Part of supporting the demand for Linux in consumer electronics is ensuring there is a common Linux base that is maintained and supported for the typical lifetime of a consumer device, usually two years, and that supports a large variety of consumer electronics products. The Linux kernel is released at such a rapid pace that until now, device makers were doing significant back-porting, bug testing and driver development on their own, which carried substantial cost in terms of time-to-market, as well as development and engineering effort to maintain those custom kernels.
The Linux Foundation’s Consumer Electronics (CE) workgroup founded the Long Term Support Initiative (LTSI) to address this issue collaboratively. Today, the project provides for both an annual release of a Linux kernel suitable for supporting the lifespan of consumer electronics products and regular updates of those releases for two years. Linux kernel maintainer Greg Kroah-Hartman oversees this maintenance and the LTSI kernel tree for this industry-wide project created and supported by Hitachi, LG Electronics, NEC, Panasonic, Qualcomm Atheros, Renesas Electronics Corporation, Samsung Electronics, Sony and Toshiba.
This week the CE working group is releasing the LTSI 3.4 kernel. It is based on the Linux 3.4.25 kernel release and includes a number of backported features from newer releases.
Highlights from today’s release include:
* The Contiguous Memory Allocator (CMA), which is extremely useful for embedded devices that have very limited hardware resources and will better handle the large memory requirements of multimedia applications. CMA originally was merged into the 3.4.0 kernel release, but its functionality was quite limited. Since then, the feature has been significantly improved in thekernel.orgreleases and those fixes have been added to the LTSI 3.4 kernelrelease. For more information about this kernel option, please visit LWN.net.
* AF_BUS, a kernel-based implementation of the D-Bus protocol. This feature was created for systems that required a faster D-Bus speed than the existing userspace method could provide, specifically the automotive entertainment systems. For more information about this feature, please see LWN.net.
* CoDel (controlled delay), a transmission algorithm that optimizes TCP/IP network buffer control, is backported for LTSI 3.4. This is a feature used to help control the “buffer bloat” problem that has been identified by the networking community as an issue that all devices need to be aware of. This feature was backported from the 3.5.0 kernel.orgrelease. For more information about it, please see this LWN.net post.
Platform specific board support was backported from newer kernel versions, allowing the Armadillo 800, AT91, kzm9d, kzm9g, and Marzen platforms to work properly with this release.
For more information about LTSI and the latest release, please visit the LTSI website.