[U-Boot] Re-introducing support for OLD hardware

[Jason Mitchell]

Hi there
Thanks for the advice.

The DTP append work-around sounds like a horrible hack that might come to
bite me later, so I am going to rather go with re-introducing SMDK6410 back
into the U-boot and maintain it.
The benefits are then of course that we will be retrofitting something
modern in the field, as opposed to a loader that is 7 years old.

I will clone the current mainline and start investigating how to best
approach this.

Thanks and Regards,
Jason Mitchell

On 12 April 2018 at 16:01, Tom Rini <trini at konsulko.com> wrote:

> On Thu, Apr 12, 2018 at 09:04:20AM +0200, Jason Mitchell wrote:
> > Good day all
> >
> > I am currently faced with a task of having to run new software on ageing
> > hardware. We have currently about 1000 units in the field of a machine
> that
> > runs Windows CE using the Samsung S3C6410.
> >
> > Because these are considerable assets its not a simple case of replacing
> > them with new, more modern hardware.
> >
> > The goal is to be able to get these existing boards to run Ubuntu so that
> > we can run GoLang applications, so we need the GUI with just a relatively
> > recent browser.
> >
> > The board in question is a near perfect clone of the SMDK6410, which was
> > supported fully in U-boot in the past, indeed I can select SMDK6410 and
> > compile a working U-boot using 1.3.4 sources
> >
> > After much effort I managed to get a tailored (tailored as in having
> > changed the memory configuration to match the hardware) U-boot V1.3.4
> > compiled and running for this chip, the problem now, obviously we have a
> > fairly recent Linux kernel compiled and it won't boot because the Device
> > Tree Blob doesn't exist on such an old version of U-boot.
> >
> > So my questions are:
> >
> > - Has anyone perhaps created a branch or fork of the current or nearly
> > current version of U-boot and patched in this support. I see a lot of
> > Chinese websites where they seem to have done this but the language
> barrier
> > is a big problem. Also a lot of dead links are another problem.
> >
> > - If there isn't something out there, would it be possible to run through
> > the steps with me to add support for this CPU again. I don't mind doing
> the
> > work, the main issue is I have no clue how U-boot actually works
> internally.
> >
> > I have FULL JTAG access to this board, with a perfectly functional
> OpenOCD
> > setup. This is how we are able to program versions of U-boot into the
> FLASH.
>
> There's two options:
> 1) You can re-introduce support for the SMDK6410 into mainline U-Boot
> and be an active maintainer of it.  It was removed due to lack of active
> maintainers.
>
> 2) You can, for Linux, use the "appended DTB" work-around to boot a
> modern kernel from an old bootloader.
>
> --
> Tom
>