Support 'delay until Real_Time.Time_Last'.

  * common/a-reatim.ads (FreeRTOS_Tick): New.
    (Time): Limit range to what's possible with the underlying 32-bit
      FreeRTOS clock.
    (Time_First): Revert to Time'First.
  * common/a-retide.adb (Delay_Until): Rework.

  * test-arduino-due/testbed.adb: End with delay until Time_Last.
  * test-stm32f4/testbed.adb: Likewise.
  * test-stm32f429i/testbed.adb: Likewise.

common/a-reatim.ads

@@ -33,6 +33,8 @@
 -- --
 ------------------------------------------------------------------------------
 
+-- Modified from GCC 4.9.1, then GCC 7.1.0, for Cortex GNAT RTS.
+
 package Ada.Real_Time with
  SPARK_Mode,
  Abstract_State => (Clock_Time with Synchronous,
@@ -149,9 +151,13 @@ private
  -- Replaces Duration, which has a different representation on
  -- systems with 32-bit Duration.
 
- type Time is new Time_Base;
+ FreeRTOS_Tick : constant := 0.001;
+ -- FreeRTOSConfig.h has set configTICK_RATE_HZ to 1000
+
+ type Time is new Time_Base range 0.0 .. (2 ** 32 - 1) * FreeRTOS_Tick;
+ -- and configUSE_16_BIT_TICKS to 0 (so we get 32-bit clock values).
 
- Time_First : constant Time := 0.0;
+ Time_First : constant Time := Time'First;
 
  Time_Last : constant Time := Time'Last;
 

common/a-retide.adb

@@ -6,7 +6,7 @@
 -- --
 -- B o d y --
 -- --
---  Copyright (C) 1992-2010, 2016, Free Software Foundation, Inc.  --
+-- Copyright (C) 1992-2010, 2016-2017, Free Software Foundation, Inc. --
 -- --
 -- GNARL is free software; you can redistribute it and/or modify it under --
 -- terms of the GNU General Public License as published by the Free Soft- --
@@ -29,6 +29,8 @@
 -- --
 ------------------------------------------------------------------------------
 
+-- Modified from GCC 4.9.1 for Cortex GNAT RTS.
+
 with Interfaces;
 
 package body Ada.Real_Time.Delays is
@@ -40,12 +42,14 @@ package body Ada.Real_Time.Delays is
  Convention => C,
  External_Name => "vTaskDelay";
  Timespan_To_Delay : constant Time_Span := T - Clock;
- -- ??? need to round, see ARM
- Ticks_To_Delay : constant Integer := Timespan_To_Delay / Tick;
  begin
- if Ticks_To_Delay > 0 then
+ if Timespan_To_Delay > 0.0 then
+ -- Need to avoid problems with ambiguity; and the version in
+ -- Real_Time returns Integer, whereas we actually want
+ -- Unsigned_32.
  vTaskDelay
- (Ticks_To_Delay => Interfaces.Unsigned_32 (Ticks_To_Delay));
+ (Interfaces.Unsigned_32
+ (Standard."/" (Timespan_To_Delay, Tick)));
  end if;
  end Delay_Until;
 

test-arduino-due/testbed.adb

@@ -111,11 +111,5 @@ begin
  -- Check streams
  Streams.Check (42);
 
- declare
- use type Ada.Real_Time.Time;
- begin
- loop
- delay until Ada.Real_Time.Clock + Ada.Real_Time.Seconds (10);
- end loop;
- end;
+ delay until Ada.Real_Time.Time_Last;
 end Testbed;

test-stm32f4/testbed.adb

@@ -108,11 +108,5 @@ begin
  -- Check streams
  Streams.Check (42);
 
- declare
- use type Ada.Real_Time.Time;
- begin
- loop
- delay until Ada.Real_Time.Clock + Ada.Real_Time.Seconds (10);
- end loop;
- end;
+ delay until Ada.Real_Time.Time_Last;
 end Testbed;

test-stm32f429i/testbed.adb

@@ -108,11 +108,5 @@ begin
  -- Check streams
  Streams.Check (42);
 
- declare
- use type Ada.Real_Time.Time;
- begin
- loop
- delay until Ada.Real_Time.Clock + Ada.Real_Time.Seconds (10);
- end loop;
- end;
+ delay until Ada.Real_Time.Time_Last;
 end Testbed;