[PATCH 2/3] m68k: Add support for M68040 CPU

[Kuan-Wei Chiu]

Hi Tom,

On Thu, Dec 18, 2025 at 01:00:32PM -0600, Tom Rini wrote:
> On Thu, Dec 18, 2025 at 06:52:51PM +0000, Kuan-Wei Chiu wrote:
> > Add support for the Motorola 68040 architecture. Currently, m68k
> > support in U-Boot is primarily focused on ColdFire (MCF5xxx) variants.
> > Introduce the necessary infrastructure to support the classic M680x0
> > series, specifically targeting the M68040 as emulated by QEMU.
> > 
> > The implementation includes exception vectors, early startup code, and
> > minimal CPU initialization and relocation stubs. It also defines the
> > standard m68k boot information structure used for passing hardware
> > information to the operating system. To ensure compatibility, ColdFire-
> > specific library objects such as cache and interrupt handling are
> > excluded from the build when M68040 is selected.
> > 
> > Additionally, apply a specific workaround during the early memory
> > reservation stage. Use a manual loop to clear global data instead of
> > the standard memset() function, as utilizing memset() at this point was
> > observed to cause a hang on the QEMU platform.
> > 
> > Signed-off-by: Kuan-Wei Chiu <visitorckw at gmail.com>
> [snip]
> > diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
> > index 8ade6f7b9d1..a41c375f6be 100644
> > --- a/arch/m68k/Kconfig
> > +++ b/arch/m68k/Kconfig
> > @@ -56,6 +56,9 @@ config MCF5441x
> >          select DM_SERIAL
> >  	bool
> >  
> > +config M68040
> > +    bool
> > +
> 
> The file is unfortunately inconsistent about tabs vs spaces, but all the
> new options should be tab-indent only, and no extra blank lines added.

I'll fix this in v2.

BTW, do you think it would be helpful to add a check in checkpatch.pl
to warn about space indentation in Kconfig files?

Regards,
Kuan-Wei