src/sim/emul_driver.hh

   1 /*
   2  * Copyright (c) 2014 Advanced Micro Devices, Inc.
   3  * All rights reserved
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Author: Steve Reinhardt
  29  */
  30
  31 #ifndef __SIM_EMUL_DRIVER_HH
  32 #define __SIM_EMUL_DRIVER_HH
  33
  34 #include <string>
  35
  36 #include "params/EmulatedDriver.hh"
  37 #include "sim/sim_object.hh"
  38
  39 class Process;
  40 class ThreadContext;
  41
  42 /**
  43  * EmulatedDriver is an abstract base class for fake SE-mode device drivers.
  44  *
  45  * Specific drivers that allow applications to communicate with simulated
  46  * hardware inside gem5 can be created by deriving from this class and
  47  * overriding the abstract virtual methods.
  48  *
  49  * Currently only open(), ioctl(), and mmap() calls are supported, but other
  50  * calls (e.g., read(), write()) could be added as needed.
  51  */
  52 class EmulatedDriver : public SimObject
  53 {
  54   protected:
  55     /**
  56      * filename for opening this driver (under /dev)
  57      */
  58     const std::string &filename;
  59
  60   public:
  61     EmulatedDriver(EmulatedDriverParams *p)
  62         : SimObject(p), filename(p->filename)
  63     {
  64     }
  65
  66     /**
  67      * Check for a match with this driver's filename.
  68      */
  69     bool match(const std::string &s) const { return (s == filename); }
  70
  71     /**
  72      * Abstract method, invoked when the user program calls open() on
  73      * the device driver.  The parameters are the same as those passed
  74      * to openFunc() (q.v.).
  75      * @return A newly allocated target fd, or -1 on error.
  76      */
  77     virtual int open(Process *p, ThreadContext *tc,
  78                      int mode, int flags) = 0;
  79
  80     /**
  81      * Abstract method, invoked when the user program calls ioctl() on
  82      * the file descriptor returned by a previous open().  The parameters
  83      * are the same as those passed in to ioctlFunc() (q.v.).
  84      * @return The return code for the ioctl, or the negation of the errno
  85      * (see the SyscallReturn class).
  86      */
  87     virtual int ioctl(Process *p, ThreadContext *tc, unsigned req) = 0;
  88
  89     /**
  90      * Virtual method, invoked when the user program calls mmap() on
  91      * the file descriptor returned by a previous open().  The parameters
  92      * are the same as those passed in to mmapFunc() (q.v.).
  93      * @return The return ptr for the mmap, or the negation of the errno
  94      * (see the SyscallReturn class).
  95      */
  96     virtual Addr mmap(Process *p, ThreadContext *tc, Addr start,
  97                       uint64_t length, int prot, int tgtFlags, int tgtFd,
  98                       int offset) { return -EBADF; }
  99 };
 100
 101 #endif // __SIM_EMUL_DRIVER_HH