gcc/ada/libgnat/i-vxwork__x86.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                  GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                --
   4 --                                                                          --
   5 --                      I N T E R F A C E S . V X W O R K S                 --
   6 --                                                                          --
   7 --                                   S p e c                                --
   8 --                                                                          --
   9 --                     Copyright (C) 1999-2020, AdaCore                     --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  17 --                                                                          --
  18 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNARL was developed by the GNARL team at Florida State University.       --
  28 -- Extensive contributions were provided by Ada Core Technologies, Inc.     --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 --  This is the x86 VxWorks version of this package
  33
  34 --  This package provides a limited binding to the VxWorks API
  35 --  In particular, it interfaces with the VxWorks hardware interrupt
  36 --  facilities, allowing the use of low-latency direct-vectored
  37 --  interrupt handlers. Note that such handlers have a variety of
  38 --  restrictions regarding system calls and language constructs. In particular,
  39 --  the use of exception handlers and functions returning variable-length
  40 --  objects cannot be used. Less restrictive, but higher-latency handlers can
  41 --  be written using Ada protected procedures, Ada 83 style interrupt entries,
  42 --  or by signalling an Ada task from within an interrupt handler using a
  43 --  binary semaphore as described in the VxWorks Programmer's Manual.
  44 --
  45 --  For complete documentation of the operations in this package, please
  46 --  consult the VxWorks Programmer's Manual and VxWorks Reference Manual.
  47
  48 pragma Warnings (Off, "*foreign convention*");
  49 pragma Warnings (Off, "*add Convention pragma*");
  50
  51 with System.VxWorks;
  52
  53 package Interfaces.VxWorks is
  54    pragma Preelaborate;
  55
  56    ------------------------------------------------------------------------
  57    --  Here is a complete example that shows how to handle the Interrupt 0x33
  58    --  with a direct-vectored interrupt handler in Ada using this package:
  59
  60    --  with Interfaces.VxWorks; use Interfaces.VxWorks;
  61    --  with System;
  62    --
  63    --  package P is
  64    --
  65    --     Count : Integer;
  66    --     pragma Atomic (Count);
  67    --
  68    --     procedure Handler (Parameter : System.Address);
  69    --
  70    --  end P;
  71    --
  72    --  package body P is
  73    --
  74    --     procedure Handler (Parameter : System.Address) is
  75    --     begin
  76    --        Count := Count + 1;
  77    --        logMsg ("received an interrupt" & ASCII.LF & ASCII.NUL);
  78    --     end Handler;
  79    --  end P;
  80    --
  81    --  with Interfaces.VxWorks; use Interfaces.VxWorks;
  82    --  with Ada.Text_IO; use Ada.Text_IO;
  83    --  with Ada.Interrupts;
  84    --  with Machine_Code; use Machine_Code;
  85    --
  86    --  with P; use P;
  87    --  procedure Useint is
  88    --
  89    --     --  Be sure to use a reasonable interrupt number for target board.
  90    --     --  This one is an unreserved interrupt for the Pentium 3 BSP
  91    --
  92    --     Interrupt : constant := 16#33#;
  93    --
  94    --     task T;
  95    --
  96    --     S : STATUS;
  97    --
  98    --     task body T is
  99    --     begin
 100    --        loop
 101    --           Put_Line ("Generating an interrupt...");
 102    --           delay 1.0;
 103    --
 104    --           --  Generate interrupt, using interrupt number
 105    --
 106    --           Asm ("int %0",
 107    --                Inputs =>
 108    --                  Ada.Interrupts.Interrupt_ID'Asm_Input
 109    --                    ("i", Interrupt));
 110    --        end loop;
 111    --     end T;
 112    --
 113    --  begin
 114    --     S := intConnect (INUM_TO_IVEC (Interrupt), Handler'Access);
 115    --
 116    --     loop
 117    --        delay 2.0;
 118    --        Put_Line ("value of count:" & P.Count'Img);
 119    --     end loop;
 120    --  end Useint;
 121    -------------------------------------
 122
 123    subtype int is Integer;
 124
 125    type STATUS is new int;
 126    --  Equivalent of the C type STATUS
 127
 128    OK    : constant STATUS := 0;
 129    ERROR : constant STATUS := -1;
 130
 131    type VOIDFUNCPTR is access procedure (parameter : System.Address);
 132    type Interrupt_Vector is new System.Address;
 133    type Exception_Vector is new System.Address;
 134
 135    function intConnect
 136      (vector    : Interrupt_Vector;
 137       handler   : VOIDFUNCPTR;
 138       parameter : System.Address := System.Null_Address) return STATUS;
 139    --  Binding to the C routine intConnect. Use this to set up an user handler.
 140    --  The routine generates a wrapper around the user handler to save and
 141    --  restore context
 142
 143    function intContext return int;
 144    --  Binding to the C routine intContext. This function returns 1 only if the
 145    --  current execution state is in interrupt context.
 146
 147    function intVecGet
 148      (Vector : Interrupt_Vector) return VOIDFUNCPTR;
 149    --  Binding to the C routine intVecGet. Use this to get the existing handler
 150    --  for later restoral
 151
 152    procedure intVecSet
 153      (Vector  : Interrupt_Vector;
 154       Handler : VOIDFUNCPTR);
 155    --  Binding to the C routine intVecSet. Use this to restore a handler
 156    --  obtained using intVecGet
 157
 158    procedure intVecGet2
 159      (vector       : Interrupt_Vector;
 160       pFunction    : out VOIDFUNCPTR;
 161       pIdtGate     : not null access int;
 162       pIdtSelector : not null access int);
 163    --  Binding to the C routine intVecGet2. Use this to get the existing
 164    --  handler for later restoral
 165
 166    procedure intVecSet2
 167      (vector       : Interrupt_Vector;
 168       pFunction    : VOIDFUNCPTR;
 169       pIdtGate     : not null access int;
 170       pIdtSelector : not null access int);
 171    --  Binding to the C routine intVecSet2. Use this to restore a
 172    --  handler obtained using intVecGet2
 173
 174    function INUM_TO_IVEC (intNum : int) return Interrupt_Vector;
 175    --  Equivalent to the C macro INUM_TO_IVEC used to convert an interrupt
 176    --  number to an interrupt vector
 177
 178    procedure logMsg
 179      (fmt : String; arg1, arg2, arg3, arg4, arg5, arg6 : int := 0);
 180    --  Binding to the C routine logMsg. Note that it is the caller's
 181    --  responsibility to ensure that fmt is a null-terminated string
 182    --  (e.g logMsg ("Interrupt" & ASCII.NUL))
 183
 184    type FP_CONTEXT is private;
 185    --  Floating point context save and restore. Handlers using floating point
 186    --  must be bracketed with these calls. The pFpContext parameter should be
 187    --  an object of type FP_CONTEXT that is declared local to the handler.
 188    --
 189    --  See the VxWorks Intel Architecture Supplement regarding these routines
 190
 191    procedure fppRestore (pFpContext : in out FP_CONTEXT);
 192    --  Restore floating point context - old style
 193
 194    procedure fppSave (pFpContext : in out FP_CONTEXT);
 195    --  Save floating point context - old style
 196
 197    procedure fppXrestore (pFpContext : in out FP_CONTEXT);
 198    --  Restore floating point context - new style
 199
 200    procedure fppXsave (pFpContext : in out FP_CONTEXT);
 201    --  Save floating point context - new style
 202
 203 private
 204
 205    type FP_CONTEXT is new System.VxWorks.FP_CONTEXT;
 206    --  Target-dependent floating point context type
 207
 208    pragma Import (C, intConnect, "intConnect");
 209    pragma Import (C, intContext, "intContext");
 210    pragma Import (C, intVecGet, "intVecGet");
 211    pragma Import (C, intVecSet, "intVecSet");
 212    pragma Import (C, intVecGet2, "intVecGet2");
 213    pragma Import (C, intVecSet2, "intVecSet2");
 214    pragma Import (C, INUM_TO_IVEC, "__gnat_inum_to_ivec");
 215    pragma Import (C, logMsg, "logMsg");
 216    pragma Import (C, fppRestore, "fppRestore");
 217    pragma Import (C, fppSave, "fppSave");
 218    pragma Import (C, fppXrestore, "fppXrestore");
 219    pragma Import (C, fppXsave, "fppXsave");
 220 end Interfaces.VxWorks;