Re: STM32F4 GNAT Run Time System - roadmap

[jan.de.kruyf@gmail.com]

On Tuesday, June 9, 2015 at 2:02:25 PM UTC+2, Simon Wright wrote:
> Looking for some input on priorities for work.
> 
> * Standard library packages.
> * Other MCUs.
> * Finalization.
> * ?
> 
> Standard library packages
> -------------------------
> 
> An obvious omission is the rest of the Ada.Containers.Bounded* packages:
>   Doubly_Linked_Lists
>   Ordered_Maps
>   Hashed_Sets
>   Ordered_Sets
>   Multiway_Trees
>   Synchronized_Queues
>   Priority_Queues
> 
> Any other nice-to-haves? (I haven't looked at Annex G, might be
> problematic!)
> 
> Other MCUs
> ----------
> 
> STM have just released a significant number of affordable Nucleo
> development kits. The NUCLEO-F091RC has 48 MHz Cortex-M0 core, 256-KB
> Flash, 32-KB SRAM, which would just-about take my current testbed
> program; for the princely sum of UKP7.94 + p&p, 88 in stock in UK for
> next day delivery from Farnell[0].
> 
> The problem with this is that different MCUs require different compiler
> options, and building GCC for ARM with multilibs is only supported in
> the ARM fork at [1]; so far there are only GCC 4.9-based releases. GCC
> 4.9 is a perfectly competent compiler, of course.
> 
> Finalization
> ------------
> 
> It would be very nice to be able to use the generalized container
> iterators of Ada 2012 (generalized array iterators are already OK).
> 
> They require finalization: I've implemented finalization and generalized
> iteration over Bounded_Vectors in the 'finalization' branch at [2].
> 
> Unfortunately, adding finalization to a restricted runtime triggers bugs
> in GCC.
> 
> I've raised two GCC PRs; "gnatbind generates invalid code when
> finalization is enabled in restricted runtime"[3], and "Front-end error
> if exception propagation disabled"[4].
> 
> =====================================================================
> [0] http://uk.farnell.com/stm32-mcu-nucleo-board-flexible-prototyping
> [1] https://launchpad.net/gcc-arm-embedded
> [2]
> https://sourceforge.net/p/stm32f4-gnat-rts/code/ci/finalization/tree/
> [3] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66205
> [4] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66242

Good Morning Simon,
Here is a b-xxx.adb with 'Suppress_Standard_Library_On'
-----------------------

pragma Ada_95;
pragma Source_File_Name (ada_main, Spec_File_Name => "b~demo.ads");
pragma Source_File_Name (ada_main, Body_File_Name => "b~demo.adb");

package body ada_main is
   pragma Warnings (Off);

   E03 : Short_Integer; pragma Import (Ada, E03, "last_chance_handler_E");
   E05 : Short_Integer; pragma Import (Ada, E05, "linux_kernel_E");
   E19 : Short_Integer; pragma Import (Ada, E19, "niniel_E");
   E26 : Short_Integer; pragma Import (Ada, E26, "niniel__ioctl_E");
   E30 : Short_Integer; pragma Import (Ada, E30, "secondary_stack_E");


   procedure adainit is
   begin
      null;

      E05 := E05 + 1;
      E03 := E03 + 1;
      if E19 = 0 then
         Niniel'Elab_Body;
      end if;
      E19 := E19 + 1;
      if E26 = 0 then
         Niniel.Ioctl'Elab_Body;
      end if;
      E26 := E26 + 1;
      E30 := E30 + 1;
   end adainit;

end ada_main;

-------------------------------------

All the quoted strings are my own stuff. Since I cannot use any standard library in kernel programming.
 j.