Nearly 2 years ago, the Linux Foundation’s Consumer Electronics (CE) working group created the Long Term Support Initiative (LTSI) Linux kernel for consumer electronics devices in order to have a common stable platform released every 2 years, and share the kernel development work among competing companies including Hitachi, LG Electronics, NEC, Panasonic, Qualcomm Atheros, Renesas Electronics Corporation, Samsung Electronics, Sony and Toshiba.
Last week, the CE working group has released LTSI 3.4 kernel, based on Linux 3.4.25 kernel release and including several backported features from newer kernels including:
- 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 the kernel.org releases and those fixes have been added to the LTSI 3.4 kernel release. 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.org release. For more information about it, please see this LWN.net post.
This release also includes patches for specific board / processor support:
- Armadillo 800 board – Based on Renesas R-Mobile A1 processor
- AT91 – Patches for Atmel SoCs (ARM9)
- kzm9d platform – Based on Renesas Emma Mobile EV2 SoC
- kzm9g platform – Based on Renesas R-Mobile APE5R processor (Board: KMZ-A9-GT)
- Marzen development board – Based on Renesas R-Car H1 (Quad Cortex A9 @ 1GHz + IMG SGX543MP2 GPU) automotive processor