcc and binutils binaries to find those shared libraries regardless of the installation location of the toolchain.

However, due to gdb 8.0 requiring a C++11 compiler on the host machine (at least gcc 4.8), our bleeding edge toolchains are now built in a Debian Jessie system instead of Debian Squeeze, which means that at least glibc 2.14 is needed on the host system to use them.

The only toolchains for which the tests are not successful are the MIPS64R6 toolchains, due to the Linux kernel not building properly for this architecture with gcc 7.x. This issue has already been reported upstream.

Stable toolchain updates

We haven’t changed the component versions of our stable toolchains, but we made a number of fixes to them:

  • The armv7m and m68k-coldfire toolchains have been rebuilt with a fixed version of elf2flt that makes the toolchain linker directly usable. This fixes building the Linux kernel using those toolchains.
  • The mips32r5 toolchain has been rebuilt with NaN 2008 encoding (instead of NaN legacy), which makes the resulting userspace binaries actually executable by the Linux kernel, which expects NaN 2008 encoding on mips32r5 by default.
  • Most mips toolchains for musl have been rebuilt, with Buildroot fixes for the creation of the dynamic linker symbolic link. This has no effect on the toolchain itself, but also the tests under Qemu to work properly and validate the toolchains.

Other improvements

We made a number of small improvements to the toolchains.free-electrons.com site:

  • Each architecture now has a page that lists all toolchain versions available. This allows to easily find a toolchain that matches your requirements (in terms of gcc version, kernel headers version, etc.). See All aarch64 toolchains for an example.
  • We added a FAQ as well as a news page.

As usual, we welcome feedback about our toolchains, either on our bug tracker or by mail at info@free-electrons.com.