Re: [PATCH 03/18] MIPS: add generic support for multiple machines within a single kernel

[Felix Fietkau <nbd@openwrt.org>]

On 2010-11-23 7:51 PM, Gabor Juhos wrote:
> Hi Arnaud,
> 
>> On Tue, Nov 23, 2010 at 10:06 AM, Gabor Juhos <juhosg@openwrt.org> wrote:
>>> This patch adds a generic solution to support multiple machines based on
>>> a given SoC within a single kernel image. It is implemented already for
>>> several other architectures but MIPS has no generic support for that yet.
>>>
>> Is this the way `arch/mips' wants to go to support multiple machine
>> within a same kernel image ? 
> 
> I don't know yet what will be the chosen way.
> 
>> Flattened Device Tree is the other way to achieve that. I remind the latter
>> being proposed by Felix Fietkau on #openwrt.
> 
> FDT makes sense when the bootloader supports that. FDT makes sense when the
> bootloader supports that, but i'm not aware of any AR71xx/AR724x/AR913x based
> board which has such bootloader. Additionally, the device-tree support for 
> MIPS
> has been added only recently and none of the existing MIPS boards are using 
> that
> yet AFAIK. If that will be widely used we can consider to switch to that 
> later.
We don't need boot loader support, we can make a simple loader stub that
passes the FDT data to the kernel. It would certainly be better than our
current cmdline hack ;)
I think using FDT would save us a lot of maintenance work, as we
wouldn't have to change the kernel for every single new board that we
add support for.

- Felix