File : system-pikeos-x86.ads


   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                        GNAT RUN-TIME COMPONENTS                          --
   4 --                                                                          --
   5 --                               S Y S T E M                                --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                       (PikeOS x86/32 zfp Version)                        --
   9 --                                                                          --
  10 --          Copyright (C) 1992-2016, Free Software Foundation, Inc.         --
  11 --                                                                          --
  12 -- This specification is derived from the Ada Reference Manual for use with --
  13 -- GNAT. The copyright notice above, and the license provisions that follow --
  14 -- apply solely to the  contents of the part following the private keyword. --
  15 --                                                                          --
  16 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  17 -- terms of the  GNU General Public License as published  by the Free Soft- --
  18 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  19 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  20 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  21 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  22 --                                                                          --
  23 --                                                                          --
  24 --                                                                          --
  25 --                                                                          --
  26 --                                                                          --
  27 -- You should have received a copy of the GNU General Public License and    --
  28 -- a copy of the GCC Runtime Library Exception along with this program;     --
  29 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  30 -- <http://www.gnu.org/licenses/>.                                          --
  31 --                                                                          --
  32 -- GNAT was originally developed  by the GNAT team at  New York University. --
  33 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  34 --                                                                          --
  35 ------------------------------------------------------------------------------
  36 
  37 pragma Restrictions (No_Exception_Propagation);
  38 --  Only local exception handling is supported in this profile
  39 
  40 pragma Restrictions (No_Exception_Registration);
  41 --  Disable exception name registration. This capability is not used because
  42 --  it is only required by exception stream attributes which are not supported
  43 --  in this run time.
  44 
  45 pragma Restrictions (No_Implicit_Dynamic_Code);
  46 --  Pointers to nested subprograms are not allowed in this run time, in order
  47 --  to prevent the compiler from building "trampolines".
  48 
  49 pragma Restrictions (No_Finalization);
  50 --  Controlled types are not supported in this run time
  51 
  52 pragma Restrictions (No_Tasking);
  53 --  Tasking is not supported in this run time
  54 
  55 pragma Discard_Names;
  56 --  Disable explicitly the generation of names associated with entities in
  57 --  order to reduce the amount of storage used. These names are not used anyway
  58 --  (attributes such as 'Image and 'Value are not supported in this run time).
  59 
  60 package System is
  61    pragma Pure;
  62    --  Note that we take advantage of the implementation permission to make
  63    --  this unit Pure instead of Preelaborable; see RM 13.7.1(15). In Ada
  64    --  2005, this is Pure in any case (AI-362).
  65 
  66    pragma No_Elaboration_Code_All;
  67    --  Allow the use of that restriction in units that WITH this unit
  68 
  69    type Name is (SYSTEM_NAME_GNAT);
  70    System_Name : constant Name := SYSTEM_NAME_GNAT;
  71 
  72    --  System-Dependent Named Numbers
  73 
  74    Min_Int               : constant := Long_Long_Integer'First;
  75    Max_Int               : constant := Long_Long_Integer'Last;
  76 
  77    Max_Binary_Modulus    : constant := 2 ** Long_Long_Integer'Size;
  78    Max_Nonbinary_Modulus : constant := 2 ** Integer'Size - 1;
  79 
  80    Max_Base_Digits       : constant := Long_Long_Float'Digits;
  81    Max_Digits            : constant := Long_Long_Float'Digits;
  82 
  83    Max_Mantissa          : constant := 63;
  84    Fine_Delta            : constant := 2.0 ** (-Max_Mantissa);
  85 
  86    Tick                  : constant := 0.000_000_001; --  1 ns
  87 
  88    --  Storage-related Declarations
  89 
  90    type Address is private;
  91    pragma Preelaborable_Initialization (Address);
  92    Null_Address : constant Address;
  93 
  94    Storage_Unit : constant := 8;
  95    Word_Size    : constant := 32;
  96    Memory_Size  : constant := 2 ** 32;
  97 
  98    --  Address comparison
  99 
 100    function "<"  (Left, Right : Address) return Boolean;
 101    function "<=" (Left, Right : Address) return Boolean;
 102    function ">"  (Left, Right : Address) return Boolean;
 103    function ">=" (Left, Right : Address) return Boolean;
 104    function "="  (Left, Right : Address) return Boolean;
 105 
 106    pragma Import (Intrinsic, "<");
 107    pragma Import (Intrinsic, "<=");
 108    pragma Import (Intrinsic, ">");
 109    pragma Import (Intrinsic, ">=");
 110    pragma Import (Intrinsic, "=");
 111 
 112    --  Other System-Dependent Declarations
 113 
 114    type Bit_Order is (High_Order_First, Low_Order_First);
 115    Default_Bit_Order : constant Bit_Order := Low_Order_First;
 116    pragma Warnings (Off, Default_Bit_Order); -- kill constant condition warning
 117 
 118    --  Priority-related Declarations (RM D.1)
 119 
 120    --  For simplicity there is a 1-1 correspondence between Ada and PikeOS
 121    --  priorities. PikeOS priority 0 is reserved by the idle thread, so not
 122    --  available to Ada.
 123 
 124    --  PikeOS priorities are 0 .. 255
 125 
 126    --  Priorities greather than 245 are reserved to the system software (PSSW)
 127 
 128    --  This implementation reserves priorities 224-239 to interrupts
 129 
 130    --  Priorities 240-245 are reserved to HM and PikeOS exception handlers
 131 
 132    Max_Priority           : constant Positive := 223;
 133    Max_Interrupt_Priority : constant Positive := 239;
 134 
 135    subtype Any_Priority       is Integer range   1 .. Max_Interrupt_Priority;
 136    subtype Priority           is Any_Priority
 137      range Any_Priority'First .. Max_Priority;
 138    subtype Interrupt_Priority is Any_Priority
 139      range Priority'Last + 1 .. Any_Priority'Last;
 140 
 141    Default_Priority : constant Priority :=
 142                         (Priority'First + Priority'Last) / 2;
 143 
 144 private
 145 
 146    type Address is mod Memory_Size;
 147    Null_Address : constant Address := 0;
 148 
 149    --------------------------------------
 150    -- System Implementation Parameters --
 151    --------------------------------------
 152 
 153    --  These parameters provide information about the target that is used
 154    --  by the compiler. They are in the private part of System, where they
 155    --  can be accessed using the special circuitry in the Targparm unit
 156    --  whose source should be consulted for more detailed descriptions
 157    --  of the individual switch values.
 158 
 159    Atomic_Sync_Default       : constant Boolean := False;
 160    Backend_Divide_Checks     : constant Boolean := False;
 161    Backend_Overflow_Checks   : constant Boolean := True;
 162    Command_Line_Args         : constant Boolean := False;
 163    Configurable_Run_Time     : constant Boolean := True;
 164    Denorm                    : constant Boolean := True;
 165    Duration_32_Bits          : constant Boolean := True;
 166    Exit_Status_Supported     : constant Boolean := False;
 167    Fractional_Fixed_Ops      : constant Boolean := False;
 168    Frontend_Layout           : constant Boolean := False;
 169    Machine_Overflows         : constant Boolean := False;
 170    Machine_Rounds            : constant Boolean := True;
 171    Preallocated_Stacks       : constant Boolean := False;
 172    Signed_Zeros              : constant Boolean := True;
 173    Stack_Check_Default       : constant Boolean := False;
 174    Stack_Check_Probes        : constant Boolean := False;
 175    Stack_Check_Limits        : constant Boolean := False;
 176    Support_Aggregates        : constant Boolean := True;
 177    Support_Atomic_Primitives : constant Boolean := True;
 178    Support_Composite_Assign  : constant Boolean := True;
 179    Support_Composite_Compare : constant Boolean := True;
 180    Support_Long_Shifts       : constant Boolean := True;
 181    Always_Compatible_Rep     : constant Boolean := True;
 182    Suppress_Standard_Library : constant Boolean := True;
 183    Use_Ada_Main_Program_Name : constant Boolean := False;
 184    Frontend_Exceptions       : constant Boolean := False;
 185    ZCX_By_Default            : constant Boolean := True;
 186 
 187    --  Select the appropriate entry point, linker script, and libraries for a
 188    --  PikeOS partition.
 189 
 190    --  Traditionally the entry point of a native application is _p4_entry. For
 191    --  an APEX application, it is _begin.
 192 
 193    --  In order to use the same link options for both personalities, _begin is
 194    --  used for native as well.
 195 
 196    pragma Linker_Options
 197      ("-u_begin" & ASCII.NUL & "-e_begin" & ASCII.NUL &
 198        "-nostdlib" & ASCII.NUL &
 199        "-T../scripts/app-ld-script" & ASCII.NUL &
 200        "-lvm" & ASCII.NUL & "-lp4" & ASCII.NUL & "-lstand" & ASCII.NUL &
 201        "-lgcc");
 202 
 203 end System;