big.LITTLE Processing Update – In-Kernel Switcher vs Global Task Scheduling

big.LITTLE processing is a new technology announced by ARM in 2011 that allows an SoC to feature low power cores (e.g. Cortex A7) together with high performance cores (e.g. Cortex A15) in order to optimize power consumption. I’ve previously detailed two big.LITTLE software implementation methods: In-kernel switcher which runs tasks on either Cortex A7 or Cortex A15 depending on the load, but both processors can not run simultaneously. Heterogeneous multiprocessing (now called Global Task Scheduling) that assigns tasks to relevant Cortex A7 or Cortex A15 cores, and if needed, allows all cores to run at the same time. Linaro has just provided a update for the big.LITTLE software implementation. There are currently only two SoCs that ship in products with Linaro b.L kernel support: ARM’s reference Test Chip 2 (TC2) tile for the Versatile Express development platform, configured as an SoC with 2 Cortex-A15 cores and 3 Cortex-A7 cores. Samsung-LSI’s […]

Linux Kernel 3.10 Released

Linus Torvalds has announced the release of Linux Kernel 3.10: So I delayed this by a day, considering whether to do another -rc, but decided that there wasn’t enough upside. Sure, it hasn’t been as quiet as I’d like, and we had this long discussion about an inode list locking scalability issue over the last week or two, but in the end that issue turned out to not be new, and while we may end up back-porting the eventual resolution to 3.10, it wasn’t a reason to delay the release. Similarly, while I might wish for fewer pull requests during the late rc’s (and particularly the ones that came in Friday evening -inconvenient for a weekend release), at some point delaying things doesn’t really help things, and just makes the pent up demand for the next merge window worse. In other words, I could really have gone either way, but […]

Linaro 13.06 Release With Linux Kernel 3.10 and Android 4.2.2

Linaro 13.06 has been released with Linux Kernel 3.10-rc6 and Android 4.2.2. Linux Linaro Stable (LSK) preview is based on kernel 3.9.6. There seems to have been a lot of activity for the LAVA and Builds and Integration teams, with LAVA support for new SoC such as Huawei K3V2 and Broadcom Capri from 2 companies which have recently joined Linaro as members, and well as continuous build for Linaro Stable Kernel. On the kernel side, more work has been done for multi-platform support (unified kernel), uprobes, eMMC power mamangement, and more. Here are the highlights of this release: LAVA LAVA Core As part of the effort to improve the developer experience with LAVA, the different client tools were consolidated into a single package, which simplifies the process of updating the tools and makes it easier for the team to provide new features for LAVA users. LAVA now supports KVM devices, […]

Linaro 13.05 Release With Linux Kernel 3.10, Android 4.2.2, and Ubuntu Raring Ringtail

Linaro 13.05 has just been released with Linux Kernel 3.10-rc2 and Android 4.2.2. This is the first release with Ubuntu 13.04 (Raring Ringtail) images. There’s also Linux Linaro Stable (LSK) preview based on kernel 3.9.4. BeagleBone Black support has been added and preliminary hwpack and images are available, an Android Arndale image with virtual framebuffer is also available. You can now get a desktop environment (XFCE) on Aarch64 / ARMv8. Hardware packs with Real-time Linux kernel (PREEMPT_RT) can be downloaded for Pandaboard and Arndale. More work has gone into Aarch64, big.LITTLE HMP, and ARM virtualization (KVM). Finally an UEFI is available not only for Vexpress boards, but also Samsung Origen and Arndale boards, as well as Texas Instruments Pandabord and Beagleboard. Here are the highlights of this release: LAVA First prototype production run of LAVA Lmp completed, tested functional. Beaglebone Black is now running in LAVA. TC2s is now running […]

$40 SunnyCube V7 Tablet Powered by WonderMedia WM8880 Dual Core SoC

There’s a war going on in China at this very moment, a war fought between Chinese tablet SoC manufacturers to get the cheapest dual core tablet on the market, and according to diverse reports, it seems VIA Wondermedia may have won a battle with WM8880 dual core SoC, as the upcoming SunnyCube V7 tablet will sell for 249 RMB (About $40 US), just 20 RMB (~$3) more than AllWinner A13 based tablets. The rest of the world should be able to get it for about $50 – $55 from websites such as Aliexpress, after paying for “free” shipping. SunnyCube V7 Specifications: SoC – VIA WM8880 Dual core Cortex A9 processor @ 1.5GHz + Mali-400 MP2 GPU System Memory – 512MB RAM Storage – 4GB Flash Display – 7-inch WVGA (800×480) display Video Playback – H.264, WMV, MPEG2/4, VP8 (up to 1080p) Camera – Front and rear cameras Battery – Unknown […]

Linaro Releases IKS big.LITTLE Implementation Source Code

Yesterday, Linaro announced the released of the IKS (In-kernel switcher) implementation for big.LITTLE processor which allows the SoC to switch between individual Cortex A7 or Cortex A15 cores to optimize power consumption. Currently, the only consumer device using supporting big.LITTLE the Samsung Galaxy S4 thanks to Samsung Exynos 5 Octa featuring 4 ARM Cortex A7 and 4 ARM Cortex A15 cores. IKS implementation can only make use of 4 cores at a time in this processor, since it must choose between A7 or A15 depending on the load. HMP (Heteregenous Multi-Processing) implementation is currently worked on in order to be able to use all 8 cores, and distributes tasks to the right core for the job. You can read my previous post for differences between IKS and HMP. Linaro explains the current source still needs a few more modifications before being upstream to mainline. The code was developed for and […]

Linaro 13.04 Release With Linux Kernel 3.9 and Android 4.2.2

Linaro 13.04 has just been released. It features Linux Kernel 3.9-rc7 and Android 4.2.2. A lot of work has been done on ARMv8 (Cortex A53) with further work on OpenEmbedded, more testing, and updates to the GCC toolchain. Calxeda EnergyCore server has been added to LAVA, Origen Quad now gets hardware video acceleration in Android Jelly Bean. Still more cleanup has been done on the kernel side with regards to Samsung and ST SoC, and a big.LITTLE porting guide is now available (linaro login required). Here are the highlights of this release: LAVA Prototype of a new publishing system is used to overcome performance problems with android-build.linaro.org. Calxeda EnergyCore support is merged in LAVA, and an isolated system has been set up for web benchmarking. Fedora support is merged in LAVA. A user can submit LAVA jobs using a Fedora pre-built image. Boot commands are untangled from LAVA dispatcher. They’re now […]

Linaro 13.03 Release with Linux Kernel 3.9 and Android 4.2.2

Linaro 13.03 is now available, and features Linux Kernel 3.9-rc3 and Android 4.2.2. This month, Linaro has released their first Origen Quad Android image, as well as Tiny Android build for Arndale. The ALIP image listed in the download page is still based on Ubuntu 12.11, but as doc Bormental noticed earlier this month, the latest ALIP Quantal 13.03 image is available for download at https://releases.linaro.org/latest/ubuntu/quantal-images/alip. Some development tools (gcc, g++, vi, make..) are now included in Android, so you can develop and build natively from your Android device. Linaro has kept on cleaning the Linux kernel ARM tree for Exynos and ST Ericson SoCs. More work has been done on big.LITTLE for both IKS and HMP, as well as ARMv8 OpenEmbedded, and an initial GRUB port on ARM UEFI is now available. Here are the highlights of this release: Automation and Validation A simple CLI tool for communicating with […]