Re: Inspirels Ada on cortex tutorial linker issue

[Devin <devin.inspiredby@gmail.com>]

On Sunday, July 24, 2016 at 9:41:17 AM UTC+2, Simon Wright wrote:
> Devin writes:
> 
> > Yes, after looking at the assembly, I recompiled using:
> > $ gcc -c -mcpu=cortex-m0 -mthumb -mfloat-abi=soft program.adb
> >
> > From the looks of it, the exception handling is added at compile time
> > when making the program.o file?  Would I be able to edit system.ads to
> > turn off exception handling?
> 
> It turns out that it's the .fnstart/.fnend assembler directives.
> 
> It is indeed system.ads that needs changing, but I'd strongly advise not
> editing the installed one (unless you never intend to compile Ada for
> the Pi natively!).
> 
> I've been playing around with my own native system.ads and I can't see
> what needs to be tweaked. However, if I create a minimal runtime system
> using one of the AdaCore-supplied ARM system.ads's
> (ravenscar-sfp-stm32f4/arch, to be exact) the offending asm constructs
> don't appear.
> 
> To create this minimal RTS you need
> * a directory, say rts/
> * containing an empty directory adalib/
> * and a directory adainclude/ containing the system.ads to be used.
> 
> Then compile with this RTS:
> 
>  $ gcc --RTS=rts -c -u -f -mcpu=cortex-m0 -mthumb -mfloat-abi=soft program.adb
> 
> I've put a copy of the RTS I used at
> https://www.dropbox.com/s/iyff5ir5bl41hpd/rts.tar.gz?dl=0
> 
> Hope this works for you!

That got me quite a bit further to getting it running.  I did have to comment out a line:

pragma Restrictions (No_Task_At_Interrupt_Priority);

in order to get it to compile, it causes an error:

fatal error: system.ads is incorrectly formatted
unrecognized or incorrect restrictions pragma: No_Task_At_Interrupt_Priority
compilation abandoned

If I comment the line out, it compiles and links fine (but I can not get openOCD to load the firmware to the Nucleo32).

In openocd I get a warning saying that there are no flash banks found for addresses 10000000 and 10000100 and it says it writes 0 bytes from file program.bin and resets the target.  The Nucleo32 then starts running the same firmware that it shipped with.

Thank you very much for all your help, Simon.