gcc/ada/libgnat/i-vxwork.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) 1999-2018, 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 package provides a limited binding to the VxWorks API
  33
  34 --  In particular, it interfaces with the VxWorks hardware interrupt
  35 --  facilities, allowing the use of low-latency direct-vectored interrupt
  36 --  handlers. Note that such handlers have a variety of restrictions regarding
  37 --  system calls and language constructs. In particular, the use of exception
  38 --  handlers and functions returning variable-length objects cannot be used.
  39 --  Less restrictive, but higher-latency handlers can be written using Ada
  40 --  protected procedures, Ada 83 style interrupt entries, or by signalling
  41 --  an Ada task from within an interrupt handler using a binary semaphore
  42 --  as described in the VxWorks Programmer's Manual.
  43 --
  44 --  For complete documentation of the operations in this package, please
  45 --  consult the VxWorks Programmer's Manual and VxWorks Reference Manual.
  46
  47 pragma Warnings (Off, "*foreign convention*");
  48 pragma Warnings (Off, "*add Convention pragma*");
  49 --  These are temporary pragmas to suppress warnings about mismatching
  50 --  conventions, which will be a problem when we get rid of trampolines ???
  51
  52 with System.VxWorks;
  53
  54 package Interfaces.VxWorks is
  55    pragma Preelaborate;
  56
  57    ------------------------------------------------------------------------
  58    --  Here is a complete example that shows how to handle the Interrupt 0x14
  59    --  with a direct-vectored interrupt handler in Ada using this package:
  60
  61    --  with Interfaces.VxWorks; use Interfaces.VxWorks;
  62    --  with System;
  63    --
  64    --  package P is
  65    --
  66    --     Count : Integer;
  67    --     pragma Atomic (Count);
  68    --
  69    --     Level : constant := 1;
  70    --     --  Interrupt level used by this example
  71    --
  72    --     procedure Handler (parameter : System.Address);
  73    --
  74    --  end P;
  75    --
  76    --  package body P is
  77    --
  78    --     procedure Handler (parameter : System.Address) is
  79    --        S : STATUS;
  80    --     begin
  81    --        Count := Count + 1;
  82    --        logMsg ("received an interrupt" & ASCII.LF & ASCII.NUL);
  83    --
  84    --        --  Acknowledge VME interrupt
  85    --
  86    --        S := sysBusIntAck (intLevel => Level);
  87    --     end Handler;
  88    --  end P;
  89    --
  90    --  with Interfaces.VxWorks; use Interfaces.VxWorks;
  91    --  with Ada.Text_IO; use Ada.Text_IO;
  92    --
  93    --  with P; use P;
  94    --  procedure Useint is
  95    --
  96    --     --  Be sure to use a reasonable interrupt number for  board.
  97    --     --  This one is the unused VME graphics interrupt on the PPC MV2604
  98    --
  99    --     Interrupt : constant := 16#14#;
 100    --
 101    --     task T;
 102    --
 103    --     S : STATUS;
 104    --
 105    --     task body T is
 106    --     begin
 107    --        loop
 108    --           Put_Line ("Generating an interrupt...");
 109    --           delay 1.0;
 110    --
 111    --           --  Generate VME interrupt, using interrupt number
 112    --
 113    --           S := sysBusIntGen (1, Interrupt);
 114    --        end loop;
 115    --     end T;
 116    --
 117    --  begin
 118    --     S := sysIntEnable (intLevel => Level);
 119    --     S := intConnect (INUM_TO_IVEC (Interrupt), handler'Access);
 120    --
 121    --     loop
 122    --        delay 2.0;
 123    --        Put_Line ("value of count:" & P.Count'Img);
 124    --     end loop;
 125    --  end Useint;
 126    -------------------------------------
 127
 128    subtype int is Integer;
 129
 130    type STATUS is new int;
 131    --  Equivalent of the C type STATUS
 132
 133    OK    : constant STATUS := 0;
 134    ERROR : constant STATUS := -1;
 135
 136    type VOIDFUNCPTR is access procedure (parameter : System.Address);
 137    type Interrupt_Vector is new System.Address;
 138    type Exception_Vector is new System.Address;
 139
 140    function intConnect
 141      (vector    : Interrupt_Vector;
 142       handler   : VOIDFUNCPTR;
 143       parameter : System.Address := System.Null_Address) return STATUS;
 144    --  Binding to the C routine intConnect. Use this to set up an user handler.
 145    --  The routine generates a wrapper around the user handler to save and
 146    --  restore context
 147
 148    function intContext return int;
 149    --  Binding to the C routine intContext. This function returns 1 only if the
 150    --  current execution state is in interrupt context.
 151
 152    function intVecGet
 153      (Vector : Interrupt_Vector) return VOIDFUNCPTR;
 154    --  Binding to the C routine intVecGet. Use this to get the existing handler
 155    --  for later restoral
 156
 157    procedure intVecSet
 158      (Vector  : Interrupt_Vector;
 159       Handler : VOIDFUNCPTR);
 160    --  Binding to the C routine intVecSet. Use this to restore a handler
 161    --  obtained using intVecGet
 162
 163    function INUM_TO_IVEC (intNum : int) return Interrupt_Vector;
 164    --  Equivalent to the C macro INUM_TO_IVEC used to convert an interrupt
 165    --  number to an interrupt vector
 166
 167    function sysIntEnable (intLevel : int) return STATUS;
 168    --  Binding to the C routine sysIntEnable
 169
 170    function sysIntDisable (intLevel : int) return STATUS;
 171    --  Binding to the C routine sysIntDisable
 172
 173    function sysBusIntAck (intLevel : int) return STATUS;
 174    --  Binding to the C routine sysBusIntAck
 175
 176    function sysBusIntGen (intLevel : int; Intnum : int) return STATUS;
 177    --  Binding to the C routine sysBusIntGen. Note that the T2 documentation
 178    --  implies that a vector address is the proper argument - it's not. The
 179    --  interrupt number in the range 0 .. 255 (for 68K and PPC) is the correct
 180    --  argument.
 181
 182    procedure logMsg
 183      (fmt : String; arg1, arg2, arg3, arg4, arg5, arg6 : int := 0);
 184    --  Binding to the C routine logMsg. Note that it is the caller's
 185    --  responsibility to ensure that fmt is a null-terminated string
 186    --  (e.g logMsg ("Interrupt" & ASCII.NUL))
 187
 188    type FP_CONTEXT is private;
 189    --  Floating point context save and restore. Handlers using floating point
 190    --  must be bracketed with these calls. The pFpContext parameter should be
 191    --  an object of type FP_CONTEXT that is declared local to the handler.
 192
 193    procedure fppRestore (pFpContext : in out FP_CONTEXT);
 194    --  Restore floating point context
 195
 196    procedure fppSave (pFpContext : in out FP_CONTEXT);
 197    --  Save floating point context
 198
 199 private
 200
 201    type FP_CONTEXT is new System.VxWorks.FP_CONTEXT;
 202    --  Target-dependent floating point context type
 203
 204    pragma Import (C, intConnect, "intConnect");
 205    pragma Import (C, intContext, "intContext");
 206    pragma Import (C, intVecGet, "intVecGet");
 207    pragma Import (C, intVecSet, "intVecSet");
 208    pragma Import (C, INUM_TO_IVEC, "__gnat_inum_to_ivec");
 209    pragma Import (C, sysIntEnable, "sysIntEnable");
 210    pragma Import (C, sysIntDisable, "sysIntDisable");
 211    pragma Import (C, sysBusIntAck, "sysBusIntAck");
 212    pragma Import (C, sysBusIntGen, "sysBusIntGen");
 213    pragma Import (C, logMsg, "logMsg");
 214    pragma Import (C, fppRestore, "fppRestore");
 215    pragma Import (C, fppSave, "fppSave");
 216 end Interfaces.VxWorks;