Re: Device trees and armv5

[Jason Thorpe <thorpej%me.com@localhost>]

> On Sep 4, 2025, at 5:41 AM, Jonathan A. Kollasch <jakllsch%kollasch.net@localhost> wrote:
> 
> No technical reason; we just haven't hand any ARMv5 SoCs added since we
> started using device trees.

Indeed, I’ve been interested in converting existing legacy evbarm to device trees, as well (I sure wish I still had the boards, sigh).  So, I 100% support the idea of using the device tree mechanism for this.

>> Also, what is the preferred way to add support for a new system: Fixing device trees so GENERIC also works with armv5, 
>> or adding a new set of kernel configuration files specific to the EV3 to arch/evbarm/conf?
>> 
> 
> Ideally it should be part of GENERIC.

While I agree, I think it comes with a caveat — I am not 100% certain that you’ll be able to boot a built-for-armv6 GENERIC on an armv5 system.  Maybe it’ll be OK if the early bootstrap code can diverge early enough to avoid armv6-isms.  But you’ll also want to double-check that GCC doesn’t emit code for the armv6 configuration that won’t run on armv5.

(Sorry for being vague about this… it’s been an awfully long time since I thought about any of this.)

-- thorpej