isa_fake.hh revision 2665:a124942bacb8 
1/*
2 * Copyright (c) 2004-2005 The Regents of The University of Michigan
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 * Authors: Miguel Serrano
29 *          Ali Saidi
30 */
31
32/** @file
33 * Declaration of a fake device.
34 */
35
36#ifndef __ISA_FAKE_HH__
37#define __ISA_FAKE_HH__
38
39#include "dev/tsunami.hh"
40#include "base/range.hh"
41#include "dev/io_device.hh"
42
43/**
44 * IsaFake is a device that returns -1 on all reads and
45 * accepts all writes. It is meant to be placed at an address range
46 * so that an mcheck doesn't occur when an os probes a piece of hw
47 * that doesn't exist (e.g. UARTs1-3).
48 */
49class IsaFake : public BasicPioDevice
50{
51  public:
52    struct Params : public BasicPioDevice::Params
53    {
54        Addr pio_size;
55    };
56  protected:
57    const Params *params() const { return (const Params*)_params; }
58
59  public:
60    /**
61      * The constructor for Tsunmami Fake just registers itself with the MMU.
62      * @param p params structure
63      */
64    IsaFake(Params *p);
65
66    /**
67     * This read always returns -1.
68     * @param req The memory request.
69     * @param data Where to put the data.
70     */
71    virtual Tick read(Packet *pkt);
72
73    /**
74     * All writes are simply ignored.
75     * @param req The memory request.
76     * @param data the data to not write.
77     */
78    virtual Tick write(Packet *pkt);
79};
80
81#endif // __TSUNAMI_FAKE_HH__
82