Thanks Martin,
That information saves me a lot of time, what I was also thinking of doing
is letting the compiler tell me
how to be compatible, this is where ueForth (being in C) can help, for each
C word compile with -S and
see what the assembly listing looks like and compare this to what the
amForth word has and make the adjustments.

Thanks again,
John S

On Tue, Jan 13, 2026 at 8:52 AM Martin Kobetic <[email protected]> wrote:

> Hi John,
> That is a sweet looking board. I need to resist the urge to get one too.
> I've got plenty that I didn't even use yet :).
>
> I'm not that well versed in ARM yet, but the errors sound like the
> instruction mode
> is being switched around for some reason. Maybe we need to ensure somehow
> that
> it sticks with Thumb? There may also be some issue with interworking, I
> haven't quite
> wrapped my head around that either. A lot to do still.
>
> Some interesting references
>
> https://stackoverflow.com/questions/28669905/what-is-the-difference-between-the-arm-thumb-and-thumb-2-instruction-encodings
>
> https://developer.arm.com/documentation/dui0203/j/interworking-arm-and-thumb/about-interworking
>
> Best regards,
> Martin
>
> On Tue, Jan 13, 2026 at 12:40 AM John Sarabacha <[email protected]>
> wrote:
>
> > Hi Martin,
> > The Cortex-M7 doesn't like the assembler instructions for arm/words, some
> > examples:
> > ./words/dup.s:4: Error: Thumb does not support this addressing mode --
> `str
> > tos,[psp,#-4]!'
> > ./words/nip.s:4: Error: instruction not supported in Thumb16 mode --
> `adds
> > psp,#4'
> > ./words/abs.s:4: Error: Thumb does not support conditional execution
> > ./words/abs.s:5: Error: incorrect condition in IT block -- `b DO_NEXT
> >
> > Tried different options for the GCC compiler/assembler without success.
> >
> > FYI
> > John S
> >
> > On Mon, Jan 12, 2026 at 1:13 PM John Sarabacha <[email protected]>
> > wrote:
> >
> > > Hi Martin,
> > > Some information on my Cortex-M7 based target platform, Arduino
> > > development environment is being is used
> > > https://www.pjrc.com/store/teensy41.html
> > >
> > > Regards,
> > > John S
> > >
> > > On Mon, Jan 12, 2026 at 12:04 PM John Sarabacha <[email protected]>
> > > wrote:
> > >
> > >> Hi Martin,
> > >> I will be trying to host amForth on an arm-m7 (600Mhz) platform which
> > was
> > >> being evaluated a few years ago. I will be using the same process as I
> > used
> > >> for CH32X033. Any learning I will pass on, M7 is significantly
> different
> > >> than M4 so by sticking to thumb type instructions there should be some
> > >> common issues.
> > >>
> > >> Regards,
> > >> John S
> > >>
> >
> >
>
> _______________________________________________
> Amforth-devel mailing list for http://amforth.sf.net/
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/amforth-devel
>

_______________________________________________
Amforth-devel mailing list for http://amforth.sf.net/
[email protected]
https://lists.sourceforge.net/lists/listinfo/amforth-devel

Reply via email to