Linux mainline work
Work progresses at a steady pace on integraton of rk devices into mainline kernels. A lot of the work is coming from rockchip staff, particularly for the rk3288 target, but that is resulting in lots of rk30 and rk31 boards getting better and better support along the way. Much work still remains.
Mmind's linux-rockchip (Google mirror ) is one of the repositories of interest, particularly the "devel/workbench" branch, which contains some of the latest and greatest rockchip patches, collected into a tree before they are merged upstream. This branch _will_ have turbulence and rebasing to keep it up to date, but it's a good starting point.
Radxa Rock configuration and howto for building mainline kernel+dtb http://radxa.com/Rock/Linux_Mainline
Linux 4.x (Rockchip Linaro SDK)
Rockchip have released a kernel in Github.
Linux 3.0.x (Stock android style kernels)
You will need appropriate toolchain gcc for crosscompiling the linux 3.0.x sources. gcc up to 4.6.2 should work for rk29xx sources and gcc up to 4.4.4 should work for rk30xx/31xx sources. gcc 4.6.3 from Ubuntu 12.04 seems to work also. Unfortunately not all available toolchains work under all Linux systems.
Linux on Rockchip devices has no configuration mechanism.
The layout of your board - eg. what peripherial is connected to which pin - is stored in arch/arm/mach-rk??/board-*.c
There should be also corresponding arch/arm/configs/*_defconfig
To build a kernel for your device you need to find a repo which has the correct board file. This is specially important for tablets which have different screen resolution, different peripherials, etc.
|Repo||JB 4.2.x SDK||KK 4.4.x SDK||Versions||Devices||Notes|
|x||x||3.10.30, 3.0.36||?|| 3.0.x originally used for Radxa/Ubuntu effort|
3.10 branches and master follow current Rockchip work
|Dee-UK||x||3.0.36||?||from Rockchip KitKat beta|
|HenrikNilsson||x||x||3.0.36||?||phjanderson fork for 4.2.x case|
|Galland||3.0.36||RK3188 stick Cozyswan S400||originally for Picuntu effort|
|alok sinha2001||3.0.36, 3.0.8||? 3188||originally for Picuntu effort|
|mark.sch||3.0.36+||QC802||ethernet with DHCP working, stable with Debian Wheezy 7.6|
|omegamoon||x||3.0.101||MK808 (RK3066) and MK908 (RK3188) TV sticks||with backports from linux-sunxi 3.4.x|
|phjanderson||3.0.36||Neo X7|| rkpatchomatic OC tool,|
marvin android build tool,
|crewrktablets||?||?||?||Odys Loox, Xpress, Next, NEO X8, NEO X7, BQ-Kepler2, BQ-Pascal2, Arnova AN8CG3, M820c3G, Hyundai H900, Meying M11HD|
|vurrut||?||?||?||BQ-Pascal and others|
|joaquimorg||?||?||?||BQ-Pascal2 and others|
Rockchip kernel source 1080p fix
Unfortunately all kernel souce code snapshots released up to the current date (Aug 2013) contain a display bug that disables 1080p resolution on most PC monitors, due to an outdated parsing of the EDID (the monitor capabilities information).
This bug was patched long ago in the Linux kernel but needs to be applied to any source code released by Rockchip to ensure 1080p on all modern PC displays.
For reference, see the patch to RK kernel.