[PATCH] arm: Backward compatibility to U-Boot v2020.04

[Dorde Stojicevic]

Hi all,

sorry that it took a while to get the response from Lynx but it couldn´t be helped unfortunately.

I got the response from Lynx:

" Hello Dorde.

I’ve got a replay from our engineering team. We do not support u-boot, so we don’t have any plans to make SRP “ARM64 kernel“ compatible.

We work with board with default u-boot (for now it is U-Boot SPL 2020.04).

So, you are free to make any changes in u-boot to make SRP run in newest version of u-boot.
"

I am a bit surprised by the response that they don´t seem really interested in it, but it is how it is. So we are free to apply the patch to our liking.

Let me know how we proceed from here
Dorde


Dorde Stojicevic

Networks and Cybersecurity

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-----Original Message-----
From: Stojicevic Dorde (11SIEPT1) 
Sent: Friday, February 6, 2026 4:17 PM
To: 'Tom Rini' <trini at konsulko.com>
Cc: Quentin Schulz <quentin.schulz at cherry.de>; u-boot at lists.denx.de
Subject: RE: *EXT* Re: Re: Re: [PATCH] arm: Backward compatibility to U-Boot v2020.04 ***CAUTION_Invalid_Signature***

Nice. 😊

From what I know, Lynx wanted the "feature" of being able to impersonate Linux, so once it´s builtin between real OS and U-Boot, it is a no-brainer with "nothing to be changed".

But it seems like that detection in U-Boot was not working properly, then Lynx built on top (unaware of the check that needed to be inplace), and then I came with my "quick´n´dirty" solution. 😊

Maybe the really-proper-solution would be that Lynx just does the complete proper impersonation of Linux, if that is what they really want as a feature. But to clarify this, we would need some one from their side. I have contact with them, should I establish a trilateral talk on this topic?

Greetings and nice weekend
Dorde

-----Original Message-----
From: Tom Rini <trini at konsulko.com> 
Sent: Friday, February 6, 2026 4:04 PM
To: Stojicevic Dorde (11SIEPT1) <dorde.stojicevic at rohde-schwarz.com>
Cc: Quentin Schulz <quentin.schulz at cherry.de>; u-boot at lists.denx.de
Subject: *EXT* Re: Re: Re: [PATCH] arm: Backward compatibility to U-Boot v2020.04 ***CAUTION_Invalid_Signature***

On Fri, Feb 06, 2026 at 06:28:39AM +0000, Dorde Stojicevic wrote:
> Hi,
> 
> yes of course.
> 
> Here it is:
> 
> $ mkimage -l build/ed7ct-cb.srp
> FIT description: LynxSecure 2025.10.0-39844b80e0 SRP (aarch64)
> Created:         Thu Feb  5 13:58:31 2026
>  Image 0 (kernel-1)
>   Description:  LynxSecure 2025.10.0-39844b80e0 SRP (aarch64)
>   Created:      Thu Feb  5 13:58:31 2026
>   Type:         Kernel Image
>   Compression:  uncompressed
>   Data Size:    262512264 Bytes = 256359.63 KiB = 250.35 MiB
>   Architecture: AArch64
>   OS:           Linux

So, we're getting somewhere. It seems like before our validation check wasn't working and so claiming to be Linux, but not being Linux, wasn't caught and failed. The right path here is to add IH_OS_LYNXSECURE to include/image.h and handling of it in the various boot/ files that need it. Then the its should have 'os = "lynxsecure"' so that it sets that field correctly.

--
Tom
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