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Linux 3.7 kernel to support multiple ARM platforms

morgaine

Interesting progress on the Linux kernel front for ARM platforms, which have traditionally needed a hotch potch of different kernels -- linux-37-kernel-to-support-multiple-arm-platforms .

 

From the article linked by Slashdot, "The initial 3.7 image will support highbank, vexpress, mvebu, socfpga, and picoxcell", so it doesn't sound like it's directly relevant to Raspberry Pi just yet.  Hopefully it gets us one step closer to uniform ARM support though.

  • What makes this even more intriguing is this comment:

     

    "Up until now there has been a separate Linux kernel build for each of the ARM platforms or SoCs, which is one of the several problems when it comes to ARM based Linux. The merging of ARM multi-platform support into Linux 3.7 will put an end to this problem, enabling the new kernel to not only target multiple platforms but also be more in line with its x86 counterpart."

  • in reply to GeorgeIoak

    all we're really talking about here is 'device tree' though. Comparing to x86 isn't really fair as x86 has had a relatively narrow definition historically, mainly to retain backward compatibility with the earliest of PC's. These days ACPI bridges the gaps and gives you some sort of hardware description (despite ACPI's flaws).

    Arm doesn't have that particular mechanism or history. Devicetree basically does the fill-in-the-gaps piece and provides a standard way to describe the hardware. At which point multi-platform is easy, you just read the devicetree and load the necessary drivers - one of which would be the currently compile time selected base board.

    You'll likely still need a different kernel if you want to take advantage of a Cortex A15 vs the Pi's ARM11 and that kernel probably won't run on the Pi. Not that x86 is any different in this respect, a Corei7 kernel probably won't run on a 386.

     

    It'll largely only matter to the distros anyway, they're the ones that want to build one-size-fits-nothing kernels. Arm is still specialised enough that people will still be building custom kernels for some time yet.

    This may change with windows 8 supporting Arm and driving some standardisation (and probably ACPI) into this space.