Re: [PATCH V2 22/22] MIPS: Add multiplatform BMIPS target

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On Mon, Nov 17, 2014 at 1:16 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> I still think this is different in the sense that ARM multiplatform
> support is about combining platforms from separate mach-* directories,
> while your approach was to rewrite multiple mach-* directories into
> a single new one that remains separate from the others. While this is
> a great improvement, it doesn't get you any closer to having a
> combined BMIPS+RALINK+JZ4740+ATH79 kernel for instance. I don't know
> if such a kernel is something that anybody wants, or if it's even
> technically possible.
>
> If you wanted to do that however, starting with BMIPS you'd have
> to make it possible to define a new platform without the
> arch/mips/include/asm/mach-bmips/ directory (this should be possible
> already, so the hardest part is done), replace all global function
> calls (arch_init_irq, prom_init, get_system_type,  ...) with generic
> platform-independent implementations or wrappers around per-platform
> callbacks, and move the Kconfig section for CONFIG_BMIPS_MULTIPLATFORM
> outside of the "System type" choice statement.
> Until you do that, your platform isn't "more multipliplatform" than
> the others really, it just abstracts the differences between some
> SoCs nicer than most.

I guess a big blocker for such a real mips multiplatform kernel is
that there is still no defined (standard) interface for passing a
device tree to the kernel from the bootlader on mips, unlike on arm
(at least I'm not aware of any). And unless there is one, having a
multiplatform kernel does not make much sense, as there is no sane way
to tell apart different platforms on boot. But maybe we should just
define a way, and require new platforms to use it ;-)


Jonas
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux